Prospects for dog rabies elimination in Nigeria by 2030.

The attainment of the global target of zero dog-mediated human rabies by 2030 depends on functional rabies programmes. Nigeria, a rabies-endemic country, and the most populous country in Africa has a very poor rabies control strategy with a score of 1.5 out of 5 based on the Stepwise Approach towards Rabies Elimination (SARE). In this article, we report a scoping review that we conducted to highlight the strengths, weaknesses, opportunities and threats as well as situational analysis of rabies control in Nigeria and suggest a timeline for key activities that are needed to ensure zero by 30. Our findings reveal that rabies is grossly under-reported as only 998 human and 273 dog-suspected rabies cases were reported across Nigeria between 2017 and 2022. Our literature review also demonstrates a paucity of information on rabies in both human and animal health sectors. A total of 49 studies on dog rabies in Nigeria, with a predominance of reports from the North Central geopolitical region (48%, n = 23) were therefore included in this study. Currently, only 16.2% (n = 6/37) of Nigerian states have available data related to the estimated dog populations, the dog ownership rates, the vaccination status of dogs or the incidence of dog bites. Based on a dog-to-human ratio of 1:16.3, we estimated that the dog population in Nigeria was 12,969,368 (95% CI: 12,320,900-13,617,836). Thus, to attain herd immunity and dog rabies control in Nigeria, at least 9.1 million dogs must be vaccinated annually. Our review reveals that, despite the strengths and available opportunities to achieve rabies control in Nigeria by 2030, the weaknesses and challenges will make the attainment of zero by 30 very difficult or impossible. Nigeria's best-case scenario by the year 2030 is SARE stage 3-4 (control-elimination) out of 5. Otherwise, the rabies control programme might not surpass SARE stages 2-3. To attain zero by 30, Nigeria must re-strategize its current rabies control programme by funding and implementing the national strategic plan for rabies control, creating a rabies desk office in the 37 states (FCT inclusive), rigorously conducting mass vaccination campaigns, providing post-exposure prophylaxis, prioritizing mass enlightenment with a focus on responsible pet ownership and conduct baseline national rabies surveillance in the animal and human health sectors.

Assessing the mechanisms of multi-drug resistant non-typhoidal Salmonella (NTS) serovars isolated from layer chicken farms in Nigeria.

BACKGROUND: In Nigeria, there have been reports of widespread multiple antimicrobial resistance (AMR) amongst Salmonella isolated from poultry. To mitigate the impact of mortality associated with Salmonella on their farms, farmers resort to the use of antimicrobials without sound diagnostic advice. We conducted this study to describe the AMR patterns, mechanisms and genetic similarities within some Salmonella serovars isolated from different layer farms. METHOD: We determine the AMR profiles of two hundred Salmonella isolates, selected based on frequency, serovar, and geographical and sample type distribution. We also assessed the mechanisms of multi-drug resistance for specific genetic determinants by using PCR protocols and gene sequence analysis. Pulsed-field gel electrophoresis (PFGE) was conducted on seven selected serovars to determine their genetic relatedness. RESULTS: Of 200 isolates, 97 (48.5%) revealed various AMR profiles, with the multiple antibiotic resistance (MAR) index ranging from 0.07-0.5. Resistance to ciprofloxacin was common in all the multi-drug resistant isolates, while all the isolates were susceptible to cefotaxime, ceftazidime, and meropenem. Genotypic characterization showed the presence of resistance genes as well as mutations in the nucleotide genes with subsequent amino acid substitutions. Fifteen isolates (43%) of S. Kentucky were indistinguishable, but were isolated from four different states in Nigeria (Ogun, n = 9; Kaduna, n = 6; Plateau, n = 3, and: Bauchi, n = 2). PFGE revealed 40 pulsotype patterns (Kentucky, n = 12; Larochelle, n = 9; Virchow, n = 5; Saintpaul, n = 4; Poona, n = 3; Isangi, n = 2, and; Nigeria, n = 2). CONCLUSION: This study recorded strictly related but diversely distributed Salmonella serovars with high AMR rates in poultry. We recommend strict regulation on antimicrobial use and regular monitoring of AMR trends among bacteria isolated from animals and humans to inform public policy.

Rabies virus infection is associated with variations in calbindin D-28K and calretinin mRNA expression levels in mouse brain tissue.

