Purpose: Microsporidial infections have been recognized as an
increasingly important infection in immuncompromised patients,
particularly those infected with HIV/AIDS. This study was designed to
study immune responses associated with experimental Encephalitozoon
intestinalis infection in immunocompetent rats. Materials and Methods:
Thirty-four Rats in 3 groups, A (Control), B (Intraperitoneal) and C
(Oral) were given injections of 0.5 ml of 2 x 10 6 of purified spores
of Encephalitotozoon intestinalis spores and were observed for serum
specific IgG for 21 days using both direct and indirect ELISA.
Results: In indirect ELISA, specific lgG were detected on days 7, 14
and 21 for the group B rats and on day 21 for group C and in direct
ELISA method, specific lgG were detected in-group B rats on days 7 and
21, for group C rats on day 21 only, while in the control rats,
specific lgG were not detected. There was no significant difference
between the direct and indirect methods (df=1, X 2 , P>0.05). E.
intestinalis was observed in stool samples of rats in 1/12 (08.33%) on
days 14 and 21 in group B, and in 4/10 (33.33%), 3/10 (25.00%) and 2/10
(16.67%) on days 7, 14 and 21 respectively in group C. In group A,
which is the control rats, no microsporidia were observed on days 0, 7,
14 and 21. Conclusions: There were no changes in the T-lymphocyte
counts of rats prior to and after inoculation with spores. Extensive
lesions were observed along the intestinal walls especially on the
middle and lower sections of group C rats only