Molecular detection of Torque teno sus virus from domestic pigs in North Central, Nigeria, 2022-2023.

Torque teno sus virus (TTSuV) is a ubiquitous virus affecting domestic pigs and wild boars, classified into two major species: TTSuV1 and TTSuV2. In Nigeria, there is a paucity of information on TTSuV. This study investigated the prevalence, genetic diversity, and phylogenetic relationships of TTSuV genotypes in domestic pigs in Nigeria, as well as those found globally. A total of 94 (47 serum and 47 tissue) samples collected from pigs across the six geopolitical zones of Nigeria were analysed using PCR and sequencing techniques. Phylogenetic analysis was conducted to compare the sequences with those around the globe. The overall prevalence of TTSuV infection was 81 %. The Southwest zone recorded the highest prevalence (89.29 %), followed by the North Central zone (86.67 %), and the South recorded the least (33.33 %). TTSuV1 was the most common genotype, detected in 37.23 % of samples, while TTSuVk2a (15.96 %) and TTSuVk2b (27.66 %) were also prevalent. TTSuVk2b was newly reported in Nigeria, with a higher prevalence in 2023 compared to 2022. Coinfections between multiple TTSuV genotypes were common, particularly in the North Central zone, where 57.14 % of pigs were co-infected with TTSuVk2a and TTSuVk2b. The Nigerian strains of TTSuV closely clustered with global strains, indicating a high degree of genetic similarity. This suggests the role of international trade in the spread of TTSuV and provides useful molecular insights into patterns of animal movement and potential co-infections with other swine viruses. Thus, there is a need for continuous surveillance of TTSuV, particularly in regions where pig farming is prominent.