Characterization of Lumpy Skin Disease in Northern Bangladesh: Clinical, Pathological, Biochemical, and Molecular Perspectives

Abstract

Lumpy skin disease (LSD) is an economically important disease of cattle, considered as a threat to the livestock industry. This study aimed to assess the clinical symptoms, gross pathology and histopathology, serum biochemical values, and molecular characterization of LSD in cattle. Cattle in Dinajpur, Thakurgaon, Nilphamari, and Rangpur affected by LSD were initially diagnosed through clinical signs and gross lesions. Blood samples were then collected for biochemical analysis and molecular detection through PCR, and sequencing was performed to characterize the LSD virus (LSDV). The prevalence of LSD in northern areas of Bangladesh was 33.44%. The recorded clinical signs were high fever; firm, raised skin nodules around the head, neck, and limbs; swelling of the limbs and brisket area; and rough hair coat, nasal discharge, dyspnea, corneal opacity, and severe weakness. Grossly, a well-defined, hard swelling of around 1-3.00 cm in diameter in the skin accompanied enlargement of the nearby lymph nodes, and the nodules are composed of a hard, creamy-gray, or yellow clump of the tissue. Histopathologically, ballooning degeneration of the epidermal cell layers, intracytoplasmic eosinophilic inclusion bodies in distinct dermal and epidermal cells, necrosis with substantial infiltration of inflammatory cells, and congested blood vessels in the dermal layer were noted. While total protein, BUN, serum AST, and ALT were increased significantly (p < 0.05), the serum creatinine, GGT, and total albumin were not changed significantly compared with the healthy cattle. Phylogenetic analysis showed that the circulating isolates from northern part of Bangladesh were found in the same clades with India, Pakistan, and Thailand. Thus, this study provides crucial findings on this emerging disease, including its gross and histopathology, serum biochemical properties, and molecular epidemiology in the northern regions of Bangladesh.

Keywords: clinical signs; gross pathological; histological; phylogenic tree; serum biochemical.

Figure 1

Clinical presentation of LSD in cattle. (a) Nodule formation in the whole body of the cattle. (b) Nodules are smaller in size in the early days of infection. (c) Nodules are circumscribed, firm, raised areas with 1–3 cm in diameter. (d) Nodules are necrosed, heading to wounds and occasionally sloughing off.

Figure 2

Histopathological lesions of LSDV-affected cattle skin (H&E stain). (a) Acanthosis and vacuolation of the epidermis; (b) epidermal and follicular hyperplasia; (c) ballooning degeneration of the keratinocytes; (d, e) mononuclear cell infiltration in the dermis; (f) vasculitis with perivascular mononuclear cell infiltration; (g) dilation of the sebaceous gland; (h) intracytoplasmic eosinophilic inclusion bodies.

Figure 3

PCR amplification of lumpy skin disease virus. Well 1 contains a DNA ladder, Wells 2–6 contain different samples, and Well 7 contains negative control. LSDV DNA is shown at 203 bp by using a 100-bp DNA ladder.

Figure 4

Phylogenetic analysis of GPCR gene sequences obtained from northern Bangladesh (red triangle) with other Capri pox viruses.

Figure 5

Phylogenetic analysis of P32 gene sequences obtained from northern Bangladesh (red triangle) with other Capri pox viruses.