Seroprevalence and the determinants of lumpy skin disease virus (LSDV) in cattle reared under smallholder production systems in northwestern Bangladesh.

Lumpy skin disease (LSD) is a vector-borne transboundary disease that causes substantial productivity losses in cattle. This study was undertaken to determine the seroprevalence of LSD and the associated determinants of non-vaccinated cattle reared in smallholder production systems of northwestern Bangladesh. A cross-sectional study was conducted from November 2024 to January 2025 covering ten districts where a total of 450 non-vaccinated cattle were sampled across 100 smallholder farms. Sera were tested for LSDV-specific antibodies using a commercial ELISA kit test and thereafter risk-factors determined using a structured questionnaire. The overall on-farm seroprevalence was 95% (95% CI: 88.80-97.80). Previous history of clinical LSD on the animals was the strongest predictor of seropositivity 89.3% (OR = 8.1, p = <0.001, 95% CI = 3.44-19.1). Age was also strongly associated with seropositivity (p < 0.001), with at 47.7% (95% CI: 40.3-55.1) among cattle aged ≤ 1 year to 78.6% (95% CI = 70.8-84.8) among those aged > 3 years. A significant difference in seroprevalence was similarly observed in cows 66.8% (95% CI = 61.6-71.6) compared to bulls 52.7% (OR = 0.56; p = <0.001, 95% CI = 0.35-0.87). Indigenous cattle recorded a lower seropositivity of 56.8% (95% CI = 50.2-63.2) than Holstein-Friesian crossbreds 71.2% (OR = 0.43, p = <0.001, 95% CI = 0.31-0.58). It is concluded that LSDV exposure was widespread among cattle of the northwestern districts of Bangladesh and a history of previous infection with LSD was as the main determinant of seropositivity. Risk-based control strategies such as the vaccination of young cattle, control of vectors and producer training need to be considered.