Current infection rate of Giardia lamblia in two provinces of Thailand.

The aim of this study was to survey for the current rate of Giardia lamblia infection in three different districts in two provinces of Thailand, Surin and Samut Sakhon, in March 2002, October 2003, and March 2004. Two districts are rural areas and another is sub-urban. Volunteers of any age from Surin Province and children aged between 5 to 7 years old from three secondary schools in Samut Sakhon were enrolled for the stool examination. The method used was stool examination by both simple smear and normal saline concentration technique on fresh collected feces. All samples were tested in duplicate. Out of 3,358 healthy individuals from rural Surin Province, 75 cases (2.2%) were found positive for G. lamblia, 30 of which were below 10 years of age. By comparison, 656 individuals from sub-urban Samut Sakhon Province volunteered and 43 (6.5%) were positive for G. lamblia. Other intestinal parasites, both helminth and protozoa, were also identified from these two groups: hookworm, Enterobius vermicularis, Strongyloides stercoralis, Trichuris trichiura, Taenia species, Entamoeba histolytica, Entamoeba coli, Endolimax nana, and Blastocystis hominis. From this study, the data showed that parasitic infection acquired via fecal-oral route is still a significant problem for these two provinces of Thailand.