Decrease of Metagonimus yokogawai endemicity along the Tamjin River basin.

Area of Science:

• Infectious Diseases
• Parasitology
• Epidemiology

Background:

• The Tamjin River basin was historically a highly endemic area for Metagonimus yokogawai infection.
• Recent epidemiological data on M. yokogawai infection in this region were lacking.

Purpose of the Study:

• To determine the current prevalence and worm burden of Metagonimus yokogawai infection in residents along the Tamjin River.
• To assess changes in M. yokogawai endemicity compared to previous studies.

Main Methods:

• A small-scale epidemiological survey was conducted on 48 residents.
• Fecal samples were examined using Kato-Katz thick smear and formalin-ether sedimentation techniques.
• Adult flukes were collected from egg-positive cases after praziquantel treatment and purgation.

Main Results:

• The overall helminth egg positive rate was 50.0%, with M. yokogawai at 37.5%.
• An average of 871 adult M. yokogawai flukes were recovered per infected individual.
• While prevalence remained similar, individual worm burdens showed a remarkable decrease compared to 1977 and 1985 data.

Conclusions:

• Metagonimus yokogawai infection endemicity in the Tamjin River basin may have reduced, primarily due to decreased worm burden.
• Further investigation into snail and fish intermediate hosts is necessary to confirm the reduced endemicity.