Filarial nematodes are important and widespread parasites of animals and humans. We have been using the African bovine parasite Onchocerca ochengi as a chemotherapeutic model for O. volvulus, the causal organism of`river blindness' in humans, for which there is no safe and e¡ective drug lethal to adult worms. Here we report that the antibiotic, oxytetracycline is macro¢laricidal against O. ochengi. In a controlled trial in Cameroon, all adult worms (as well as micro¢lariae) were killed, and O. ochengi intradermal nodules resolved, by nine months' post-treatment in cattle treated intermittently for six months. Adult worms removed from concurrent controls remained fully viable and reproductively active. By serial electron-microscopic examination, the macro¢laricidal e¡ects were related to the elimination of intracellular micro-organisms, initially abundant. Analysis of a fragment of the 16S rRNA gene from the O. ochengi micro-organisms con¢rmed them to be Wolbachia organisms of the order Rickettsiales, and showed that the sequence di¡ered in only one nucleotide in 858 from the homologous sequence of the Wolbachia organisms of O. volvulus. These data are, to our knowledge, the ¢rst to show that antibiotic therapy can be lethal to adult ¢lariae. They suggest that tetracycline therapy is likely to be macro¢lari-cidal against O. volvulus infections in humans and, since similar Wolbachia organisms occur in a number of other ¢larial nematodes, against those infections too. In that the elimination of Wolbachia preceded the resolution of the ¢larial infections, they suggest that in O. ochengi at least, the Wolbachia organisms play an essential role in the biology and metabolism of the ¢larial worm.

Foot and mouth disease (FMD) is endemic in sub-Saharan Africa. Due to the complexity of the disease epidemiology and the lack of data available, there is a need to use modeling approaches to fill the gaps in our understanding of the virus circulation on this continent. Using a phylogeographic approach, we reconstructed the circulation of FMD virus serotypes A, O, SAT1, and SAT2 in Africa and evaluated the influence of potential environmental and anthropological predictors of virus diffusion. Our results show that the serotypes O and A were introduced to Africa over the last century while the SAT1 and SAT2 serotype have been circulating for at least 400 years in wildlife. Our results also suggest that, outside Southern-Africa, wildlife does not play a role in the maintenance and circulation of the disease within domestic animals. Further, the circulation of serotype O in eastern Africa appears to be facilitated by both indirect transmission through persistence in the environment and anthropological activities such as cattle movements. Evidence for the different epidemiologies of serotypes has been lacking but is essential in developing a modern approach to control of FMD viruses in Africa.

The central variable region (CVR) within the B602L gene of the African swine fever virus (ASFV) is highly polymorphic within the 23 ASFV genotypes defined by sequencing of the C-terminal end of the p72 locus. Sequencing the p54 gene further discriminates ASFV genotypes that are conserved at the p72 locus. Variation in the thymidine kinase locus is a novel additional tool for ASFV genotyping whose application for this purpose is described for the first time herein. We evaluated genetic variation at these four polymorphic loci in 39 ASFV isolates obtained from outbreaks in Kenya and a region of Eastern Uganda between 2011 and 2013. Analysis of the p72 and p54 loci revealed high genetic conservation among these isolates; all clustered within p72 genotype IX and were similar to isolates associated with earlier outbreaks in East Africa. The thymidine kinase gene of the Kenyan isolates in this study were distinct relative to Southern African isolates and synonymous substitutions were observed among viruses from central Kenya. Analysis of the CVR within the B602L gene revealed two previously unknown polymorphisms that were restricted to Western Kenya and Eastern Uganda. A novel variant was revealed within CVR subgroup XXIV and a novel CVR subgroup XXIVa that contains tetrameric repeat F which has previously only been associated with p72 genotype I, was also identified for the first time in East Africa. Phylogeographic analysis of isolates based on CVR polymorphisms revealed rapid evolution and dissemination of variants present within ASFV genotype IX in East Africa.Electronic supplementary materialThe online version of this article (10.1007/s11262-017-1521-4) contains supplementary material, which is available to authorized users.

Foot and mouth disease (FMD) is endemic in sub-Saharan Africa and can lead to important and continuous economic losses for affected countries. Due to the complexity of the disease epidemiology and the lack of data there is a need to use inferential computational approaches to fill the gaps in our understanding of the circulation of FMD virus on this continent. Using a phylogeographic approach we reconstructed the circulation of FMD virus serotypes A, O and SAT2 in Africa and evaluated the influence of potential environmental and anthropological predictors of virus diffusion. Our results show that over the last hundred year the continental circulation of the tree serotypes was mainly driven by livestock trade. Whilst our analyses show that the serotypes A and O were introduced in Africa trough livestock trades, the SAT2 serotype probably originates from African wildlife population. The circulation of serotype O in eastern Africa is impacted by both indirect transmission through persistence in the environment and anthropological activities such as cattle movements.

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