SARS-CoV and SARS-CoV -2 cross-reactive antibodies in domestic animals and wildlife in Nigeria suggest circulation of sarbecoviruses.

Anthropogenic exposure of domestic animals, as well as wildlife, can result in zoonotic transmission events with known and unknown pathogens including sarbecoviruses. During the COVID-19 pandemic, SARS-CoV-2 infections in animals, most likely resulting from spill-over from humans, have been documented worldwide. However, only limited information is available for Africa. The anthropozoonotic transmission from humans to animals, followed by further inter- and intraspecies propagation may contribute to viral evolution, and thereby subsequently alter the epidemiological patterns of transmission. To shed light on the possible role of domestic animals and wildlife in the ecology and epidemiology of sarbecoviruses in Nigeria, and to analyze the possible circulation of other, undiscovered, but potentially zoonotic sarbecoviruses in animals, we tested 504 serum samples from dogs, rabbits, bats, and pangolins collected between December 2020 and April 2022. The samples were analyzed using an indirect multi-species enzyme-linked immunosorbent assay (ELISA) based on the receptor binding domain (RBD) of SARS-CoV and SARS-CoV -2, respectively. ELISA reactive sera were further analyzed by highly specific virus neutralization test and indirect immunofluorescence assay for confirmation of the presence of antibodies. In this study, we found SARS-CoV reactive antibodies in 16 (11.5%) dogs, 7 (2.97%) rabbits, 2 (7.7%) pangolins and SARS-CoV-2 reactive antibodies in 20 (13.4%) dogs, 6 (2.5%) rabbits and 2 (7.7%) pangolins, respectively. Interestingly, 2 (2.3%) bat samples were positive only for SARS-CoV RBD reactive antibodies. These serological findings of SARS-CoV and/or SARS-CoV-2 infections in both domestic animals and wildlife indicates exposure to sarbecoviruses and requires further One Health-oriented research on the potential reservoir role that different species might play in the ecology and epidemiology of coronaviruses at the human-animal interface.

Spatiotemporal heterogeneity and determinants of canine rabies evidence at Local Government Area Level in Nigeria: Implications for rabies prevention and control.

Canine rabies poses a significant risk to humans and animals in Nigeria. However, the lack of reliable tools to evaluate the performance of existing canine rabies control programs to inform public health policy decisions poses a severe obstacle. We obtained canine rabies surveillance data from the National Veterinary Research Institute (NVRI) and supplemented these data with rabies diagnoses reported in the published studies from Nigeria. To uncover contextual factors (i.e., environmental and sociodemographic) associated with canine rabies evidence at the Local Government Area (LGA) level, we classified LGAs in Nigeria into four categories based on evidence availability (i.e., LGAs with NVRI data or published studies, both, or no evidence). We described the geographical and temporal variation in coverage. We fitted a multinomial regression model to examine the association between LGA level canine rabies evidence and potential sociodemographic and ecological determinants of canine rabies evidence. The effective annual testing during the 19 years was less than one dog/100,000 Nigerian resident-year. Our results showed that 58% of Nigerian LGAs (450/774) had not been targeted by the existing national rabies surveillance or studies on rabies, including ten states capitals with high human populations. While 16% (122/774) of Nigerian LGAs concentrated in Taraba, Adamawa, and Abia had canine rabies evidence from published studies, none of these LGAs was represented in the NVRI rabies surveillance data. We also observed an increasing trend in rabies evidence over time towards the eastern part of Nigeria. Our multinomial regression model indicated that education level, poverty, population density, land use and temperature were significantly associated with canine rabies evidence at the LGA level. This study underscores the value of combining canine rabies evidence from different sources to better understand the current disease situation for targeted intervention.

Virological investigation of fatal rabies in a minor bitten by a mongrel in Nigeria.