Rabies virus (RABV) infection leads to a fatal neurological outcome in humans and animals and is associated with major alterations in cellular gene expression. In this study, we describe the effects of RABV infection on the mRNA expression levels of two genes, encoding the Ca2+-binding proteins (Ca-BPs) calbindin D-28K (Calb1) and calretinin (Calb2), in the brains of BALB/c mice. Sixty 4-week-old mice were divided into two test groups and one control group. Mice were inoculated intramuscularly with either a street rabies virus (SRV) strain or a challenge virus standard (CVS-11) strain and sacrificed at 3-day intervals up to day 18 postinfection. A direct fluorescent antibody test (DFAT) was used to verify the presence of RABV antigen in brain tissues, and real-time quantitative PCR (RT-PCR) was used to assess gene expression. Infection with both RABV strains resulted in significant (p < 0.05) increases in Calb1 and Calb2 expression in the test animals when compared with the controls at various time points in the study. Correlation analysis indicated very weak insignificant (p > 0.05) negative and positive relationships, respectively, between Calb1 expression (r = -0.04) and Calb2 expression (r = 0.08) with viral load (CVS-11 strain). Insignificant (p > 0.05) relationships were also observed Calb1 expression (r = -0.28) and Calb2 expression (r = 0.06) and viral load for the SRV strain.The observed alterations in Calb1 and Calb2 expression in this study indicate possible impairments in neuronal Ca2+ buffering and Ca2+ homeostasis as a result of RABV infection and, consequently, possible involvement of calbindin-D28K and calretinin in the neuropathogenesis of rabies.

Cholera outbreak in some communities in North-East Nigeria, 2019: an unmatched case-control study.

BACKGROUND: Cholera, a diarrheal disease caused by the bacterium Vibrio cholerae, transmitted through fecal contamination of water or food remains an ever-present risk in many countries, especially where water supply, sanitation, food safety, and hygiene are inadequate. A cholera outbreak was reported in Bauchi State, North-eastern Nigeria. We investigated the outbreak to determine the extent and assess risk factors associated with the outbreak. METHODS: We conducted a descriptive analysis of suspected cholera cases to determine the fatality rate (CFR), attack rate (AR), and trends/patterns of the outbreak. We also conducted a 1:2 unmatched case-control study to assess risk factors amongst 110 confirmed cases and 220 uninfected individuals (controls). We defined a suspected case as any person > 5 years with acute watery diarrhea with/without vomiting; a confirmed case as any suspected case in which there was laboratory isolation of Vibrio cholerae O1 or O139 from the stool while control was any uninfected individual with close contact (same household) with a confirmed case. Children under 5 were not included in the case definition however, samples from this age group were collected where such symptoms had occurred and line-listed separately. Data were collected with an interviewer-administered questionnaire and analyzed using Epi-info and Microsoft excel for frequencies, proportions, bivariate and multivariate analysis at a 95% confidence interval. RESULTS: A total of 9725 cases were line-listed with a CFR of 0.3% in the state. Dass LGA had the highest CFR (14.3%) while Bauchi LGA recorded the highest AR of 1,830 cases per 100,000 persons. Factors significantly associated with cholera infection were attending social gatherings (aOR = 2.04, 95% CI = 1.16-3.59) and drinking unsafe water (aOR = 1.74, 95% CI = 1.07-2.83). CONCLUSION: Attending social gatherings and drinking unsafe water were risk factors for cholera infection. Public health actions included chlorination of wells and distribution of water guard (1% chlorine solution) bottles to households and public education on cholera prevention. We recommend the provision of safe drinking water by the government as well as improved sanitary and hygienic conditions for citizens of the state.

Quinolone-resistant Escherichia coli at the interface between humans, poultry and their shared environment- a potential public health risk.

BACKGROUND: Commensal Escherichia coli residing in the guts of humans and animals are reservoirs of multidrug resistance (MDR) genes, including quinolone resistance genes, in humans and poultry. This study aimed to characterize quinolones resistance in E. coli recovered from poultry workers, chickens, and poultry farm/market environments in Abuja, Nigeria. METHODS: This was a cross-sectional study conducted between December 2018 and April 2019 comprising poultry workers, chickens and their poultry farm/market environments. This study characterized E. coli isolates from stool, faecal and environmental samples using antimicrobial susceptibility testing and whole-genome sequencing methods. Core-genome multilocus sequences-based phylogeny was used to determine the relatedness between quinolone-resistant E. coli isolates. Data were analyzed using descriptive statistics. RESULTS: Of 110 E. coli isolates, quinolone-resistant phenotypes were observed in 68.2% (n = 75) isolates. Whole-genome sequencing detected plasmid-mediated quinolone resistance (PMQR) genes in 63.6% (n = 70) isolates. The most prevalent PMQR gene detected in 56 of these 70 E. coli isolates was qnrS1, followed by qnrB19 in 14 isolates and aac(6')-lb-cr in two isolates. Fifteen ciprofloxacin and 19 nalidixic acid-resistant isolates respectively showed double mutations in the quinolone-resistance determining regions (QRDRs) of gyrA, with single or double mutations in parC, and a single mutation in parE. The most prevalent amino-acid substitutions observed were S83L + D87N in gyrA (46.5%, n = 20), S80I in parC (51.2%, n = 22) and S458A in parE (14%, n = 6). About 2.9% (2/70) of PMQR isolates were extended-spectrum beta-lactamase (ESBL) producers while 2.9% (2/70) had plasmid-mediated colistin resistance (PMCR) genes. CONCLUSIONS: PMQR genes were prevalent in E. coli isolates recovered from healthy humans, chickens and poultry farm/market environments. PMCR genes (mcr-1.1) occurred in PMQR-positive isolates recovered from manure and drinking water originating from poultry farm/market environments. It was found that the gene encoding ESBL coexisted with qnrS-positive isolates of human and avian origin. Horizontal transfer of PMQR genes among E. coli isolates in the human-poultry-environment interface has public health implications for the spread of antimicrobial resistance. Relevant government agencies should enforce regulations to restrict the use of critically important antimicrobials in poultry production.

