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Infection Control ofAerosol Transmissible
Diseases
The Chain Model of Communicable Diseases
�Sources of infection /Reservoirs
Portals of exit
�Modes of transmission
Portals of entry
�Susceptible hosts
The chain of infection: portals of exit of a pathogen
Portal of exit: routes by which the infectious agents escapes the human or animal reservoirs (some diseases may have several portals of exit)
Portals of exit:
� Respiratory tract (nasal/respiratory secretions)
� GI tract (saliva, vomitus, stool)
� Genital/urinary tract (urine, semen, vaginal secretions
� Breaks in skin (skin rash, needle sticks, bites of mosquitos)
Modes of Transmission
� Direct Transmission� Direct Contact
� Droplet
� Indirect Transmission� Vehicle-borne
� Vector-borne
� Airborne (sometimes claimed as vehicle-borne)
� Vertical transmission (mother to infant)
Infectious aerosols are generated when an some ill person sneezes, coughs or speaks.
Source: Department of Medical Microbiology, Edinburgh University
Transmission of Infections by Respiratory Aerosols
Expulsion of infectious material into the air through sneezing, coughing or through aerosol-generating medical procedures such as sputum induction creates large droplets and smaller aerosols.
speaking and breathing generate smaller amounts of aerosols
1. Droplets: Bacterial or viral laden droplets (10-100 µ)
• land directly on mucosal lining of nose, mouth, eyes of nearby persons or can be inhaled.
• Highest exposures within 1-2 meters
2. Airborne: aerosols become smaller by evaporation; small aerosols (≤ 10 microns) remain suspended for longer periods, if inhaled travel deep into the lungs (pl tbc).
3. Contact: Aerosols/ secretions contaminate nearby surface. Touch surfaces �can infect self or others.
Relative contribution of three routes varies with agent.
7
Transmission of Infections by Respiratory Aerosols
Modes of Transmission viaInfectious Respiratory Secretions
� Airborne: tuberculosis, measles (2 hours), varicella, smallpox, SARS, avian influenza
� Droplet: meningococcal meningitis, rubella, pertussis, common cold, SARS, influenza*
� Indirect contact: (fomite) RSV, SARS, influenza (15 min hands, 2-48 hours on certain surfaces)
*Influenza traditionally droplet, increasing evidence for airborne component
Infection Control in a Health CareSetting Review
Basic Principles
� All body fluids are potentially infectious (except sweat) � blood and blood-tinged fluids including open-wounds
� respiratory secretions, saliva, stool, urine, vomit, semen, vaginal secretions, breast milk, other body fluids such as pericardial and synovial fluids
� Minimize exposure to potentially infectious body fluids
� Infection control measures designed to “break the chain” of transmission
Standard Precautions in Health Care Settings
1. Appropriate hand hygiene
2. Barrier protective equipment:� if splash, splatter, or sprays can be reasonably anticipated
� appropriate PPE (Personal protective equipment) as needed: gloves, gown, mask, eye protection (face shield, goggles)
3. Proper use and handling of patient care equipment
Standard Precautions in Health Care Settings
4. Proper environmental cleaning and disinfection
5. Proper handling of linen
6. Adherence to bloodborne pathogens standards
7. Proper patient placement
8. Respiratory hygiene/cough etiquette
9. Safe injection practices
Expanded Isolation Precautions:
� Transmission-based Standards : when standard precautions are not enough
� Additional measures based on mode of transmission
� Contact Precautions
� Droplet Precautions
� Airborne Precautions
Aerosol Transmissible Diseases in Health Care and Public Safety Settings
� Droplet
� Meningococcal meningitis
� Pertussis
� Mumps
� Rubella (German measles)
� Strep pharyngitis
� Influenza
� Airborne
� Tuberculosis
� Varicella (chickenpox)
� Measles
� SARS
� Avian influenza
� Smallpox
� Influenza
Reasons for Respiratory Protection
� Engineering controls not feasible or sufficient
� Employees must wear N95 respirators (or higher level of protection) in the following circumstances
� Entering a room with patient with suspect or confirmed airborne infectious disease
� When performing high-hazard (aerosol-generating) procedures on persons with suspect/confirmed airborne infectious disease or influenza
� When emergency response employees/others must transport in a closed vehicle, a patient with suspect/confirmed airborne infectious disease
Transmission-Based Precautions: Droplet Precautions
� Single room preferred, no special ventilation
� Patient: Mask if transport necessary. Instruct on
respiratory hygiene/cough etiquette
� HCWs wear surgical or procedure mask within 6
feet (1,8 m) of patient. Eye protection if splash,
spray anticipated
(in addition to Standard Precautions)
Transmission-Based Precautions: Airborne Precautions
� Airborne Infection Isolation Room (AIIR) - intended to prevent transmission of infectious agents suspended in the air that
remain infectious over long distances
� Patient: Mask if transport necessary (as tolerated).
