Abstract
Livestock trading through live animal markets are potential pathways for
the introduction and spread of economically important pathogens like the
African swine fever virus (ASFV) to new areas in several countries. Due
to the high demand for live pigs in Nigeria both for restocking and
slaughter, live pigs are sold at designated live pig markets (LPM) in
the country. This involves movement of pigs over long distances.
Despite, reports of ASF outbreaks following restocking of pigs bought
from LPMs, there is paucity of information on the role of LPMs in the
epidemiology of ASF. In this study, data and pig samples (whole blood,
sera, tissue) were collected from 4 selected LPMs in Nigeria (Dawaki,
Katsit, Numan & Pandam) between 2019 and 2020. Samples were analysed by
polymerase chain reaction (PCR) and Enzyme-linked Immunosorbent Assay
(ELISA). Four genes of ASFV positive samples were characterized to
identify the circulating genotypes. Results revealed trade activities
involving transportation of pigs from these selected markets to 42 major
cities and towns in thirteen (13) States of Nigeria. PCR results
revealed an overall ASF prevalence of 10.77% (66/613). ASFV was
confirmed by PCR in all the selected LPMs with a prevalence rate of
3.13%-23.81%. The phylogeny revealed genotype I and serogroup 4 based
on the p72 protein that encodes the B646L gene and the
EP402R gene encoding the CD2V. While sequence analysis of CVR of
B602L gene revealed 8 tetrameric repeats variants, six of which
have never been reported in Nigeria. Analysis of sera samples recorded a
seroprevalence of 6.9% (16/217) within the study period. Findings from
this study show that LPM are hotspots and channels for transmission and
continuous spread of ASFV in Nigeria. Therefore, for ASF to be
controlled in Nigeria, disease surveillance and regulation at LPMs are
critical.