An assessment of the operationality and factors influencing the effectiveness of rabies surveillance in Gombe State, Nigeria.

Rabies remains a burden in Africa, disproportionately affecting the most vulnerable despite the availability of effective vaccines. Nigeria, the most populous African country, needs rapid disease control actions and commitments to achieve the goal of eliminating dog-mediated rabies by 2030. Surveillance is an essential element of effective disease control strategies. This study examined the current state of operationality of the rabies surveillance system for early case detection and management in Gombe state, Nigeria, through a One Health lens. It further examined the barriers impeding the effectiveness of the surveillance based on the perception of surveillance workers. Qualitative and quantitative methods were used to assess the structure of the system and its functioning. Data on dog bite and rabid cases obtained from the veterinary services in Gombe state were analysed descriptively. A total of 13 key informants were interviewed using a semi-structured interview guide. Qualitative data were analysed using thematic analysis to explore in depth the factors that influenced the operationality of the system. A total of 157 potential human exposures to rabies were identified in this study, out of which two people reportedly died at the health facility after showing symptoms highly suggestive of rabies. In terms of rabies surveillance and control, cross-sectoral collaboration was found between the human health and veterinary sectors for risk assessment of potential rabies exposures and its management. Some identified factors affecting the operations of the surveillance were inadequate funding, lack of infrastructure, lack of feedback from higher authorities and insufficient knowledge of rabies prevention and management. To improve the capacity for case detection and management within the state, the appropriate authorities may focus on increasing awareness about the disease to the populace to increase the number of cases identified by the system, employ more workers and strengthen the surveillance capability of existing workers.

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.

Whole Genome Sequencing for Rapid Characterization of Rabies Virus Using Nanopore Technology.

Genomic data can be used to track the transmission and geographic spread of infectious diseases. However, the sequencing capacity required for genomic surveillance remains limited in many low- and middle-income countries (LMICs), where dog-mediated rabies and/or rabies transmitted by wildlife such as vampire bats pose major public health and economic concerns. We present here a rapid and affordable sample-to-sequence-to-interpretation workflow using nanopore technology. Protocols for sample collection and the diagnosis of rabies are briefly described, followed by details of the optimized whole genome sequencing workflow, including primer design and optimization for multiplex polymerase chain reaction (PCR), a modified, low-cost sequencing library preparation, sequencing with live and offline base calling, genetic lineage designation, and phylogenetic analysis. Implementation of the workflow is demonstrated, and critical steps are highlighted for local deployment, such as pipeline validation, primer optimization, inclusion of negative controls, and the use of publicly available data and genomic tools (GLUE, MADDOG) for classification and placement within regional and global phylogenies. The turnaround time for the workflow is 2-3 days, and the cost ranges from $25 per sample for a 96 sample run to $80 per sample for a 12 sample run. We conclude that setting up rabies virus genomic surveillance in LMICs is feasible and can support progress toward the global goal of zero dog-mediated human rabies deaths by 2030, as well as enhanced monitoring of wildlife rabies spread. Moreover, the platform can be adapted for other pathogens, helping to build a versatile genomic capacity that contributes to epidemic and pandemic preparedness.

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.

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.

Serosurvey for Middle East respiratory syndrome coronavirus antibody in dromedary camels and human patients at a secondary care hospital, Illela, Northwest Nigeria.

Middle East respiratory syndrome (MERS) is a serious emerging zoonosis. It is characterized by severe infection of the respiratory tract in humans. Dromedary camels are considered to be the most probable origin of the pathogenic Middle East respiratory syndrome coronavirus (MERS-CoV). This cross-sectional survey was carried out to ascertain the seroprevalence of MERS-CoV in dromedary camels at Illela border and human patients in a secondary care hospital in Illela, Sokoto State, Nigeria from November 2016 to January 2017. Serum samples from 74 camels and 39 human patients were collected while a data form was administered to the camel handlers (40) and human patients to obtain information on zoographic characteristics of dromedary camels, demographic characteristics of camel handlers and human patients and some practices of both groups which are likely to predispose to MERS-CoV infection. The serum samples were analyzed for antibodies against MERS-CoV using the indirect Enzyme-Linked Immuno-Sorbent Assay (ELISA). All the camels sampled were seropositive against MERS-CoV and 74% of the human patients had antibodies against MERS. All handlers treated their camels without consulting veterinarians and there was little or no biosecurity measures undertaken. Age, sex, and occupation were not significant determinants for the presence of MERS-CoV antibody in human patients sampled. This study serves as a baseline for similar researches and due to the high seroprevalence obtained in this study for both camels and humans, there is need for trained personnel, surveillance and diagnostic tools at our border posts and animal markets. Supplementary information: The online version contains supplementary material available at 10.1007/s00580-022-03351-3.

