Outbreak of highly pathogenic avian influenza subtype H5N8 in two multi-age chicken farms in Jos, Plateau State, Nigeria

An outbreak of highly pathogenic avian influenza (HPAI) subtype H5N8 in two multi-age chicken flocks in Jos, Plateau State, Nigeria, is described. Diagnosis was made using tissue samples from the affected farms that were submitted to the Regional Lab for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom. Pullets with broilers of 9 and 4 weeks of age respectively, from farm A (fA) and broilers, 4 weeks of age from farm B (fB) were submitted from flocks experiencing a drastic increase in mortality. The February 2019 outbreak resulted in10 – 60 % and 60 % mortality on fA and fB respectively. Clinical signs included anorexia, depression, hock sitting and sudden onset of increasing mortality. Gross lesions included edema of the head with cyanosis of comb and wattle; swollen abdomen due to ascites; generalized congestion of visceral organs with frank blood in the abdomen; congested mesenteric vessels with haemorrhages in the mucosa of small and large intestines; congested and frothy lungs with severe hemorrhagic tracheitis among others. In view of the clinical and gross pathology, HPAI was considered as the tentative diagnosis. Diagnosis of HPAI subtype H5N8 was confirmed by reverse transcriptase polymerase chain reaction and viral isolation in embryonated chicken eggs. The current outbreak has shown the presence of HPAI H5N8 in the country different from the H5N1 subtype that was introduced since 2006 in Nigeria. The co-circulation of these two subtypes if the current wave of infection is left unchecked will have adverse effects on poultry production, international trade and human health. Hence, the need for the re-evaluation and strengthening of the Government control policy to save the poultry industry from perennial economic loses.Keywords: Broilers, Highly pathogenic avian influenza (HPAI H5N8), Jos, Nigeria, Outbreaks, Pullet

Clinicopathological features and management of aspergillosis in some poultry farms in Jos metropolis, Nigeria

Aspergillosis is important in poultry production and human health but difficulty in its ante mortem diagnosis in addition to the  unsuccessful outcome of most management options has made the disease a lingering nightmare to farmers. This study presents the clinicopathological features and management of aspergillosis in some poultry farms in Jos metropolis, Nigeria. Thirteen cases of  aspergillosis from 12 poultry farms were confirmed and managed from April, 2019 to March, 2020 with 7.6% cases in a mixed turkey-broiler farm, 15.4% in broilers and 76.9% in layers. The ages affected ranged from 3 weeks to 21 weeks with 69.2% cases in pullet grower birds of 10 – 21 weeks compared to young chicks, 3 – 9 weeks with 30.8%. The rainy season accounted for 61.8% cases while mortality ranged from 1.0% to 17.4%. The clinical features were consistent and included dyspnoea; inappetence; retarded growth and mortality. While necropsy showed consolidated lungs with caseous nodules; liver with raised grayish or yellowish irregular nodules; peritonitis with the peritoneum and air sacs laced with caseous nodules; diphtheritic membrane and caseous nodules on intestinal mucosa; haemorrhagic bursitis with granulomata; caseous nodules on osseous tissues as well as nodules on the skin and skeletal muscles. Confirmatory diagnoses of  aspergillosis were made by culturing nodules on Sabouraud’s Dextrose Agar. Antifungal susceptibility testing showed CuSO4 to be more susceptible which was used at the dosage of 3g/10L of drinking water for at least 7 days in all the cases. Concurrent bacterial infections were seen in some of the cases and were treated concurrently with antibiotics based on susceptibility testing while farmers using moldy feeds were asked to withdraw such feeds. Conclusively, aspergillosis is prevalent in Jos metropolis with severe impact on production and  may be a silent killer disease in poultry due to constraints in diagnosis and its management. Keywords: Aspergillosis, clinicopathological features, Jos, management, Nigeria, poultr

Mortality of Clarias gariepinus caused by Aeromonas caviae and nitrite toxicity in a fish farm

