Pneumocystis jirovecii colonization and infection among non HIV-infected patients

Abstract

Objective and method: The epidemiology of pneumocystosis has changed in the last decade with a decreased incidence in HIV infected patients, and the emerging concept of Pneumocystis colonization. The study objective was to describe Pneumocystis infection as well as colonization among non-HIV infected patients in the Rouen teaching hospital and cancer institute. A retrospective study was made of all patients with a positive respiratory sample for Pneumocystis jirovecii between January 1, 2000 and June 6, 2007.

Results: Fifty-four cases were reported (46 cases of pneumocystosis and eight of asymptomatic carriage) and an increasing yearly incidence over the study period was observed. Underlying diseases for pneumocystosis were haematological malignancies (n=25; 54%), organ transplantation (n=8; 17.4%), inflammatory disorders (n=6; 13%), and solid cancer (n=5; 10.8%). Sixty-five per cent of patients were under long-term steroid therapy. The overall mortality rate was 21.4%. The CD4 count for 26 patients, ranged from 18 to 1449/mm(3) (median: 107). Eight cases of asymptomatic carriage were reported with an underlying immunodepression (n=6) and pulmonary disease (n=2).

Discussion: The increasing incidence of pneumocystosis in immunosuppressed patients without AIDS is due to more frequent favorable conditions and progress of diagnostic tools. The clinical presentations are severe. Prophylaxis is badly codified because there is no threshold value for CD4 count. Colonization could present a warning value.