Prevalence and risk factors associated with SARS-CoV-2 infections among veterinary practitioners and dogs patients, June-August 2020, Lagos, Nigeria.

BACKGROUND: Lagos State is the epicenter of COVID-19 in Nigeria, having the highest number of cases and death. Veterinary practitioners play an important role in public health and risk exposure to SARS-CoV-2, the virus that causes COVID-19 while attending to animal patients and owners. We determined the prevalence of covid-19 among veterinary practitioners and their dog patients in Lagos, and the associated risk factors during the lockdown. METHODS: We administered questionnaires, reviewed clinical records and conducted serological test to determine the COVID-19 status of 112 veterinary practitioners and 154 dog patients and to assess the associated factors in nine veterinary clinics or hospitals between June to August 2020. Data were analyzed using descriptive statistics, bivariate and multivariate analyses at 5% significant level. RESULT: The mean age of participants was 37.5±10.5 and 66 (58.9%) were male. COVID-19 cases among the veterinary practitioners and dogs were 29 (25.9%) and 3 (2%), respectively. Predictors of COVID-19 cases among veterinary practitioners were contact with a SARS-CoV-2 infected dog (AOR: 25.42; CI 4.73-136.66); being a veterinary doctor working during the lockdown (AOR: 6.11; CI 1.56-24.00) and not disinfecting examination table after attending to dogs (AOR: 12.43; CI 1.39-110.99). CONCLUSION: Veterinary practitioners and dogs in Lagos were exposed to SARS-COV-2 virus during the COVID-19 lockdown. Contact with SARS-CoV-2 infected dogs, being a veterinary doctor working during the lockdown and not disinfecting examination tables after clinical examination were predictors of COVID-19 cases among veterinary practitioners in Lagos State. Strict Infection, Prevention and Control measures are recommended in veterinary practice.

Rabies virus infection is associated with alterations in the expression of parvalbumin and secretagogin in mice brain.

Infection with the deadly rabies virus (RABV) leads to alteration of cellular gene expression. The RABV, similar to other neurodegenerative diseases may be implicated in neuronal death due to an imbalance in Ca2+ homeostasis. Parvalbumin (PV) and Secretagogin (Scgn), two members of the Calcium-Binding Proteins (CBPs) are useful neuronal markers responsible for calcium regulation and buffering with possible protective roles against infections. This study investigated whether infection with rabies virus causes variance in expression levels of PV and Scgn using the Challenge virus standard (CVS) and Nigerian Street Rabies virus (SRV) strains. Forty-eight, 4-week-old BALB/c mice strains were divided into two test groups and challenged with Rabies virus (RABV) infection and one control group. The presence of RABV antigen was verified by direct fluorescent antibody test (DFAT) and real-time quantitative PCR (qRT-PCR) was used to assess PV and Scgn gene expression. Infection with both virus strains resulted in significant (p < 0.05) increases in expression during early infection. Mid-infection phase caused reduced expression for both genes. However, as infection progressed to the terminal phase, a lower increase in expression was measured. Gene expression and viral load correlation indicated no positive relationship. Neurons with these CBPs may have a greater capacity to buffer calcium and be more resistant to degenerative changes caused by RABV. This implies that, when PV and Scgn expression levels are kept adequately high, the integrity of neurons may be maintained and degeneration caused by RABV infection may be prevented or stopped, hence, these are possible constituents of effective rabies therapy.

Awareness and knowledge of canine rabies: A state-wide cross-sectional study in Nigeria.

Rabies is a highly fatal disease that is endemic in Nigeria. The poor community awareness and knowledge of canine rabies have thwarted the realization of zero deaths from dog mediated human rabies. This study aimed to assess the awareness and knowledge of canine rabies in Kwara state. A total of 1,460 questionnaires were administered to respondents in the three senatorial zones of the state using open data kit (ODK) on mobile phones between September 2019 to January 2020. The rabies awareness rate was 38.1%. The mean knowledge score was 3.78 ± 2.15. Only 10.6% (n = 59/557) of the respondents had satisfactory knowledge of canine rabies. Respondents had poor knowledge of the mode of transmission, symptoms, prevention, and the control measures needed to eliminate canine rabies. Only 20.1% of respondents owned at least a dog. Dog owners were 3.85× (95% CI: 2.89, 5.13; p < 0.01) more likely to be aware of canine rabies and were 1.78× (95% CI: 1.22-2.60; p = 0.003) more likely to have satisfactory knowledge about canine rabies than non-dog owners. Respondents with tertiary education were at least 6.81× (95% CI: 4.24, 10.92; p < 0.01) more likely to be aware of rabies than respondents with no formal education. The findings of this study showed very low awareness and knowledge of canine rabies among residents of Kwara state. Mass sensitization of the populace on the dangers of rabies should be intensified. Such interventions should be targeted at the general public and dog owners.

