United We Defeat Malaria in Asia and the Pacific

S E P T E M B E R 2 0 1 9

The APLMA / APMEN Strategy

S T R A T E G I C G O A L

To achieve substantial, sustainable progress toward an Asia Pacific Free of Malaria by 2030 by bolstering country leadership, benchmarking progress, and brokering policy, technical and financing solutions

1

LeadershipThere is more demonstrable, more broad-based leadership commitment to eliminate malaria, spanning Asia Pacific.

2

Country SupportTargeted national programs have adopted more effective and evidence-based strategies and interventions that are suited to malaria elimination in Asia Pacific.

3

FinancingFinancing for malaria is increased for Asia Pacific in 2020-2022.

4

AccessIncreased access to quality assured priority malaria commodities in at least five countries by 2022

APLMA Leader’s Dashboard 2018

10 Years of APMEN

Established in 2009 to focus attention on the work of malaria elimination in Asia Pacific

Laid strong foundation for endorsement of malaria elimination as a goal at the 10th East Asia Summit in 2015

Multisectoral network with partners from Government, academia, research institutes, NGOs

Strong partnerships• Complementary

role with WHO• Greater

integration with APLMA

Evolving role in the region

APMEN Key Guiding Principles

Country Ownership

• Initiatives developed and led by NMCP managers, in collaboration with partner institutions

• More central role of NMCPs in APMEN Working Groups

South-South Collaboration

• Significant malaria technical expertise in Asia Pacific

• Shared elimination challenges

• Need for increased self-reliance in region as external support for technical assistance tapers down

• APMEN plays a brokering role

Responsiveness to the diverse elimination contexts

• Varying stages of journey on path to elimination

• Type of support needed varies based on level of transmission risk

Foundation for regional health security against mosquito-borne diseases

• Better targeting of high-risk populations

• Increasing information-and knowledge-sharing among Network members

• Developing sub-regional support platforms to aid country-risk and receptivity mapping, as well as sub-regional quality assurance mechanisms

APMEN Strategic Areas of Work

Improved capacity to implement Surveillance and Responsesystems for elimination

Enhanced Vector Control and surveillance capacity

Early adoption of novel technologies for safe and effective radical cure of P.Vivax

Improved effectiveness and efficiency of malaria Programs

To generate evidence and share knowledge and best practices for countries in the Asia Pacific region to accelerate and maintain progress towards national and regional malaria elimination targets

Number of Indigenous Cases

01 – 20,00020,001 – 100,000100,001 – 500,000500,001 – 1,000,000

People’s Republic of China

Afghanistan

PakistanIndia

Indonesia

Timor - Leste Papua New Guinea

Solomon Islands

Vanuatu

PhilippinesThailand

Bangladesh

Nepal

DPR Korea

Republic of Korea

Viet Nam

Sri Lanka

Bhutan

Malaysia

Cambodia

Lao PDR

Myanmar Source: World Malaria Report 2018

We thank all our partners for making this course possible and contributing in many different ways!

We thank all our partners for making this course possible and contributing in many different ways!

Sincere deep thanks to our Specialist Presenters from all over the world!

We thank all our partners for making this course possible and contributing in many different ways!

Sincere deep thanks to our Specialist Presenters from all over the world!

And, of course, welcome and thanks to our very special course participants from across Asia‐Pacific!!!

Developing Entomological Working Plan

Dr. Chusak Prasittisuk

Former WHO Regional Entomologist, Regional Advisor on Malaria and Regional Advisor on Vector Borne Disease Control , WHO Regional Office for Southeast Asia Region, New Delhi, India

Former Coordinator, Communicable Diseases Control, WHO Regional Office for Southeast Asia Region, New Delhi, India

Advisor to Faculty of Tropical Medicine, Mahidol University 

Second International Malaria Vector Surveillance for Elimination Course, Kasetsart Universiy, Bangkok, Thailand, 29 Sept.‐11 Oct. 2019 

Learning ObjectivesBy the end of training session participants should be able to understand , describe the roles of entomological studies  and be able to perform the followings:‐

1.Plan for vector surveillance‐preliminary , routine, spot check, foci investigations2.Understand entomological information required for effective planning for vector control to control/eliminate malaria. 3.Vector Susceptibility/Resistance to insecticides 4. Monitoring and evaluation on impact of control measures , e.g. LLINs. IRS6. Investigate persistence transmission areas and recommend control measures7 Investigate foci of transmission in low transmission and elimination areas8. Outbreak investigations and response

Vector Surveillance

• Types of entomological activity according to malaria epidemiological situation

• Why, Where, and When it should be applied

Types of Vector Surveillance

Preliminary surveyRoutine regular observations ( Longitudinal studies)Special studies/spot checksFoci investigationsVigilance‐ integral part of epidemiological vigilance systemOutbreak investigations

Preliminary survey‐ Short‐term surveys for  baseline data collection for planning purposes

Routine/regular observations (Longitudinal studies)‐to monitor/evaluate impact of control measures , sentinel site observation

Spot checks –surveys in selected localities to supplement routine observations 

Foci investigations‐ short term investigations in low endemic /elimination areas

Outbreak investigation –to investigate and identify possible drivers of the increase in transmission and gaps in protection 

Vigilance –Integral part of epidemiological vigilsncesystem

Monitoring vector susceptibility /resistance to insecticides –Preliminary and monitoring 

• Country‐wide plan• Vector species against currently used insecticides and candidate

insecticides ,• larvae and adults• Select location with history of high seasonal densities• Timing and period• Testing methods and discrimination dosage• Arrangement of the team• Preparation of standard diagnostic insecticides

Monitoring and evaluation of impact of vector control measures‐routine/regular in sentinel sites

Residual  efficacy of IRS formulations Residual efficacy of LLINs Phisicall integrity of LLINs Residual efficacy of larvicides Acceptability/use of control measures Effectiveness of single or combine interventions

Investigate persistence malaria transmission areas –spot checks• Surveys in selected localities to investigate factors related persistence malaria transmission, mainly in active foci where persistencetransmission observed.

• To correlate entomological factors related with case investigation, temporal malaria incidence, rainfall, land usage, human behavior, and other related epidemiological data to inform rapid and effective response. 

• To enable evaluation of intervention effectiveness and gaps in protection. 

Foci Investigation• In very low transmission settings where cases are clustered into high risk areas 

• WHO recommends establishing foci management systems • to investigate, classify, respond to, and monitor foci to systematically interrupt transmission toward malaria eliminate

• Entomological surveillance and vector control are key components of foci investigation and response,

• Given the epidemiological trigger, rapid diagnosis and treatment is the most effective response to prevent infecting mosquitoes that could then sustain or increase malaria incidence. 

• Following effective case management,‐ case investigations collect important information on the case’s 

demographics, behavior, occupation, and possible gaps in protection 

Three Types of Foci

•Active: focus with ongoing transmission•Residual non‐active: focus where transmission was interrupted recently (< 3 years)•Cleared: focus with no local transmission for >3 years

Active Foci

• Primary objective: To monitor foci with active transmission towards interruption of transmission.

• Secondary objectives:• To correlate entomological data in focus with case investigation, temporal malaria incidence, rainfall, land usage, human behavior, and other meta‐data to inform rapid and effective response. 

