National seroprevalence and risk factors of bluetongue virus in domestic ruminants in Peru

Abstract

Bluetongue virus (BTV) is a global infection primarily transmitted among domestic and wild ruminant populations through Culicoides spp. midges. Infection is highly prevalent across temperate and tropical regions; however, significant changes in the global distribution of BTV have been observed in recent years. We aimed to evaluate the national BTV seroprevalence and its risk factors among domestic ruminants (cattle, sheep and goats) in Peru. Ruminant sera (cattle= 3 452, sheep= 2 786 and goats=1 568) were collected using a random, two-stage clustering method and analyzed by c-ELISA. The national BTV seroprevalence was 12.7% (95% CI: 11.00-14.63%) and the seropositivity rate for each species was 19.29% (95% CI: 16.0%–31.1%) in cattle, 8.4 (95% CI: 6.6%–10.5%) in sheep, and 9.2% (95% CI: 5.6%–14.8%) in goats. Bivariate and multiple logistic regression analysis were used to evaluate risk factors for BTV seropositivity and to estimate Odds Ratios (OR) with 95% CI. We found that age, altitude, and maximum temperature were identified as crucial factors influencing the prevalence of BTV seroprevalence in cattle, sheep and goats. Older animals, particularly cattle and goats between 6 and 24 months and above 24 months, exhibited a significantly higher likelihood of BTV infection. Additionally, higher altitudes above 3000 masl played a protective role, reducing the risk of BTV transmission. Furthermore, increased maximum temperatures, especially exceeding 30 °C, were associated with a greater prevalence of BTV. This study lays the groundwork for identifying BTV serotypes and Culicoides spp. in different regions, including altitudes above 3000 masl, to enhance BTV surveillance in Peru.