[Endemic area of paragonimiasis in Vietnam].

We studied 155 patients with chronic pulmonary disease from a mountainous area in north-west Vietnam, in March, 1993. Sputum was collected from patients and examined for the presence of Paragonimus eggs using a light microscope. Forty four of the patients (approximately 28%) were diagnosed with and treated for human paragonimiasis. Forty two of these cases were purely pleural-pulmonary forms whereas the remaining two cases also involved problems with the central nervous system. Most of the patients had eaten freshwater crabs (Ranguna luangprabangensis) which had been insufficiently cooked. This appears to be the main source of infection as these crustaceans are often highly contaminated with metacercariae. Most of the patients were children (aged 11 +/- 5 years) and male (30 of the 44). Sputum samples were also collected from 225 healthy people from the same area during the period March 1993 to April 1996. The samples were examined using a light microscope and 11 (approximately 5%) were found to contain Paragonimus eggs. A number of animals were also tested. Three pet dogs (of 14 tested), 2 wild dogs (of 2 tested) and 2 domestic pigs (of 15 tested) were found to be infected with the fluke. This is the first report of an area with endemic paragonimiasis in Vietnam. Human infections probably also occur in other areas. They are a threat to public health and may be confused with tuberculosis.