Sero-epidemiological survey and risk factors associated with bovine brucellosis among slaughtered cattle in Nigeria.

Bovine brucellosis is endemic in Nigeria; however, limited data exist on nationwide studies and risk factors associated with the disease. Using a cross-sectional sero-epidemiological survey, we determined the prevalence of and risk factors for brucellosis in slaughtered cattle in three geographical regions of Nigeria. Serum samples from randomly selected unvaccinated cattle slaughtered over a period of 3 years (between December 2010 and September 2013) from northern, southern and south-western Nigeria were tested for antibodies to Brucella abortus using the Rose Bengal test. Data associated with risk factors of brucellosis were analysed by Stata Version 12. In all, 8105 cattle were screened. An overall seroprevalence of 3.9% (315/8105) was recorded by the Rose Bengal test, with 3.8%, 3.4% and 4.0% from the northern, southern and south-western regions, respectively. Bivariate analysis showed that cattle screened in northern Nigeria were less likely to be seropositive for antibodies to Brucella spp. than those from south-western Nigeria (odds ratio = 0.94; 95% confidence interval: 0.73-1.22). However, logistic regression analysis revealed that breed ( p = 0.04) and sex ( p £ 0.0001) of cattle were statistically significant for seropositivity to Brucella spp. The study found that brucellosis was endemic at a low prevalence among slaughtered cattle in Nigeria, with sex and breed of cattle being significant risk factors. Considering the public health implications of brucellosis, we advocate coordinated surveillance for the disease among diverse cattle populations in Nigeria, as is carried out in most developed countries.

Some risk factors for Taenia solium cysticercosis in semi-intensively raised pigs in Zuru, Nigeria.

The prevalence of Taenia solium cysticercosis in live pigs and at post mortem was determined in the Zuru area of Kebbi State, Nigeria. Prevalence rates of 5.85% (n = 205) and 14.40% (n = 118), respectively, were obtained from live pigs examined by lingual palpation and post-mortem examination. There was a significant (p<0.05) association between sex and infectivity for meat inspection and a positive non-significant (p>0.05) relationship between age and infectivity. Human taeniosis was assessed by direct microscopy of stool samples from volunteers; a prevalence of 8% (n = 50) was obtained. Environmental (soil, water and water from washed vegetables) samples were analysed; one of the water samples and some soil samples were positive for taeniid ova. Of the pig-rearing households that responded to the questionnaire survey 93% (n = 100) allow their pigs to scavenge freely around residential areas and refuse dumps, 2% had epileptic patients and over 80% did not have knowledge on how T. solium infection is acquired and its public health significance. To obtain baseline data for effective control and possible eradication, there is the need for a serological and epidemiological survey of this significant parasitic zoonosis in the study area and other parts of Nigeria where pigs are reared and/or pork is consumed.

Newcastle disease virus in West Africa: new virulent strains identified in non-commercial farms.

Forty-four Newcastle disease virus (NDV) strains, obtained between 2002 and 2007 from different poultry species in Nigeria, Niger, Burkina Faso and Cameroon, were phylogenetically analysed based on partial F sequences. Lineage 2 viruses were genetically identical or similar to the locally used LaSota vaccine strain and were mostly detected in commercial farms. Lineage 1, 3 and 4 strains were only sporadically found, and their origin was less clear. Twenty-one strains from backyard farms and live bird markets formed three new clusters within lineage 5, tentatively named 5f, 5g and 5h. All of these strains were predicted to be virulent based on their F protein cleavage site sequence. Minimal genetic distances between new and previously established sublineages ranged from 9.4 to 15.9%, and minimal distances between the new sublineages were 11.5 to 17.3%. Their high genetic diversity and their presence in three different Sub-Saharan countries suggest that these new sublineages represent the NDV variants indigenous to West Africa.