Coxiella burnetii exposure at the human-livestock interface in Southern Punjab, Pakistan: A serological one health investigation.

Abstract

Coxiella burnetii, the causative agent of Q fever, is an important zoonotic pathogen affecting livestock and humans worldwide. In Pakistan, epidemiological evidence remains limited, particularly at the human-livestock interface. This study aimed to determine the seroprevalence of C. burnetii and identify associated risk factors among livestock and livestock-exposed humans in Southern Punjab, Pakistan. A cross-sectional study was conducted across six districts, including 4758 livestock comprising goats, sheep, cattle, buffaloes, and camels, and 1019 humans with livestock-associated exposure. Serum samples were tested for the presence of antibodies against C. burnetii using an ELISA assay. Overall 17.65% and 21.98% seroprevalence rates were observed among livestock and humans, respectively at individual-level while 67.3% and 32.3% seroprevalence rates were observed at the herd- and household-level, respectively. Tick infestation, larger herd size, extensive husbandry, transhumant production, and reproductive problems were associated with higher odds of seropositivity. Among humans, livestock ownership, raw milk consumption, placenta handling, family history of abortion, and uncertainty regarding tick exposure were associated with seropositivity. These findings provide evidence of substantial prior exposure to C. burnetii among livestock and humans and highlight Q fever as an underrecognized zoonotic health concern. Integrated One Health surveillance combining serology with molecular and environmental testing, together with improved farm biosecurity and targeted public awareness, is warrant to reduce occupational exposure and ultimately strengthen disease prevention strategies.