Brucella Exposure Beyond Traditional Risk Groups: Serological and Molecular Evidence Among Urban Pregnant Women in Punjab, Pakistan

Brucellosis is a neglected zoonosis that may cause serious complications during pregnancy, yet evidence of Brucella exposure among pregnant women in urban settings of Pakistan is limited. This cross-sectional study investigated Brucella exposure among 900 pregnant women recruited through household and community visits in selected urban areas across ten districts of Punjab, Pakistan, from January to June 2026. Demographic, obstetric, clinical, and potential exposure data were collected using a structured questionnaire. Serum samples were tested for anti-Brucella IgM and IgG by ELISA and serum agglutination testing (SAT) as well as genus and species-specific PCR. Seventy-two women (8.0%) were seropositive, 11 (1.2%) had borderline serological results, and 817 (90.8%) were seronegative. No clinical diagnosis of brucellosis or classification of infection as acute or chronic was established. Brucella DNA was detected in 40 (4.4%) samples, including eight women who were seronegative by serology. B. abortus was detected more frequently than B. melitensis. Seropositivity was independently associated with animal contact, raw milk consumption, previous miscarriage, and low household income. Seropositive women reported assessed clinical symptoms more frequently than seronegative women, although these symptoms were non-specific. These findings provide evidence of Brucella exposure among pregnant women in selected urban communities and identify animal contact and raw milk consumption as important potential exposure factors. Further prospective studies are needed to determine the temporal relationship between Brucella exposure and pregnancy outcomes.