Q fever in patients with acute febrile illness: a hospital-based study from North India

Q fever is an underrecognised zoonosis with significant global and regional variation. Data on its burden in North India are limited. This study aimed to determine the frequency and clinical profile of Q fever among patients presenting with acute febrile illness in a tertiary care hospital in Kashmir.

A hospital-based study was conducted over 18 months in which patients with fever ≤3 weeks were enrolled after excluding other defined infections. Serum and whole blood samples were tested for Coxiella burnetii using enzyme-linked immunosorbent assay (ELISA) for phase I/II immunoglobulin M (IgM) and IgG antibodies and conventional polymerase chain reaction (PCR) targeting the IS1111a gene. Demographic and clinical data were analysed using SPSS version 22.0 and R software, with statistical significance set at p<0.05.

Of 96 patients, 15.6% were positive by ELISA, PCR or both. The highest positivity occurred in the 31-40 y age group (45%; p=0.002). The Ganderbal (35.3%) and Srinagar (18.5%) districts showed the highest prevalence (p=0.043). Significant association was observed with a shorter hospital stay (p<0.001). IgG phase II ELISA demonstrated better sensitivity (50%) than IgM phase II ELISA (25%), while PCR provided early detection.

A frequency of 15.6% for Q fever was observed, especially in the adult age group. PCR outperformed serological assays in early detection, while IgM phase II ELISA showed poor sensitivity. Strengthened clinical suspicion, enhanced diagnostic capacity and integrated One Health surveillance are essential for effective control.