Zoonotic fungal diseases and animal ownership in Nigeria

Background: The growing interest in keeping animals as pets in Nigeria and other resource-poor countries highlights the possibility of transmission of zoonotic infections to humans. These zoonoses which are usually caused by viruses, bacteria, parasites and fungi, are naturally transmitted to humans, causing various degrees of morbidity and mortality with attendant economic and or public health consequences.Materials and method: In the present review, a computerized search of existing literature was conducted using the Google search engine and PubMed electronic database to identify and download relevant publications on zoonotic fungal infections in Nigeria. The key words used were zoonotic fungal disease and Nigeria while the Boolean operator ‘AND’ was used to combine and narrow the searches. Additional information was obtained by searching the medical and veterinary libraries for journals not listed in the database. The available publications were thereafter reviewed and findings qualitatively described.Results: Our findings revealed that fungal diseases with zoonotic potential lack sufficient attention in Nigeria. This suggests that fungi are yet to be considered as major causes of morbidity and mortality in animals and humans in Nigeria, and may account for the few reports available on zoonotic fungal diseases in the country.Conclusion: There is a need to raise awareness of the extent of health problems caused by zoonotic fungal diseases in Nigeria in order to better appreciate their burden and public health consequences, and also provide an integrated platform for development of effective prevention and control strategies.Keywords: Zoonoses, Fungal disease, Humans, Animals, Nigeri

Serologic Evidence of Exposure to West Nile Virus among Humans in Ibadan, Southwestern Nigeria

Background: Cases of fever without diagnoses of malaria and/or typhoid are usually regarded as undifferentiated febrile illness (UFI) in Nigeria. We studied the contribution of WNV (an arbovirus) to UFI in humans in southwestern Nigeria.Materials and methods: Sera from 188 consenting humans visiting two health care facilities in Ibadan, and 25 horse grooms from Lagos and Ibadan were screened for WNV antibodies by cELISA and a subset by PRNT. Pertinent demographic/clinical data were collected and blood samples screened for Plasmodium spp, Salmonella typhi and S. paratyphi antibodies. Student’s t-test and binary logistic regression were used for data analysis.Results: Overall, 156 participants (73.2%, 95% CI: 67.3-79.2 [n=213]) were positive for WNV antibodies. Being clinically ill was associated (p=0.001) with WNV seropositivity while “active” and “non-active” participants had comparable (p=0.21) seroprevalence of 74.6% and 62.5%, respectively. Forty-five percent (18/40) of febrile participants had WNV antibodies only, thereby accounting for UFI. The 18-66 year olds had higher (75.8%) seroprevalence than those ≤ 17 years (47.4%) while seropositivity obtained for the horse grooms (56.0%) was significantly lower than for the remaining 188 individuals (75.5%). Participants were mostly exposed to WNV (75.5%) than Plasmodium (33.5%) and S. typhi (39.9%) while PRNT showed that 10.5% of tested humans had protective WNV antibodies.Conclusions: This study revealed serologic evidence of exposure of the participants to WNV and contribution of the virus (or related flaviviruses) to UFI in the study area. High prevalence of the antibodies indicates endemicity of southwestern Nigeria for WNV.Key words: Humans, anti-WNV antibody, prevalence rate, undifferentiated febrile illness, southwestern Nigeria

Analysis of Culex and Aedes mosquitoes in southwestern Nigeria revealed no West Nile virus activity

Introduction: Amplification and transmission of West Nile virus (WNV) by mosquitoes are driven by presence and number of viraemic/susceptible avian hosts. Methods: in order to predict risk of WNV infection to humans, we collected mosquitoes from horse stables in Lagos and Ibadan, southwestern Nigeria. The mosquitoes were sorted and tested in pools with real-time RT-PCR to detect WNV (or flavivirus) RNA using WNV-specific primers and probes, as well as, pan-flavivirus-specific primers in two-step real-time RT-PCR. Minimum infection rate (MIR) was used to estimate mosquito infection rate. Results: Only two genera of mosquitoes were caught (Culex, 98.9% and Aedes, 1.0%) totalling 4,112 females. None of the 424 mosquito pools tested was positive for WNV RNA; consequently the MIR was zero. Sequencing and BLAST analysis of amplicons detected in pan-flavivirus primer-mediated RT-PCR gave a consensus sequence of 28S rRNA of Culex quinquefasciatus suggesting integration of flaviviral RNA into mosquito genome. Conclusion: While the latter finding requires further investigation, we conclude there was little or no risk of human infection with WNV in the study areas during sampling. There was predominance of Culex mosquito, a competent WNV vector, around horse stables in the study areas. However, mosquito surveillance needs to continue for prompt detection of WNV activity in mosquitoes.Pan African Medical Journal 2016; 2

Plantibodies in human and animal health: a review.