In Nigeria, farming of freshwater fish, mainly that of Clarias gariepinus has gained prominence as means of improved protein supply and livelihood. Many farmers suffer untold losses in their bid to make a living from commercial fish production. Among the major causes of infectious disease outbreaks in fish farms are pathogenic bacteria of the genus Aeromonas. This is a case report of outbreak of Aeromonas caviae infection complicated by nitrite toxicity in Clarias gariepinus. Carcasses of 17 African catfish juveniles and two water samples were presented to the poultry and fish clinic of the Veterinary Teaching Hospital, University of Jos for investigation. The fishes had been on medication (Fish cure antibiotic +®) for over 5 days with cumulative mortality of 230 out of 2,500 fishes (9.2 %). Necropsy was conducted and samples were taken for microbial analysis and histopathology while water samples were subjected to chemical analysis. Gross lesions were broken barbels, cutaneous depigmentation, branchial pallor, ascites, renal and splenic congestion. Histologically, there was dissociation of hepatic cords, necrosis of hepatocytes with vacuolation and mononuclear cellular infiltrations. Also, there was renal tubular epithelial necrosis with mononuclear and heterophilic infiltration while micro abscesses were observed in the brain. Marked Zenker’s necrosis and edema were seen in the skeletal muscles. Organism isolated from livers and kidneys was identified as Aeromonas caviae and was susceptible to enrofloxacin, furaltadone and florfenicol. Nitrite in fish pond water was 1mg/L. Bath medication with enrofloxacin at 33mg/litre of water for 6 hours treatment per day was done to reduce the mortality. The farmer was advised to change the source of water for the fish pond immediately. It is recommended that to avoid losses in fish farming, farmers should check the quality of water intended for use on fish farms and ensure early health check on fingerlings purchased for rearing

Molecular characterization and epidemiology of the highly pathogenic avian influenza H5N1 in Nigeria

Avian influenza caused infection and spread throughout Nigeria in 2006. Carcass samples (lung,liver, spleen, heart, trachea and intestine) from the different regions of Nigeria were processed for virus isolation. Infective allantoic fluids were tested for avian influenza viruses (AIV) and Newcastle disease virus using monospecific antisera. Thirty-five isolates were generated and characterized molecularly using the haemagglutinin gene. The molecular analysis indicated that different sublineages of the highly pathogenic avian influenza (HPAI) H5N1 viruses spread throughout Nigeria. We compared the Nigerian isolates with others from Africa and results indicated close similarities between isolates from West Africa and Sudan. Some of the analysed viruses showed genetic drift, and the implications of these for future epidemiology and ecology of avian influenza in Africa require further evaluation. The spread of primary outbreaks was strongly linked to trade (legal and illegal), live bird markets, inappropriate disposal, and poorly implemented control measures. No strong correlation existed between wild birds and HPAI H5N1 in Nigeria.ARC–Onderstepoort Veterinary Institute, South Africa; The Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria; The Helena Jooste Bursary and National Veterinary Research Institute, Nigeria

Surveillance for African Swine fever in Nigeria, 2006-2009

African swine fever (ASF) has had significant economic and social impact in Nigeria since 1997. However, there has been no effective national response to bring it under control. In this report, we confirm that ASF is still prevalent and widespread in Nigeria. Results from both serosurveillance and virological analyses indicated that ASF is present in most of the agro-ecological zones of the country. Nine per cent (9%) of serum samples and 48% of tissue samples were positive for ASF virus antibody and genome, respectively. Areas with high pig-related activities (marketing, consumption and farming) have higher prevalences compared with areas with less pig activities. Farm-gate buyers, marketing systems and transport of untested pigs within the country assist with the circulation of the virus. Only by putting in place a comprehensive routine surveillance and testing system, reorganizing the market and transportation systems for pigs, implementing on-farm bio-security protocols and considering the option of compensation will it be possible to achieve a significant reduction in ASF prevalence in Nigeria