Serological and Molecular Survey for Dengue Virus Infection in Suspected Febrile Patients in Selected Local Government Areas in Adamawa State, Nigeria.

Dengue is a disease caused by the dengue virus that is primarily transmitted by Aedes aegypti mosquitoes. Currently, the disease poses a threat to public health, with about 390 million people reported to be infected annually across the endemic regions of the world. In Nigeria, the disease is under-reported and often misdiagnosed as malaria. This study was designed to conduct a serological and molecular survey for dengue virus infection in febrile patients in three Local Government Areas (LGAs) in Adamawa State, Nigeria, from September through December 2020. Serum samples from 424 patients were analysed by Enzyme-Linked Immunosorbent Assay (CALBIOTECH, Dengue Virus IgM ELISA). Thick and thin smear microscopic techniques were used to determine the presence of malaria parasites. Overall, 19.4% patients were sero-positive for dengue in the three study locations. A total of 11%, 14.5% and 12.3% participants were found to be co-infected with dengue and malaria in Mubi, Jimeta and Numan, respectively. The CDC DENV1-4 RT-PCR Assay reagent was used for serotype-specific detection and identification of circulating serotypes. From the ELISA-positive samples, 11 (2.6%) cases were confirmed to be dengue serotype 1 by Real-Time PCR and sequencing and were found to be in circulation in all the three study areas. With an overall sero-prevalence of 19.4%, dengue virus infection may be one of the major causes of febrile illnesses across the study locations; hence, public healthcare professionals should not neglect other aetiologies of febrile illnesses and the need to conduct laboratory diagnoses to determine the possible causes of febrile illnesses.

Antibiotic prescription practices amongst veterinarians in Nigeria.

The high rate of antibiotic resistance constitutes a global threat to the continuous use of these drugs, because of increasing treatment failures. The aim of this study was to survey antibiotic prescription practices of veterinarians and the possible contribution to antimicrobial resistance (AMR) and antimicrobial stewardship (AMS) in Nigeria during the COVID era. This was a cross-sectional study that used a 33-question survey questionnaire administered to registered veterinarians in Nigeria. The study was both online survey and hard copy administered during the annual meeting of the veterinarians from July to October 2021. Descriptive statistics, bivariate analysis using Chi-square test were also done to analyze the results, while a two-tailed P-value of <0.05 at 95% confidence level was considered statistically significant. IBM SPSS Version 26 was used to analyze the data. A total of 172 respondents completed the online and hard copy questionnaire. Majority of the respondents engaged majorly in mixed veterinary practice (72.1%). A total of 53.5% were aware of the country's policy concerning antibiotic prescription, while majority (64.5%) do not do culture and sensitivity before antibiotic prescription. Majority (34.3%) felt that the risk of potential adverse drug reaction could affect their decision when choosing to prescribe an antibiotic to the owner. Majority (51.2%) felt that some antibiotics were over prescribed, while 26.7% opined that all antibiotics were appropriately prescribed. To improve antibiotic use and practice amongst veterinarians in Nigeria, dependence on laboratory services for antibiotic prescription, enforcement of national guidelines and monitoring of antibiotic prescription amongst the veterinarians is essential to curb over-prescription and strengthen antimicrobial stewardship.

SARS-CoV-2 seroprevalence at urban and rural sites in Kaduna State, Nigeria, during October/November 2021, immediately prior to detection of the Omicron variant.