� Health care workers (HCWs):
� N95 respirator prior to entry into room, discarded after exit.
� Higher level respirators for aerosol-gen procedure. Careful attention to proper putting on & taking off (don/doff) respirator, including seal check.
� Hand hygiene before & after don/doff.
� Alert others if need to transfer
(in addition to Standard Precautions)
� Facemasks
� A facemask is a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment.
N95 respirator
N95 respirator is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles.
Meningitis epidemicaMeningococcal Disease
19
Epidemiology
Pathogen: Neisseria meningitidis
Reservoir: Humans are the only natural reservoir of meningococcus
Source of infection: Ill person and asymptomatic carrier
Transmission: by respiratory droplet spread or by direct contact with nasal or throat secretions
Up to 5%–10% of people may be asymptomatic carriers with nasopharyngeal colonization by N. meningitidis.
Incubation period: 3-4 days (range 2-10 days)
Communicability: 1-2 days before onset, until pathogens are no longer present in discharges from nose and mouth 20
Incidence of meningococcal disease peaks among persons in three age groups:
� infants and children aged
Clinical Features
Abrupt onset of fever, meningeal symptoms, hypotension, and rash
Fatality rate 10%-15%, up to 40% in meningococcemia
� Meningococcal Meningitis: most common presentation of invasive disease
Result of hematogenous dissemination
Clinical findings: fever, headache, stiff neck
� Meningococcemia
Bloodstream infection
May occur with or without meningitis
Clinical findings: fever, petechial or purpuric rash, hypotension, shock, acute adrenal hemorrhage, multiorgan failure 22
Glass test: rash that does not fade under pressure is a sign of meningococcal septicaemia
23
Methods of control
Control of patient, contacts and the immediate environment:
Report to local health authority: Obligatory case report in
most countries, (in Hungary immediate report)
Respiratory isolation for 24 hours after start of AB
Concurrent disinfection: Of discharges from the nose and
throat and articles soiled therewith. Terminal cleaning.
Protection of contacts: Close surveillance of household, daycare, and other intimate contacts for early signs of illness,
Prophylactic administration of antibiotic24
Preventive measures
Meningococcal Conjugate Vaccines (MenACWY)
Meningococcal B vaccine (rekombinant) - Bexsero
Meningococcal vaccination is recommended for persons at increased risk for meningococcal disease:
� infants
� adolescents/young adults
� microbiologists who are routinely exposed to isolates of N. meningitidis
� military recruits
� persons who travel to and reside in countries in which N. meningitides is hyperendemic or epidemic, particularly areas in the Sub-Saharan African “meningitis belt”
25
Scarlet fever
26
Scarlet fever is a form of streptococcal disease characterized by a skin rash, occurring when the infecting strain produces a pyrogenic exotoxin (erythrogenic toxin)
Pathogen: group A Streptococcus
Reservoir: Humans
Source of infection: Ill person and asymptomatic carrier
Transmission: by respiratory droplet spread or by direct contact
Incubation period: Short, usually 1–3 days, rarely longer
Communicability: In untreated, uncomplicated cases, 10–21 days; with adequate penicillin treatment, transmissibility generally ends within 24 hours
27
Clinical Features
streptococcal sore throat, strawberry tongue, fever, rush (fine erythema, felt like sandpaper)
typically, the scarlet fever rash does not involve the face, but there is flushing of the cheeks and circumoral pallor
High fever, nausea and vomiting often accompany severe infections.
