Outbreak investigation of acid fly attack among residential students in a tertiary care centre in South India

Abstract

Paederus dermatitis is the skin irritation resulting from contact with the haemolymph of certain rove beetles, a group that is comprised by the genus Paederus. In May 2018, there was an increase in the number of residential students reporting with burning skin lesions. In this context, an outbreak investigation was conducted. A team of public health specialists visited these residential buildings and premises. The inmates who were affected were interviewed and examined. Suspected insects were collected and entomologically evaluated by the Zoological Survey of India. On examination of the affected individuals, it was observed that the rashes were very much suggestive of acid fly toxin induced lesions. Inspection of the premises, revealed small heaps of dried leaves with moisture at two sites which could have served as a suitable environment for acid fly multiplication. Our study concluded that Paederus fuscipes as the causative agent. Top storeys of buildings, illuminated at night, facing potentially wet areas were considered to be the potential risk factor. Fly proofing of the building, cleaning the institution premises and chemical treatment was suggested as appropriate control measures.