Emergence of scrub typhus-associated neurological signs in central India: An unusual manifestation in febrile illness cases in Madhya Pradesh, India

<h2>Abstract</h2><h3>Problem considered</h3> Scrub typhus, a re-emerging zoonotic infection, often manifests as acute undifferentiated febrile illness (AUF), posing a significant epidemiological threat in tropical and subtropical regions. Its nonspecific clinical presentation complicates timely diagnosis, increasing the risk of severe morbidity. Understanding its epidemiology and clinical characteristics is crucial for effective disease control, particularly in areas prone to outbreaks. <h3>Methods</h3> This prospective cross-sectional study assessed the prevalence and clinical features of scrub typhus through detailed patient history, clinical examination, and commercial IgM ELISA, following DHR guidelines. <h3>Results</h3> Among 911 AUF patients from tribal-dominated regions of Madhya Pradesh, India, 22.3% [95% CI: 19.6–25.1] were seropositive for anti- O<i>. tsutsugamushi</i>-specific IgM antibodies, indicating widespread transmission across 17 of 24 districts, particularly in tribal populations, between August 2018 and July 2020. Patient ages ranged from 9 months to 86 years, with 41.2% under 15 years and 35.5% in the working-age group (31–60 years). Notably, 16.7% of seropositive patients exhibited nervous system involvement alongside other clinical signs. Both genders showed similar susceptibility, and 32.3% of seropositive cases reported fever lasting 7–15 days. Peak seropositivity was observed during the monsoon at 38%, followed by the post-monsoon period at 20.4%. <h3>Conclusion</h3> This study demonstrates the significant burden of scrub typhus in tribal regions of Madhya Pradesh, India, with high seropositivity during the monsoon and post-monsoon seasons. The association of prolonged fever with organ involvement emphasize the need for early detection, inclusion of scrub typhus in differential diagnoses, and region-specific preventive measures, particularly in endemic areas like Central India.