Rabies is a deadly viral disease transmitted through bites of infected animals. Outbreaks continue to escalate in Africa, with fatalities in humans, especially in rural areas, but are rarely reported. About 40% casualties occur among children of < 15 years. A 5-year-old boy on referral from a Primary Health Care Centre to a tertiary hospital presented with anxiety, confusion, agitation, hydrophobia, photo-phobia and aero-phobia, seven weeks after he was bitten by a stray dog in a rural community in Nigeria. The patient did not receive post-exposure prophylaxis and died 48 hours post admission. Confirmatory diagnosis was rabies and the phylogenetic analysis of the partial N-gene sequence of the virus localized it to Africa 2 (genotype 1) Lyssaviruses. There was 95.7-100% and 94.9-99.5% identity between the isolate and other genotype 1 Lyssaviruses and 100% homology with rabies viruses from Mali, Burkina Faso, Senegal and Central African Republic.

Seroprevalence of Spotted Fever Group Rickettsiae in extensively managed sheep and goats in Nigeria, West Africa.

Sheep and goats raised extensively are frequently infested by Ixodid ticks that may act as vectors or reservoirs of Spotted Fever Group Rickettsiae (SFGR). A study to determine the seroprevalence of SFGR infection in 300 sheep and goats in Plateau State, Nigeria was conducted from September to November, 2018 using the Indirect Fluorescence Antibody Test (IFAT). Overall, 85 out of 300 animals (28.3%) were seropositive to SFGR. Relatively higher seroprevalence was recorded in sheep than goats (28.8% vs 28.0%) but the difference was not statistically significant (p > 0.05). Furthermore, seropositivity was not affected by age, sex or location of the animals screened in this study. This is the first serological study to report the prevalence of SFGR in sheep and goats using IFAT in this study area. The presence of SFGR antibodies in domestic ruminants is of public health concern considering the close association between farmers and their animals occasioned by the management system practiced in the study area. This finding calls for further studies to evaluate the level of human exposure to this group of pathogen.

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.

Molecular characterization of Capripox viruses obtained from field outbreaks in Nigeria between 2000 and 2016.

Capripox virus infections are endemic diseases of livestock in Nigeria, but there are limited data on molecular characterization of circulating viruses. In this study, we investigated field outbreaks of Capripox virus infections in Nigeria via partial sequencing of viruses obtained from field samples. Eleven selected samples, collected from 2000-2016 from cattle (9), sheep (1) and goat (1) in three states in Nigeria and Capripox virus genome positive by PCR and real-time qPCR, were characterized using our newly developed partial sequencing protocol. This method for genetic characterization of Capripox virus strains allows a first, short molecular classification of strains responsible for the investigated field outbreaks in the country. Phylogenetically, the eight LSDV samples obtained from 2010 to 2016 are closely related to already published strains occurring in Greece and Serbia in the years 2015 and 2016, respectively, whereas the isolate from 2000 shows high similarity to the South African NI-2490 strain. These data indicate that there was a change of LSDV strains circulating in Nigeria between the years 2000 and 2010. The samples isolated from a goat and a sheep in different years seem to be related to already known GTPV strains, but clearly differ from all current published GTPV strains. Interestingly, both newly detected GTPV strains show up to 100% similarity compared to each other and led to clinical disease in sheep and goats. It is long known that some strains of GTPV and SPPV are able to infect both sheep and goats, but in most cases lead to more severe disease in only one of these species. Further genetic characterization of these isolates could provide more insight into pathogenesis and virulence factors of Capripox viruses, especially GTPV and SPPV.

Co-infection of peste des petits ruminants and goatpox in a mixed flock of sheep and goats in Kanam, North Central Nigeria.

Peste-des-petits-ruminants (PPR) and Goat pox (GTP) are two devastating and economically important transboundary animal diseases of small ruminants in Africa and Asia that have been difficult to control. This study however, investigated an outbreak of PPR and GTP in a mixed flock of indigenous sheep and goats in Kanam, North Central Nigeria. A total of nine sera and seven tissues (lungs, spleen, scab and skin) samples were collected and analysed in the laboratory using competitive enzyme linked immunosorbent assay (cELISA) for PPR antibodies and polymerase chain reaction (PCR) for detection of PPR virus (PPRV) and GTP virus (GTPV). Gene fragments of the nucleoprotein of PPRV and the G-protein-coupled chemokine receptor (GPCR) of GTPV were amplified and sequenced to confirm the presence of the causative viruses. Serologically, antibodies to PPRV were detected in all (9/9) sera collected. GTPV and PPRV was detected in corresponding samples (42.8% n = 3/7) of the scab/skin samples collected by both PCR and RT-PCR technique. The phylogenetic analysis of PPRV revealed that the virus belongs to lineage IV and clustered with viruses from Gabon and Cameroon. Similarly, the GTPV also clustered with other sequences from Burkina Faso and Yemen. The positive cELISA, RT-PCR and PCR results from samples collected from the same animals confirmed co-infection of PPR and GTP in this mixed flock of sheep and goats. This is the first report of concurrent infection of PPR and GTP in mixed flock of sheep and goats in Nigeria. Our findings underscore the need for farmers to vaccinate their flock to control spread and economic losses as result of these diseases.

