Analysis of Recent Serotype O Foot-and-Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages.

Foot-and-mouth disease (FMD) is endemic in Kenya where four serotypes (O, A, SAT 1 and SAT 2) of the virus are currently in circulation. Within 2010 and 2011, the National Laboratory recorded an increase in the number of FMD outbreaks caused by serotype O virus. The characteristics of these viruses were determined to ascertain whether these were independent outbreaks or one single strain spreading throughout the country. The sequences of the complete VP1-coding region were analysed from viruses sampled within different areas of Kenya during 2010 and 2011. The results indicated that the 2010 to 2011 outbreaks in Kenya were caused by four independent strains. By comparison with earlier type O isolates from Eastern Africa, it was apparent that the outbreaks were caused by viruses from three different lineages of topotype EA-2 and a fourth virus strain belonging to topotype EA-4. The topotypes EA-1 and EA-3 were not detected from these outbreaks. Implications of these results for FMD control in Eastern Africa are discussed.

Challenges for Serology-Based Characterization of Foot-and-Mouth Disease Outbreaks in Endemic Areas; Identification of Two Separate Lineages of Serotype O FMDV in Uganda in 2011.

Control of foot-and-mouth disease (FMD) in Uganda by ring vaccination largely depends on costly trivalent vaccines, and use of monovalent vaccines could improve the cost effectiveness. This, however, requires application of highly specific diagnostic tests. This study investigated outbreaks of FMD in seven Ugandan districts, during 2011, using the PrioCHECK® FMDV NS ELISA, solid-phase blocking ELISAs (SPBEs) and virus neutralization tests (VNTs), together with virological analyses for characterization of the responsible viruses. Two hundred and eighteen (218) cattle and 23 goat sera as well as 82 oropharyngeal fluid/epithelial tissue samples were collected. Some 50% of the cattle and 17% of the goat sera were positive by the PrioCHECK® FMDV NS ELISA, while SPBEs identified titres ≥80 for antibodies against serotype O FMD virus (FMDV) in 51% of the anti-NSP positive cattle sera. However, 35% of the anti-NSP positive cattle sera had SPBE titres ≥80 against multiple serotypes, primarily against serotypes O, SAT 1 and SAT 3. Comparison of SPBEs and VNTs for the detection of antibodies against serotypes O, SAT 1 and SAT 3 in 72 NSP positive cattle sera showed comparable results against serotype O (P = 0.181), while VNTs detected significantly fewer samples positive for antibodies against SAT 1 and SAT 3 than the SPBEs (P < 0.001). Detection of antibodies against serotype O was consistent with the isolation of serotype O FMDVs from 13 samples. Four of these viruses were sequenced and belonged to two distinct lineages within the East Africa-2 (EA-2) topotype, each differing from the currently used vaccine strain (EA-1 topotype). The relationships of these lineages to other serotype O viruses in the Eastern Africa region are discussed. To enhance the control of FMD in Uganda, there is need to improve the specificity of the SAT-SPBEs, perform vaccine matching and implement improved regional FMD control.

Use of ethnoveterinary remedies in the management of foot and mouth disease lesions in a diary herd.

An outbreak of Foot and Mouth Disease (FMD) affecting 95 (57.2%) out of 166 cattle occurred in a medium-scale dairy farm in Kikuyu district, Kenya. Ethnoveterinary remedies of natural Soda ash solution (97% sodium bicarbonate), honey and finger millet flour were used to manage the FMD lesions. The lesions were washed with soda ash solution to remove the necrotic tissue after which raw honey and finger millet flour were applied to the cleaned lesions. The lesions were examined daily and those with necrotic material washed again with the Soda ash solution. Honey and finger millet flour were applied daily for three days. There was rapid healing of the lesions with the animals resuming feeding after three days. The fast healing of the lesions vindicates the use of these cheap, locally available and easy to apply products in the management of FMD lesions. However, more studies are needed to evaluate further their potencies.

Growth and mortality in sheep and goats under high tsetse challenge in Kenya.

Trypanosomosis is a major impediment to livestock production and economic development in those areas of Africa where it is endemic. Although small ruminants appear to perform better than cattle in various agro-ecological zones, the importance of trypanosomosis has not been extensively investigated in these livestock. This study was designed to investigate the prevalence of trypanosomosis in sheep and goats in an endemic area and to evaluate the performance of different breeds under high tsetse challenge and the potential role of chemoprophylaxis in the control of the disease. The results showed that tsetse flies feed readily on small ruminants, and that these animals are susceptible to trypanosomosis. The Small East African goats acquired fewer infections than the Black Head Persian and Dorper sheep used in the study. In both sheep and goats, chemoprophylaxis with isometamidium chloride (Samorin, Rhone Merieux, Annecy, France) was protective, resulting in fewer infections and higher body weight gain. Trypanosomosis caused anaemia in both sheep and goats, and animals whose PCV fell below 15% rarely recovered, even with trypanocidal drug treatment. The peak transmission period was between 1 and 3 months after the peak tsetse fly density, which raises the possibility of effective strategic prophylaxis.

Genomic analysis of some Japanese isolates of Getah virus.

Using the reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing, capsid protein and non-structural protein 1 (nsP1) regions of Sagiyama virus and eight Getah virus strains were analysed. The viruses were isolated from Malaysia and various areas of Japan over a period of 30 years. Based on the available published sequence data, oligonucleotide primers were designed for RT-PCR and the sequences were determined. Our findings showed that though there were differences in the nucleotide sequences in the nsP1 region, there was 100% amino acid homology. On the other hand, in the capsid region, the nucleotide differences caused a major difference in the amino acid sequence. Therefore, the difference in the capsid region is one of the useful markers in the genetic classification between Sagiyama virus and strains of Getah virus, and might be responsible for the serological difference in complement fixation test. The genomic differences among the Getah virus strains are due to time factor rather than geographical distribution.