Gnathostoma infection in South Vietnam

Abstract

Four species of Gnathostoma have been documented in Vietnam: G. spinigerum, G. hispidum, G. doloresi, and G. vietnamicum. The only species known to infect humans is G. spinigerum. Infections in animals have been reported in Vietnam since 1914. Recently, reports have revealed a high prevalence among pigs (24.1%), eels (11%), and dogs (4.3%). The first human infection was reported in 1963. Based mainly on findings of larvae from tissue, the number of reported human cases was still low, until 1999 (4 cases). Since 1999, however, more than 600 cases from different cities of south Vietnam have been diagnosed based on clinical symptoms and signs, eosinophilia and ELISA at the Department of Parasitology, School of Medicine, University of Pharmacy and Medicine, Ho Chi Minh City. Larvae were founded in tissue, or from the intestinal lumen, of 14 cases. The main clinical manifestation was subcutaneous swelling with or without eruption. In addition to improving recognition of this, until now, neglected infection and diagnostic abilities, the environmental, cultural, social and dietary changes may be responsible for the increasing number of cases. Immunoblot and IgG subclass antibodies should be used for more sensitive screening or more specific confirmation in human cases. The infection status in animal and fish are under ongoing evaluation. Based on the extend of human and animal infection, appropriate interventions will be needed in the future.