First report of acute African swine fever in pig farms on the west coast of India: pathological and molecular insights

Figure 1. Map of Goa, a state on the west coast of India, showing the locations of affected pig farms (red dots).

Figure 2. (A) ASF-affected local and crossbred pigs from farm A showing signs of huddling, lethargy, weakness, and cyanosis of the ears and snout (arrow). (B) ASF-affected crossbred pig from farm A showing scattered, variably sized black hemorrhagic spots (arrow) on the skin of the inguinal region and abdomen. (C) ASF-affected crossbred pig from farm A showing severe red discoloration of the abdominal skin (arrow). (D) ASF-affected Large White Yorkshire pig from farm B showing severe and widespread subcutaneous hemorrhages all over the body.

Figure 3. (A) Spleen of pig 1 showing splenomegaly, severe congestion, and dark-colored areas of infarction (arrow). The enlarged, dark red, diffusely congested liver is also visible. (B) Spleen of pig 2 showing multifocal, raised dark areas of infarction (arrow) and hemorrhages on the splenic surface (arrow). (C) Kidney of pig 1 showing severe diffuse congestion and hemorrhagic patches. (D) Cut section of the same kidney showing severe congestion and dark red blood clots in the renal pelvis (arrow). (E) Enlarged, dark, congested liver of pig 2. The enlarged heart with hyperemic blood vessels is also visible (arrow). (F) Lung of pig 2 showing edema, congestion, and petechial hemorrhages (arrow).

Figure 4. Histopathological lesions in ASF-infected pigs. (A) Spleen showing severe hyperemia with abundant red blood cells in the red pulp and severe lymphoid depletion with atrophy of the lymphoid follicle (arrow) in the white pulp (H&E stain, × 100). (B) Kidney showing hyperemia of the capillary tufts, necrosis, and marked reduction in Bowman’s space in a glomerulus (white arrow), along with a globally sclerotic (obsolescent) glomerulus (black arrow). An area of severe hyperemia and hemorrhage within the intertubular spaces is also visible on the right (H&E stain, × 200). (C) Kidney showing severe hyperemia and hemorrhage in the interstitial (white arrow) and glomerular capillaries (black arrow) (H&E stain, × 200). (D) Liver showing dilatation and congestion of central veins and sinusoidal capillaries, along with necrotic and degenerative changes in hepatocytes. Also note perivascular lymphocyte infiltration and the presence of cellular debris and erythrocytes within the central vein (arrow) (H&E stain, × 200). (E) Lung showing thickened alveolar wall due to mononuclear cellular infiltration and hemorrhages in the septa (H&E stain, × 100). (F) Trachea showing moderate infiltration of…

Figure 5. Phylogenetic analysis based on partial p72 gene sequences of ASFV from two farms in Goa, India (triangle mark), and other ASFV reference sequences obtained from NCBI Genbank. The country name is followed by the year of outbreak and GenBank accession number. Multiple sequence alignments were performed using the Clustal W tool in MEGA12, and a phylogenetic tree was constructed using the Neighbor-Joining method with the Tamura–Nei model and 1,000 bootstrap replicates.

Figure 6. Phylogenetic analysis based on partial p72 gene sequences of ASFV from two farms in Goa, India (triangle mark), and other ASFV reference sequences obtained from NCBI Genbank. The country name is followed by the year of outbreak and GenBank accession number. Multiple sequence alignments were performed using the Clustal W tool in MEGA12, and a phylogenetic tree was constructed using the maximum likelihood method with the Tamura–Nei model and 1,000 bootstrap replicates.

Figure 7. Phylogenetic analysis based on the E183L gene encoding p54. Sequences of ASFV from two farms in Goa, India (triangle mark), were compared with other ASFV reference sequences obtained from NCBI Genbank. The country name is followed by the year of outbreak and GenBank accession number. Multiple sequence alignments were performed using the Clustal W tool in MEGA12, and a phylogenetic tree was constructed using the Neighbor-Joining method with the Tamura–Nei model and 1,000 bootstrap replicates.

Figure 8. Phylogenetic analysis based on the E183L gene encoding p54. Sequences of ASFV from two farms in Goa, India (triangle mark), were compared with other ASFV reference sequences obtained from NCBI Genbank. The country name is followed by the year of outbreak and GenBank accession number. Multiple sequence alignments were performed using the Clustal W tool in MEGA12, and a phylogenetic tree was constructed using the maximum likelihood method with the Tamura–Nei model and 1,000 bootstrap replicates.