An Investigation into the High Prevalence of Hepatitis B in a Rural Area of Kerala State, India: Hypothesis on sp. (Diptera: Tabanidae) Transmission.

Objective: Since 2005 there have been several reports of hepatitis B outbreak in the state of Kerala in southern India. Objective of this study was to analyze such outbreaks and to explore hypothesis pertaining the transmission mode.

Methods: Retrospective observational study involving cases of acute hepatitis B acquired between 1 January 2015 and 31 December 2015 and their family members residing in Mazhuvanoor village in Ernakulam district of Kerala State in southern India.

Results: 59 houses were included in the survey. The number of patients diagnosed to have acute viral hepatitis B was 59. Majority (66.10%) were over 50 years old. There were no cases below the age of 15 years. All 59 patients claimed to have been bitten frequently by a fly which was identified as "deer fly" belonging to the genus .

Conclusion: Given the current understanding of mechanical transmission of pathogens in both humans and animals by insects belonging to the Tabanidae family which also includes , it is plausible that the same mechanism may hold true for hepatitis B also. However this needs to be proven in further studies both at the laboratory level and at field studies.