Background: Antibodies are essential part of vertebrates\u2019 adaptive immune system; they can now be produced by transforming plants with antibody-coding genes from mammals/humans. Although plants do not naturally make antibodies, the plant-derived antibodies (plantibodies) have been shown to function in the same way as mammalian antibodies. Methods: PubMed and Google search engines were used to download relevant publications on plantibodies in medical and veterinary fields; the papers were reviewed and findings qualitatively described. Results: The process of bioproduction of plantibodies offers several advantages over the conventional method of antibody production in mammalian cells with the cost of antibody production in plants being substantially lesser. Contrary to what is possible with animal-derived antibodies, the process of making plantibodies almost exclusively precludes transfer of pathogens to the end product. Additionally, plants not only produce a relatively high yield of antibodies in a comparatively faster time, they also serve as cost-effective bioreactors to produce antibodies of diverse specificities. Conclusion: Plantibodies are safe, cost-effective and offer more advantages over animal-derived antibodies. Methods of producing them are described with a view to inspiring African scientists on the need to embrace and harness this rapidly evolving biotechnology in solving human and animal health challenges on the continent where the climate supports growth of diverse plants

POSSIBLE MECHANISMS UNDERLYING BACTERIAL-VIRAL INTERACTIONS IN RESPIRATORY DISEASES: A REVIEW

Background: Respiratory diseases are frequent and economically significant problems in both humans and animals. The potential losses resulting from decrease in average daily gain and feed efficiency, as well as the cost of preventing or treating these diseases are substantial. Although synergistic relationships between bacteria and viruses have been documented to aggravate these diseases, the pathogenic mechanisms remain poorly understood. Materials and method: For this review, PubMed and Google search engines were used to select about 45 publications on bacterial-viral interactions in respiratory conditions. Studies on animal models were also included in the review. The publications were compared and summarized using a narrative review approach and findings were described qualitatively. Results: Respiratory diseases are exacerbated by interactions between bacteria and viruses in both humans and animals. Possible mechanisms underlying this synergism were found to include, among others, increased bacterial adherence due to viral infection, reduction of mucociliary clearance, diminished chemotaxis, immature phagocytes and decreased surfactant levels. Conclusion: Interactions between bacteria and viruses make management of respiratory diseases difficult. However, exploration of the highlighted mechanisms responsible for this synergism in the development and production of novel antimicrobials and vaccines against these pathogens is crucial to improving management, prevention and control of respiratory infections. This may be particularly beneficial in this era of increasing antibiotic resistance

Identification of a Putative Novel Genotype of Avian Hepatitis E Virus from Apparently Healthy Chickens in Southwestern Nigeria

Avian hepatitis E virus (aHEV) is the major etiological agent of hepatitis-splenomegaly syndrome (HSS), big liver and spleen disease (BLSD), and hepatic rupture hemorrhage syndrome (HRHS) in chickens. Infections with aHEV cause a significant decrease in egg production and increased mortality in chickens worldwide. However, studies on the prevalence of aHEV in Nigeria are scarce. In this study, serum (n = 88) and fecal samples (n = 110) obtained from apparently healthy layer chickens from three states in southwestern Nigeria were analyzed by nested reverse transcription-polymerase chain reaction (nRT-PCR) targeting the helicase and capsid gene for the presence of aHEV. Avian HEV was detected in 12.5% (n = 11/88) of serum samples and 9.1% (n = 10/110) of fecal samples tested. Phylogenetic analysis showed that five of the twelve identified aHEV sequences belonged to genotype 2. The remaining seven sequences were only distantly related to other known aHEV isolates. After amplification of the near-complete ORF2 fragment (1618 bp) and part of the ORF1 (582 bp) of isolate YF40_aHEV_NG phylogenetic analysis revealed a nucleotide sequence identity between 79.0 and 82.6% and 80.1 and 83.5%, respectively, to other known aHEV strains, indicating that the Nigerian isolate YF40_aHEV_NG belongs to a novel aHEV genotype. This is the first report of co-circulation of aHEV genotypes in chickens in Nigeria.Peer Reviewe

ANTIBIOTIC RESISTANCE PROFILING AND MICROBIOTA OF THE UPPER RESPIRATORY TRACT OF APPARENTLY HEALTHY DOGS IN IBADAN, SOUTH WEST NIGERIA.