During convalescence, desquamation of the skin occurs at the tips of fingers and toes
28
Circumoral pallor Strawberry tongue
Poststreptococcal sequelae:
� otitis media or peritonsillar abscess
� acute glomerulonephritis (1–5 weeks, mean 10 days)
� acute rheumatic fever (mean 19 days)
� rheumatic heart (valvular) disease occurs days to weeks after acute streptococcal infection
Most cases of scarlet fever occur in children under 10 (usually between 3 and 5 years of age)
29
Methods of control
Control of patient, contacts and the immediate environment:
Report to local health authority: Obligatory case report in most countries (including Hungary )
Isolation: Drainage and secretion precautions may be terminated after 24 hours’ effective antibiotherapy; AB therapy should be continued for 10 days to avoid development of rheumatic heart disease
Concurrent disinfection: Of purulent discharges and all articles soiled therewith. Terminal cleaning.
Investigation of contacts and source of infection
Prevention: aspecific (higiene) 30
Varicella/Chickenpox
Background
� Infectious agent: Varicella-Zoster virus
� Source: ill person
� Mode of transmission: respiratory or direct contact with lesions
� incubation period: 14 to 16 days (range of 10 to 21 days)
� Clinical features: fever, rash (itchy, fluid-filled blisters that eventually turn into scabs in 1 week); the rash may first show up on the face, chest, and back then spread to the rest of the body, including inside the mouth, eyelids, or genital area
� Period of communicability: 1 to 2 days before the onset of rash until lesions have formed crusts
� Preventive measures: vaccination
• > 90% of population infected by 15 yrs
• attack rates 90% for household contacts
Complications:
– bacterial skin infections
– pneumonia
– encephalitis, post varicella cerebritis
Risk of death:
lower for children than infants
increases with age for adolescents/adults– 30% for perinatally exposed infants
– 2/100,000 aged 1-14
– 2.7/100,000 aged 15-19
– 25.2/100,000 aged 30-4933
Varicella vaccine
attenuated live virus vaccine
For: susceptible children above 1 year, susceptible women planning pregnancy
Contraindications: immunedeficiency
Efficacy
• 96-100% seroconversion within 4-6 weeks post vaccination
• > 90% with high titers after 20 years
• < 2% breakthrough of varicella - mild symptoms
Varicella in pregnancy
• ~2% transmission to fetus
• intrauterine infection more common in 1st trimester
• congenital infection: scarring, limb deformities, cataracts, CNS involvement, chorioretinitis
• neonatal or childhood zoster
Varicella in neonates
• during maternal varicella 24% of fetuses get transplacentally infected
• critical times
– in 5 days before to 2 days after birth
– neonates < 28 weeks gestation or
Influenza
Importance of Influenza
� One of the most important Emerging and Reemerging infectious diseases
� Causes high morbidity and mortality in communities (epidemic) and worldwide (pandemic)
� Epidemics are associated with excess mortality
Leading Causes of Deaths in the US
� Heart Disease
� Cancer
� CVD
� Chr Obst Lung Dis
� Accidents
� Pneumonia & Influenza
� Diabetes Mellitus
� HIV
� Suicide
� Homicide
Influenza
� Influenza is an acute respiratory illness characterized by fever, headache, myalgia, coryza, sore throat and cough. Cough is frequently severe and protracted.
� Duration of illness is usually 2-7 days.
� Infectious agent: Orthomyxoviridae - Influenza A, B és C
� Reservoir: human, animals (type A only)
� Transmission
� Incubation period 1-3 days
� Transmission: from person- to- person through respiratory secretions either as droplets (close contact) or as airborne infection by droplet nuclei suspended in the air.
� Incubation period 1-3 days
� Temporal pattern
�peak December - March in temperate climate
�may occur earlier or later
� Communicability: 1 day before to 5 days after onset (adults)
Diagnosis
Influenza infection causes a clinical syndrome not easily distinguished from other respiratory infections.
Influenza-like illness (ILI) case definition
An acute respiratory infection with:
measured fever of ≥ 38 C°
and cough;
with onset within the last 10 days
Since the clinical picture of influenza is nonspecific, its specific diagnosis –in case of need – is confirmed by laboratory tests, by virus isolation, identification of specific antigens or antibody rise
Antigenic Shift
� This term denotes MAJOR changes in hemagglutinin and neuraminidase resulting from reassortment of gene segments involving two different influenza viruses.
� When this occurs, worldwide epidemics may be the consequence since the entire population is susceptible to the virus.
Antigenic Drift & Shift
Antigen drift: MINOR changes in hemagglutinin and neuraminidase of influenza virus.
