Presentation by Tabitha Kimani, Esther Schelling, Margaret Ngigi and Thomas Randolph at the 13th conference of the International Society for Veterinary Epidemiology and Economics, Maastricht, the Netherlands, 20-24 August 2012.
Economic analysis of Rift Valley fever prevention and control options from a multi-sectoral perspective in Kenya
1. Economic analysis of Rift Valley fever
prevention and control options from a multi-
sectoral perspective in Kenya
T. Kimani1,4, E. Schelling2, M. Ngigi3, T. Randolph1
1 International Livestock Research Institute, Kenya
2 Swiss Tropical and Public Health Institute, Basel
3 Egerton University, Kenya
4 Food and Agriculture Organization of the United Nations, Kenya
Presented at the 13th conference of the International Society of
Veterinary Epidemiology and Economics (ISVEE), Maastricht,
Netherlands, 20-24 August 2012
2. Introduction: Rift Valley fever
• Mosquito borne viral zoonosis, Africa and Middle East
• Epizootics, every 3-15 years
• Last two outbreaks in Eastern Africa: 1997-98, 2006-07
• Higher than normal rainfall, prolonged flooding, after a prolonged
drought
• Mosquito to animals
• Infected animal and animal products to people
• Impacts: economy wide
• Livestock
• Mortality; morbidity; trade bans, control costs
• Public health
• Mortality, morbidity and control costs
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3. Objective: CBA (livestock sector) and CEA (public health) of RVF control
options, period: 2006-2015, assumed outbreak in 2014/2015
Approach: Step 3: Identification of
Step 1: alternate prevention
Transmission (SEIR) Model: strategies, simulation, by
(poster 08.74, MSc, Fuhrimann ) farming systems, for high
risk areas (20.2/65 million
Livestock animals)
demography
Step 4: CBA & CEA:
RVF impact •Mortality (RVF and other)
Control •Milk loss (drought,
mesures RVF(abortions and
reductions),other abortions
Step 2: •RVF Market effects, control
Asses public health costs and costs, 2014/2015 DALYs
DALYs of 2006/2007 RVF- •Pastoral system
(MSc Thesis- A. Bitek) (13.5 m animals)
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5. Strategies
• Vaccination Schemes
• Baseline = 2008 – 2014, coverage 4-7% sheep and goats
only,
• Option 1 = 2 mass vaccinations 2012 (41-51%); 2013 (28-
33%); 4 species; ear tag & monitor 3 years
• Option 2 = 1 mass vaccination 2012 (41-51%); annual
vaccination of young animals only ( 6-11%); 4 species; ear
tag
• Enhanced surveillance from 2012, shorter reaction time (delay of 3
weeks from 6 weeks in 2007)
• Larvicidal –limited application; reduce infection pressure by 7.5%
• Pour-on treatments; 10% of susceptible animals (without ear tags);
3 applications; delay of 4 weeks; 6 weeks protection
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6. Results: Simulated Infected Proportions
0.250
Proportion infected
0.200
0.150
0.100
0.050
-
Prevention and Control Strategy
Cattle Sheep Goats Camels
None of the evaluated measures and assumed levels of application
would stop an RVF epidemic
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7. • 24 month Livestock producer losses-2006-07
US$ 225 Million RVF Milk loss Drought and
3% other abortions
Drought and milk loss
baseline 10%
mortality
82% RVF Direct
mortality
5%
RVF Market effects ( US$ 9.3 million)
RVF Outbreak containment (US$ 5.23million)
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8. Estimated RVF Impacts 2014/2015
90,000,000
80,000,000
70,000,000
60,000,000
Million US$
50,000,000
40,000,000
30,000,000
20,000,000
10,000,000
-
S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11
Prevention and Control Strategy
Losses Control costs
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9. Average annual impacts 2008 - 2015
60.00
50.00
40.00
Million US$
30.00
20.00
10.00
-
S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11
Prevention and Control Strategy
PV RVF losses PV other losses
• 8 years:1 RVF outbreak, 3 droughts & 3 normal years
• RVF impacts are relatively lower,
• Likely to be overlooked in the on going resilience building livestock
development activities
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11. Public Health Costs and CEA -on going
•4,035.6 DALYs
estimated for 06/07
outbreak
•Next step
•Adjust DALYs for
underreporting
•Quantify the human
RVF transmission
from a known number
of infected animals
•Estimate costs/DALY
Human RVF risk sources
averted
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12. Additional analysis
• The other two farming systems
• Sensitivity analysis
• Apply Social Accounting Matrix to estimate
economy wide impacts of RVF under
different control strategies
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13. Conclusions
• This analysis more or less show that unless control measures are
stepped up, the next RVF epizootic is likely to have devastating
impacts.
• The current baseline vaccination of 4-7% of small ruminants
would barely have any impacts on reducing magnitude
• Increasing vaccination coverage for all species would yield
significant reductions in outbreak magnitude
• RVF epidemics have significant impacts, but higher impacts are
attributed to other causes.
• Need for tools to address market level impacts e.g. food safety
credibility and safe slaughter systems.
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14. Acknowledgements
Funding from the International Development Research Centre
(IDRC) via the Agriculture and Health Research Platform of CGIAR
CDC Kenya and the Kenya Medical Research Institute
Thank you for listening
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