Abstract. To capture lessons from the 2007 Rift Valley fever (RVF) outbreak, epidemiological studies were carried out in Kenya and Tanzania. Somali pastoralists proved to be adept at recognizing symptoms of RVF and risk factors such as heavy rainfall and mosquito swarms. Sandik, which means "bloody nose," was used by Somalis to denote disease consistent with RVF. Somalis reported that sandik was previously seen in 1997/98, the period of the last RVF epidemic. Pastoralists communicated valuable epidemiological information for surveillance and early warning systems that was observed before international warnings. The results indicate that an all or none approach to decision making contributed to the delay in response. In the future, a phased approach balancing actions against increasing risk of an outbreak would be more effective. Given the time required to mobilize large vaccine stocks, emergency vaccination did not contribute to the mitigation of explosive outbreaks of RVF.* Address correspondence to Christine C. Jost, International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya. E-mail: c.jost@cgiar.org 66 JOST AND OTHERS approach, participants were asked to focus on the period when the RVF outbreak was observed and to divide the individual piles of counters previously used to rank the livestock species by numbers into two sub-groups: those that developed RVF and those that did not. For those that had RVF, the counters were further subdivided into the proportion that died and the proportion that recovered. This method provided an estimate of the incidence of RVF in each species during the outbreak, as well as the outbreak case fatality rates and the overall mortality rate during the outbreak.Abortions attributable to RVF. Using the results of the proportional piling exercise for the relative numbers of each livestock species as the starting point, participants were asked to allocate the counters into two groups in proportion to those livestock that were pregnant before the RVF outbreak and those that were not. For the pregnant group, participants next divided the counters in proportion to those animals that aborted because of RVF and those that carried their pregnancies to full term. The pregnant pile was then restored, and participants asked to divide the counters to represent the proportions that would have been expected to abort in a normal year (with no RVF outbreak) and those that would have carried to full term. Supplementary questioning probed the causes of abortion other than RVF.Disease impact matrix score. For each livestock species a matrix was constructed on the ground, with benefits derived from that species along the y axis and diseases on the x axis. Participants were given 100 counters and asked to allocate them among the livestock-associated benefits according to the relative importance of each benefit, with the most important benefit receiving the highest number of counters. The counters for each benefit were then sub-allocated to each disease to show the relative negative ...

BackgroundPeste des petits ruminants (PPR) is a contagious viral disease of small ruminants. Serum samples from sheep (n = 431) and goats (n = 538) of all ages were collected in a cross-sectional study in Turkana County, Kenya. The objective was to estimate the sero-prevalence of PPR virus (PPRV) infection and associated risk factors in both species.PPRV competitive enzyme-linked immuno-sorbent assay (c-ELISA) analysed the presence of antibodies in the samples. All analyses were conducted for each species separately. Multivariable logistic regression models were fitted to the data to assess the relationship between the risk factors and PPRV sero-positivity. Mixed-effect models using an administrative sub-location as a random effect were also fitted to adjust for possible clustering of PPRV sero-positivity. Intra-cluster correlation coefficients (ρ) that described the degree of similarity among sero-positive responses for each species in each of the six administrative divisions were estimated.ResultsGoats had a significantly higher sero-prevalence of 40% [95% confidence interval (CI): 36%, 44%] compared to sheep with 32% [95% CI: 27%, 36%] (P = 0.008). Combined sero-prevalence estimates were heterogeneous across administrative divisions (n = 6) (range 22% to 65%) and even more across sub-locations (n = 46) (range 0% to 78%). Assuming that PPRV antibodies are protective of infection, a large pool of PPRV susceptible middle age group (>6 months and < 24 months) in both species was estimated. This was based on the low sero-prevalence in this group in goats (14% [95% CI: 10%, 20%]) and in sheep (18% [95% CI: 13%, 25%]). Regression analysis returned significant risk factors across species: in sheep - vaccination status, age and administrative division; in goats - sex, age, administrative division and sex*age interaction. The intra-sub-location correlation coefficients varied widely across divisions (range <0.001 to 0.42) and across species within divisions.ConclusionsBiological, spatial and socio-ecological factors are hypothesized as possible explanations for variation in PPRV sero-positivity in the Turkana pastoral ecosystem.

In May 2011 in Turkana County, north-western Kenya, tissue samples were collected from goats suspected of having died of peste des petits ruminant (PPR) disease, an acute viral disease of small ruminants. The samples were processed and tested by reverse transcriptase PCR for the presence of PPR viral RNA. The positive samples were sequenced and identified as belonging to peste des petits ruminants virus (PPRV) lineage III. Full-genome analysis of one of the positive samples revealed that the virus causing disease in Kenya in 2011 was 95.7% identical to the full genome of a virus isolated in Uganda in 2012 and that a segment of the viral fusion gene was 100% identical to that of a virus circulating in Tanzania in 2013. These data strongly indicate transboundary movement of lineage III viruses between Eastern Africa countries and have significant implications for surveillance and control of this important disease as it moves southwards in Africa.

Peste des petits ruminants is a major economic disease affecting the pastoral herders in Kenya, with outbreaks in Turkana County having devastating effects on the Turkana livelihoods. Turkana County is a region associated with natural and manmade disasters, poor infrastructure and insecurity. There is limited essential data on livestock diseases and economic analysis. This study has attempted to estimate the direct economic loses occasioned by outbreaks of Peste des petits ruminants (PPR) based on perceived loss of benefits experienced by the Turkana people. Parameters for the analytical model were derived from secondary data, informal interviews and focused group discussions using participatory epidemiology methods. Results shows that losses due to PPR were estimated at US$ 19.1 million and mortality of small stock due to PPR constituted the greatest economic loss valued at US$ 16.8 million being 88% of the total losses. Other losses due to lost milk and weight loss constitute approximately 12% of the total losses. PPR has serious economic impacts on pastoral livelihoods, and previous estimation of PPR losses in Kenya was grossly undervalued. This study strengthens the basis for developing a system for the economic assessment of livestock diseases in areas with scanty data based on parameters derived from participatory epidemiology approaches for use in the mathematical model.

Peste des petits ruminants virus that causes a highly infectious and often fatal disease of sheep and goats is confirmed by various diagnostic techniques among them being isolation of the virus from cell culture systems, viral ribonucleic acid (RNA) detection by molecular assays, and viral antigen detection by immunocapture enzyme-linked immunosorbent assay (IC ELISA), immunohistochemistry (IHC), and AGAR gel test. Whereas most of the confirmatory diagnostic procedures require pathological samples to be stored frozen to preserve integrity of the peste des petits ruminants (PPR) virus RNA, samples for IHC tests are preserved in 10% formalin. In this study, nine formalin-fixed pathological samples from three goats suspected of PPR were processed for extraction of PPR viral RNA and analyzed for detection with real-time reverse transcription-polymerase chain reaction (qRT-PCR) assay. The results showed that five out of the nine tested samples returned positive for presences PPR viral genome. This study has established that field pathological samples of PPR-suspected cases, collected and stored in 10% formalin for up 2 years, could be used for PPR virus RNA extraction for disease virus confirmation.

We report the first complete genome sequence of a lineage III peste des petits ruminants virus (KN5/2011) using RNA extracted from goat lung tissue collected in Kenya in 2011. The genome shows the highest nucleotide sequence identity with lineage II peste des petits ruminants viruses (PPRVs) (86.1 to 87.2%) and the lowest with lineage IV PPRVs (82.5 to 83.8%).