Prioritization of zoonotic diseases of public health significance in Nigeria using the one-health approach.

Nigeria, with a population of over 190 million people, is rated among the 10 countries with the highest burden of infectious and zoonotic diseases globally. In Nigeria, there exist a sub-optimal surveillance system to monitor and track priority zoonoses. We therefore conducted a prioritization of zoonotic diseases for the first time in Nigeria to guide prevention and control efforts. Towards this, a two-day in-country consultative meeting involving experts from the human, animal, and environmental health backgrounds prioritized zoonotic diseases using a modified semi-quantitative One Health Zoonotic Disease Prioritization tool in July 2017. Overall, 36 of 52 previously selected zoonoses were identified for prioritization. Five selection criteria were used to arrive at the relative importance of prioritized diseases based on their weighted score. Overall, this zoonotic disease prioritization process marks the first major step of bringing together experts from the human-animal-environment health spectrum in Nigeria. Importantly, the country ranked rabies, avian influenza, Ebola Virus Disease, swine influenza and anthrax as the first five priority zoonoses in Nigeria. Finally, this One Health approach to prioritizing important zoonoses is a step that will help to guide future tracking and monitoring of diseases of grave public health importance in Nigeria.

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.

Spatial clustering of pathology submissions during the initial introduction and spread of avian influenza H5N1 in poultry in Nigeria in 2006-2007.

Highly pathogenic avian influenza (HPAI) virus H5N1 spread throughout Nigeria between 2006 and 2007. Bird samples collected across the country were submitted through the free-of-charge (FOC) program to the National Veterinary Research Institute, Vom (NVRI-Vom) laboratory. The present article describes the spatial distributions and evaluated clustering of the FOC submissions from poultry farms at the global, local, and focal levels between 2006 and 2007 epidemic in Nigeria. Spatial statistics evaluating clustering of the FOC submissions were implemented using the Moran's I test, the purely spatial cluster analysis with the SaTScan Poisson model, and the Bithell's linear score test. A significant global clustering of the FOC submissions was observed. Significant local clusters of submissions were observed in the North-East, North-Central, and South-West zones. There was significant decline in FOC submissions with increasing distance from NVRI-Vom. These results indicated that the geographic area of influence of the FOC submission program in Nigeria was limited to regions closer to the diagnostic laboratory. This work provides a detailed insight into the surveillance activities during the HPAI outbreaks in Nigeria, and should assist policy-makers and field veterinarians to improve the effectiveness of national eradication plans in the face of any outbreak of animal diseases.

Evaluating a surveillance system: live-bird market surveillance for highly pathogenic avian influenza, a case study.

INTRODUCTION: Highly pathogenic avian influenza H5N1 was first reported in poultry in Nigeria in February 2006. The only human case that occurred was linked to contact with poultry in a live bird market (LBM). LBM surveillance was instituted to assess the degree of threat of human exposure to H5N1. The key indicator was detection of H5N1 in LBMs. We evaluated the surveillance system to assess its operations and attributes. METHODS: We used the US Centers for Disease Control and Prevention (CDC) updated guidelines for evaluating public health surveillance systems. We reviewed and analyzed passive surveillance data for HPAI (January 2006-March 2009) from the Avian Influenza National Reference Laboratory, and live bird market surveillance data from the Food and Agriculture Organization of the United Nations, Nigeria. We interviewed key stakeholders and reviewed reports of live bird market surveillance to obtain additional information on the operations of the system. We assessed the key system attributes. RESULTS: A total of 299 cases occurred in 25 (72%) states and the Federal Capital Territory (FCT). The system detected HPAI H5N1 virus in 7 (9.5%) LBMs; 2 (29%) of which were from 2 (18.2%) states with no previous case. A total of 17,852 (91.5%) of samples arrived at the laboratory within 24 hours but laboratory analysis took over 7 days. The sensitivity and positive predictive value (PPV) were 15.4% and 66.7% respectively. CONCLUSION: The system is useful, flexible, complex and not timely, but appears to be meeting its objectives. The isolation of HPAI H5N1 virus in some of these markets is an indication that the markets are possible reservoirs of the virus in Nigeria. We recommend that the Federal Government of Nigeria should dedicate more funds for surveillance for HPAI as this will aid early warning and reduce the risk of a pandemic.

Spatio-temporal epidemiology of highly pathogenic avian influenza (H5N1) outbreaks in Nigeria, 2006-2008.

From 2006 to 2008, outbreaks of highly pathogenic avian influenza A (HPAI) virus of the H5N1 subtype occurred among poultry in Nigeria. We described the spatio-temporal patterns of the HPAI H5N1 outbreaks in Nigeria. Data of suspected and laboratory confirmed outbreaks maintained at the National Veterinary Research Institute Vom was analyzed using descriptive and exploratory analyses, GIS mapping, global and local spatial statistical analyses using the Cuzick-Edwards' (C-E) test and SaTScan Space-Time Scan Statistic. A total of 1654 suspected outbreaks were reported from 32 of the 36 States and the Federal Capital Territory (FCT), 299 were confirmed HPAI H5N1 positive from 27 states and FCT. The outbreaks occurred as three distinct epidemic waves with peak periods of January-March mainly in the North-West, North-Central and North-East regions during 2006 and 2007 and July-September in the South-West and South-South regions in 2007. Three spatio-temporal clusters were identified extending across States and international borders, consistent with disease transmission occurring through local and long-distance spread. This calls for enhanced strategies by the states and regional authorities to improve surveillance, prevention and control measures at the states, national and international levels.

