Postmortem and Histopathological Findings in a High-Mortality Outbreak at Rangamati Pig Farm: Assessing the Potential of “African Swine Fever’’

Abstract

In November 2023, an outbreak of high mortality among pigs was reported at the Pig Development Farm in Rangamati Sadar, Rangamati District, Bangladesh, housing approximately 400 pigs. The outbreak was characterized by sudden high mortality in young pigs following convulsions and the adults also presents with off-feed behavior, dehydration, weakness, and eventual mortality. A detailed postmortem and histopathological evaluation were conducted on an adult pig submitted to the Department of Pathology and Parasitology at Chattogram Veterinary and Animal Sciences University. Gross pathological findings included severe hemorrhagic lesion in skin and subcutaneous muscle, splenomegaly, extensive hemorrhagic lymphadenopathy, petechial hemorrhages in multiple organs, pulmonary edema, and hepatic congestion. Histopathological examination also revealed lymphoid depletion, thrombosis, necrosis, and diffuse hemorrhages in lymph nodes and spleen; alveolar edema and necrotizing bronchopneumonia in the lungs; necrosis of Kupffer cells in the liver; and renal hemorrhages with tubular necrosis in the kidneys. The observed pathological features, particularly the combination of severe hemorrhagic splenomegaly, lymphadenopathy, and disseminated intravascular coagulation-like changes, strongly align with African swine fever (ASF). Given Bangladesh's proximity to ASF-endemic regions such as India and Myanmar, the diagnosis raises serious concerns about the spread and management of ASF. While similarities in gross and histopathological findings with classical swine fever (CSF) may lead to diagnostic challenges, the presence of hallmark features such as severe hemorrhagic splenomegaly and lymph node necrosis is indicative of ASFV infection. This report underscores the necessity for robust surveillance, precise diagnostic tools, and stringent control strategies to address this emerging threat in Bangladesh.