This results from mutation in the RNA segments coding for either the HA or NA
This involves no change in serotype; there is merely an alteration in amino acid sequence of HA or NA leading to change in antigenicity.
Antigen shift: MAJOR changes in hemagglutinin and neuraminidase resulting from reassortment of gene segments involving two different influenza viruses.
When this occurs, worldwide epidemics may be the consequence since the entire population is susceptible to the virus.
Known flu pandemics
Name of pandemic
Date DeathsCase fatality
rateSubtypeinvolved
1889–1890 flu pandemic(Asiatic or
Russian Flu)
1889–1890 1 million 0.15%possibly H3N8
or H2N2
1918 flu pandemic
(Spanish flu)1918–1920 20 to 100 million 2% H1N1
Asian Flu 1957–1958 1 to 1.5 million 0.13% H2N2
Hong Kong Flu 1968–1969 0.75 to 1 million
Types of Vaccine
� Inactivated, consisting of (1) whole-virus, (2) subvirion, (3) purified surface antigen. Only subvirion or purified antigen should be used in children. Any of the three can be used for adults. (TIV – trivalent)
�Live attenuated (LAIV) - nasal spray
Contraindications of LAIV (nasal) fluvaccine
� Children younger than 2 years
� Adults 50 years and older
� People with a history of severe allergic reaction to any component of the vaccine or to a previous dose of any influenza vaccine
� Children 2 years through 17 years of age who are receiving aspirin therapy or aspirin-containing therapy.
� Pregnant women
� People with weakened immune systems (immunosuppression)
Inactivated Influenza Vaccine Recommendations
� children 6 months through 4 years (59 months) of age
� Persons 50 yrs or older
� Persons with heart, pulmonary, renal and metabolic diseases
� Residents of nursing homes and other chronic-care facilities
� Persons 6 mos-18 yrs old receiving aspirin therapy (Reye-sy)
� Women who are or will be pregnant during the influenza season
� Household members of persons in high-risk groups
� Health care workers and others providing essential community services
CDC Influenza Vaccine Recommendation
Seasonal Influenza in Healthcare Settings
Multi-faceted approach
� Flu vaccine for HCWs
� Implementation of respiratory hygiene and cough etiquette
� HCWs with ILI stay home
� Source Control
Seasonal Influenza in Healthcare Settings: Isolation Precautions
� Droplet precautions for all patients with suspect influenza (ILI)
� ILI Temp >37.8 C (100 F) plus new cough or sore throat
� Ideally, place patients in single room
� Surgical mask for close patient contact
� Employer may allow N95 during routine care as option
� Patient should be transported with surgical mask.
Seasonal Influenza in Healthcare Settings: Isolation Precautions
� For aerosol-generating procedures: N95 respirator + standard precautions (gown, gloves, goggles for spray/splash)
� Aerosol generated procedures
� Sputum induction, bronchoscopy, elective intubation and extubation, autopsies
� CPR, emergent intubation, open suctioning of airways
Tubercolosis
TB as a Worldwide Public Health Issue
� World population ~ 6 billion
� ~ 1in 3 people in world infected
� ~ 9.4 million new cases of active TB/year
� 1.7 million deaths/year
� US population 280 million
� ~ 3-5% infected
� ~ 11,000 cases/year
� ~ 5-7% mortality
Estimated TB incidence rates
Natural History of TB Infection
Exposure to TB
No infection
(70-90%)Infection
(10-30%)
Latent TB
(90%)
Active TB
(10%)
Untreated
Die within 2 years Survive
Treated
Die Cured
Never develop
Active disease
Tuberculosis
� Infectious agent: Mycobakterium tuberculosis
� Mode of transmission: respiratory (rarely enteral)
� Incubation period: 2-12 weeks
� Clinical Features(pulmonary TB) a bad cough that lasts 3 weeks or longer; coughing up blood or sputum; weakness or fatigue, weight loss, no appetite, chills, fever, sweating at night
56
Treatment
� Four or more drugs required for the simplest regimen
� 6-9 or more months of treatment required
� Person must be isolated until non-infectious
� Directly observed therapy to assure adherence/completion recommended
� Side effects and toxicity common
� May prolong treatment
� May prolong infectiousness
� Other medical and psychosocial conditions complicate therapy
� TB may be more severe
� Drug-drug interactions common
TB – continues as a public health issue in the world
� Old public health concepts (isolation of infectious
individuals, closely monitored treatment, recognition and
preventive treatment for infected contacts,) are still
critical, but will not eradicate TB
� Early diagnosis and prompt treatment especially of pulmonary disease
� Use of observed / supervised treatment where necessary