BACKGROUND: Nigeria is Africa's most populated country. By November 2021 it had experienced three waves of SARS-CoV-2 infection. Peer-reviewed seroprevalence data assessing the proportion of the Nigerian population that have been infected were extremely limited. METHODS: We conducted a serosurvey in one urban site (n = 400) and one rural site (n = 402) in Kaduna State, Nigeria between 11 October 2021 and 8 November 2021. Z-tests were used to compare seroprevalence across age groups, locations and sexes. T tests were used to determine whether age or household size are associated with seropositivity. Associations between seropositivity and recent history of common Covid-19 symptoms were tested using logistic regression. RESULTS: SARS-CoV-2 antibodies were detected in 42.5% an 53.5% of participants at the urban and rural sites, respectively The overall age- and sex- stratified seroprevalence was 43.7% (42.2% for unvaccinated individuals). The data indicate an infection rate in Kaduna State ≥359-fold the rate derived from polymerase chain reaction-confirmed cases. In the urban site, seroprevalence among females and participants aged <20 was lower than other groups. Reporting loss of sense of taste and/or smell was strongly associated with seropositive status. Associations with seropositivity were also found for the reporting of dry cough, fever, headache, nausea and sore throat. CONCLUSIONS: This study provides baseline SARS-CoV-2 seroprevalence in Kaduna State, Nigeria, immediately prior to the spread of the Omicron variant. It indicates that in October/November 2021, approximately 56% of the population did not have detectable antibodies, and population subgroups with particularly low seroprevalence remain. It highlights limitations in using PCR-confirmed cases to estimate infection rates. The data will inform public health strategies in Nigeria and other sub-Saharan African countries with limited SARS-CoV-2 seroprevalence data.

Assessing knowledge, attitude, and practices of veterinarians towards antimicrobial use and stewardship as drivers of inappropriate use in Abuja, Nigeria.

INTRODUCTION: Antimicrobial resistance (AMR) has recently gained worldwide recognition, as the emergence of multi-drug resistant organisms has led to increased mortality and economic burden. This study aimed to assess knowledge, attitudes, and practices of veterinarians towards rational antimicrobial prescribing and identify factors influencing use. METHODS: We interviewed veterinary doctors in Abuja, Nigeria using a 50-point questionnaire distributed via WhatsApp mobile application. The questionnaire inquired about their experiences, knowledge, attitudes, and practices towards AMR and stewardship. We analyzed the data by calculating frequencies and proportions. RESULTS: Of 220 registered veterinarians, 144 (65.5%) participated in the survey. Most (52.8%) were within the age group 30 - 39 years; males (72.2%), with a Master's degree (42.4%) and worked in public service (44.4%). Three-quarters (75.7%) had good knowledge of antimicrobials; 47.2% had received training on stewardship while 88.9% reported that they believed that overuse of antimicrobials was the major contributory factor towards AMR. Antimicrobial stewardship regulations are important in veterinary practice. Veterinarians were aware of the occurrence of resistant pathogens and agreed that restricting antimicrobial use in animal health care was necessary to reduce AMR. CONCLUSION: Most respondents referred to the veterinary formulary (VF) when in doubt of the appropriate antimicrobial agent to administer. We recommend that the VF be updated following the WHO list of critically-important-antimicrobials (CIA) and veterinarians educated not to use these CIAs in the treatment of food animals.

Molecular identification and prevalence of trypanosomes in cattle distributed within the Jebba axis of the River Niger, Kwara state, Nigeria.

BACKGROUND: Trypanosomiasis is a fatal disease that threatens the economy of at least 37 countries in sub-Saharan Africa, particularly with regard to livestock farming. In this study, we investigated the prevalence of trypanosome infection in cattle, and molecularly identified the species of trypanosomes in infected cattle and the spatial distribution of trypanosome-infected herds along the Jebba axis of the River Niger. METHODS: A randomized cross-sectional study was conducted along the Jebba axis of the River Niger by screening cattle from 36 herd clusters by nested PCR using ITS-1 generic primers. Data generated were analysed using the Chi-square test at a 95% confidence interval. RESULTS: Microscopic examination revealed three infected cattle out of 398 examined, representing 0.8% prevalence. Twelve animals (3.0%) were positive by PCR. Our results showed a decline in the packed cell volume of infected animals (24.7%). The infection rates were categorized as single infection in 11/12 (91.7%) and mixed infection in 1/12 (8.3%). Animals were most frequently infected by Trypanosoma congolense (50.0%), with T. congolense Savannah being the most prevalent subspecies (71.4%). Aside from the infection rate by age (10.0%) and relative distance of animals from the River Niger (56.2%), statistical differences in every other parameter tested were based on mere probabilistic chance. Spatial data showed that the disease was prevalent among herds located less than 3 km from the River Niger. CONCLUSIONS: Six species of trypanosomes were identified in cattle herds along the Jebba axis of the River Niger, with T. congolense being the most prevalent. Age and relative distance of herds from the River Niger may be risk factors for trypanosome infection in cattle herds in this area.

Detection and genetic characterisation of Toxoplasma gondii circulating in free-range chickens, pigs and seropositive pregnant women in Benue state, Nigeria.