• To enable evaluation of intervention effectiveness and gaps in protection. 

Minimum indicators required

• Vector species • Larval habitats• Receptivity• Seasonality• Insecticide resistance• Indoor resting density (if capacity is available and if IRS is implemented, or if a program wants to assess IRS feasibility)

• Biting behavior • Bio‐efficacy

Additional data sets to be analyzed

• Index case investigation • Malaria incidence • Rainfall and temperature• Human behavior (high capacity)• Land usage • Timing and coverage of vector control intervention• Vulnerability • ACT and RDT stocks• Available budget

Residual non‐active and cleared

• Primary objective: To rapidly investigate receptivity and gaps in protection in a non‐malarious focus where an index case is detected.

• Secondary objectives:‐To identify potential drivers of transmission that could contribute to onward transmission from the index case.‐To correlate entomological data in focus with case investigation, temporal malaria incidence in nearby foci, rainfall, land usage, human behavior, and other meta‐data to inform rapid and effective response.

Minimum indicators required

• Vector species • Receptivity• Larval habitats• Seasonality• Insecticide resistance• Indoor resting density (if capacity is available and if IRS is implemented/being considered)• Biting behavior (if capacity is available)

Additional data sets to be analyzed

•Malaria incidence• Rainfall and temperature• Human behavior (high capacity)• Timing and coverage of vector control interventions• Land usage• Vulnerability • Available budget

Vigilance

• Topography , • Ecology • Receptivity• Presence and absence of primary ,secondary and local vectors

• Vulnerability • History of malaria• Epidemiological and rporting system

Outbreak investigation• outbreak is defined as a significant and unexpected increase in malaria incidence in a specific geographical area (i.e. a focus, village, district, or region), triggering a response.

• entomological investigation of an outbreak to identify possible drivers of the increase in transmission and gaps in protection that may be due to insecticide resistance, coverage of existing interventions, or changes in vector behavior.

• combined with that on human behavior, rainfall, and any interruptions in service delivery (e.g. ACT stock‐outs), can help inform responses.

• Rapid diagnosis and treatment is the most critical response, followed by active case detection, drug‐based approaches, and/or vector control interventions based on investigation of drivers of transmission

Objectives of Outbreak investigations

• Primary objective: To inform rapid responses to immediately suppress transmission following an unexpected and significant increase in malaria cases. • Secondary objective: To identify drivers of transmission and gaps in protection, correlate with changes in receptivity and vulnerability, and improve surveillance and intervention strategies. Lessons learned at this site may also be applied to other sites. 

Minimum indicators required

• Vector species • Larval habitats• Receptivity• Insecticide resistance• Indoor resting density (if IRS is implemented, or assessing IRS feasibility)• Biting behavior (time and location)

Additional data set to be analyzed

•Malaria incidence • Vulnerability • ACT and RDT stocks• Rainfall and temperature • Land usage• Available budget

Management ‐Resources

• Human• Fund• Supplies and equipment• Operating cost• Transport

Thank you

Entomological studies to support malaria control/elimination and other vector borne

disease control programmes

Dr. Chusak Prasittisuk

Former WHO Regional Entomologist, Regional Advisor on Vector Borne Disease Control and Regional Advisor on Malaria, WHO Regional Office for Southeast Asia Region, New Delhi, India

Former Coordinator, Communicable Diseases Control, WHO Regional Office for Southeast Asia Region, New Delhi, India

Advisor to Faculty of Tropical Medicine, Mahidol University

Second International Malaria Vector Surveillance for Elimination Course, Kasetsart Universiy, Bangkok, Thailand, 29 Sept.-11 Oct. 2019

Learning Objectives

By the end of training session participants should be able to understand the roles of entomological studies on the followings:-

1. Significant of identification of the vectors , distribution , habitats , bionomics , seasonal prevalence related to transmission of malaria

2. Mosquito vector identification, sampling and entomological techniques, base line survey

3. Be able to describe vector surveillance

4. Entomological information for effective planning /evaluation of interventions for vector control to control and eliminate malaria.

Vector species identification

• To study vector species compositions change over time at each site (i.e. temporal population trends).

• Understanding primary , secondary and local vectors and their bionomics• Analyze this entomological data with malaria incidence and other climatic

factors (e.g. rainfall) allows us to identify drivers of transmission and when and where interventions may be most effective.

Objectives are:-1.Primary objective: To identify species-specific vector populations and temporal population trends. 2.Secondary objective: To correlate vector data with climatic factos and malaria incidence data towards understanding drivers of transmission.

Sampling Methods

• Human landing catches (HLC)

• Human baited traps (HBT)

• Indoor resting collections (IRC)

• CDC light trap (CDC-LT)

• Human odor baited traps (HOBT)

• Animal odor baited traps (AOBT)

• Outdoor resting collections (ORC)

• CO2 baited trap

• Gravid traps

• Window exit traps (WET)

• Larval surveys

Entomological techniques

• Anopheles identification keys- Morphology

• Molecular identification – PCR

• Salivary gland dissections

• Ovary dissections

• CS ELISA – sporozoite detection

• BM ELISA – host blood detection

• PCR – parasite detection

• WHO Susceptibility Test (tube assay )

• CDC bottle assay

• Kdr PCR or biochemical assay

• WHO Bioassay ( Cone )

Baseline Surveys

• Vector species identification• Biting time ( cycle)• Place of biting ( endophagy, exophagy )• Resting habits ( endophilic, exophagic )• Host preference (anthropophilc , zoophilic)• Insecticide resistance • Bio-efficacy of vector control interventions• Larval habitat characterization

Why collect information of Vectors ?

For planning effective vector control Vector species present Vector density and seasonality Vector behavior Feeding location, blood meal preference Biting time Resting location Vector longevity Vector infection and infectivity rate Vector insecticide susceptibility Larval habitat- oviposition preference -ecology

Why collect information of vectors ?

We need to know field performance of interventions:-Residual efficacy of IRS formulations

Residual efficacy of LLINs

Phisical integrity of LLINs

Residual efficacy of larvicides

Acceptability/use of control measures

Effectiveness of single or combine interventions

Questions from the Vector Borne Diseases Control Programme

• Information on the epidemiology of malaria is essential if the disease is to be controlled.

• Entomological, parasitological and clinical studies provide useful information on the characteristics of malaria transmission in an area as well as the habits and habitats of the specific vector species.

• identification of the vectors responsible for transmission of the disease

• provision of basic information on the habits and habitats of vector species for purposes of planning for effective control measures

• monitoring the impact of control measures (for example, by determining changes in vector population density, rates of infection, susceptibility of vectors to insecticides, and residual effects of insecticides on treated surfaces)

• contributing to the investigation of problem areas where control measures prove unsuccessful

• Vector control programmes should be planned on the basis of entomological studies.

Questions ( continued)

• Is there seasonal or perennial malaria transmission in the area? If so, in which specific situation and what are the geographical limits of the disease?

• Are there any important mosquito borne diseases other than malaria, and if so which ones?

• Which anopheline species are present in the area?

Which of them are important as vectors of malaria?

Has there been any vector incrimination through the identification of sporozoites?

• What proportion of the vector species feed on humans? Among the vectors that feed on humans, what proportion rest indoors?