Babesia canis and Babesia rossi co-infection in an untraveled Nigerian dog.

A sexually intact 6-month-old female Alsatian dog was presented to the Veterinary Clinic of the National Veterinary Research Institute, Vom, Plateau State, Nigeria, for the following complaints: anorexia, hemoglobinuria, fever, tick infestation and general malaise. Microscopy revealed piroplasms with a wide range of sizes (1-5 µm in length) in red blood cells, raising a suspicion of a co-infection with two or more Babesia species. Specific PCR assays for canine Babesia spp. and DNA sequencing revealed the presence of Babesia canis and Babesia rossi co-infection. This study constitutes the first report of co-infection with B. canis and B. rossi in the West African sub-region and the first report of autochthonous B. canis on the African continent. Practitioners should be aware of potential changes in the species/sub-species of Babesia causing canine babesiosis in this region.

Evolutionary dynamics of multiple sublineages of H5N1 influenza viruses in Nigeria from 2006 to 2008.

Highly pathogenic A/H5N1 avian influenza (HPAI H5N1) viruses have seriously affected the Nigerian poultry industry since early 2006. Previous studies have identified multiple introductions of the virus into Nigeria and several reassortment events between cocirculating lineages. To determine the spatial, evolutionary, and population dynamics of the multiple H5N1 lineages cocirculating in Nigeria, we conducted a phylogenetic analysis of whole-genome sequences from 106 HPAI H5N1 viruses isolated between 2006 and 2008 and representing all 25 Nigerian states and the Federal Capital Territory (FCT) reporting outbreaks. We identified a major new subclade in Nigeria that is phylogenetically distinguishable from all previously identified sublineages, as well as two novel reassortment events. A detailed analysis of viral phylogeography identified two major source populations for the HPAI H5N1 virus in Nigeria, one in a major commercial poultry area (southwest region) and one in northern Nigeria, where contact between wild birds and backyard poultry is frequent. These findings suggested that migratory birds from Eastern Europe or Russia may serve an important role in the introduction of HPAI H5N1 viruses into Nigeria, although virus spread through the movement of poultry and poultry products cannot be excluded. Our study provides new insight into the genesis and evolution of H5N1 influenza viruses in Nigeria and has important implications for targeting surveillance efforts to rapidly identify the spread of the virus into and within Nigeria.

Highly pathogenic avian influenza virus subtype H5N1 in Africa: a comprehensive phylogenetic analysis and molecular characterization of isolates.

Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level.

Reassortant avian influenza virus (H5N1) in poultry, Nigeria, 2007.

Genetic characterization of a selection of influenza virus (H5N1) samples, circulating in 8 Nigerian states over a 39-day period in early 2007, indicates that a new reassortant strain is present in 7 of the 8 states. Our study reports an entirely different influenza virus (H5N1) reassortant becoming predominant and widespread in poultry.

Field and laboratory findings of the first incursion of the Asian H5N1 highly pathogenic avian influenza virus in Africa.

In mid-January 2006 an outbreak of avian influenza in domestic birds was recorded in Kaduna State, Nigeria. The virus responsible for the outbreak was characterized as a highly pathogenic avian influenza H5N1 (A/chicken/Nigeria/641/06), belonging to the Qinghai lineage. The index case occurred on a farm containing mixed avian species including free-range birds. Clinical signs and mortality were observed in chickens, geese and ostriches. The present paper describes the clinical, pathological and virological findings of this outbreak.

The comparative pathogenicity of strains of eight serovars and untypable strains of Mannheimia haemolytica in experimental pneumonia of sheep.

The experimental induction of pneumonic pasteurellosis in groups of conventionally reared lambs by 8 serovars (A1, A2, A6, A7, A8, A9, T10, and A11) and untypable (UT) strains of Mannheimia haemolytica (Mh) were examined and compared. The groups of lambs were inoculated intratracheally with 1.4 x 10(8) +/- 0.6 x 10(8) (mean +/- SD) colony-forming units of the Mh serovars or UT isolates in the 6-hour log phase of growth. The variables measured as indicators of disease severity were clinical score, percentage lung consolidation and microbiological re-isolation. The clinical parameters for each group were computed daily for 6 days post infection and the lambs which died were necropsied while the remaining lambs were killed on day 7 pi and the extent of lung consolidation was measured. Clinically, the mean scores for the M. haemolytica serovars were A1 (6.1), A2 (18.8), A6 (0.5), A7 (17.4) and A9 (8.5). The mean percent lung lesion scores for M. haemolytica serovars were A1 (12.5), A2 (66.3), A6 (5.0), A7 (51.3), A9 (33.8) and A11 (2.5). The percent mean pneumonic lung lesions recorded for groups inoculated with A2, A7 and A9 were significantly (P < 0.05) higher than the extent of lung lesions in the other groups. A statistically significant correlation was observed between clinical scores and the severity of the lung lesions (r = 0.96, P < 0.01). High titres of M. haemolytica were recovered from lung lesions, with 10 to 100 times the number of organisms inoculated being present in the lung lesions of lambs inoculated with serovars A2 and A7. These data indicate that although M. haemolytica serovars A1, A2, A6, A7, A9 and A11 are important primary lung pathogens of lambs, serovars A2, A7, and A9 are to be regarded as highly virulent strains that have a greater predilection than the other serovars for causing pneumonia in lambs.