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.

Baseline epidemiology and associated dog ecology study towards stepwise elimination of rabies in Kwara state, Nigeria.

Understanding domestic dog population dynamics and ecology is crucial to any effective rabies control program. This study was conducted as part of the baseline epidemiological studies necessary for the establishment of the Kwara Rabies Rapid Alert System "KRRAS". This study aimed to determine the dog population structure of Kwara State by assessing the dog ownership, vaccination status, and prevalence of dog bites. A total of 1460 questionnaires were administered to respondents in the three senatorial zones of the state using Open Data Kit (ODK) between June 2019 to January 2020. Of the 1460 households surveyed, 293 (20.1 %) owned at least one dog with an average of 2.25 dogs per household. The male to female ratio was 1.9:1 and 79.3 % (n = 523/659) of the owned dogs were local breeds. A total of 785 dogs was enumerated (659 dogs from 293 households and 126 free-roaming dogs) and 7811 persons which resulted in a dog-human ratio of 1:9.95. The estimated dog population is 376,789 (95 % CI: 343,700 - 379,878). Only 31 % (n = 204/659) of households vaccinated their dogs against rabies. The prevalence of dog-bite was 13 % (n = 193/1460) of which only 27 % of the victims (n = 61/225) received post-exposure prophylaxis (PEP). Dog ownership was significantly impacted by the ethnicity of respondents. Hausa (OR: 3.76; 95 % CI: 1.15-12.4; p < 0.001) and Nupe (OR: 4.48; 95 % CI: 1.77-11.33; p < 0.001) respondents owned dogs than Yoruba respondents. The rabies vaccination status of owned dogs was significantly impacted by the level of education (OR: 5.03; 95 % CI: 1.50-16.83; p < 0.001); history of previous dog bite incidents (OR: 1.74; 95 % CI: 0.95-3.17; p < 0.001); the breed of the dog with exotic dogs being more vaccinated (OR: 2.79: 95 % 0.64-12.05; p < 0.001). Similarly, Male dogs (OR: 1.49, 95 % 1.03-2.86; p < 0.001) and partially confined dogs (OR: 1.09, 95 % 0.45-2.11, p < 0.001) were found to be vaccinated against rabies. The results of the study showed low dog vaccination coverage, and high number of free roaming dogs. Hence, a threat to public health. The low dog vaccination coverage is below the 70-80 % target recommended for herd immunity by the World Health Organization.

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.

Seroprevalence of brucellosis and associated risk factors among abattoir workers in Bauchi State, Nigeria.

INTRODUCTION: Brucellosis is a reemerging and neglected zoonotic disease. It is an occupational bio-hazard and a public health problem. The objective of the study was to determine the seroprevalence of brucellosis and its risk factors among abattoir workers in Bauchi state. METHODS: A cross-sectional study was conducted in the three senatorial district abattoirs of Bauchi State. Abattoir workers (n=284) were selected by stratified random sampling. Data were collected using an adapted questionnaire. Serum samples collected, were screened for brucellosis with Rose Bengal Plate Test (RBPT), tested with Enzyme Linked Immunosorbent Assay (ELISA). Seropositive participants were positive for both RBPT and ELISA. Data were described in proportions and analyzed using bivariate and multivariate analysis. RESULTS: Participants were all male, age range: 18-70 years (mean 35 ±13 years). Ninety-five participants were seropositive (seroprevalence 33.5%) after laboratory testing. Following bivariate analysis, using personal protective equipment (PPE) [OR: 0.5 CI95%=0.3>OR: 0.5 CI95%=0.3-0.9] was significantly protective against brucellosis. Slaughtering of animals (OR: 2.19 CI95%= 1.2-3.7), assisting in animal parturition (OR: 2.25 CI95%= 1.3-3.7), working with an open cut/wound (OR:2.1 CI95%= 1.1-3.9) and eating while working in the abattoir [OR:2.4 CI95%= 1.1>OR:2.4 CI95%= 1.1-4.9] were risks of brucellosis. Multivariate analysis showed that slaughtering of animals: Adjusted Odds-Ratio (AOR) = 1.92; CI95% = 1.03 - 3.59) and assisting in animal parturition (AOR = 2.43; CI95% = 1.40 - 4.23) remained significantly associated with brucellosis. CONCLUSION: Seroprevalence of brucellosis among abattoir workers in Bauchi state is high. Workers should use PPEs and animal parturitions should be handled by trained personnel alone.

