Sero-Detection of Avian Influenza A/H7 in Nigerian Live-Bird Markets in Plateau State

Avian influenza has been reported in domestic birds in Nigeria since 2006 and subtype H5 of the Gs/Gg lineage has continued to be detected up till date. It has been suggested that waterfowls and local birds sold in live-bird markets may be natural reservoir and source of reinfection of different subtype of avian influenza in poultry farms. This study aims at serodetection of avian influenza virus in waterfowls and local birds at live-bird markets in Plateau State, Nigeria. A total of three hundred and nine (309) blood samples were  collected over a period of three months and two hundred and ninety-two (292) sera were analysed by c-ELISA for influenza A nucleoprotein using standard protocols. Haemagglutination Inhibition (HI) specific for subtypes H5, H9, and H7 was also carried out using standard protocols on ELISA positive samples. The results showed seroprevalence of 5.14% (n=15) for influenza A. Serotype H7 was thereafter detected by HI in 5 of the 15 influenza A positive samples. The H7 positive sera also reacted with H7N3, H7N4, H7N1 and H7N7 virus strains with HI titre ranging between 1:32 to 1:512. This investigation for the first time showed serological evidence of influenza A subtype H7 in local birds and waterfowls sold at the live bird market in Nigeria. Further virological surveillance to isolate the virus is important in order to better understand influenza virus epidemiology in Nigeria and the potential risk that other subtypesof influenza poses to poultry production and public health. Keywords: Influenza A, subtype H7, serological detection, live bird market, Nigeria

Effect of methanolic stem bark extract of Azadihiracta Indica on morbidity and mortality of chickens experimentally infected with velogenic Newcastle disease virus (kudu 113)

Newcastle Disease (ND) is a dangerous disease of poultry all over the world. Economically, ND is characterized by mortality which may reach up to  100% in affected poultry farms. This study was designed to evaluate the protective properties of crude methanolic extract of Azadihiracta indica in chickens experimentally infected with a velogenic strain of ND virus. A hundred- day old cockerel was brooded for three weeks before randomly  divided into five equal groups (I, II, III, IV and V). They were not vaccinated with ND vaccine LaSota. At six weeks of age, each bird in groups I-IV was inoculated with 0.2mL of the live ND viral inoculum intramuscularly while group V was not inoculated with the virus. Thereafter, groups I, II and III were daily given in drinking water 200mg/kg, 400mg/kg and 600mg/kg of Azadihiracta indica extract, respectively whereas, groups IV and V were not treated with the extract. All the groups were monitored for the onset of clinical signs, morbidity and mortality rate. In all the groups inoculated with the ND virus, about 80% birds showed signs of depression, gasping, coughing, increased thirst, complete inappetence, huddling, diarrhoea, partial/complete paralysis on day 2 post inoculation (PI). A hundred percent (100%) mortality rate was recorded for groups I and IV by day 5 PI and  in groups II and III on day 6 PI. Therefore, under the conditions of this study, oral administration of Azadihiracta indica extract does not protect birds from ND. Keywords: Azadihiracta indica stem bark; methanolic extract; chickens; Newcastle diseas