Seroprevalence and Detection of Avian Influenza Type A in Ducks at Nikli and Bajitpur Upazila of Bangladesh

Abstract

Waterfowl are the natural reservoir of avian influenza viruses and ducks may play a role in the maintenance of avian influenza type A. The aim of the present study was to investigate the seroprevalence and detection of avian influenza virus (AIV) type A in duck. This study was carried out during July 2013 to December 2013 on AIV type A from semi-scavenging farm at Nikli and Bajitpur upazila of Kishoregonj district in Bangladesh. A total of 368 blood samples were collected from duck and tested by indirect ELISA for seroprevalence. For detection of AIV type A, The cloacal swabs were collected from 75 duck and subjected to RNA extraction and real time RT-PCR (rRT-PCR) with specific primer and probe for detection of matrix (M) gene. The average seroprevalance of AIV type A in seven different age groups was found to be 90.21%. The highest (25.81 %) seroprevalence was found in 5 months age of birds and the lowest (2.44 %) was found in 12 months age of birds. As regard to area distribution, the average degree of seroprevalence was 93.51% from Nikli had the highest order than Bajitpur (86.88%) upazila of Bangladesh. In case of cloacal sample by using rRT-PCR, out of 15 pooling cloacal samples, two pooling samples (13.33%) that contain 10 samples were positive and 13 pooling samples showed negative (86.67%) for AIV type A in duck. It can be concluded that the long distance movement of duck flocks, may influence outbreak of avian influenza virus (AIV) type A among different poultry species in Bangladesh. Therefore, it needs to develop control strategy for future dissemination of AIV in duck population.

Prevalence and Distribution of Avian Influenza Viruses in Domestic Ducks at the Waterfowl-Chicken Interface in Wetlands

“…High AI seroprevalence (63.8%) in ducks at an individual level was recorded in the present study, which is similar to a previous study (55.6%) conducted in the northeastern and western parts of Bangladesh [ 41 ]. Variable individual level of AI seroprevalence was previously reported to be 15–90.2% in Bangladesh [ 8 , 9 , 13 , 14 , 42 ]. Complex production systems involving household ducks and rice production are likely to be important epidemiological factors for the maintenance and spread of IAVs, which might explain the existing high AI seroprevalence in the study sites [ 43 ].…”

“…In earlier published data, AI seroprevalence in household and free-range ducks in various regions of Bangladesh was found to be 30–90.2% [ 8 , 9 , 13 , 14 ]. AI viral prevalence in the same populations was reported to be 24–89%, irrespective of subtype [ 15 , 16 ].…”

“…HPAI H5N1 subtype was reported in ducks in live bird markets of Bangladesh since 2007 [ 11 ]. The country does not have a formal health information system for duck rearing [ 13 ] and very few studies have explored the risk factors associated with IAVs in Bangladesh [ 17 , 18 , 19 ]. Notably, no data are available about the investigations of AI serological and viral prevalence with associated risk factors in ducks in different rearing systems in Haor areas of Bangladesh.…”

“…The large water bodies serve as a site for intermingling between free-range ducks and wild waterfowl populations, resulting in the transmission of IAVs [ 27 ]. For the farmers’ families, it is a common practice to share dwelling places with ducks and chickens [ 13 ] and such close proximity between humans and avian species may results in the emergence of novel IAV strains of pandemic potential circulating between humans, ducks and chickens.…”