Evaluation of PPR Seroconversion in the Provinces of N’Djamena, Chari Baguirmi, Hadjar Lamis, Bahr Elgazal, and Lac

Objective: The objective of this study was to evaluate the post-vaccination seroconversion of small ruminants after the 2022-2023 vaccination campaign against peste des petits ruminants, as part of the national PPR control and eradication strategy. Methodology and Results: The study was conducted in the study area comprising the provinces of Chari-Baguirmi, N’Djamena, Bahr Elgazale, Kanem and Lac. It involved the collection of 1687 samples of sera from small ruminants, which were analysed in the laboratory using the Eliza competition diagnostic method. Statistical analyses of the data obtained were carried out using the R Studio 4.1.2 software. The data analyses made it possible to assess post-vaccination seroconversion at the level of the study area, regions and municipalities, as well as to see the effect of sex, marking and the “vaccinated and unvaccinated animal” aspect on PPR seroconversion. At the level of the study area, an overall seroconversion of 73.56% (higher than the rate set by the national strategy) was obtained, but it was distributed differently between provinces and municipalities. Conclusion and Application of Results: Provinces such as Bahr Elgazal (69.84%) and Lac (68.78%) experienced a seroconversion to decaf of the rate set by the national strategy for the control and eradication of PPR. The municipalities with low seroconversion rates were the 1st district of the city of N’Djamena (54.29%) and Amsileb (49.02%). Thus, it would be suggested that the General Directorate of Veterinary Services, through its Animal Health Directorate, intensify its efforts in municipalities with a low seroconversion rate and maintain the gains made in those with high rates. In this context, it is important to ensure that vaccines are administered appropriately and that the cold chain is functioning properly to achieve the objective of the national strategy for the control and eradication of peste des petits ruminants in Chad.