Admitted medical records, from January 1988 to December 1995, of
28 symptomatic amebic patients who lived in the east-southeast area of
Tokyo were
studied retrospectively, in order to
find the present characteristics of symptomatic amebiasis due to
Entamoeba histolytica in this
area. Categorized by disease, there were 14 cases of colitis, 9 cases
of liver abscess, 4 cases of
colitis with liver abscess, and 1 case of liver abscess with brain
abscess. Patients consisted of 26
Japanese males, 0 Japanese females, 1 non-Japanese male and 1 non-Japanese
female. The
mean age of colitis patients and liver abscess patients was 55·4
years old and 41·3 years old,
respectively. The presumed place of contraction was Japan in 64% of
the patients. Forty-eight
percent of male patients indicated that they engaged in homosexual or
bisexual practices, and
36% of male patients who denied such sexual practices or did not answer
the question had no
history of marriage. Positive rate of serum titre for Treponema
pallidum hemagglutination test
(TPHA) and human immunodeficiency virus antibody was 42·9% and 0%,
respectively. Sixty-seven percent of TPHA-positive patients indicated that
they engaged in male homosexual or
bisexual practices. Zymodeme patterns of E. histolytica isolated
from 4 colitis patients were
XIV in 1 case and II in 3 cases. Symptomatic amebiasis in the
east-southeast area of Tokyo is a
disease which predominantly afflicts males, especially those in their
middle age, and most
patients contract the disease in Japan. The high rates of patients who
engaged in male
homosexual or bisexual practices and the high rates of patients with
positive TPHA suggest
that amebiasis is likely to be sexually transmitted disease in homosexual
and
bisexual men in
the east-southeast area of Tokyo, and zymodeme II may be the predominant
type in
symptomatic amebic colitis in this area.