Larval Gnathostoma: morphological identification and probable source of a case of human eye infection in Assam, India

Abstract

The present communication deals with morphological identification of a parasite specimen sent from a private eye hospital at Guwahati, Assam after its extraction alive from the aqueous humor in the right eye of a non-tribal rural woman from Assam. The parasite 3 mm X 0.3 mm in size, characterized by the presence of a distinct anterior head bulb armed with four rows of hooklets numbering less than 40 per row and spination along the transverse striations present throughout the body was identified as the third stage larva of a pig gnathostome, Gnathostoma doloresi. Interview based investigation to ascertain the source of G. doloresi infection reported here for the first time in the 32 year old non-vegetarian house wife having no history of raw fish consumption revealed water used for domestic purpose from a pond adjacent to domestic pig pastured swampy area and the fresh water fishes as the possible sources of infection which might have occurred by accidental ingestion of infected cyclops present in pond water or by direct skin penetration of the larval stage of the parasite during descaling and evisceration of infected fishes prepared for cooking and consumption.