Kyasanur Forest Disease: An Epidemiological Investigation and Case-Control Study in Shivamogga, Karnataka, India-2022

ObjectiveKyasanur Forest Disease (KFD) is a viral zoonosis reported from Karnataka, India. We investigated cases in the Shivamogga district, Karnataka, to describe the epidemiology and identify risk factors in the affected block in 2022.MethodsA case was defined as a laboratory-confirmed KFD-positive resident of Shivamogga from 1 January-31 May 2022. We extracted the records of KFD cases from district surveillance. We conducted a 1:3 case-control study in the Thirthahalli block. We enrolled laboratory-confirmed KFD-positive Thirthahalli residents from January to May 2022 as cases, and residents without “fever with myalgia” as controls. We reported adjusted odds ratios (aOR) with 95% confidence intervals (CI).ResultsShivamogga reported 35 cases, with a median age of 46 (4–75) years, of which 51% were men, and one death. Among 25 cases and 90 controls, knowledge of avoiding recent monkey death sites was low (cases = 0%, controls = 11%). Monkey death sites within 500 m [aOR = 8.6 (1.8–41.9)] and household tick exposure [aOR = 3.7 (1.3–10.7)] were independent risk factors.ConclusionThis was a laboratory-confirmed cluster of KFD cases in Thirthahalli, with residence near a monkey death site and household tick exposure considered significant risk factors. We recommend evaluating monkey carcass disposal procedures and increasing awareness of tick protective measures.