ENTAMOEBA-HISTOLYTICA CYST PASSERS - CLINICAL PROFILE AND SPONTANEOUSERADICATION OF INFECTION

The present study was carried out to examine whether Entamoeba histoly tica cyst passers suffer from any parasite-related bowel symptoms and to assess the frequency of spontaneous eradication of this infection. The study was carried out in two parts. In part I, stool samples were collected at random from 3536 individuals living in rural communities around Delhi. E. histolytica was isolated by the culture technique in 345 (9.7%) subjects. There was no increase in the prevalence rate of b owel symptoms in the culture-positive compared to the culture-negative subjects. One hundred twenty-four (36%) of the culture-positive subje cts agreed to take part in a longitudinal study; the subjects were lef t untreated and clinical assessment and stool examinations were carrie d out at three-month intervals. One hundred eighteen (95.2%) subjects had eradicated their parasite spontaneously at the end of one year; no ne developed any features of invasive amebiasis. Part II of the study was carried out on 625 patients attending our Gastroenterology Clinic. Positive cultures of E. histolytica were obtained from 99 (15.2%) pat ients. Again, there was no increase in the prevalence,rate of bowel co mplaints in the culture-positive compared to the culture-negative subj ects. Moreover, histological appearances of the rectal biopsy specimen s were not significantly different between the two groups. Twenty-eigh t (28.2%) patients agreed to the longitudinal study and all eradicated the parasite spontaneously within five months; none developed any evi dence of invasive amebiasis. It is concluded that E. histolytica cyst passers do not suffer from any parasite-related bowel complaints. In t his setting, there appears little justification in treating cyst passe rs since most of these subjects eradicate the parasite spontaneously w ithout suffering from any invasive disease.