• Where do most of the vector mosquitoes prefer to bite humans, and where does most man-vector contact take place, indoors or outdoors? What is the peak biting time of the vector?

Questions ( continued)

• How many infective bites are received on average per night per person?

• Which type of water bodies is preferred for breeding by a particular vector species in the area?

• During which epidemiological and economic conditions should a vector control strategy to reduce transmission be recommended or not recommended?

• What proportions of the vector population are susceptible or resistant to operational insecticides?

• How can we determine the duration of efficacy of an insecticide deposited on a surface (e.g. a sprayed wall or an insecticide-treated bed net)?

• How do different vector control options affect malaria transmission, malaria morbidity and mortality? Which vector control options are appropriate against the specific habits and habitats of the vector species? How can we evaluate the short and long-term effectiveness of a vector control strategy?

Questions ( continued )

• What is the estimate cost to provide a practical vector control operations ?

• Malaria entomology is not limited to vector control. Any malaria control strategy should be based on a thorough understanding of the transmission characteristics of the disease..

• Entomological studies are also important in the estimation of the expected impact from various control measures. Enomologist may be asked whether some measures are more useful than others and whether some control measures are dangerous to implement.

Vector Surveillance

• Define types of entomological activity according to epidemiological situation

• Outline the why, where, and when it should be applied

Types of Entomological Surveillance

Preliminary survey

Routine regular observations ( Longitudinal studies)

Special studies/spot checks

Foci investigations

Vigilance- as integral part of epidemiological vigilance system

Sampling of Malaria Vectors

Depend on Objectives of Study :-• Type of studies /investigations/surveillance and information

needed ?• Vector species • Biology and behavior of the vectors • Human behavior and housing conditions• Community structures• Topography and environmental condition/in the sites selected

for sampling• Limitation of the sampling methods• Samples size• Security of the areas

Collection Methods for Adult Mosquito

A. Hand Collection

Human-landing catch (HLC)

Collection of indoor- or

outdoor resting mosquitoes

B. Baited-Traps

Human baited trap

(or Human net-in-net trap)

Animal baited trap

( or Animal net-in-net trap)

.

C. Odor-Baited Traps

Human E-net or

Monkey E-net

D. Light Traps

CDC light trap

E. Window trap collection

(exit traps)

F. Spray sheet collection of

indoor-resting mosquitoes

Verification /Certification of malaria free

• Epidemiological information ???

• Entomological information ???

Thank You

Human mosquito‐borne diseases other than malaria

Structure

ArbovirusesYellow feverChikungunyaZikaDengueJapanese encephalitisWest Nile and many others

Filariasis

Aedes aegypti & Ae. albopictus

Arbovirus is an informal name used to refer to any viruses that are transmitted by arthropod vectors. The word arbovirus is an acronym (arthropod-borne virus). Arboviruses can affect both animals (including humans) and plants. In humans, symptoms of arbovirus infection generally occur 3–15 days after exposure to the virus and last three or four days.The most common clinical features of infection are fever, headache, and malaise, but encephalitis and hemorrhagic fever may also occur.

We will discuss here only mosquito‐borne arboviruses, and only the more prominent ones, NOT tick‐borne arboviruses such as Crimean‐Congo Haemorrhagic Fever.

There are more than 500 known arboviruses of which approximately 100 are capable of causing disease in humans. The major arthropod vectors of arboviruses are mosquitoes, ticks, sandflies, and biting midges.

Yellow fever Flavivirus

•Symptoms of yellow fever include fever, headache, muscle pain, nausea, vomiting and fatigue, also jaundice. The "yellow" in the name refers to the jaundice that affects some patients.•A small proportion of patients who contract the virus develop severe symptoms and approximately half of those die within 7 to 10 days.•Aedes aegypti primary vector for human to human transmission, other Aedes and other genera for sylvatic.•The virus is endemic in tropical areas of Africa and in Central and South America.•Generally, more than 90% of cases occur in sub‐Saharan Africa, where an estimated 51,000 to 380,000 severe cases of yellow fever occur each year with 19,000 to 180,000 deaths•Large epidemics of yellow fever occur•Yellow fever is prevented by an extremely effective vaccine, which is safe and affordable. A single dose of yellow fever vaccine is sufficient to confer sustained immunity and life‐long protection against yellow fever disease. A booster dose of the vaccine is not needed. The vaccine provides effective immunity within 10 days for 80‐100% of people vaccinated, and within 30 days for more than 99% of people vaccinated.

https://www.who.int/news‐room/fact‐sheets/detail/yellow‐fever Yellow fever is difficult to diagnose, especially during the early stages. A more severe case can be confused with severe malaria, leptospirosis, viral hepatitis (especially fulminant forms), other haemorrhagic fevers, infection with other flaviviruses(such as dengue haemorrhagic fever), and poisoning.

Yellow fever is currently endemic in 47 countries and is responsible for between 29,000 to 60,000 deaths annually (WHO 2016). D

World Health Organization. Yellow fever fact sheet.UpdatedMay 2016. http://www.who.int/mediacentre/factsheets/fs100/en/ (accessed 29 June 2017).

Map shows in red the approximate distribution of the 'infected zones'.

Chikungunya (Alphavirus, Togaviridae)

•It causes fever, muscle pain, headache, nausea, fatigue and rash and sometimes also severe joint pain, occasionally fatal.•Joint pain is often debilitating and can vary in duration…months or even years.•The disease shares some clinical signs with dengue and zika, and can be misdiagnosed in areas where they are common.•There is no cure for the disease. Treatment is focused on relieving the symptoms.•Chikungunya has been identified in over 60 countries in Asia, Africa, Europe and the Americas.•Outbreaks increasing in frequency, sometimes involving millions of cases per annum.• Human to human transmission by infected Aedes aegypti and Ae. albopictus mosquitoes. Sylvatic other Aedes.

https://www.who.int/news‐room/fact‐sheets/detail/Chikungunya

Most patients recover fully, but in some cases joint pain may persist for several months, or even years. Occasional cases of eye, neurological and heart complications have been reported, as well as gastrointestinal complaints. Serious complications are not common, but in older people, the disease can contribute to the cause of death. Often symptoms in infected individuals are mild and the infection may go unrecognized, or be misdiagnosed in areas where dengue occurs.

first described during an outbreak in southern Tanzania in 1952.

Zika Flavivirus

•Infections in humans are mostly asymptomatic or symptoms mild and include fever, rash, conjunctivitis, muscle and joint pain, malaise or headache. Symptoms typically last for 2–7 days. Most people with Zikavirus infection do not develop symptoms.•Zika virus infection during pregnancy can cause infants to be born with microcephaly and other congenital malformations, known as congenital Zika syndrome. Infection with Zika virus is also associated with other complications of pregnancy including preterm birth and miscarriage.•Originally sylvatic among non-human-primates, now human to human transmission by way of Aedesaegypti and Ae. albopictus (day-biting)

https://www.who.int/news‐room/fact‐sheets/detail/Zika‐virus

first described from a monkey in the Zika Forest in Uganda in 1947

Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific. From the 1960s to 1980s, rare sporadic cases of human infections were found across Africa and Asia, typically accompanied by mild illness.The first recorded outbreak of Zika virus disease was reported from the Island of Yap (Federated States of Micronesia) in 2007. This was followed by a large outbreak of Zika virus infection in French Polynesia in 2013 and other countries and territories in the Pacific. In March 2015, Brazil reported a large outbreak of rash illness, soon identified as Zikavirus infection, and in July 2015, found to be associated with Guillain-Barré syndrome.

