Rift Valley fever (RVF) is a zoonotic disease, which caused several epidemics in humans in many countries of Africa. Using an inhibition enzyme-linked immunosorbent assay (ELISA), real-time reverse transcription PCR, and nested one-step reverse transcription PCR, we conducted a cross-sectional study in populations of sheep and goats from the Mongo County in 2014 to determine the circulation of the Rift Valley fever virus (RVFV) in small ruminants from this area. From a total of 201 small ruminants (95 sheep and 106 goats), the overall IgG seroprevalence against the RVFV was 6.47% (13/201). No RVFV RNA was detected in the animal plasmas. Logistic regression analysis showed that age, species, sex, and locality were not the significant risk factors. The findings of this study highlight the risk of RVF for domestic ruminants bred in this region and for the human rural population living in contact with these animals and they emphasize the need to develop adequate control measures to limit this threat.

The aim of this study was to provide information on trypanosome species infecting trypanotolerant cattle from southern Gabon. The study was conducted on 224 trypanotolerant cattle from three regions located in southern Gabon, using ITS1 primer-based PCR. Seventy-two (32%) N’dama cattle were found polymerase chain reaction (PCR) positive with trypanosomes. The overall prevalence of trypanosomosis was 57% (63/110), 4% (4/100), and 36% (5/14) in the Gala section of the Nyanga ranch, the Miyama ranch, and Ossiele, respectively. Trypanosoma congolense and Trypanosoma vivax were identified. In Gala section and Ossiele, T. congolense and T. vivax were found. In the Miyama ranch, only T. vivax was identified. Mixed infections were also found. The forest (9%) and savannah (63%) subgroups of T. congolense were identified. The presence of the two subgroups was detected in 16 out of 56 cattle (29%). T. congolense and T. vivax would appear to be the main agents responsible for bovine trypanosomosis in southern Gabon. Although trypanotolerant, N’dama cattle may serve as a reservoir, and this should be further studied. On the other hand, these trypanotolerant cattle can be reared in such tsetse infested areas, which gives them an advantage compared to other trypanosensitive breeds, and this shows that they represent a key factor in biodiversity which has to be promoted.

In order to estimate the seroprevalence and to assess risk factors of Toxoplasma gondii and Neospora caninum in the province of Nyanga, in southern Gabon, a cross-sectional study was conducted in sheep and goats in the county of Mongo. Serological screening was performed using an indirect multi-species enzyme-linked immunosorbent assay and a commercial direct agglutination test to test serum samples for the presence of anti-N. caninum and anti-T. gondii Immunoglobulines (Ig) G antibodies, respectively. From a total of 201 small ruminants, including 95 sheep and 106 goats, the overall anti-N. caninum and anti-T. gondii IgG seroprevalences were 31.3% (n=63) and 45.8% (n=95), respectively. Statistical analyses showed that adult small ruminants were 4 times more likely to be infected with T. gondii than young animals (p<0.001; OR=4.27; 95% CI: 2.07-8.81). The locality was significantly associated with T. gondii seropositivity (p=0.001). The Dilemba (p<0.001; OR=0.07), Moulengui-Binza (p=0.023; OR=0.05) and Rina-Nzala localities (p=0.005; OR=0.1) were not identified as risk localities associated with T. gondii infection. The seroprevalence of N. caninum was significantly higher in sheep (42.1%) than goats (21.7%). The species was not associated with N. caninum infection (p=0.005; OR=0.27; 95% CI: 0.11-0.68). In Bibora, small ruminants were almost 4 times more likely to get Neospora infection than the animals in the other localities (p=0.04; OR=3.98; 95% CI: 1.06-14.93). The serological prevalence of N. caninum and T. gondii could suggest a considerable impact on the reproductive process from these pathogens in sheep and goats within the Mongo County and a high exposure of humans to T. gondii.