Toxoplasma gondii parasites present strong but geographically varied signatures of population structure. Populations sampled from Europe and North America have commonly been defined by over-representation of a small number of clonal types, in contrast to greater diversity in South America. The occurrence and extent of genetic diversity in African T. gondii populations remains understudied, undermining assessments of risk and transmission. The present study was designed to establish the occurrence, genotype and phylogeny of T. gondii in meat samples collected from livestock produced for human consumption (free-range chickens, n = 173; pigs, n = 211), comparing with T. gondii detected in blood samples collected from seropositive pregnant women (n = 91) in Benue state, Nigeria. The presence of T. gondii DNA was determined using a published nested polymerase chain reaction, targeting the 529 bp multicopy gene element. Samples with the highest parasite load (assessed using quantitative PCR) were selected for PCR-restriction fragment length polymorphism (PCR-RFLP) targeting the surface antigen 3 (SAG3), SAG2 (5' and 3'), beta-tubulin (BTUB) and dense granule protein 6 (GRA6) loci, and the apicoplast genome (Apico). Toxoplasma gondii DNA was detected in all three of the populations sampled, presenting 30.6, 31.3 and 25.3% occurrence in free-range chickens, pigs and seropositive pregnant women, respectively. Quantitative-PCR indicated low parasite occurrence in most positive samples, limiting some further molecular analyses. PCR-RFLP results suggested that T. gondii circulating in the sampled populations presented with a type II genetic background, although all included a hybrid type I/II or II/III haplotype. Concatenation of aligned RFLP amplicon sequences revealed limited diversity with nine haplotypes and little indication of host species-specific or spatially distributed sub-populations. Samples collected from humans shared haplotypes with free-range chickens and/or pigs. Africa remains under-explored for T. gondii genetic diversity and this study provides the first detailed definition of haplotypes circulating in human and animal populations in Nigeria.

Genetic relatedness of multidrug resistant Escherichia coli isolated from humans, chickens and poultry environments.

BACKGROUND: Inappropriate use of antimicrobial agents in animal production has led to the development of antimicrobial resistance (AMR) in foodborne pathogens. Transmission of AMR foodborne pathogens from reservoirs, particularly chickens to the human population does occur. Recently, we reported that occupational exposure was a risk factor for multidrug-resistant (MDR) Escherichia coli (E. coli) among poultry-workers. Here we determined the prevalence and genetic relatedness among MDR E. coli isolated from poultry-workers, chickens, and poultry environments in Abuja, Nigeria. This study was conducted to address the gaps identified by the Nigerian AMR situation analysis. METHODS: We conducted a cross-sectional study among poultry-workers, chickens, and poultry farm/live bird market (LBM) environments. The isolates were tested phenotypically for their antimicrobial susceptibility profiles, genotypically characterized using whole-genome sequencing (WGS) and in silico multilocus sequence types (MLST). We conducted a phylogenetic single nucleotide polymorphism (SNPs) analysis to determine relatedness and clonality among the isolates. RESULTS: A total of 115 (26.8%) out of 429 samples were positive for E. coli. Of these, 110 isolates were viable for phenotypic and genotypic characterization. The selection comprised 47 (42.7%) isolates from poultry-workers, 36 (32.7%) from chickens, and 27 (24.5%) from poultry-farm or LBM environments. Overall, 101 (91.8%) of the isolates were MDR conferring resistance to at least three drug classes. High frequency of resistance was observed for tetracycline (n = 102; 92.7%), trimethoprim/sulfamethoxazole (n = 93; 84.5%), streptomycin (n = 87; 79.1%) and ampicillin (n = 88; 80%). Two plasmid-mediated colistin genes-mcr-1.1 harboured on IncX4 plasmids were detected in environmental isolates. The most prevalent sequence types (ST) were ST-155 (n = 8), ST-48 (n = 8) and ST-10 (n = 6). Two isolates of human and environmental sources with a SNPs difference of 6161 originating from the same farm shared a novel ST. The isolates had similar AMR genes and plasmid replicons. CONCLUSION: MDR E.coli isolates were prevalent amongst poultry-workers, poultry, and the poultry farm/LBM environment. The emergence of MDR E. coli with novel ST in two isolates may be plasmid-mediated. Competent authorities should enforce AMR regulations to ensure prudent use of antimicrobials to limit the risk of transmission along the food chain.

Identification of Coronaviruses, Paramyxoviruses, Reoviruses, and Rotaviruses among Bats in Nigeria.

Bats are often consumed by some ethnic groups in Nigeria despite association of bats with many important emerging viruses. More than 300 bats representing eight species were captured during 2010-2011 in eight locations of northern Nigeria. Available fecal swabs (n = 95) were screened for the presence of arenaviruses, CoVs, paramyxoviruses (PMVs), reoviruses, rhabdoviruses, and influenza viruses using generic reverse transcription-polymerase chain reaction assays. Here, we document the detection of CoVs, PMVs, reoviruses, and rotaviruses (RVs) in Nigerian bats. The Nigerian bat CoVs are grouped within other bat SARS-CoV-like viruses identified from Ghana in a sister clade next to the human SARS-CoV clade. The phylogenetic analysis indicated a broad range of RVs present in Nigerian bats, some cluster with human RVs and some represent novel species. Our study adds that continuing global surveillance for viruses in bats to understand their origin, adaptation, and evolution is important to prevent and control future zoonotic disease outbreaks.

