Decreased prevalence of intestinal cryptosporidiosis in HIV-infected patients concomitant to the widespread use of protease inhibitors.

Before the introduction of protease inhibitors in the treatment of HIV-infected patients infection by Cryptosporidium parvum was frequent with an incidence estimated to be approximately 1 per 100 patient-years (PY) in patients with CD4 cell counts < 200 x 10/6/l. No therapy has yet been demonstrated to be effective in this potentially life-threatening disease. In a previous study paromomycin administered for 1 month led to complete remission in 18 out of 24 patients with intestinal cryptosporidiosis; however 10 patients relapsed after reduction or interruption of paromomycin. The Agence Nationale de Recherche contre le SIDA (ANRS) 055 trial a multicentre double-blind randomized placebo-controlled trial was designed to assess the efficacy of paromomycin as maintenance therapy for chronic diarrhoea due to Cryptosporidium. Seventy-two enrolments were scheduled over a period of 12 months. However in January 1997 after a period of 14 months only 13 patients had been enrolled and the trial was thus interrupted. The aim of the present study was to explain this lower than expected enrolment rate by testing the hypothesis of a decreasing frequency of cryptosporidiosis related to improvement of immunity in patients treated with protease inhibitors. (excerpt)