Ancylostoma ceylanicum infections in humans in Vietnam

Ancylostoma ceylanicum is recognized as the only zoonotic hookworm species that is able to mature into adult stage in the human intestine. While human infections caused by this hookworm species have been reported from neighboring countries and this hookworm is prevalent in dogs in Vietnam, human infection has never been reported in Vietnam. The present study, therefore, aimed to identify human infections with A. ceylanicum in Vietnam. A total of 526 fecal samples from the residents in Long An Province were collected and the presence of hookworm eggs was detected by the Kato-Katz method. The results indicated that the overall prevalence of human hookworm infection was 85/526 (16.2%). After filter paper culture, 3rd stage larvae were successfully obtained from 48 egg-positive samples. The larvae were identified for their species using semi-nested PCR-RLFP on the cox1 gene. As a result, two hookworm species were confirmed; single species infections with Necator americanus or A. ceylanicum, and mixed infections with both species were found in 47.9%, 31.3%, and 20.8% of the samples, respectively.