Sample collection
During the period of ASFV outbreaks in northern Vietnam, infected pigs
showed clinical signs of high fever (41 – 42°C), diarrhea, vomiting,
anorexia and reflexes, depression, dyspnea, haemorrhages in the skin,
neurological signs, coma and death. Typical gross findings at the
post-mortem examination were haemorrhagic lesions in multiple organs,
including diffuse haemorrhage in superficial inguinal (Fig 1a),
mandibular, pulmonary, gastrohepatic, renal and mesenteric (Fig 1b)
lymph nodes, in addition to hyperemic splenomegaly with friable
consistency and dark discoloration (Fig 1c), petechial haemorrhage in
the renal cortex, diffuse haemorrhage in the renal pelvis (Fig 1d),
haemorrhage in pericardium and myocardium (Fig 1e, f), swollen liver and
oedema of the gall bladder wall, hemorrhagic cerebral meninges with
oedema and interstitial oedema of the lungs. A blood sample was
collected for real-time polymerase chain reaction (qPCR) work, and
tissue samples from various organs were fixed in 10% neutral buffered
formalin and routinely processed for histopathological examination.
Background information for each pig was tabulated in Table 1.
Ethics statement: The diseased pigs were collected at moribund stage and
humanely euthanized by veterinarians. There was no unnecessary pain
inflicted on the animals because all sampling procedures were conducted
during necropsy.