Cost of illness of scrub typhus in South India – a population-based, mixed-methods study

Background: Scrub typhus is a potentially life-threatening acute febrile illness found in many parts of Asia. This study aimed to estimate the cost of illness among scrub typhus cases in Tamil Nadu, South India and explore treatment-seeking behaviour. Methods/Principal Findings: Cases were enrolled from a population-based cohort study on scrub typhus in 32,279 individuals living in rural villages. Data on direct and indirect costs were collected using structured questionnaires from 311 scrub typhus cases of which 26 were severe. Thirteen cases with severe infections (or their relatives) underwent in-depth interviews to understand treatment-seeking pathways. Conclusions/Significance: Hospitalisation, common in both severe and non-severe patients, was the driving factor for high costs. Early case recognition may reduce hospitalisations and health expenditure in highly endemic settings. Authors summary: Scrub typhus is an important cause of fever in many Asian countries, including China, India, Vietnam and Japan. It is caused by the intra-cellular bacteria Orientia (mostly O. tsutsugamushi) and transmitted to humans by trombiculid mite larvae (“chiggers”). Scrub typhus is potentially life-threatening, but treatable with cheap antibiotics such as doxycycline and azithromycin. In this study, the cost of illness was determined in 311 cases identified as part of a cohort study on the incidence of scrub typhus in a rural setting in South India. In-depth interviews were conducted to determine treatment seeking behaviour. The mean overall cost of illness per case was USD 189, disaggregating to USD 1,321 for severe cases and USD 86 for non-severe cases. Hospitalisations were found to be the driving factor for high costs in both mild and severe cases, often leading to health expenditures exceeding the average monthly household income of USD 236.