Bat and Lyssavirus Exposure among Humans in Area that Celebrates Bat Festival, Nigeria, 2010 and 2013.

Using questionnaires and serologic testing, we evaluated bat and lyssavirus exposure among persons in an area of Nigeria that celebrates a bat festival. Bats from festival caves underwent serologic testing for phylogroup II lyssaviruses (Lagos bat virus, Shimoni bat virus, Mokola virus). The enrolled households consisted of 2,112 persons, among whom 213 (10%) were reported to have ever had bat contact (having touched a bat, having been bitten by a bat, or having been scratched by a bat) and 52 (2%) to have ever been bitten by a bat. Of 203 participants with bat contact, 3 (1%) had received rabies vaccination. No participant had neutralizing antibodies to phylogroup II lyssaviruses, but >50% of bats had neutralizing antibodies to these lyssaviruses. Even though we found no evidence of phylogroup II lyssavirus exposure among humans, persons interacting with bats in the area could benefit from practicing bat-related health precautions.

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.

Human Exposure to Novel Bartonella Species from Contact with Fruit Bats.

Twice a year in southwestern Nigeria, during a traditional bat festival, community participants enter designated caves to capture bats, which are then consumed for food or traded. We investigated the presence of Bartonella species in Egyptian fruit bats (Rousettus aegyptiacus) and bat flies (Eucampsipoda africana) from these caves and assessed whether Bartonella infections had occurred in persons from the surrounding communities. Our results indicate that these bats and flies harbor Bartonella strains, which multilocus sequence typing indicated probably represent a novel Bartonella species, proposed as Bartonella rousetti. In serum from 8 of 204 persons, we detected antibodies to B. rousetti without cross-reactivity to other Bartonella species. This work suggests that bat-associated Bartonella strains might be capable of infecting humans.

Heat induced epitope retrieval for rabies virus detection by direct fluorescent antibody test in formalin-fixed dog brain tissues.

There is a great need for a chemical method of tissue preservation that would allow sample storage for extended periods at room temperature. This study aimed at retrieving and detecting rabies virus antigen by direct fluorescent antibody test (DFAT) in formalin-fixed dog brain tissues. Forty fresh dog brain specimens were collected as paired samples from rabies suspected cases that were received for postmortem detection of rabies in the Central Diagnostic Laboratory, National Veterinary Research Institute, Vom. One portion of each paired sample was prepared for fresh fluorescent antibody testing and the other portion was prepared for epitope retrieval and florescent antibody testing following fixation in 10% neutral buffered formalin. DFAT on formalin-fixed tissue exhibited a sensitivity of 100% in comparison to DFAT on fresh-tissue. No false positive result was obtained in formalin-fixed DFAT procedure, demonstrating 100% specificity. There was no apparent difference in the intensity of fluorescence in DFAT on fresh sample and formalin-fixed DFAT following heat induced epitope retrieval (concordance = 98%; 95% C.I. 0.9660 to 0.9903). The strength of agreement between DFAT on formalin-fixed and DFAT on fresh tissue was very good (Cohen's kappa coefficient value= 1.000; 95% C.I. 1.000-1.000). This study provides new information on the retrieval of rabies antigen by heat induced epitope retrieval for DFAT on formalinized tissues. Formalin could therefore, be used henceforth to fix tissues of rabies suspected cases for routine diagnosis, transportation or archival purposes. The heat induced epitope retrieval can be routinely used to retrieve rabies virus antigen for DFAT in cases where only formalin-fixed tissues are available or when preservation by freezing is difficult.

Complete genome sequence of a street rabies virus isolated from a dog in Nigeria.

A canine rabies virus (RABV) was isolated from a trade dog in Nigeria. Its entire genome was sequenced and found to be closely related to canine RABVs circulating in Africa. Sequence comparison indicates that the virus is closely related to the Africa 2 RABV lineage. The virus is now termed DRV-NG11.