CRYPTOSPORIDIUM INFECTION AND CD4 COUNTS

Cryptosporidium infection in immunocompetent persons is associated with self-limited diarrhea. In contrast, in persons with the acquired immunodeficiency syndrome (AIDS), cryptosporidiosis causes persistent enteritis that is refractory to treatment. In our clinical practices, we observed men infected with the human immunodeficiency virus (HIV) who had self-limited diarrhea due to Cryptosporidium infection. To better define the characteristics associated with self-limited disease, we did a retrospective chart review of HIV-seropositive patients with Cryptosporidium infection. We compared 13 HIV-positive persons with self-limited cryptosporidiosis with 34 persons with AIDS who had persistent Cryptosporidium infection. The mean CD4 count was significantly greater in patients with self-limited infection (312 cells/mm3, range, 14 to 651 cells/mm3) than in patient with persistent infection (57 cells/mm3, range 4 to 150 cells/mm3, P < 0.001). A similar relationship was found for the mean CD8 count, the mean ratio of CD4 to CD8 count, and the mean hematocrit. All patients with CD4 counts of 180 cells/mm3 or greater (n = 8) cleared the infection spontaneously over a period of 7 days to 1 month. This observation is important both in predicting the natural history of Cryptosporidium infection and in designing therapeutic trials.