Histopathological and health risk assessment of heavy metals in the straw-colored fruit bat, Eidolon helvum, in Nigeria.

There is heightening concern regarding heavy metals environmental pollution requiring renewed global attention because of their bioaccumulation and toxicity at varying levels. The concern is most important in the highly migratory Eidolon helvum (E. helvum) that is very common and traverses wide geographical areas within the sub-Saharan Africa. The present study aimed to evaluate levels of cadmium (Cd), lead (Pb), and zinc (Zn) bioaccumulation in 24 E. helvum of both sexes from Nigeria to assess their indirect health risks to the human consumers of the bats in addition to their direct bioaccumulation and toxic damages in the bats themselves based on standard procedures. Lead, Zn, and Cd bioaccumulation concentrations were 2.83 ± 0.35, 0.42 ± 0.03, and 0.05 ± 0.01 mg/kg, respectively, with significant (p < 0.05) Pb bioaccumulation compared to either Cd or Zn in the affected bats. However, only Pb (markedly) and Cd (marginally) bioaccumulated above small mammals' critical threshold levels as there are no existing established threshold levels for bats. Sex played no major role in their bioaccumulation levels. The bioaccumulation levels posed no life-long non-carcinogenic nor carcinogenic risks to the human consumers of the bats at detected concentrations. The observed lungs, liver, and kidney histopathological changes suggested the possible direct effects of the metals in the bats. Nevertheless, other anthropogenic factors might be responsible as no significant (p > 0.05) correlation existed between cellular changes and the bioaccumulation levels. The presence of the heavy metals and their bioaccumulations above critical threshold levels suggested some levels of environmental contamination and pollution, which might have direct and indirect health implications to the bats and their human consumers.

Risk assessment and preventive health behaviours toward COVID-19 amongst bushmeat handlers in Nigerian wildlife markets: Drivers and One Health challenge.

Over 70% of emerging infectious diseases are zoonotic and 72% of them have wildlife reservoirs with consequent global health impacts. Both SARS-CoV-1 and SARS-CoV-2 emerged certainly through wildlife market routes. We assessed wildlife handlers' zoonotic risk perceptions and preventive health behaviour measures toward COVID-19 during pandemic waves, and its drivers at wildlife markets using Health Belief Model (HBM) constructs. A cross-sectional study was conducted at purposively selected wildlife markets in Nigeria between November 2020 and October 2021. Descriptive, univariate, and multivariable logistic regressions analyses were performed at 95% confidence interval. Of the 600 targeted handlers in 97 wildlife markets, 97.2% (n = 583) participated. Consumers were the majority (65.3%), followed by hunters (18.4) and vendors (16.3%). Only 10.3% hunters, 24.3% vendors and 21.0% consumers associated COVID-19 with high zoonotic risk. Also, only few handlers practiced social/physical distancing at markets. Avoidance of handshaking or hugging and vaccination was significantly (p = 0.001) practiced by few handlers as preventive health behaviours at the markets. All the socio-demographic variables were significantly (p<0.05) associated with their knowledge, risk perceptions, and practice of preventive health behaviours toward COVID-19 at univariate analysis. Poor markets sanitation, hygiene, and biosecurity (OR=3.35, 95% CI: 2.33, 4.82); and poor butchering practices and exchange of wildlife species between shops [(OR=1.87; 95% CI: 1.34, 2.60) and (OR=2.03; 95% CI: 1.43, 2.88), respectively] were more likely to significantly influence COVID-19 emergence and spread at the markets. To tackle the highlighted gaps, collaborations between the public health, anthropologists, and veterinary and wildlife authorities through the One Health approach are advocated to intensify awareness and health education programmes that will improve perceptions and behaviours toward the disease and other emerging diseases control and prevention.

Effects of Dietary Lanthanum Chloride on Growth Performance, Hematology and Serum Biochemistry of Juvenile Clarias gariepinus Catfish Fed Diets Amended with Mixtures of Aflatoxin B1 and Fumonisin B1.

This study aimed to determine the effects of dietary lanthanum chloride on the growth and health performance of juvenile Clarias gariepinus when fed diets experimentally contaminated with mixtures of aflatoxin B1 and fumonisin B1. A control diet, (mycotoxin free, diet A), mycotoxin contaminated (diet B), and two mycotoxin-contaminated diets amended with lanthanum chloride (200 mg/kg, diet C; and 400 mg/kg, diet D), were fed to 450 fish divided equally into five groups (each with three replicates) for 56 days. The fish were randomly sampled at the time points: day 7, 28 and day 56 for the zootechnical, hematological and serum biochemical evaluations. The fish fed the diets amended with lanthanum chloride exhibited significantly (p < 0.05) better performance indices compared with the fish fed only the mycotoxin-contaminated diet. Lanthanum chloride elicited significant (p < 0.05) increases in erythrocytes and leucocytes count and significant (p < 0.05) reduction in serum transaminase, alkaline phosphatase, lactate dehydrogenase activities, urea and uric acid concentrations in the fish fed the diets contaminated with mixtures of aflatoxin B1 and fumonisin B1. The study indicates that juvenile Clarias gariepinus may be beneficially cultured with mycotoxin-contaminated grains amended with 200 to 400 mg/kg lanthanum chloride.

West Nile virus neutralizing antibody prevalence in donkeys from northern Nigeria.

BACKGROUND: This study aimed to evaluate the prevalence of anti-West Nile virus (WNV) neutralizing antibodies in donkeys from two areas in northern Nigeria. METHODS: Serology was determined by a virus neutralization test in samples collected from 205 healthy adult donkeys. RESULTS: Fifty-seven donkeys (27.8%) tested seropositive for WNV. Donkeys from Zaria were 2.6 times more likely to have been exposed to WNV (p<0.001). CONCLUSION: The results of this study demonstrate that this zoonotic pathogen is prevalent in these areas and that measures should be implemented to reduce the risk for both humans and equids.

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.