Zika virus infection and microcephaly in Vietnam. The Lancet Infectious Diseases . Volume 17, Issue 8, Pages

805-806 (August 2017) . DOI: 10.1016/S1473-3099(17)30412-7

Zika: Spread from Africa to Asia (1940’s?) , then French Polynesia (2013), then into Central & South America (2015)

As of July 2019, a total of 87 countries and territories have had evidence of autochthonous mosquito‐borne transmission of Zika virus (ZIKV), distributed across four of the six WHO Regions (African Region, Region of the Americas, South‐East Asia Region, and Western Pacific Region)

Zika virus in Asia

Veasna Duong, Philippe Dussart, Philippe Buchy

International Journal of Infectious DiseasesVolume 54, Pages 121-128 (January 2017)

DOI: 10.1016/j.ijid.2016.11.420

Dengue Flaviviridae

•Most cases asymptomatic, the majority of symptomatic dengue infections (i.e. those infections leading to symptoms in patients) lead to a mild or moderate flu‐like illness, but as many as 5% of symptomatic dengue cases can develop into a severe life‐threatening disease defined as severe dengue •There are 4 distinct, but closely related, serotypes of the virus that cause dengue (DEN‐1, DEN‐2, DEN‐3 and DEN‐4). Recovery from infection by one provides lifelong immunity against that particular serotype.•Subsequent infections (secondary infection) by other serotypes increase the risk of developing severe dengue.•The incidence of dengue has grown dramatically around the world in recent decades. A vast majority of cases are asymptomatic and hence the actual numbers of dengue cases are underreported and many cases are misclassified. One estimate indicates 390 million dengue infections per year (95% credible interval 284–528 million), of which 96 million (67–136 million) manifest clinically (with any severity of disease).Dengue is found in tropical and sub‐tropical climates worldwide, mostly in urban and semi‐urban areas.•Severe dengue is a leading cause of serious illness and death among children in some Asian and Latin American countries.•There is no specific treatment for dengue/ severe dengue, but early detection and access to proper medical care lowers fatality rates below 1%.•Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus•Dengue prevention and control depends on effective vector control measures.

First described from Japan in 1943, spread from Asia‐Pacific region to the Americas in the 1970s and Africa in 1984. 

DENV Co‐circulation. Cumulative number of DENV types reported by decade since 1943.

Trends Microbiol. 2014 Mar; 22(3): 138–146. doi: 10.1016/j.tim.2013.12.011

Synthetic pyrethroids against adults and Temephoslarviciding, high levels of insecticide resistance… 

Japanese encephalitis Flavivirus

•Most cases of JE are asymptomatic, but JEV is the main cause of viral encephalitis in many countries of Asia with an estimated 68 000 clinical cases every year.•The case-fatality rate among those with encephalitis can be as high as 30%. Permanent neurologic or psychiatric sequelae can occur in 30%–50% of those with encephalitis.•The main JEV transmission cycle involves Culex tritaeniorhynchus mosquitoes and similar species that lay eggs in rice paddies and other open water sources, with pigs and aquatic birds as principal vertebrate amplifying hosts.•Humans are generally thought to be dead-end JEV hosts, i.e. they seldom develop enough viremia to infect feeding mosquitoes. •Safe and effective vaccines are available to prevent JE .In the pre-JE-vaccination era, tens of thousands of JE cases were often reported annually in Asia. During 1965–1975, more than 1 million cases were reported in China alone.

https://www.who.int/immunization/diseases/japanese_encephalitis/en/, and Grant L Campbell, Susan L Hills, Marc Fischer, Julie A Jacobson, Charles H Hoke, Joachim M Hombach, Anthony A Marfin, Tom Solomon, Theodore F Tsai, Vivien D Tsu & Amy S Ginsburg. Estimated global incidence of Japanese encephalitis: a systematic review. Volume 89, Number 10, October 2011, 766‐774E

The first case of Japanese encephalitis viral disease (JE) was documented in 1871 in Japan.

Main distribution of Japanese encephalitis

However…..JEV is divided into five genotypes (G1‐G5), and each genotype has its own distribution pattern. The distribution of different JEV genotypes has changed markedly in recent years. JEV G1 has replaced G3 as the dominant genotype in the traditional epidemic areas in Asia, while G3 has spread from Asia to Europe and Africa and caused domestic JE cases in Africa. G2 and G5, which were endemic in Malaysia, exhibited great geographical changes as well. G2 migrated southward and led to prevalence of JE in Australia, while G5 emerged in China and South Korea after decades of silence

Vector Borne Zoonotic Dis. 2019 Jan;19(1):35‐44. doi: 10.1089/vbz.2018.2291. Epub 2018 Sep 12.Changing Geographic Distribution of Japanese Encephalitis Virus Genotypes, 1935‐2017.Gao X1,2,3, Liu H4, Li X2,3, Fu S2,3, Cao L2,3, Shao N2,3, Zhang W2,3, et al

West Nile Virus Flavivirus

Infection with WNV is typically asymptomatic (no symptoms) in about 80% of infected people, but can lead to West Nile fever or severe West Nile disease in about 20% of cases. •. Symptoms include fever, headache, tiredness, and body aches, nausea, vomiting, occasionally with a skin rash (on the trunk of the body) and swollen lymph glands.•The symptoms of severe disease (also called neuroinvasive disease, such as West Nile encephalitis or meningitis or West Nile poliomyelitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis.. •Ancestral home of WNV is Africa, but in 1999  WNV circulating in Israel and Tunisia was imported in New York producing a large and dramatic outbreak that spread throughout the continental United States of America (USA) in the following years. The WNV outbreak in USA (1999‐2010) highlighted that importation and establishment of vector‐borne pathogens outside their current habitat represent a serious danger to the world..•WNV is now commonly found in Africa, Europe, the Middle East, North America and West Asia.•Birds are the reservoir hosts of WNV. Mosquitoes of the genus Culex are generally considered the principal vectors of WNV, in particular Cx. pipiens. WNV is maintained in mosquito populations through vertical transmission (adults to eggs).

….first isolated in a woman in the West Nile district of Uganda in 1937.

https://www.who.int/news‐room/fact‐sheets/detail/west‐nile‐virus

The Usutu virus (USUV) is a flavivirus that is drawing increasing attention because of its potential for emergence. First isolated in Africa, it was introduced into Europe where it caused significant outbreaks in birds, such as in Austria in 2001. Since then, its geographical distribution has rapidly expanded, with increased circulation, especially in the last few years. Similar to West Nile virus (WNV), the USUV enzootic transmission cycle involves Culex mosquitoes as vectors, and birds as amplifying reservoir hosts, with humans and other mammals likely being dead-end hosts.

Geographical distribution of USUV. Countries where USUV was detected in wildlife (birds, mosquitoes, horses, etc.) are indicated in green; countries where USUV was detected in healthy blood donors are represented in blue; and countries where USUV caused symptomatic, acute infections are shown in orange. The arrows represent the presumed bird migration event that led to introduction of USUV in Europe, according to Engel et al. [7].