� BCG vaccine
Recommendations for BCG in UK
� Infants living in an area of the UK with an incidence of TB of 40 / 100,000 or greater
� All infants, children and young people aged up to under 16 years of age with a parent or grandparent born in a country where the annual incidence is 40 / 100,000 or greater (Hungary 11/100,000)
� Previously unvaccinated, tuberculin negative, contacts of cases of respiratory TB (follow NICE TB Guideline)
Recommendations for BCG (con)
� Previously unvaccinated, tuberculin-negative new entrants under 16 years of age who have lived for a prolonged period (at least 3 months) in a country with a high TB incidence
� Individuals at occupational risk (page 397, TB Chapter (Nov 2007), Green Book (note advice on HCWs)
� Travellers and those going to work abroad: may be required for previously unvaccinated, tuberculin negative, individuals aged under 16 going to live or work with local people in a country with a high incidence of TB
� Where vaccine requested: assess for specific risk factors for TB
BCG vaccine is good at:
� Protection of neonates and children against serious forms of primary disease such as meningeal and disseminated TB
� Protecting against death
Immunization coverage
Targeted Screening for TB
� The CDC recommends that the following should be screened for TB:
• Close contacts to individuals with active TB disease
• HIV Infected individuals
• Injection drugs users and users of other high risk substances
• Individuals with medical conditions that are at greater risk for TB
• Individuals/Employees in high risk congregate settings
• Healthcare workers who serve high-risk clients
• Individuals born in countries with high prevalence/incidence
• Infants and children exposed to high risk adults
• WDH recommends that all healthcare facilities conduct the CDC evaluation to determine the frequency for employee screening.
Surveillance
� Tbc must be reported (symptoms, lab tests-DNA)
� Contacts must be screened (tuberculin test for thoseunder 14 years of age, or those who had an X-ray less than threen months ago.
� Screening must be repeated in three months and oneyear.
Legionella
Background
July 21st, 1976: First Discovered at the American Legion Convention.
A thin and flagellated gram-negative bacterium.
Grows best in warm water sources such as: hot tubs, cooling towers, hot water tanks, large plumbing systems, or parts of the air-conditioning systems of large buildings.
� Pathogen: Legionella genus
� Source: warm freshwater environment
� Transmission: Inhalation of mist or vapor contaminated with the bacteria - NOT spread by human-human interaction!
� Incubation period: 2-10 days
� Opportunistic Disease: underlying illness/weak immune system.
� Nosocomial infections are major concerns.
� Middle-aged, elderly, COPD, smokers and other genetic susceptible patients are primary targets.
Symptoms
� Early Symptoms
� Malaise, muscle aches, lethargy and slight headaches.
� High Fever, non-productive cough, abdominal pain, diarrhea.
� Late Symptoms
� Extreme lethargy, comatose state
� Impaired kidney and liver functioning
� Nervous System disorders
Diagnosis
� Urinary Antigen Test
� The serogroup of Legionella often times overlap with other immunocompromised diseases.
� Culture
� Lung biopsy, respiratory secretions, sputum
� Less preferable technique
Prevention
� Regularly maintain and clean cooling towers and evaporative condensers to prevent growth of Legionnaires’ disease Bacteria (LDB). This should include twice-yearly cleaning and periodic use of chlorine or other effective biocide.
� Maintain domestic water heaters at 60°C (140°F). The temperature of the water should be 50°C (122°F) or higher at the faucet.
� Avoid conditions that allow water to stagnate. Large water-storage tanks exposed to sunlight can produce warm conditions favorable to high levels of LDB. Frequent flushing of unused water lines will help alleviate stagnation.
Diphtheria
Revised March 2002
Corynebacterium diphtheriae
� Aerobic gram-positive bacillus
� Toxin production occurs only when C. diphtheriaeinfected by virus (phage) carrying tox gene
Tonsillitis Diphtheria
Diphtheria Epidemiology
� Reservoir: Human carriers (Usually asymptomatic)
� Transmission: Respiratory (Skin and fomites rarely)
� Temporal pattern: Winter and spring
� Communicability: Transmission may occur as long as virulent bacilli are present in discharges and lesions. Effective antibiotic therapy promptly terminates shedding, without antibiotics, organisms usually persist 2 weeks or less and seldom more than 4 weeks.
