When Zoonosis Meets Genetics: Brucellosis and Gilbert Syndrome in a Young Woman From Rural Nepal.

Brucellosis is a neglected zoonotic infection in Nepal that is often underdiagnosed, particularly in regions considered to have low prevalence. Its presentation can mimic autoimmune or hepatic disorders, complicating timely diagnosis and management. Coexistence with hereditary conditions such as Gilbert syndrome can further obscure the clinical picture. We present a case of a 28-year-old woman who presented with progressive jaundice, low-grade fever, arthralgia, and weakness. History revealed recurrent jaundice and similar symptoms in family members. The exam showed scleral icterus and hepatosplenomegaly. Labs indicated anemia, leukopenia, and unconjugated hyperbilirubinemia with normal liver enzymes. Brucellosis was confirmed by positive serology and treated with doxycycline and rifampicin, resolving systemic symptoms. Persistent hyperbilirubinemia and family history suggested underlying Gilbert syndrome. This case highlights the diagnostic complexity when infectious and hereditary causes of jaundice coexist. It emphasizes the need for heightened clinical suspicion for brucellosis even in regions of Nepal not traditionally recognized as endemic. A systematic diagnostic approach is essential in patients with unexplained jaundice, particularly when common infectious and autoimmune causes are excluded.