Foot and mouth disease in the Borana pastoral system, southern Ethiopia and implications for livelihoods and international trade

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. 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 in 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 endemic nature of FMD in Borana pastoral herds is discussed in terms of the direct household-level impact of the disease, and the increasing export of cattle and chilled beef from Ethiopia.

Epidemiological study on foot and mouth disease in cattle: Seroprevalence and risk factor assessment in Kellem Wollega Zone, West Ethiopia

“…The finding of this study was in agreement with the previous report in the Borana pastoral land where over all seropositivity of 21% was reported (Rufael et al, 2008). However, the seroprevalence was slightly lower than the previous findings in Ethiopia (Sahle, 2004) in which a seropositivity of 26.5% was reported.…”

“…Serotype O was more prevalent followed by types A, SAT-2, SAT-1 and C, respectively. Serotype C was not identified after 1983; however, a serotype C specific antibody in cattle was reported (Sahle, 2004;Gelaye et al, 2005;Legess, 2008;Rufael et al, 2008).…”

“…During the period from 1999 -2008 on average over 77.7 numbers of FMD outbreaks were reported every year to Ministry of Agriculture and Rural Development (Gelaye et al, 2005). Recent seroprevalence studies of FMD in different districts and localities in the central, south west, northwest and in south pastoral areas of Ethiopia revealed seroprevalence of the FMD in the range of 2.5 -21% (Bogale, 2005;Gelaye et al, 2005;Rufael et al, 2008). Regardless of its huge economic importance, FMD occurrence and risk factors associated with the disease was not substantially investigated throughout Ethiopia to indicate the real magnitude and burden of the disease in the country.…”

Seroprevalence and risk factors for peste des petits ruminants and selected differential diagnosis in sheep and goats in Tanzania

“…Domestic cattle were sampled in western Sudan and serological evidence of BTV infection was found in 19.4% of them (58 of 299) [63]. Our results are more in line with those from [59] and [60]. A high seroprevalence is expected from a virus that often gives a subclinical or unapparent disease in ruminants and is spread very efficiently by its vector [12].…”

“…Age is a documented risk factor for FMDV exposure in cattle, both in endemic and epidemic settings [58,59]. A higher age gives a longer time to be exposed in the endemic setting, and the higher mortality seen in younger animals leaves the older seropositive animals to be sampled [59,60]. Also in line with the results for PPR, female animals were identified to be at a higher risk than males for FMDV exposure.…”