Presentation- Kristy Jones

.The Impact of Climate Change on the Epidemiology and Control of Rift Valley FeverV. Martin, V. Chevalier, P. Ceccat, A. Anyamba, L. De Simone, J. Lubroth, S. de La Rocque and J. Domenech

Article Presented by Kristy Jones

Project Overview

• Introduction• What is Rift Valley Fever?• What areas have been affected?

• Discussion on Climate• Climate and its affiliation with outbreaks.

• Forecasting of the virus• Determining outbreaks

• Conclusion

Introduction

• Transmission• Epidemiology

What areas have been affected?

• History of major outbreaks

• Important recorded outbreaks

What is Rift Valley Fever?

Transmission

http://journal.frontiersin.org/article

Animals and Humans • Vectors• Direct or indirect

contact with the blood • Unpasteurized or

uncooked milk

No human-to-human transmission

Transmission Vectors

• Virus transmitted to eggs

• Virus transmitted from female infected vector to host

• Females typically lay up to 300 eggs, but only live 14-21 days

www.theverge.com/2015/5/21/8634813/mosquitoes-disease-sex-dengue-yellow-fever

Epidemiology

Animals • Cattle, buffalo, sheep, goats, and

camels.• Causes abortions in pregnant animals

and high mortality in young animals. • Massive hepatic necrosis and

pantropic hemorrhage.

Humans• Mild to severe influenza-like disease. • Can progress to hemorrhagic fever,

hepatitis, encephalitis, ocular disease and sometimes death.

History of Major Outbreaks

• Major Outbreaks• Southern Africa

• 1950• 1974-1975

• Zimbabwe, Zambia and Mozambique www.travelnotes.org/Africa

Important Recorded Outbreaks

Pictures from www.worldatlas.com/webimage/countrys/af.htm

1973• Sudan• Near

irrigation.

1977• Egypt• After the

flooding of Aswan dam near irrigation.

1987 and 1988• West

Africa• Newly

constructed dam.

1997-1998• East

Africa• High

rainfalls which resulted in flooding

Important Recorded Outbreaks

Pictures from www.worldatlas.com/webimage/countrys/af.htm

1997• Kenya and

Somalia• Humans

and livestock affected

1998• Hodh El

Gharbi• First

identified through humans.

2000• Saudi

Arabia and Yemen

• First time outside of Africa.

2006• Kenya• Reemerg

ed and emerged in Somalia & Tanzania.

Recorded Outbreaks

Epidemic Outbreaks with Climate Relation

• East Africa - plateau grasslands• High rainfalls

• Saudi Arabia and West Africa• Semi-arid zones

• Egypt and Yemen• Irrigated zones

Discussion on Climate

Climate and its Affiliation with Outbreaks

• Increased Vectors• Rainfall• Global Warming

Climate and its Affiliation with Outbreaks

Increased Vectors

Precipitation

Increased Rain

Flooding

El Niño

Flooding

Global Warming

Alters Biology of

VectorsFloods and Droughts

Rainfall

https://extension.entm.purdue.edu/publichealth/images/downloads/delayed-hatching.jpg

Aedes mosquitoes

• Life cycle• Virus

transmission• Population

explosion

Rainfall

Other vectors• New vectors

spread virus

El Niño• East Africa

affected• Aedes breeding

habitats http://journal.frontiersin.org/article

RainfallTypical tropical conditions versus El Niño

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• Precipitation• Trade winds

• Tropical circulation• Global mean

temperature

RainfallEl Niño with Africa

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• Precipitation• Trade winds

• Tropical circulation• Global mean

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Rainfall

• Precipitation• Trade winds

• Tropical circulation• Global mean

temperature

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Trade winds versus tropical regions

Global Warming

Extremes in the hydrological cycles• Global warming

enhances floods and droughts

• Extends rainfall activity, spreading across the continent

Picture 2 - www.timeslive.co.za/africa/2012/10/02/nigeria-seasonal-floods-kill-148-red-crossPicture 1 - www.standardmedia.co.ke/lifestyle/article/2000111390/experts-predict-massive-el-nino-weather-from-july

Picture 2

Picture 1

Global Warming

Affecting the biology of the vector• Increasing feeding frequency• Increase egg production.• Decreasing length of development cycle.• Decrease incubation period.

Results in increased vectors• Similar vectors in surrounding areas

display this ability.

Global Warming

Dry day prediction

Martin et al 2008

Global Warming

Precipitation prediction

Martin et al 2008

Forecasting of the virus

Determining Outbreaks

• Measure rainfall and vegetation• Tracking of vector populations • Emergency Prevention System for

Transboundary Animal Diseases program

Determining Outbreaks Measure of rainfall and

vegetation• Remote-sensing • High resolution radiometer sensors

Tracking vector populations • Comparison of vegetation and

viral activity• Continuously collecting data

Potential risk for Rift Valley fever (RVF) in February 2007 – Martin et al 2008

Determining Outbreaks Emergency Prevention

System for Transboundary Animal Diseases programs

• Set up by the Food and Agriculture Origination of the United Nations (FAO)

• Ability to report early outbreaks• Assistance in containing the

virus.• Monitoring climate activity

Conclusion

Ongoing Concerns• Climate• Global

Warming

Ongoing Concerns

Climate Change

1. Major threat involving both human and animal health issues• Impacts food production, access and

distribution

2. Abnormal changes in temperature and rainfall• Increase frequencies floods

3. Public concern• Spread of the diseasewww.businessinsider.com/six-innovations-to-help-

humans-make-it-through-the-droughts-and-floods-of-climate-change-2012-8

Ongoing Concerns

Global Warming

1. Vectors learn to adapt • Increases their populations

2. Rift Valley Fever in new areas• In 2000 vectors started migrating to Saudi Arabia • New vectors pick up virus and start spreading

disease

Both Climate and Global Warming Lead to:

3. Forecasting epidemics early• Idea is still new• Not entirely fault proof

Storms do not always produce the same amount of precipitation !!http://dnr.wi.gov/org/caer/ce/eek/

earth/groundwater/precip.htm

Works Cited

Daubney, R., J.R. Hudson, and P.C. Garnham. 1931. Enzootic hepatitis or Rift Valley fever. An undescribed virus disease of sheep, cattle and man from East Africa. The Journal of Pathology and Bacteriology. 34:545– 79.

Martin, V., V. Chevalier, P. Ceccat, A. Anyamba, L. De Simone, J. Lubroth, S. de La Rocque and J. Domenech. 2008. The Impact of Climate Change on the Epidemiology and Control of Rift Valley Fever. Revue Scientifique Et Technique Office International des Epizooties 27: 413-426.

Questions

• Does the preventative measures that the Food and Agriculture Origination of the United Nations (FAO) use assist with prevention of Rift Valley Fever? How could it be more effective?

• Since the original outbreak of the virus it has slowly migrating north into Saudi Arabia what are the most likely causes?