An epidemiological survey of the serotypes of footand- Mouth disease virus in circulation in the somaliecosystem in Kenya
Regular reporting in Kenya occurs every year in all the provinces of the country except North-Eastern Kenya where serotypes O and A have been encountered in the past but current epidemiological maps on the disease have little indication of the occurrence of the disease in the whole Somali Ecosystem (SES) in Kenya. The main objective of this study was to determine the circulating FMDV serotypes and strains in the Somali ecosystem of Kenya in order to determine the relevant vaccines and effective control methods to be employed. The study also investigated why the disease is under-reported in the SES where the main occupation of the people is pastoralism and a region which holds a substantial population of susceptible livestock estimated at 15 million. Serology results obtained indicated that four main serotypes of FMD virus are in circulation in the SES namely, O, A, SAT 2 and SAT 1 in order of frequency. Insignificantly few animals were serotype C reactive. One serotype only (serotype O) was isolated in the samples collected from clinical cases of FMD. This isolate was sent to World Reference Laboratory, Pirbright, UK for confirmatory diagnosis and sequencing. From sequencing results it is closely related to the vaccine strain ‘O’77/78 produced locally by Kenya Veterinary Vaccines Production Institute. Vaccination with this strain would therefore protect the animals in the region from more outbreaks caused by this strain though vaccine matching may have to be to confirm antigenic relationship. The phylogenetic mapping places this O strain of FMDV in the East African topotype 1. Five point five percent (5.5%) of the animals sampled for oro-pharyngeal fluid were found to be carriers of the serotype O FMDV by Antigen detection Elisa but 14.89% by Polymerase chain reaction. Two sets of questionnaires were used to determine constraints that have led to under-reporting and lack of confirmation of FMD in the Somali-ecosystem. One was administered to the Veterinary service providers and the other to animal owners. A total of 95.4% (41/43), of the service providers respondents interviewed indicated that they face various constraints in collection of samples and submission for confirmation of FMD. These constraints in order of significance were; lack of transport, lack of cold chain, lack of sampling kits, lack of pastoralists cooperation, poor infrastructure, poor disease reporting channels, inadequate personnel and funding. Others are political interference, delay of laboratory results and use of ethno-veterinary management (herbs) by pastoralists to treat FMD cases rendering seeking of conventional management of the disease unnecessary. Several risk factors were reported that affect spread of FMD in the SES. The most significant ones are animal movement, common grazing/watering points poor surveillance, lack of farmer knowledge on the importance of control, porous borders, no vaccination programmes, wildlife-livestock interface, lack of farmer cooperation and insecurity/cattle rustling. It is recommended that vaccination programmes in the region should make use of quadrivalent vaccines with all the prevailing serotypes in circulation (O, A, SAT1 and SAT 2).