RABIES IN A SET OF EIGHT-WEEK OLD PUPPIES IN NIGERIA: THE NEED FOR REVIEW OF CURRENT DOG ANTIRABIES VACCINATION SCHEDULE.

BACKGROUND: Rabies is endemic in Nigeria with clinical cases reported mainly in dogs and occasionally in livestock from all the geo-ecological zones of the country. Detection of rabies virus antigen in puppies at the age of five to ten weeks and in apparently healthy dogs shedding the virus in their saliva have been reported in some parts of Nigeria. MATERIAL AND METHOD: This report describes a clinical rabies in a set of eight weeks old puppies confirmed by antigen detection using the direct fluorescent antibody test (DFAT), the direct rapid immunohistochemical test (DRIT), and RT-PCR. RESULTS: it was positive for all test used including the RT-PCR which amplified at 750 bp from the gel electrophoresis. CONCLUSION: Occurrence of rabies in puppies of this age, within which they are acquired and owned by other unsuspecting members of the public, is of grave public health consequences. People that love puppies, especially children, who are fond of carrying and playing with them, are also faced with the risk of exposure to rabies. Consequently, review of the existing dog antirabies vaccination schedule at twelve weeks of age in Nigeria, is recommended to ensure effective immunization of this age group of dogs and for the overall safety of the vulnerable members of the public.

Correction to: First confirmation of rabies in Zamfara State, Nigeria-in a sheep.

Unfortunately the Abstract was missing in the original version of this article. The Abstract is published below.

First confirmation of rabies in Zamfara State, Nigeria-in a sheep.

The first case of rabies virus (RABV) infection was identified in Zamfara State Nigeria, in August 2015. A sheep was exposed to RABV consequence of a mad-dog bite. Barely a month after the bite wound had healed-off the sheep owner filed a complaint to Gusau veterinary clinic of observed neurological signs and in-appetence on the animal. Signs suspicious of rabies such as unilateral corneal opacity of the right eye, muscular tremors, hydrophobia and salivation were further observed on clinical examination. Variable-shaped viral antigens were detected from the brain tissues by fluorescent antibody test (FAT), and the presumptive diagnosis of RABV infection was confirmed by a positive FAT result. This report describes ruminant (sheep) rabies, its mode of transmission and subsequent public health implications. Control and prevention of this deadly disease in domestic dogs and livestock need to be stepped up.

Comparative assessment of seller's staining test (SST) and direct fluorescent antibody test for rapid and accurate laboratory diagnosis of rabies.

BACKGROUND: Rabies causes 55, 000 annual human deaths globally and about 10,000 people are exposed annually in Nigeria. Diagnosis of animal rabies in most African countries has been by direct microscopic examination. In Nigeria, the Seller's stain test (SST) was employed until 2009. Before then, both SST and dFAT were used concurrently until the dFAT became the only standard method. OBJECTIVE: This study was designed to assess the sensitivity and specificity of the SST in relation to the 'gold standard' dFAT in diagnosis of rabies in Nigeria. METHODS: A total of 88 animal specimens submitted to the Rabies National Reference Laboratory, Nigeria were routinely tested for rabies by SST and dFAT. RESULTS: Overall, 65.9% of the specimens were positive for rabies by SST, while 81.8% were positive by dFAT. The sensitivity of SST in relation to the gold standard dFAT was 81.0% (95% CIs; 69.7% - 88.6%), while the specificity was 100% (95% CIs; 76% - 100%). CONCLUSION: The relatively low sensitivity of the SST observed in this study calls for its replacement with the dFAT for accurate diagnosis of rabies and timely decisions on administration of PEP to prevent untimely deaths of exposed humans.