Rabies virus infection in mice up-regulates B7-H1 via epigenetic modifications.

Rabies virus infection is an endemic disease which remains central to public health issues. The presence of epigenetics associated with the over-expression of B7-H1 in mice brain infected with rabies virus was investigated for the first time. A significant increase (p < 0.05) in mRNA level of B7-H1 as the disease progressed was observed. The percentage of methylated region was significantly (p < 0.05) higher in infected tissues relative to uninfected. DNA methyltransferase (DNMT) and histone acetylase (HAT) activities were also significantly (p < 0.05) higher in most infected brain tissues. HAT had a relatively higher proportion than DNMT when compared to the normal. Paradoxically, it can be inferred that the rabies virus uses epigenetic mechanisms as a means of manipulating host genes, as there was an increase in global DNMT and HAT activities with concomitant increase in B7-H1 promoter methylation and expression.

Identification of mobile colistin resistance genes (mcr-1.1, mcr-5 and mcr-8.1) in Enterobacteriaceae and Alcaligenes faecalis of human and animal origin, Nigeria.

Colistin is a last-resort drug used to treat infections caused by multidrug-resistant Gram-negative bacteria that have developed carbapenem resistance. Emergence and rapid dissemination of the nine plasmid-mediated mobile colistin resistance genes (mcr-1 to mcr-9) has led to fear of pandrug-resistant infections worldwide. To date, there is only limited information on colistin resistance in African countries where the drug is widely used in agriculture. In this Nigerian study, 583 non-duplicate bacterial strains were isolated from 1119 samples from humans, camels, cattle, dogs, pigs and poultry using colistin-supplemented MacConkey agar, among which 17.0% (99/583) were colistin-resistant. PCR (mcr-1 to mcr-9) and whole-genome sequencing (WGS) identified mcr in 21.2% (21/99) of colistin-resistant isolates: mcr-1.1 (n = 13), mcr-8.1 (n = 5), mcr-1.1 and mcr-8.1 (n = 2), and mcr-1.1 and mcr-5 (n = 1). Of the 21 mcr-positive strains, 9 were isolated from human samples, with 8 being Klebsiella pneumoniae, and 6 of these human K. pneumoniae had a high colistin MIC (>64 µg/mL). In contrast, 9 of the 12 mcr-positive animal isolates were Escherichia coli, of which only 2 had a colistin MIC of >64 µg/mL. This study is the first to report mcr-1 in Alcaligenes faecalis and the emergence of mcr-5 and mcr-8 in Nigeria. WGS determined that mcr-1 was localised on an IncX4 plasmid and that 95.2% of mcr-1 harbouring isolates (20/21) transferred colistin resistance successfully by conjugation. These findings highlight the global spread of colistin resistance and emphasise the urgent need for co-ordinated global action to combat resistant bacteria.

Understanding fish production and marketing systems in North-western Nigeria and identification of potential food safety risks using value chain framework.

Fish production systems in North-western Nigeria have a significant role in food, nutrition and income generations to families, yet an important setup for zoonotic disease transmission. The aim of this study was to provide a broad knowledge of the structure, activities and food safety risks of the fish value chains operating in North-western Nigeria using the value chain framework. A total of 16 focus groups and 8 key informant interviews were conducted to gather data from fish producers, fish sellers and fish processors in selected peri-urban and rural settlements in Kaduna State. In addition, 129 semi-structured questionnaires and observation checklists were used in this study to gather evidence-based data, such as demography of value chain actors, product characterization, and food safety risks. The fish value-chain in North-western Nigeria is characterised by four main stakeholders, namely, fish producers, transporters, as well as raw- and processed-fish-sellers (wholesalers, retailers). Two major sources were identified supplying farmed fish to North-western Nigeria: the distributors from the central and southern part of the country and the fish farmers within the North-western and North-eastern regions of Nigeria. Raw-fish-wholesalers within the two major markets sold most of their high-value products to raw-fish-retailers, while low-value products were routed to raw-fish-retailers in the rural communities, processed-fish-retailers and household consumers in rural settlements. There were no large companies operating and no differentiation of chains between aquaculture and wild fishery. Raw fishes not sold and began to rot were sold to street vendors at a cheaper price and household consumers. Fish production and supply chains were characterised by poor structural and sanitary support for food safety and hygiene measures. Food safety risks identified were related to lack of biosecurity measures in fish farms, lack of cold chain and access to running water, poor hygiene practices by all handlers, lack of fish inspection at all levels, lack of use of protective clothing and limited health inspection of handlers. In overall, government control of activities in fish value chains was relatively poor leading to the absence of food safety regulatory enforcement characterised by lack of institutional goals on improving food safety measures in a chain-wide distribution. Hence, this study points the significant structural, sanitary and hygiene limitations along the fish value chain components. It provides a baseline for microbial food safety risk assessments, and information required for policy-making regarding implementation of disease control programmes, as the sector is fast-evolving in Sub-Saharan Africa.