Diphtheria Clinical Features
� Incubation period 2-5 days (range, 1-10 days)
�May involve any mucous membrane
�Classified based on site of infection� Anterior nasal
� Tonsillar and pharyngeal
� Laryngeal
� Cutaneous
� Ocular
� Genital
Pharyngeal and Tonsillar Diphtheria
� most common sites of diphtheria infection
early symptoms: malaise, sore throat, anorexia, and low-grade fever < 38°C(101°F).
-within 2-3 days, a bluish-white membrane - varying in size from covering a small patch on the tonsils to covering most of the soft palate
- extensive pseudomembrane formation may result in respiratory obstruction.
75
Pharyngeal and Tonsillar Diphtheria
Insidious onset of exudative pharyngitis
Exudate spreads over 2-3 days and may form adherent membrane
Membrane may cause respiratory obstruction
Fever usually not high but patient appears toxic
� Complications:
Most attributable to toxin
Severity of generally related to extent of local disease
Most common complications are myocarditis and neuritis
Death occurs in 5%-10% for respiratory disease
Diphtheria Toxoid Vaccine
� Formalin-inactivated diphtheria toxin
� Schedule: Four doses + boosterBooster every 10 years!
� Efficacy: Approximately 95%
� Duration: Approximately 10 years
� Should be administered with tetanus toxoid as DTaP, DT, or Td
Pertussis
Revised August 2002
Pertussis (whooping cough)
� Bordetella pertussis - Fastidious gram negative bacteria
� Incubation period 5-10 days (up to 21 days)
� Reservoir: human
� Transmission: Respiratory droplets (Airborne rare)
� Communicability Maximum in catarrhal stage
� Secondary attack rate: up to 90%
Pertussis Pathogenesis
� Attachment to cilia of ciliated epithelial cells in respiratory tract
� Pertussis antigens allow evasion of host defenses (lymphocytosis but impaired chemotaxis)
� Local tissue damage in respiratory tract
� Systemic disease may be toxin mediated
Pertussis Clinical Features
Clinical Features: Slow onset, similar to minor upper respiratory infection with nonspecific cough
Fever usually minimal throughout course
� Primary stage 1-2 weeks
� Paroxysmal cough stage 1-6 weeks
� Convalescence Weeks to months
Pertussis Complications
ConditionPneumonia 5,2%Seizures 0,8%Encephalopathy 0,1%Death 0,2%Hospitalization 20%
Cases reported to CDC 1997-2000 (N=28,187)
83
*Cases reported to CDC 1997-2000 (N=28,187)
Acellular Pertussis Vaccine
� Purified "subunit" vaccines
� Intended to reduce adverse reactions
� Together with Diphtheria and Tetanus vaccine(DTaP)
Maesles (Morbilli)
Paramyxovirus (RNA)
One antigenic type
Hemagglutinin important surface antigen
Rapidly inactivated by heat and light
Measles Virus
Measles Epidemiology
Reservoir - Human
Transmission –Respiratory, Airborne
Temporal pattern - Peak in late winter and spring
Incubation period – 10-12 days
Communicability: 4 days before to 4 days after rash onset
Measles Pathogenesis
Respiratory transmission of virus
Replication in nasopharynx and regional lymph nodes
Primary viremia 2-3 days after exposure
Secondary viremia 5-7 days after exposure with spread to tissues
Rash: 2-4 days after prodrome, 14 days after exposure
Maculopapular, becomes confluent
Begins on face and head
Persists 5-6 days
Fades in order of appearance
ConditionDiarrhea – 8%Otitis media – 7%Pneumonia – 6%Encephalitis – 0,1%Death – 0,2%Hospitalization -18%
Measles Complications
Measles Vaccine
Composition: Live virus
Efficacy: 95% (range, 90%-98%)
Duration of Immunity: Lifelong
Schedule: 2 doses
Should be administered with mumps and rubella as MMR
For infants >12 months of age (MMR given before 12 months is noteffective enough)
Mumps
91
Mumps
Paramyxovirus - RNA virus, one antigenic type
Respiratory transmission of virus
Replication in nasopharynx and regional lymph nodes
