The Characteristics of Blastocystis Hominis Infection in Outpatient Health Surveys of a Medical Center in Taiwan
摘要
Blastocystis hominis has not been endemic or epidemic in Taiwan, but with increasing immigration and international travel, this protozoan is found more frequently. We investigated the characteristics of B. hominis infection in Taiwan. Descriptive and retrospective analyses were performed in individuals who had undergone outpatient examinations in a medical center in Taiwan between January 1 and December 15, 2002. From the patients’ charts, we recorded their age, sex, occupation and/or residence, nationality, therapeutic medication and its effect on B. hominis infection, and associated risk factors. A total of 7,754 participants, including 220 immigrants, completed health surveys. Among them, 1,975 had undergone routine stool examination. Thirty-one(1.6%)had B. hominis infection. Their mean age was 34.4+-11.7 years(range:23 to 71 years), and they were predominantly younger than 30 years(51.6%), female(71.0%), immigrants(71.0%), and from southeastern Asia(45.2%). Nine subjects were Taiwanese, including six overseas volunterers and three native residents, all of whom had contact with immigrants in the past. All infected patients were asymptomatic except for one who had constipation. Fifteen(48.4%)were treated with metronidazole or mebendazole. In five(16.1%), the infection resolved spontaneously without medication, and 11(35.5%)were lost to follow-up. Only five subjects had systemic disease. Therapeutic choices differed significantly with sex(p=0.04)but not age or occupation(p＞0.1). In summary, B. hominis infection is not limited to immigrants to Taiwan, and transmission among native residents may occur. Thus, aggressive screening for B. hominis infection and active treatment are indicated.