Molecular study of rabies virus in slaughtered dogs in Billiri and Kaltungo local government areas of Gombe state, Nigeria.

Rabies is one of the most dreadful diseases and a major viral zoonosis which has been shown to cause an almost 100% fatality rate in infected victims. It is characterized by acute progressive encephalitis in mammals. This study determined the genotypic characteristics of rabies virus in dogs slaughtered for human consumption based on sequence of a fragment of nucleoprotein gene. Brain tissues were collected from 50 dogs slaughtered in Billiri and Kaltungo Local Government Areas of Gombe State, Nigeria. Direct fluorescent antibody test (DFAT) was used to screen for the presence of rabies virus antigen. Viral RNA isolated from DFAT positive brain tissues were subjected to the reverse transcription polymerase chain reaction (RT-PCR) followed by sequencing of the amplicons. Maximum Likelihood (ML) was used to construct a phylogenetic tree for sequences obtained with 1000 bootstrap replicates. The DFAT detected rabies antigen in 3 (6%) of the 50 dog brain tissues, from which 1 (2%) was positive by RT-PCR. ML phylogeny approach of the nucleotide sequences inferred members as originating lyssavirus genus and dog species. Essentially, MK234794 in this study displayed 99.3% sequence similarity with other related rabies viruses in the Africa 2 cluster (Nigeria, Cameroon, Chad and Niger). Interestingly, MK234794 showed no cluster relation with the Africa 1a, 1b, 3 and Africa 4 clades, respectively. This indicates there is in-country and trans-boundary circulation of the rabies viruses with no co-circulation between the Africa lineages, especially as dogs are continuously being traded due to consumption of dog meat in West Africa. This finding has given additional insight into the molecular epidemiology of rabies virus in Nigeria, therefore providing more baseline information for future design of rabies control programs in the country.

Induction of Rabies Virus Infection in Mice Brain may Up and Down Regulate Type II Interferon gamma via epigenetic modifications.

As feared and deadly human diseases globally, Rabies virus contrived mechanisms to escape early immune recognition via suppression of the interferon response. This study, preliminarily investigated whether Rabies virus employs epigenetic mechanism for the suppression of the interferon using the Challenge virus standard (CVS) strain and Nigerian street Rabies virus (SRV) strain. Mice were challenged with Rabies virus (RABV) infection, and presence of RABV antigen was assessed by direct fluorescent antibody test (DFAT). A real time quantitative Polymerase chain reaction (qRT-PCR) was used to measure the expression of type II interferon gamma (IFNG) and methylation specific quantitative PCR for methylation analysis of 1FNG promoter region. Accordingly, DNA methyltransferase (DNMT) and histone acetyltransferase (HAT) enzymes activities were determined. RABV antigen was detected in all infected samples. A statistically significant increase (p < 0.05) in mRNA level of IFNG was observed at the onset of the disease and a decrease as the disease progressed. An increase in methylation in the test groups from the control group was observed, with a fluctuation in methylation as the disease progressed. DNMT and HAT activities also agree with methylation as there was an observed increase activity in test group compared with control group. Similar fluctuation pattern was observed in both CVS and SRV groups as the disease progressed with HAT, being the most active proportionally. This study suggests that epigenetic modification via DNA methylation and histone acetylation may have played a role in the expression of type II interferon gamma in Rabies virus infection. Graphical abstract.

Extended-spectrum ß-lactamase-producing Escherichia coli among humans, chickens and poultry environments in Abuja, Nigeria.

