Cross-species surveillance and risk factors associated with Avian Coronavirus in North-Central and South West Regions of Nigeria.

Infectious bronchitis viral (IBV) (Avian coronavirus) diseases is among the major reproductive diseases affecting the avian production in Africa. There is scanty information on its current status and vaccination compliance among captive wild birds (CWB) and indigenous chickens (LC) in Nigeria. This study aimed to assess the exposure and the risk factors associated with IBV in CWB and LC from North-central and South west regions of Nigeria. Sera samples from 218 LC and 43 CWB were examined for IBV IgG using enzyme linked immunosorbent assay. Also, owners of LC and managers of CWB were interviewed using a pre-tested structured checklist. An overall IBV prevalence of 42.9% (112/261) was obtained. Captive wild birds and indigenous chickens had 11.6% (5/43) and 49.1% (107/218) prevalence respectively with a significant difference (p< 0.0001, OR= 7.3, 95% CI= 2.8-19.3). Also, geo-location indicated significant difference in IBV exposure among birds (p<=0.034). Furthermore, the study showed that there had never been laboratory screening on all acquired wild birds for exposure to infectious agents in the study location while none of these birds (LB/CWB) had history of vaccination. Since IBV is endemic in Nigeria, the use of vaccine for prophylactic measure should be advocated among LC and CWB owners in order to avoid unnecessary losses. Also, the essence of screening for infectious agents in newly acquired wild birds should be considered crucial for health sustenance and public safety.

Detection and molecular characterization of a first isolate of rabbit haemorrhagic disease virus in Nigeria.

Rabbit haemorrhagic disease virus (RHDV) was recovered from necropsied rabbits that died during an outbreak characterized by epistaxis, incoordination, paralysis, and multi-organ haemorrhages in Ilorin, Nigeria. The haemagglutination test (HA) and RT-PCR assay targeted against a fragment of the RHDV VP60 gene were performed on liver, spleen, and kidney homogenates; faeces; and urine obtained from the rabbits. Amplicons were purified, sequenced, and phylogenetically analysed. The liver homogenates yielded the highest HA titres while RT-PCR of liver, spleen, and kidneys yielded the expected 1252 bp band. Sequence and phylogenetic analyses revealed that the Nigerian RHDV strain (RHDV/NGR/ILN/001) was 98.57%, 97.95%, and 96.70% homologous with RHDV2 (RHDVGI.2) strains from the Netherlands, Germany, and France, respectively. RHDV/NGR/ILN/001 induced tracheal, intestinal, and mediastinal lymph node haemorrhages, pulmonary oedema and congestion, and enlarged, necrotic liver in experimentally inoculated rabbits. The implications of this study, which is the first report of RHDV in Nigeria, are discussed.

Cross-species surveillance and risk factors associated with Avian Coronavirus in North-Central and South West Regions of Nigeria

@#Infectious bronchitis viral (IBV) (Avian coronavirus) diseases is among the major reproductive diseases affecting the avian production in Africa. There is scanty information on its current status and vaccination compliance among captive wild birds (CWB) and indigenous chickens (LC) in Nigeria. This study aimed to assess the exposure and the risk factors associated with IBV in CWB and LC from North-central and South west regions of Nigeria. Sera samples from 218 LC and 43 CWB were examined for IBV IgG using enzyme linked immunosorbent assay. Also, owners of LC and managers of CWB were interviewed using a pre-tested structured checklist. An overall IBV prevalence of 42.9% (112/261) was obtained. Captive wild birds and indigenous chickens had 11.6% (5/43) and 49.1% (107/218) prevalence respectively with a significant difference (p< 0.0001, OR= 7.3, 95% CI= 2.8-19.3). Also, geo-location indicated significant difference in IBV exposure among birds (p<0.034). Furthermore, the study showed that there had never been laboratory screening on all acquired wild birds for exposure to infectious agents in the study location while none of these birds (LB/CWB) had history of vaccination. Since IBV is endemic in Nigeria, the use of vaccine for prophylactic measure should be advocated among LC and CWB owners in order to avoid unnecessary losses. Also, the essence of screening for infectious agents in newly acquired wild birds should be considered crucial for health sustenance and public safety.

Surveillance for avian influenza virus in captive wild birds and indigenous chickens in Nigeria.

Several reports of avian influenza virus (AIV) have been made on commercial chickens and wild birds in sub-Saharan Africa, but there is paucity of information of AIV among captive wild birds and indigenous chickens. Blood samples were obtained randomly from captive wild birds and chickens. AIV nucleoprotein antibody detection involved the use of enzyme immunoassay (ELISA) and subsequent subtyping with H5 and H7 AIV antigens (haemagglutination inhibition). Four hundred birds belonging to nine families and 14 species were sampled, and overall prevalence of 23% (92/400) was obtained (captive wild birds (10.4%, 5/48), indigenous birds (47.3%, 87/184) and exotic commercial birds (0.0%, 0/168)). Twelve ELISA-positive birds (13.04%) were positive to H7 antigen. Univariate analysis indicated statistical significance of AIV prevalence in captive wild birds (p < 0.0001) and exotic birds (p < 0.0001) using indigenous chickens as reference. This study gave an evidence of exposure of captive wild birds and indigenous chickens to AIV in Nigeria. Scavenging activities common among indigenously raised chickens, unrestricted movement of nonflying wild birds within the captive complex and free access by migrating wild birds to captive wild birds and local chickens were likely factors observed to promote AIV transmission. Continuous surveillance can further highlight the roles played by these birds in the epidemiology of AIV.

Prevalence of EHEC O157:H7 in patients with diarrhoea in Lagos, Nigeria.

The prevalence of sorbitol-nonfermenting Escherichia coli O157:H7 (EHEC) was assessed in 100 patients with diarrhoea by stool culture on sorbitol MacConkey agar. The cytotoxicity of the EHEC strains was analysed by Vero cell assay and the antimicrobial susceptibility pattern of the isolates was determined. Detection rate of EHEC O157:H7 was 6%. Five of the six patients were males. Three of the isolates were from children and one was from a teenager. All strains induced cytotoxic effects in the Vero cell assay. All isolates were susceptible to most of the antimicrobials tested. The results showed that diarrhoea caused by EHEC O157:H7, a potentially life-threatening pathogen, has remained common particularly among the child population of Lagos during the past 10 years (5). There must therefore be adequate meat and food inspection to improve the general hygiene of local fast food restaurants, so-called 'bukkas', which are regarded as likely sources of infection.