Avian influenza viruses (AIV) potentially transmit to swine as shown by experiments, where further reassortment may contribute to the generation of pandemic strains. Associated risks of AIV inter-species transmission are greater in countries like Nigeria with recurrent epidemics of highly pathogenic AI (HPAI) in poultry and significant pig population. Analysis of 129 tracheal swab specimens collected from apparently healthy pigs at slaughterhouse during presence of HPAI virus H5N1 in poultry in Nigeria for influenza A by RT-qPCR yielded 43 positive samples. Twenty-two could be determined by clade specific RT-qPCR as belonging to the H5N1 clade 2.3.2.1c and confirmed by partial hemagglutinin (HA) sequence analysis. In addition, 500 swine sera were screened for antibodies against influenza A virus nucleoprotein and H5 HA using competition ELISAs and hemagglutination inhibition (HI) tests. Serologically, 222 (44.4%) and 42 (8.4%) sera were positive for influenza A virus NP and H5 antibodies, respectively. Sera reacted to H5N1 and A/H1N1pdm09 strains by HI suggesting exposure of the Nigerian domestic pig population to these viruses. We report for the first time in Nigeria, exposure of domestic pigs to H5N1 virus. This poses potential public health and pandemic risk due to interspecies transmission of avian and human influenza viruses.

Porcine circovirus‐2 (PCV‐2) is associated with several disease syndromes in domestic pigs that have a significant impact on global pig production and health. Currently, little is known about the status of PCV‐2 in Africa. In this study, a total of 408 archived DNA samples collected from pigs in Burkina Faso, Cameroon, Cape Verde, Ethiopia, the Democratic Republic of the Congo, Mozambique, Nigeria, Senegal, Tanzania and Zambia between 2000 and 2018 were screened by PCR for the presence of PCV‐2. Positive amplicons of the gene encoding the viral capsid protein (ORF2) were sequenced to determine the genotypes circulating in each country. Four of the nine currently known genotypes of PCV‐2 were identified (i.e. PCV‐2a, PCV‐2b, PCV‐2d and PCV‐2 g) with more than one genotype being identified in Burkina Faso, Ethiopia, Nigeria, Mozambique, Senegal and Zambia. Additionally, a phylogeographic analysis which included 38 additional ORF2 gene sequences of PCV‐2s previously identified in Mozambique, Namibia and South Africa from 2014 to 2016 and 2019 to 2020 and available in public databases, demonstrated the existence of several African‐specific clusters and estimated the approximate time of introduction of PCV‐2s into Africa from other continents. This is the first in‐depth study of PCV‐2 in Africa and it has important implications for pig production at both the small‐holder and commercial farm level on the continent.

Despite the endemic nature of foot and mouth disease (FMD) in Nigeria, little is known about the epidemiology of the disease in pigs. FMD could pose a negative economic and social impact in the life of small-holder and commercial pig farmers in the advent of an outbreak. In this report, out of 822 pig sera collected from two states (Plateau and Enugu) in Nigeria, 12 (1.5%) tested positive for antibodies to the highly conserved non-structural 3-ABC protein of FMDV by the FMDV-NS blocking ELISA. Two serotypes of FMDV-O and SAT-2 were detected from the 3-ABC positive reactors in Plateau and Enugu States, respectively by the serotype-specific solid phase competitive ELISA (SPCE). This preliminary report suggests that domestic pigs could play an important role in the overall epidemiology of FMD in Nigeria, and should stimulate continued surveillance in the swine species in order to implement an effective FMD control program in the near future.