Viruses. 2019 Jul; 11(7): 640.Published online 2019 Jul 12. doi: 10.3390/v11070640PMCID: PMC6669749PMID: 31336826Usutu Virus: An Arbovirus on the RiseFerdinand Roesch,1 Alvaro Fajardo,2 Gonzalo Moratorio,1,2,3 and Marco Vignuzzi1,*

Lundström JO, Hesson JC, Schäfer ML, Östman Ö, Semmler T, Bekaert M, et al. (2019) Sindbis virus polyarthritis outbreak signalled by virus prevalence in the mosquito vectors. PLoS Negl Trop Dis 13(8): e0007702. https://doi.org/10.1371/journal.pntd.0007702

Zika now, what next…..?

A path through the Zika Forest leading to an observational steel tower operated by the Uganda Virus Research Institute

Ndumu, Spondweni, Wesselsbron, Rift Valley fever, Pongola, O’nyong Yong, Semliki Forest, Lumbo, etc etc etc, plus others in South America and Asia‐Pacific, waiting to escape their enzootic sylvatic cycles, just like others previously.

Estimates (in millions) of the global numbers of migrants 1990–2016. © UNHCR, reproduced with permission

Migrant and refugee populations: a public health and policy perspective on a continuing global crisisMohamed Abbas, Tammam Aloudat, Javier Bartolomei, Manuel Carballo, Sophie Durieux‐Paillard, Laure Gabus, Alexandra Jablonka, Yves Jackson, KanokpornKaojaroen, Daniel Koch, Esperanza Martinez, Marc Mendelson, Roumyana Petrova‐Benedict, Sotirios Tsiodras, Derek Christie, Mirko Saam, Sally argreaves & Didier Pittet .Antimicrobial Resistance & Infection Control volume 7, Article number: 113 (2018)

Structure

Filarial infectionsWuchereria bancroftiBrugua malayi & Brugia timori

Dirofilaria

Although the parasite damages the lymph system , most infected people have no symptoms and will never develop clinical symptoms. These people do not know they have lymphatic filariasis unless tested. A small percentage of persons will develop lymphedema. This is caused by fluid collection because of improper functioning of the lymph system resulting in swelling. This mostly affects the legs, but can also occur in the arms, breasts, and genitalia. Most people develop these symptoms years after being infected.The swelling and the decreased function of the lymph system make it difficult for the body to fight germs and infections. These people will have more bacterial infections in the skin and lymph system. This causes hardening and thickening of the skin, which is called elephantiasis. Many of these bacterial infections can be prevented with appropriate skin hygiene as well as skin and wound care .Men can develop hydrocele or swelling of the scrotum due to infection with one of the parasites that causes LF specifically W. bancrofti.

https://www.cdc.gov/parasites/lymphaticfilariasis/disease.html

Lymphatic Filariasis

Wuchereria bancrofti is a human parasitic worm that is the major cause of lymphatic filariasis. It is one of the three parasitic worms, together with Brugia malayi and B. timori, that infect the lymphatic system to cause lymphatic filariasis. These filarial worms are spread by a variety of mosquito vector species. W. bancrofti is the most prevalent of the three and affects over 120 million people, primarily in Central Africa and the Nile delta, South and Central America, the tropical regions of Asia including southern China, and the Pacific islands.[1] If left untreated, the infection can develop into a chronic disease called Lymphatic filariasis.[2] In rare conditions, it also causes tropical eosinophilia, an asthmatic disease. No vaccine is commercially available, but high rates of cure have been achieved with various antifilarialregimens and lymphatic filariasis is the target of the WHO Global Program to Eliminate Lymphatic Filariasis with the aim to eradicate the disease as a public-health problem Wuchereria bancrofti Microfilaria of Wuchereria bancrofti,

from a patient seen in Haiti. Thick blood smears stained with hematoxylin. The microfilaria is sheathed, its body is gently curved, and the tail is tapered to a point. The nuclear column (the cells that constitute the body of the microfilaria) is loosely packed, the cells can be visualized individually and do not extend to the tip of the tail.

https://en.wikipedia.org/wiki/Wuchereria_bancrofti#/media/File:Wuchereria_bancrofti_1_DPDX.JPG

Lymphatic filariasis

This image is a work of the Centers for Disease Control and Prevention, part of the United States Department of Health and Human Services, taken or made as part of an employee's official duties.

Adult female worms produce microfilariae. Feeding vector mosquitoes ingest microfilariae from the bloodstream. In the mosquito the microfilariae mature to infective larvae, which migrate to the mosquito's mouth‐parts, enter a new host via the vector's puncture wound, migrate to the lymphatics, mature, and mate.

Cecilia T. HugoExecutive Coordinator, ACTMalaria

Member, WHO‐Malaria Elimination Certification Panel

2nd International Training Course on Malaria Vector Surveillance for Elimination 29 September – 12 October 2019,  Kasetsart University

Introduction to the WHO e‐learning module on 

Malaria Entomology and Vector Control, as well as other vector control 

documents and support

https://apps.who.int/iris/bitstream/handle/10665/310862/9789241550499-eng.pdf?ua=1

https://www.who.int/malaria/publications/atoz/ppt-guidelines-malaria-vector-control.pdf?ua=1

https://apps.who.int/iris/bitstream/handle/10665/272284/9789241565578-eng.pdf?ua=1

https://www.who.int/malaria/publications/atoz/surveillance-reference-manual-webinar-apr2018.pdf?ua=1

Malaria Vector Surveillance (WHO 2018)

1. National strategy, coordination, policies and advocacy

2. Stratification 3. Diagnostics 4. Case management 5. Surveillance6. Transmission foci and

Epidemic Preparedness7. Vector Control8. Accelerating Strategies9. Prevention of Re-

establishment10.Certification

Rationale Color code for certification

 documents needed for certification evaluation

7.1 Surveillance

Decisions on which vector control methods should be implemented need to consider, among other 

factors, the susceptibility of malaria vectors to insecticides and the preferred feeding and resting 

location of adult mosquitoes; as well as oviposition preferences

7.1.1

Written entomologic surveillance standard operating procedures are available and aligned with WHO guidance

‐ Standard operating procedures for entomologic surveillance including minimum data collection as recommended by WHO‐ Maps identifying sentinel sites

7.2.1Entomologic intelligence available for all foci within last 3 years

‐ Reports of entomologic surveillance activities for at least the past three consecutive years

7.2.2Primary and secondary vector species known for all foci

‐ Reports of entomologic surveillance activities for at least the past three consecutive years

7.2.3

Basic behavioral characteristics (indoor vs. outdoor biting preferences, indoor vs. outdoor resting preferences, blood meal preferences) are known for primary and secondary vectors

‐ Journal articles or reports on vector behavior

7.3.1Insecticide resistance monitoring plan available

‐ Standard operating procedures for measurement of insecticide resistance

7.3.2Data on vector susceptibility to relevant insecticides available from sentinel sites

‐ Reports of vector susceptibility to insecticides for at least the past three consecutive years

