Asymptomatic intestinal carriage of microsporidia in HIV-positive patients in Tunisia: prevalence, species, and pathogenesis.

Asymptomatic carriage of microsporidia (ACM) has not been described in patients living with HIV (PLHIV) in Tunisia. To determine the prevalence of ACM in PLHIV followed at Tunis la Rabta hospital, describe its clinical features and course, and identify the species involved. This prospective study (2005-2009) included 71 asymptomatic PLHIV compared with 37 PLHIV with diarrhea. One stool sample per patient was examined by microscopy after Weber staining and by PCR. Species identification was confirmed by specific PCR and sequencing. In cases of ACM, a second stool sample was examined in 2010 and a clinical check-up took place in 2013. The prevalence of ACM in asymptomatic PLHIV was 11.3 % (8/71). PCR was more sensitive than microscopy (P = 0.0047). ACM was associated with stage C of HIV infection (P = 0.008) and CD4 T cells <100/μl (P = 0.033). The species involved were E. intestinalis (6 cases) and E. bieneusi (2 cases). Six PLHIV remained asymptomatic with negative stool examinations, but two developed digestive signs. ACM is common among Tunisian PLHIV and it appears to be associated with E. intestinalis.