Further evidence for very virulent infectious bursal disease virus in vaccinated chickens in Nigeria.

Reverse transcription polymerase chain reaction (RT-PCR) and partial sequencing of the VP2 hypervariable region was performed on clinical samples from two infectious bursal disease (IBD) outbreaks in Plateau state, Nigeria. IBD virus RNA was detected in all four bursa of Fabricius samples. Nucleotide sequencing and analysis of the four samples revealed high similarity to previous IBDV sequences from northern and southern Nigeria. The deduced amino acid sequences were compared to reference IBDV strains retrieved from the GenBank; virulence markers A222, I256, and I294 were conserved in both outbreak and reference sequences. Amino acid residue S254 was conserved in the outbreak viruses and previous viruses from northern Nigeria. Phylogenetic analysis revealed that all four viruses were very virulent IBDVs. These viruses clustered with vv2-1 variant viruses from Oyo and Ogun states and less closely with vv2-2 isolates from Tanzania. The nucleotide identity of the sequences in this study ranged from 99.6 to 100 % with each other. These findings are further evidence of IBD outbreaks in vaccinated chicken flocks in Nigeria.

Risk factors for Rift Valley fever virus seropositivity in one-humped camels (Camelus dromedarius) and pastoralist knowledge and practices in Northern Nigeria.

Rift Valley fever (RVF) is a complex emerging arboviral hemorrhagic disease that causes significant illness in animals and humans. Camel trade across the land borders between Nigeria and the Niger Republic occurs frequently and poses a significant risk for RVF transmission to pastoralists and traders. We carried a cross-sectional study between November 2016 and April 2017 in two northern States (Katsina and Jigawa) known for camel trade in Nigeria to investigate the seroprevalence and potential risk factors for RVFV occurrence. We collected 720 sera and administered questionnaire to pastoralists. We used the competitive enzyme-linked immunosorbent assay (c-ELISA) to determine the previous exposure to RVFV infection. We retrieved  environmental information from public data sources that might explain RVFV seropositivity at  the LGA level. To asses potential risk factors,we categorized LGAs with RVFV as "1" and those without a case" 0". We fitted a logistic model to the data  and estimated odds ratios and 95% confidence intervals. An overall 19.9% prevalence was reported among camel herd-the highest seropositivity (33.3%) was recorded in SuleTankarkar LGA. In the multivariable model, only rain-fed croplands was significantly associated with RVFV antibodies occurrence p = 0.048 (OR = 0.87, 95% CI: 0.76-0.99). Only a minority of the respondents, 19.3% (n = 17/88), knew that RVF is zoonotic. Separation of healthy animals from the infected animals was carried out by 53.4% (47/88) pastoralists while 59.1% (52/88) pastoralists still use ethnoveterinary practices to control or mitigate disease outbreaks. Our study demonstrates the presence of RVFV antibodies among camel in Nigeria and the associated risk factors. These findings highlight the need for enhancing surveillance and control efforts and the public health education of camel pastoralists. Further investigation to unravel the zoonotic transmission potential to pastoralists and other animal species is pertinent.

Investigation of African swine fever in slaughtered pigs, Plateau state, Nigeria, 2004-2006.

The occurrence of African swine fever (ASF) DNA in slaughtered pigs in the major pig producing areas of Plateau state over a 2-year period was investigated. Three hundred fifty-nine pig tissue samples from five local government councils (LGCs) were analyzed by clinical signs (C/S), postmortem (PM) lesions and polymerase chain reaction (PCR). The results of diagnosis made by C/S and PM were compared to results obtained by PCR. Out of the 359 abattoir samples, 13 (3.62%) were positive by examination of C/S and PM lesions while 346 (96.38%) were negative. Jos-north LGC had the highest occurrence of PCR positive samples (31 samples); Panyam in Mangu LGC had no positive result. PCR analysis identified 53 positive samples (14.76%); more than 40 were identified on the field. Of the samples, 306 were PCR negative, thus giving a true ASF status of pigs in Plateau state. Analysis of the results, variables involved in the ASF spread and predictable effects of such findings in the pig industry in Plateau state and Nigeria as a whole is discussed.

Factors associated with tuberculosis among patients attending a treatment centre in Zaria, North-west Nigeria, 2010.

INTRODUCTION: Tuberculosis remains a global public health problem. In 2011, tuberculosis incidence was 133 per 100,000 in Nigeria. In Nigeria, little is known about the factors associated with tuberculosis, especially in the northern part and only few studies have characterized the Mycobacterium species that cause tuberculosis infection in humans. This study determined factors associated with tuberculosis and identified Mycobacterium species causing human tuberculosis in North-West, Nigeria. METHODS: We conducted a hospital based case control study between April and July 2010 in Zaria. Cases were newly diagnosed sputum smear-positive tuberculosis patients >15 years while controls were patients >15 years attending the hospital for other reasons but were negative for tuber-culosis. We used a structured questionnaire to obtain information on demographics, knowledge of transmission of tuberculosis, and exposure to some factors. We preformed descriptive, bivariate and backward elimination logistic regression. Sputa from cases were analyzed by multiplex polymerase chain reaction (PCR) based on genomic regions of difference. RESULTS: The mean ages of the cases and controls were 36, standard deviation (SD) 9.0 and 36, SD 9.7 respectively. Only 10 (9.8%) and nine (8.8%) of cases and controls respectively had a good knowledge of the transmission of tuberculosis. Contact with a tuberculosis patient (adjusted odds ratio (AOR) 12.3, 95% confidence interval (CI) 5.2-28.8), consumption of unpasteurized milk (AOR 6.4, CI 2.4-17.2), keeping pets (AOR 5.6, CI 2.3-13.7), associating closely with cattle (AOR 5.6, CI 1.3-6.8), and overcrowding (AOR 4.8, CI 1.8-13.1) were significantly associated with tuberculosis. Of the 102 sputa analyzed, 91 (89%) were M. tuberculosis, 8 (7.8%) were M africanum. CONCLUSION: We identified possible opportunities for intervention to limit the spread of tuberculosis. We recommend that the Nigeria tuberculosis control program consider some of these factors as a way to mitigate the spread of tuberculosis in Nigeria.