Milestones

Vector species and behavior

The 30‐40 Anopheles  species that can transmit malaria in nature contribute to the complexity of malaria transmission globally. An understanding of local vector biology (species diversity and 

seasonal density fluctuations), their behaviour and ecology (preferred oviposition site, host choice and resting location ) is important to 

inform decisions on the deployment of cost effective vector  control 

interventions

Insecticide susceptibility7.3

Monitoring insecticide susceptibility is useful to predict vulnerability of 

vectors to insecticide based interventions and essential to inform choice of alternative 

insecticides

7.2

Critical Elements

Targets: Vector control should be implemented effectively to reduce malaria transmission and prevent re‐establishment of transmission

Vector control From the Draft Version: 6 May 2019; Developed by the WHO Elimination Unit

7.4.1Entomologists and vector control staff receive appropriate training

‐ Training reports

7.4.2

Written vector control strategy/guidelines available and aligned with WHO recommendations

‐ Standard operating procedures for vector control in receptive areas with risk of importation‐ Standard operating procedures for vector control in reaction to identification of a case

7.4.3Vector control strategyfor outbreaks and emergencies available

‐ Standard operating procedures for vector control in response to outbreaks

7.4.4

Universal coverage with primary vector control methods available for all at‐risk populations and receptive areas with risk of importation

‐ Reports of vector control available from five years before reaching zero indigenous cases until present time

7.4.5Supplemental vector control available in alignment with WHO recommendations

‐ Reports of vector control available from five years before reaching zero indigenous cases until present time

7.5.1Vector control coverage is routinely monitored in all foci

Vector control reports (may be included in the annual reports of malaria prograramme)

7.5.2Vector control quality is monitored in all foci

7.5.3

Impact of anti‐larval campaigns is monitored by measuring changes in adult mosquito density

SOPs of QA of Vector control;  monitoring reports

Malaria vector control programmes need to monitor vectors and 

interventions in order to quickly detect and respond to changes

Monitoring7.5

7.4 Vector control

Vector control, together with case management, is the most effective method for malaria control and 

elimination

RationaleColor code for certification

 documents needed for certification evaluationMilestonesCritical Elements

Targets: Vector control should be implemented effectively to reduce malaria transmission and prevent re‐establishment of transmission

Vector control from the draft Version: 6 May 2019; Developed by the WHO Elimination Unit

Documentation for certification of eliminationTargets: The required documentation is available to prove, beyond a reasonable doubt, that the country has had zero indigenous cases over the past three consecutive years, and has a robust surveillance system and response system in place that can prevent onward transmission from imported cases and respond promptly to outbreaks to prevent re‐establishment

Required documents Rationale Time PeriodWhere should the documents/records be available

Annual reports of entomological and vector control activities

To understand how the country got to 0 indigenous cases and whether they can prevent re‐establishment

5 years to present

National and intermediate (provincial or district) level

Vector control training reports

To ensure clinicians are up to date with guidelines

5 years to present

National and intermediate (provincial or district) level

https://apps.who.int/iris/bitstream/handle/10665/85890/9789241505802_eng.pdf?sequence=2

https://apps.who.int/iris/bitstream/handle/10665/85890/9789241505819_eng.pdf?sequence=1

Study design and data analysisProf. Richard J Maude 

MBChB BSc MRCP DTM&H MD Dphil FRGS

Head of Epidemiology DeptMahidol‐Oxford Tropical Medicine Research Unit, Bangkok

University of Oxford, UK; Harvard University, USA

Outline

• Introduction to entomological studies•Questions• Data types

•Surveillance• Types of surveillance• Entomological indicators

•Research•Operational Research• Retrospective• Prospective

Types and goals of studies for malaria control and elimination

•Entomological•Parasitological•Clinical

Empirical observations

•Theoretical studies e.g. statistical and mathematical models

Malaria strategy based on thorough understanding of  transmission characteristics

Estimation of expected impact of control measures

Decide which control and elimination measures to use for the area

Entomological studies for malaria control and elimination

• Identification of the vectors responsible for transmission of the disease

• Provision of basic information on the habits and habitats of vector species for purposes of planning effective control measures

• Monitoring the impact of control measures (for example, by determining changes in vector population density, rates of infection, susceptibility of vectors to insecticides, and residual effects of insecticides on treated surfaces)

• Contributing to the investigation of problem areas where control measures prove unsuccessful

Example questions for entomological studies• Is there malaria transmission in the area? If so, in which specific situation and what are the geographical limits of the disease?

• Are there any important mosquito borne diseases other than malaria, if so which ones?• Which anopheline species are present in the area? Which of them are important as vectors of malaria? What proportion of the vector species feed on humans? What proportion rest indoors?

• Where do most of the vector mosquitoes prefer to bite humans, and where does most man‐vector contact take place, indoors or outdoors? What is the peak biting time of the vector?

• How many infective bites are received on average per night per person?• Which type of water body is preferred for breeding by a particular vector species in the area?• During which epidemiological and economic conditions should a vector control strategy to reduce transmission be recommended or not recommended?

• What proportions of the vector population are susceptible or resistant to insecticides?• How to determine duration of efficacy of an insecticide deposited on a surface (e.g. a sprayed wall or ITN)?• How do different vector control options affect malaria transmission, malaria morbidity and mortality? Which vector control options are appropriate against the specific habits and habitats of the vector species? How to evaluate the short and long‐term effectiveness of a vector control strategy?

Considerations when planning studies

Must provide practical answer to clearly defined control‐oriented research questions when data is unavailable or inadequate.

of studiese.g. financial,manpower, time,risk

to NMCPe.g. more effective vector control, save money, save time 

vs

Study Design: Methods for Data Collection

• Surveillance• Routine, ongoing

• Surveys• One‐off/regular

• Research• Observational studies

• Quantitative• Qualitative

• Intervention trials

Malaria Entomology Data Types

SURVEILLANCE & SURVEYS• Mosquitoes:

• Adults• Larvae• Insecticide resistance

• Breeding sites

INTERVENTIONS• Vector control interventions:

• LLIN distribution• IRS• Larval source management

GEOGRAPHICALLocation:

Mosquito collection (points): latitude, longitudeAdministrative unit (polygons): village, subdistrict, district, province, country

Climate:Climate station (points): rainfall, temperature, humidityRemote sensing (rasters): surface water, land surface temperature, etc.

Land cover:Water bodiesForest/vegetation cover rasters

Other Malaria Data Types

SURVEILLANCE & SURVEYS• Humans:

• Cases• Passive surveillance• Active case detection (ACD)• Antimalarial resistance

• Therapeutic efficacy studies (TES)• Genetic markers

• Population e.g. census

INTERVENTIONS• Case management: ACT use, stocks• MDA, MSAT, FSAT

HEALTH SERVICES• Health facilities:

• Clinics• Hospitals• Village health workers• Private sector

• Staff• Vector control• Nurses• Doctors• Volunteers

• Logistics• Vehicles• Stocks and supplies

FINANCIAL:• Unit costs• Budgets

QUALITATIVE• In‐depth interviews

Surveillance

What is Surveillance?

11

What is Surveillance?

12

•OED: close observation, especially of a suspected spy or criminal.

•Early 19th century: from French, from sur‐ 'over' + veiller 'watch' (from Latin vigilare 'keep watch').

