The Global control of FMD - Tools, ideas and ideals – Erice, Italy 14-17 October 2008
Appendix 62 PARTICIPATORY EPIDEMIOLOGY AS COMPARED TO CONVENTIONAL FOOT AND MOUTH DISEASE SURVEILLANCE TOOL T. Rufael1*, A. Catley2, A. Bogale3, M. Sahle1 and Y. Shiferaw4 1
National Animal Health Diagnostic and investigation Center, Ethiopian, P.O. Box 04, Sebeta, Ethiopia e-mail: rufaelc@yahoo.com 2 Feinstein International Center, Friedman School of Nutrition Science and Policy, Tufts University, P.O. Box 1078, Addis Ababa 3 Faculty of Veterinary Medicine, Addis Ababa University, P.O. Box 34, Debre Zeit 4 Ethiopian Institute of Agricultural Research, P.O. Box 2003, Addis Ababa
ABSTRACT Participatory epidemiology (PE) was used on the Borana plateau of southern Ethiopia to understand pastoralist’s perceptions of the clinical and epidemiological features of foot-and-mouth disease (FMD) in cattle. This paper describes the use of Participatory epidemiology to collect information on the basic epidemiology of FMD and compare the data from Participatory epidemiology with estimate of conventional seroprevalence result of FMD in Borana pastoral herds. Participatory appraisal and conventional veterinary investigation methods were applied to generate information on FMD in Borana pastoral system. The participatory appraisal methods used were Matrix scoring, Clinical observation, Proportional piling, and Seasonal calendar. The validity of participatory diagnosis of disease and their perceptions of proportions of animal affected by FMD can be cross checked by modern laboratory diagnosis. Serum samples were collected from randomly selected Borana cattle herds and screening by 3ABC ELISA for Non structural protein. Positive serum samples were serotyped for specific FMDV using liquid phase blocking ELISA (Hamblin et al, 1986a, b). Matrix scoring showed good agreement between informant groups on the clinical signs of acute and chronic FMD, and findings were cross-checked by clinical examination of cattle and assessment of previous clinical FMD at herd level by detection of antibody to non structural proteins of FMD virus. The positive predictive value of pastoralist’s diagnosis of FMD at herd level was 93.1%. The annual age-specific incidence and mortality of acute FMD in 50 herds was estimated using proportional piling. The estimated mean incidence of acute FMD varied from 18.5% in cattle less than two years of age to 14.0% in cattle three to four years of age. The estimated mean mortality due to acute FMD varied from 2.8% in cattle less than two years of age to 0.3% in cattle three of age or older. Pearson correlation coefficients for acute FMD by age group were −0.12 (p>0.05) for incidence and −0.59 (p<0.001) for mortality. Estimates of the annual incidence of chronic FMD varied from 0.2% in cattle less than two years of age to 1.8% in cattle three to four years of age. The Pearson correlation coefficient for the incidence of chronic FMD by age group was 0.47 (p<0.001). Outbreaks of FMD peaked in Borana cattle during the two dry seasons and were attributed to increased cattle movement to dry season grazing areas. The mean seroprevalence of FMD was estimated at 21% (n=920) and 55.2% of herds (n=116) tested seropositive. Serotyping of 120 seropositive samples indicated serotypes O (99.2%), A (95.8%), SAT 2 (80%) and C (67.5%). The observed agreement between pastoralist perception on FMD diagnosis and conventional laboratory diagnosis from this study has proven that Borana pastoralists have an enormous wealth of knowledge on diagnosis of cattle diseases. Therefore, Participatory Appraisal methods complements FMD surveillance to gain better understanding of FMD dynamics in pastoral areas and help to formulate appropriate disease control strategies. 1. INTRODUCTION Foot-and-mouth disease (FMD) is highly contagious viral disease of cloven-hoofed domestic and wild animals. It is widely distributed and occurs most commonly in Asia, Africa, the Middle East, and parts of South America (Kitching 1999). In pastoral areas of Africa outbreaks of FMD are reported frequently but the disease remains largely uncontrolled using conventional methods (Thomson and Bastos 2005). Providing veterinary services to the communities according to the western model has proven difficult due to lack of infrastructure and the veterinarian has limited
353