BACKGROUND: Globally, chicken is known to be a reservoir for the spread of antimicrobial resistance genes to humans. In Nigeria, antimicrobial drugs are readily accessible for use in poultry production, either for preventive or therapeutic purposes. Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) are transmissible to humans because of their zoonotic potentials. People working very closely with chickens either on farms or markets are at greater risk. The aim of this study was to investigate the prevalence and zoonotic transmission of ESBL-EC among poultry-workers, chickens, and poultry environments in Abuja, Nigeria. METHODS: We conducted a cross-sectional study among workers, chickens and poultry environment in selected farms/chicken markets in Abuja. Stool, faecal, and environmental samples were collected from apparently healthy workers, chickens, and farm/market environments from December 2018 to April 2019. Data were collected electronically using an open data kit (ODK) installed on a Smartphone. Antimicrobial resistance was determined using broth micro-dilution methods against a panel of 14 antimicrobial agents. We carried out the phenotypic and genotypic characterization of the isolates. Data were analyzed by computing frequencies, proportions and spearman's correlation (ρ). RESULTS: Of 429 samples, 26.8% (n = 115) were positive for Escherichia coli (E. coli). Of the 115 E. coli isolates, 32.2% (n = 37) were confirmed ESBL producers by phenotypic characterization. Prevalence of ESBL-EC was highest among both poultry-workers (37.8%; n = 14) and chickens (37.8%; n = 14) followed by the environment (24.3%; n = 9). Both human and chicken isolates showed similar patterns of multidrug resistance to tested antimicrobials with a positive correlation (ρ = 0.91). Among ESBL producers, we observed the dissemination of blaCTX-M (10.8%; n = 4) genes. The coexistence of blaCTX-M-15 and blaTEM-1 genes was observed in 8.1% (n = 3) of the isolates, out of which (66.7%; n = 2) were chicken isolates from the farm, while a single human isolate was from the chicken market. CONCLUSIONS: ESBL-EC isolates were prevalent amongst apparently healthy individuals, chickens and the poultry farm/market environment in Abuja. It is important to educate healthcare workers that people in proximity with poultry are a high-risk group for faecal carriage of ESBL-EC, hence pose a higher risk to the general population for the spread of antimicrobial resistance.

Prevalence and risk factors for multi-drug resistant Escherichia coli among poultry workers in the Federal Capital Territory, Abuja, Nigeria.

BACKGROUND: Antimicrobial resistance has emerged as a global health threat. Antimicrobial resistant Escherichia coli infections are associated with high morbidity and expenditure when compared with infections caused by susceptible strains. In Nigeria, antimicrobial drugs are readily available over-the-counter with potential for indiscriminate use by poultry farmers and eventual development of drug resistance. The objective of this study was to investigate prevalence and risk factors for multi-drug resistant E. coli among poultry workers (PW) in Abuja, Nigeria. MATERIALS AND METHODS: A cross-sectional study was conducted among 122 randomly selected apparently healthy poultry workers (poultry-farmers/ sellers) in Municipal and Kuje Area Councils from December 2018 to April 2019. Data was collected on socio-demographics and exposure factors using a structured interviewer-administered questionnaire. E. coli was isolated and identified from stool samples of poultry workers. Antibiotic susceptibility testing was done using Kirby-Bauer disk diffusion method. Multidrug resistance (MDR) was defined as resistance to three or more classes of antimicrobials. Data was analyzed by computing proportions, prevalence odds-ratios (POR) and logistic regression at 5% significance level. RESULTS: Among PW, there were 121 males (99.2%). Mean age of the male workers was 30.6 ± 9.7years, 54.6% (n = 66) married, 57.9% (n = 70) had secondary education and 62.0% (n = 75) were farm-workers. Prevalence of E. coli was 39.7% (n = 48), highest among farm-workers (POR = 2.7, 95% Confidence Interval [CI] = 1.3-5.7; p = 0.01) compared to poultry-sellers. Of the 48 E. coli isolates, 16.7% (n = 8) were extended spectrum beta lactamase (ESBL) producers and 79.2% (n = 38) were MDR. We detected resistance against Tetracycline: (83.3%, n = 40), Sulfamethoxazole-Trimethoprim: (79.2%, n = 38), Ampicillin: (77.1%, n = 37), Streptomycin: (72.9%, n = 35), Nalidixic acid: (50%, n = 24), Gentamicin: (41.7%, n = 20), Chloramphenicol: (31.3%, n = 15), Cephalothin: (27.1%, n = 13), Nitrofurantoin: (10.4%, n = 5) and Imipenem: (6.3%, n = 3). Absence of lavatory (POR = 2.7, 95% CI = 1.1-6.7); existence of farm/market for >10years (POR = 2.5, 95% CI = 1.1-5.4) and PW's history of diarrhea in last three months (POR = 2.8, CI = 1.2-6.3) were associated with MDR. Controlling for age, absence of lavatory (adjusted OR [aOR] = 4.31, 95% CI = 1.6-11.9); PW's history of diarrhea in last three months (aOR = 3.3,95%CI = 1.3-8.5) and work exposure >10years (aOR = 0.3, 95%CI = 0.1-0.9) remained independent risk factors for MDR. CONCLUSION: Prevalence of resistant E. coli was highest among farm-workers and associated with older farms/markets, occupational exposure of over 10 years and poor hygienic measures. The management of Municipal and Kuje Area Councils were recommended to provide lavatories for public use in farm-settlements/markets. The importance of hand-hygiene and responsible use of antimicrobials in poultry production was emphasized.