Viremia 12-25 days after exposure with spread to tissues
Multiple tissues infected during viremia
Mumps Epidemiology
Reservoir: Human
Transmission: Respiratory drop nuclei (Subclinical infectionsmay transmit)
Temporal pattern: Peak in late winter and spring
Incubation period: 12-25 days
Communicability: Three days before to four days onset of active disease
Clinical Features
Nonspecific prodrome of low-grade fever, headache, malaise, myalgias
Parotitis in 30%-40%
Up to 20% of infections asymptomatic
May present as lower respiratory illness, particularly in preschool-aged children
CNS involvement: 15% of clinical casesOrchitis: 20-50% in post-pubertal malesPancreatitis 2-5%Deafness 1/20.000Death 1-3/10.000
Vaccination: Vaccine composition: Live virus Efficacy: 95% (Range, 90%-97%)Duration of immunity: LifelongAdministered with measles and rubella (MMR)
Mumps Complications
Rubella
96
Rubella Epidemiology
Pathogen: Rubella virus
Reservoir: Human
Transmission Respiratory: Subclinical cases may transmit
Temporal pattern: Peak in late winter and spring
Communicability: 7 days before to 5-7 days after rash onset
Infants with CRS may shed virus for a year or more
Rubella Pathogenesis
Respiratory transmission of virus
Replication in nasopharynx and regional lymph nodes
Viremia 5-7 days after exposure with spread to tissues
Incubation period 14 days (range 12-23 days)
Symptoms are often mild, and up to 50% of infections may be subclinical or inapparent
Prodrome of low grade fever
Maculopapular rash 14-17 days after exposure
Lymphadenopathy may begin a week before the rash and last several weeks.
Rubella Complications
Arthralgia or arthritis
children
adult female
Thrombocytopenic purpura
Encephalitis
Neuritis
Orchitis
rare
up to 70%
1/3000 cases
1/5,000+ cases
rare
rare
Congenital Rubella Syndrome (CRS)
� Placenta and fetus infected during viremia
� Infection may affect all organs
� May lead to fetal death or premature delivery
� Severity of damage to fetus depends on gestational age
� Up to 85% of infants affected if infected during first trimester
Congenital Rubella Syndrome
Deafness
Cataracts
Heart defects
Microcephaly
Mental retardation
Bone alterations
Liver and spleen damage
Vaccination
Vaccine composition: Live virus
� Efficacy: 95% (Range, 90%-97%)
� Duration of immunity: Lifelong
� Administered with measles and rubella (MMR)
Strongly recommended for susceptible women planning pregnancy
Contraindications: immunedeficiency
102
References
� CDC� 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings
http://www.cdc.gov/hicpac/2007IP/2007isolationPrecautions.html
� Guideline for Hand Hygiene in Health-Care Settings MMWR 2002; vol. 51, no. RR-16 http://www.cdc.gov/mmwr/PDF/rr/rr5116.pdf
� Cal/OSHA� Aerosol Transmissible Disease Standard http://www.dir.ca.gov/Title8/5199.html
� Appendix A http://www.dir.ca.gov/Title8/5199a.html
� Seasonal Influenza Infection Control Guidelines 2010� CDC: http://www.cdc.gov/flu/professionals/infectioncontrol/index.htm
� CDPH http://www.cdph.ca.gov/programs/immunize/Documents/CDPHGuidanceFluPreventionHCS20101105.pdf
� Cal/OSHA http://www.dir.ca.gov/dosh/Cal-OSHA_influenza_guidance_11-5-10.pdf
References
Infection Control of Aerosol Transmissible Diseases. California Department of Public Health
PANDEMIC INFLUENZA PLANNING: WHAT SCHOOLS NEED TO KNOW
Influenza: epidemiology, prevention and control. Tom D. Y. Chin
Herd Protection against Influenza. W P Glezen, P A Piedra, M J Gaglani
BCG Vaccination. Lika Nehaul
Tuberculosis: An Old Disease – New Twists, a Continuing Public Health Challenge. Jane Moore
Tuberculosis. Wyoming Department of Health Communicable Diseases
Chickenpox in Children, Adults and Pregnancy: What to do? Nayyar Raza Kazmi
Legionnaires’ Disease. Asif Khan
Thank you for your attention!