Communicable Disease Surveillance

13

“Ongoing systematic collection, analysis, and interpretation of outcome specific data for use in planning, implementing and evaluating public health policies and practices.”

Communicable Disease Surveillance System

14

A communicable disease surveillance system serves two key functions: 

1. early warning of potential threats to public health.

2. programme monitoring functions which may be disease specific or multi‐disease.

Entomological surveillance

• Regular, systematic collection, analysis and interpretation of entomological datafor risk assessment, planning, implementation, monitoring and evaluation of vector control interventions.

• All surveillance activities must be clearly linked to programme decisions to ensure optimal vector control.

Objectives of Entomological Surveillance

• Characterize receptivity to guide stratification and selection of interventions. Vector species present; characteristics that influence transmission (biting (time, place and host preference), dispersion and resting behavior) 

• Track the relative density of malaria vector species (and their bionomics)To determine the seasonality of transmission and the optimal timing of interventions.

• Track insecticide resistance as a basis for choosing insecticides. Frequency, intensity and mechanisms of resistance in the principal malaria vectors and, when possible, in secondary vectors.

• Identify other threats to the effectiveness of vector control. Change in composition and behaviour of vector populations e.g. significant change in the location in which transmission takes place.

• Monitor vector control intervention coverage and quality to identify gaps and opportunities. 

Coverage, access, use, acceptability and quality e.g. such as the physical or fabric integrity and insecticidal activity of LLINs and residual efficacy of IRS.

Types of surveillance for vector control

• Preliminary or baseline surveys

• Routine sentinel surveys for observation of trends

• Spot checks for supplementary data collection

• Focus investigations during elimination or in response to outbreaks

Preliminary or baseline surveys

• Initial, time‐limited surveys• Used to gather baseline data for planning vector control measures• Provide information on:

• Vector species present• Resting and feeding habits• Changes in species composition by season and over time• Types of water bodies used as larval habitats • Vector susceptibility to insecticides. 

(Information on local vector species and their ecology, biology and behaviour will often  have been assembled and used to inform current control or elimination strategies.) 

• Data from these types of surveys can also be used to identify appropriate sentinel surveillance sites.

Routine sentinel surveys

• Long‐term observations are made regularly, such as monthly, quarterly or annually, in fixed locations.

• Goals: identify any change in vector species density and composition, behaviour, susceptibility to insecticides and infection rates

• May explain any observed epidemiological trends in malaria transmission, and indicate the appropriate response. 

• All malaria‐endemic countries should have established entomological surveillance sites that have been carefully selected on the basis of multiple criteria.

• As transmission decreases and malaria becomes more focal, adjust location of sentinel sites.

Entomological sentinel site selection

• Should represent range of eco‐epidemiological settings in a country: different vector species, zones with different levels of malaria transmission

• Data generated at entomological sentinel sites MUST be linked to information on local malaria epidemiology

• ≥ 1 sentinel site / 500 000 nets distributed or 200 000 houses sprayed • Approx 1 site per 1 million people protected • Exact number will depend on the country’s epidemiology and population density. • The distribution and number of sites should be reviewed periodically and adapted according to epidemiological data, identified patterns of resistance and available human and financial resources.

Spot checks

• Ad‐hoc assessments are carried out in selected locations as a supplement to routine observations and when more information is required to inform programme adjustment or response. 

• Spot checks may include investigations in areas where there are:• Suspected problems in implementation of an intervention• Increase in receptivity and/or vulnerability 

e.g. due to reintroduction or proliferation of a vector species as a result of environmental changes• The presence of vulnerable populations 

e.g. due to resettlement, migration or mining• Heightened risks for importation due to increased human movement in border areas or transport routes linked to endemic countries.

Focus investigations

• Undertaken in areas of new, persistent or resurgent malaria transmission to determine why the interventions being used are no longer reducing transmission.

• Short‐term, reactive epidemiological investigations in settings of elimination or prevention of re‐establishment. 

• The trigger for a focus investigation could be an increase in the prevalence of parasite infections or clinical malaria cases.

Entomological surveillance activities

• Identify the malaria vector species• Measure species‐specific vector densities and ascertaining vector composition• Determine vector blood‐feeding habits (zoophilic, anthropophilic)• Assess other vector behaviour (exophily, endophily, exophagy, endophagy)• Monitor vector susceptibility to insecticides (frequency, intensity and mechanisms of resistance)• Measure rates of infection of vector with malaria parasite (sporozoite rate, oocyst rate)• Identify quatic habitats of immature stages of vectors and habitat characteristics

Entomological surveillance indicators

Adult vector composition• Occurrence• Density

Adult vector behavior• Human biting rate• Human blood index• Biting time• Biting location• Resting location

Adult vector insecticide resistance• Resistance frequency• Resistance status• Resistance intensity• Resistance mechanisms

Immature vector aquatic habitats• Habitat availability• Habitat occupancy• Larval density

Proxies for transmission• Sporozoite rate• Entomological inoculation rate• Receptivity

Calculation of Entomological Indicators

• Indoor resting density (by species) = # female mosquitoes / # houses inspected

• Degree of endophagy/exophagy (by species): • Ratio indoor/outdoor biting = whole night indoor/outdoor landing collections

• Human‐biting rate (by species) = average number of attempted bites/bites per collection unit per night

• Human‐landing collections = per human per collection hour• CDC light traps/pyrethrum spray catches/window exit traps: per trap per night per # human occupants in house

• Human blood index (HBI) = # mosquitoes with human blood / total # mosquitoes with blood

• Sporozoite rate = sporozoite positive mosquitoes / mosquitoes analysed

Resting habit 

• k = a correction value of 1.16• H = Human‐blood index• D = indoor resting density (total number of females collected divided by number of houses used for the spray‐sheet collection)

• M = human‐biting rate for the month• P = duration of resting indoors after feeding, in days; P = 1 + G/F, where G is the total number of half‐gravid and gravid females (spray‐sheet collections) and F is the number of freshly fed females (spray‐sheet collections)

• N = average number of persons per house (household size)

= proportion of blood meals taken on man followed by resting indoors

Efficacy of IRSThe aim of residual spraying is to reduce the chance of infected vectors reaching an infective age

Entomological Inoculation Rate (EIR)

= human‐biting rate x sporozoite rate from human landing catchesOr

= vector density x human biting rate x sporozoite rate from CDC light trap collection

… per person per time interval (night/month/year)

Number of infectious bites by adult female vectors per person per unit time

Indicates intensity of malaria parasite transmission

Vectorial capacity

The capacity of a vector population to transmit malaria in terms of the potential number of secondary inoculations originating per day from an infective person.

m = density of vectors in relation to mana = number of blood meals taken on man per vector per day (= HBI * 0.5, assuming 

gonotrophic cycle of 2 days)p = daily survival probability (or proportion of vectors surviving per day)n = incubation period in the vector (days)

reduce survival pn(e.g. residual spraying) 

reduce blood meals a2(e.g. repellants)

reduce density m (e.g. larval control)

=> EFFICACY

>> >>

Receptivity

Classification of areas according to transmission risk.

