Outbreak of lumpy skin disease in a dairy farm in Keffi, Nasarawa State, Nigeria

Abstract

A dairy farm in Keffi, Nasarawa State, North Central Nigeria reported cases of skin infections in cattle suggestive of lumpy skin disease (LSD) in the years 2014 and 2016. During the 2016 outbreak, skin biopsies were collected for laboratory investigation using histopathology and polymerase chain reaction (PCR). The samples were subjected to PCR using two sets of primers which amplified the G-protein-coupled chemokine receptor (GPCR) gene and RNA polymerase subunit gene (RPO30) of the LSD virus (LSDV). Clinical signs observed in the two outbreaks were similar and included ocular and nasal discharges, nodular skin lesion, and pyrexia and reduced milk production. Morbidity rate was 6.25% (25/400) in 2014 and the mortality rate was 2.5% (10/400). Furthermore, the second outbreak in 2016 had morbidity and mortality rates of 5% (20/400) and 0.5 % (2/400) respectively. From animals that died in the 2014 outbreak, necropsy findings included nodular lesions on the skin, muzzle, in the buccal cavity and nasal mucosa. Also, congested and oedematous lungs and enlarged lymph nodes were observed. The nodular skin lesions observed during the 2016 outbreak were larger and more numerous in the Sokoto Gudali, while the Holstein Friesian cross had smaller gross skin nodules with acute to sub-acute histopathologic changes. The histopathological examination of the skin biopsy of the HF was consistent with LSD viral lesions, while PCR detected the RPO30 and GPCR gene fragments of LSDV.

Keywords: Dairy, histopathology, Lumpy skin disease, polymerase chain reaction, Nigeria