Background: Rearing of dogs and other pets has become increasingly popular in modern society. Bacterial flora resides within the nasal and oral cavities of dogs and when chanced, can be pathogenic. Certain similarities between humans and dogs portends dangerous behavioral habits that could lead to zoonotic disease transmission. This study was aimed at isolation, identification and antibiotic profiling of bacteria from nasal swabs of apparently healthy dogs. The zoonotic risk was also considered. Methodology: A total of 173 nasal swabs were collected from 173 apparently healthy dogs. Structured questionnaires were administered to investigate human behavioral habits. Results: Two hundred and twenty two (222) bacterial isolates were obtained from the culture with ten (10) potentially pathogenic bacteria in the order of Escherichia coli (18.5%), Proteus species (17.1%), Staphylococcus aureus (14.0%), Klebsiella species (9.0%), Acinetobacter species (9.0%), coagulase negative Staphylococcus species (7.7%), Pseudomonas species (6.8%), Actinobacter species (6.8%), Citrobacter species (5.9%) and Streptococcus species (5.4%). Overall, the Gram negative isolates showed resistance to ciprofloxacin (9.3%), sparfloxacin (16.0%),perfloxacin (17.3%), ofloxacin (21.6%), chloramphenicol (34..6%), gentamycin (36.4%), streptomycin (37.%), septrin (49.4%), amoxillin (59.3%), augmentin (62.3%) while the Gram positive bacteria showed resistance to ciprofloxacin (3.3%), perfloxacin (6.7%), erythromycin (13.3%), streptomycin (21.7%), rocephin (28.3%), septrin (28.3%), gentamycin (36.7%), zinnacef (68.3%), ampiclox (81.7%) and amoxillin (85.0%). Multi-drug resistance (MDR) to three or more antimicrobials was observed in some of the isolates. Seventy - seven resistance patterns were observed, 16 in Gram positive and 61 in Gram negative bacteria. Conclusion: This study revealed MDR to two or more antimicrobials in all the isolates. These can pose antibiotic resistance challenges in situation of primary or secondary canine respiratory infections. Also, this study revealed that 82% of the dog owners/ lovers had less than 50cm face-to-face contact with these dogs while playing with them, thus increasing their chances of acquiring MDR bacteria from apparently healthy dogs

Detection and characterization of chicken astrovirus associated with hatchery disease in commercial day‑old turkeys in southwestern Nigeria

Publication history: Accepted - 25 January 2021; Published - 23 March 2021.Infectious diseases are a major obstacle to profitable poultry production in Nigeria due to the mortality and severe economic losses they cause. In particular, they are a potent threat to attainment of the food security goals of government and national self-sufficiency in food production. Thus, there is a need for continuous monitoring of the nation’s poultry population for these diseases. As part of an ongoing investigation of enteric viruses associated with poor performance or hatchery diseases in commercial poultry in southwestern Nigeria, intestinal contents from 97 condemned or runted day-old commercial turkey poults were examined for turkey astroviruses, infectious bronchitis virus, chicken astrovirus (CAstV), avian nephritis virus, avian rotavirus, avian reovirus, fowl adenovirus, and chicken parvovirus by virus isolation, electron microscopy (EM), polymerase chain reaction (PCR), and reverse transcription PCR. The samples were collected from five commercial hatcheries and five farms located in southwestern Nigeria. While all samples tested negative for other viruses, CAstV was detected in the majority (83.5%) of the birds, although some pleomorphic virus-like particles with surface projections that appeared fringed or fimbriated were observed in five of the cell culture samples by EM. Phylogenetic analysis revealed these CAstV strains belonged to the Bi clade. These findings not only implicate CAstV as the major cause of hatchery condemnations in commercial turkeys in southwestern Nigeria but also highlight the need for experimental studies to further establish its role in this disease condition

Investigation of Enteric Viruses Associated With Runting and Stunting in Day-Old Chicks and Older Broilers in Southwest Nigeria

Publication history: Accepted - 2 July 2019; Published - 16 July 2019Enteric viruses are known to have significant economic impact on poultry, especially broiler chicken flocks, because of production losses attributable to poor feed conversion and weight gain. To sustain the Nigerian poultry industry that contributes significantly to the livestock sector of the economy, there is a need to investigate commercial broiler flocks in the country for the presence of enteric viruses causing runting and stunting, growth retardation, and hatchery diseases. Gut contents were collected from 158 day-old and six 14-week old runted/stunted broiler chickens in commercial farms (ten) and hatcheries (six) located in Southwest Nigeria. The samples were examined for the presence of chicken astrovirus (CAstV), avian nephritis virus (ANV), avian rotavirus (AvRV), chicken parvovirus (ChPV), and turkey astroviruses (TAstV-1 and−2) by polymerase chain reaction (PCR) and reverse transcriptase-PCR (RT-PCR) whereas avian reovirus (ARV) and fowl adenovirus (FAdV) by virus isolation (VI), RT-PCR, and PCR. While CAstV was detected in all the birds (100%), sporadic detection of ANV (5%), and ChPV (5%) was observed in day-old and/or older birds. Four isolates were obtained by VI with one isolate being ARV positive and other three FAdV positive by RT-PCR and PCR, respectively. These findings strongly suggest CAstV as a major cause of runting and stunting as well as hatchery condemnations in commercial broilers in Southwest Nigeria, although co-infections with ANV, FAdV, ARV, and ChPV cannot be ruled out. In addition, the possible vertical and horizontal transmissions of these viruses are discussed