• Presence of competent Anopheles vectors• Suitable climate• Susceptible human population

• Various methods used ‐ ongoing review by WHO ‐ guidance on the way

Combined

Vector resistance

• Sentinel sites:• Eco‐epidemiological stratification• Distribution of important vectors• Types of interventions• Situations likely to promote resistance e.g. intensive use in agriculture

• Once confirmed:• Determine intensity and mechanisms

• Drives operational decisions:• Choice of alternative insecticide for IRS• Rotation of insecticides

Routine entomological surveillance by transmission settingINDICATOR PRIORITY BY TRANSMISSION SETTING

High, moderate or low Very low to elimination Prevention of reestablishment

Adult vector compositionOccurrenceDensity

Adult vector behaviour

Human biting rateHuman blood index Unreliable Unreliable

Biting timeBiting locationResting location

Adult vector insecticide resistance

Resistance frequencyResistance status

Resistance intensityResistance mechanism(s)

Immature vector aquatic habitats

Habitat availabilityHabitat occupancyLarval density

Proxies for transmission

Sporozoite rate UnreliableEIR Unreliable Unreliable

Receptivity

HIGH PRIORITY MODERATE PRIORITY LOW PRIORITY

Monitoring of vector control

• Implementation• Progress indicators: coverage, access, use – part of routine programme monitoring

• Quality control of products• WHO prequalified• Inspection: sampling and testing

• Performance of interventions• Durability of LLIN: prospective study of attrition, physical and fabric integrity, insecticidal bio‐efficacy

• Residual efficacy of IRS: monthly cone assays• LSM: changes in vector density

Entomological surveillance to guide programme responses

• Entomological and intervention surveillance data should have clear use in decision‐making

• Use of data in planning and implementing vector control must be well defined and efficient. 

• Integrate vector data with other relevant information: epidemiological and environmental factors for complete overview of transmission dynamics and drivers.

• For example:

SCENARIOIncrease in number of malaria cases despite good vector control coverage.

HYPOTHESISLoss of vector control effectiveness not due to poor coverage.

SURVEILLANCE RESPONSECheck intervention quality. Determine vector composition (and behaviour if possible). Assess insecticide resistance.

Partnerships: the NMCP doesn’t need to collect all the data

Expertise from …

• Other vector control programmes• Research institutions• Central or regional reference laboratories • Non‐governmental organisations• Development projects• Private sector• Other partners• Published documentation 

… should be drawn upon for technical and programme support, as appropriate.

Close collaboration and linkages with these is highly 

beneficial for the NMCP

Research

question

design

data

analysis

interpretation

PUBLICATION

Research

c/o Eric Ohuma, Uni Oxford

Surveillance       vs       Research• Ongoing• Generates hypotheses• Incomplete data on population• Simpler analysis• Rapid dissemination of results• Results not necessarily generalizable• Triggers intervention

• Time‐limited• Tests hypotheses• More complete data on sample• More complex analysis• Slower dissemination of results• Aims at generalizability• Looser link to intervention

Types of Research

• Operational Research“scientific approach to the solution of problems in the management of complex systems that enables decision makers to make better decisions”

• Retrospective• Analyse data that are already collected e.g. surveillance, surveys, meta‐analyses e.g. statistical modelling, mathematical modelling, economic modelling

• Prospective • Collect and analyse new data e.g. observational studies, intervention trials

Surveillance vs Operational Research

Operational Research is…

• More detailed evaluation of entomology and vector control 

• Usually conducted by partner institutes, including research or academic institutions

• To answer specific research questions, rather than as routine monitoring

What is Operational Research?

• Enhance operational impact of vector control actions• Covers technical, operational and managerial aspects • Aim: to address knowledge and information gaps on vectors, transmission, vector control methods and insecticide resistance 

• NMCP managers should prepare research agendas jointly with decision makers, entomologists, vector control planners and implementers and potential researchers

• Need review of ongoing research and relevance to vector control needs• Often needs external funding and resources• Undertaken jointly with relevant partners• Translate research findings into action against malaria and vectors

Problem‐solving operational research with direct relevance to vector control must be an integral component of a malaria vector control programme.

Retrospective Research

Statistical analysis

•Re‐analysis of published studies:

•Systematic review•Meta‐analysis•Cochrane reviews

•Analysis of surveillance and other data that have already been collected

Statistical modelling

• Combines surveillance data together with other information to better understand patterns and trends

Examples:• Contribution of climate to seasonal pattern• Map transmission risk• Impact of population movement on spread

Mathematical modelling

• Computer simulation of biology and epidemiology to understand past and predict future trends

Examples:• Understand contribution of different interventions on past trends• Predict future impact of interventions• Identify optimum combinations of interventions for different settings• Explore ‘what‐if?’ scenarios

Cost‐effectiveness and economic modelling

Studies economics of different interventions in different settings

Examples:• Determine costs of implementing current NSP• Predict costs of malaria elimination under different scenarios• Predict optimal set of interventions within available budget• Design budgets for future funding proposals

Prospective Research

Types of prospective research

Quantitative• Observational

• Cross‐sectional• Case‐control• Cohort

• Experimental (intervention studies)• Randomised controlled trials• Non‐randomized controlled trials

Qualitative• Surveys• In‐depth interviews

Observational Studies

Vector Control Trials

Stages in development of a new vector control product 

Wilson et al. Trends Parasitol 2015.

Hierarchy of study designs for assessing the efficacy of vector control interventions

Wilson et al. Trends Parasitol 2015.

Randomised controlled trial

• Individuals or clusters (cluster‐randomised controlled trial) are randomly allocated to receive either intervention(s) or control: 

• Intervention and control groups are then followed up for the outcome of interest. 

• Randomisation to ensure any factors that may affect the outcome, other than the intervention, are the same in the groups

• Checked by comparing baseline characteristics• Reduced by adjusting in analysis

• Gold standard for intervention studies.

intervention     vs     control

Cluster randomized trials

• Randomisation unit = cluster i.e. district, village, household• Common in vector control trials

Because:1. Many vector control tools are applied to groups of people or communities. 

e.g. IRS for households, bednets distributed to whole village

2. Can help reduce contamination between study arms that might occur if individuals within the same community received different interventions

e.g. sharing of insect repellent with family members within the same household or village. 

3. Able to assess the community‐level effect of the intervention.e.g. mass killing of mosquitoes coming into contact with LLINs can reduce transmission so that indirect protection is provided to individuals not using LLINs. 

Other trial designs

Other trial designs

Where logistical, practical, or financial constraints make the staged roll out of the intervention desirable.

Other trial designs

Sources

• WHO Malaria surveillance, monitoring and evaluationhttps://www.who.int/malaria/publications/atoz/9789241565578/en/• WHO Malaria entomology and vector controlhttps://apps.who.int/iris/bitstream/handle/10665/85890/9789241505819_eng.pdf?sequence=1• Data requirements and methods to support the evaluation of new vector control productshttps://www.who.int/malaria/publications/atoz/requirements‐vector‐control‐products/en/• Disease surveillance for malaria elimination: operational manualhttps://www.who.int/malaria/publications/atoz/9789241503334/en/• Evidence‐based vector control? Improving the quality of vector control trials. Wilson AL et al. Trends Parasitol 2015.

Thank you and good luck!

richard@tropmedres.acwww.tropmedres.ac/malaria‐epidemiology

60