Qualitative Assessment of the Clinico-Pathological Features of Highly Pathogenic Avian Influenza H5N1 Outbreaks in Commercial Poultry and Peri-Domestic Birds in Northern Nigeria

Abstract

The control of highly pathogenic avian influenza (HPAI) in Nigeria from inception is predicated on effective biosecurity by stamping out policy but outbreaks of the disease continued to re-occur with altered clinico-pathologic manifestations. This study undertook the qualitative assessment of the clinico-pathological features of HPAI H5N1 during the 2021/2022 outbreaks in commercial poultry and peri-domestic birds in northern Nigeria. A total of 22 commercial poultry farms with 53,932 laying chickens and 3 households with 120 backyard broiler chickens, 18 indigenous chickens, 10 peafowls and 9 geese were investigated for HPAI. The clinico-pathologic manifestations observed in commercial poultry were subtle compared to previous presentations of the disease except in the peafowls, geese, broilers and indigenous chickens. The interspecies mortality rates significantly varied from 1.6% to 19.6% for laying chickens and 33.3% to 100% for broilers, indigenous chickens, geese and peafowls. Based on the history of sudden and high mortality, clinical signs and post mortem lesions observed, three diseases; HPAI, very virulent Newcastle disease and fowl cholera were drawn out as differential diagnoses. However, a tentative diagnosis of HPAI was made and samples were sent to the National Veterinary Research Institute, Vom, Plateau State, Nigeria for confirmatory diagnosis. Results of the laboratory tests conducted on the samples using one step flu A screening and duplex real time RT-PCR,

"Pros and Cons of Viral Zoonotic Diseases: A Public Health Nutrition Perspective and Policy Implication in Nigeria"

“…[7]). It can spread to other parts of the world via birds migrating from one region to another and it (H5N1) can even be spread by other animals aside from birds (Ameji, et al [8]). The virus is also transmis-sible from a pregnant woman to her fetus via placenta (Yu,et al [9]) and it does not only affect the lungs but other parts of the body such as brain, liver, blood and gastrointestinal tract.…”