[An epidemiologic study on Pneumocystis pneumonia in non-HIV infected patients in China]

To analyze the epidemiologic features of Pneumocystis pneumonia (PCP) among non-HIV infected patients in China.

Sputum or bronchoalveolar lavage fluid (BALF) specimens obtained from 851 pneumonia patients without HIV infection from Jan. 2006 to Oct. 2008 were detected, using PCR and Gomori' s methenamine silver (UMS) stain for Pneumocystis jirovecii.

Of the 615 sputum specimens, P. jirovecii positive rates of PCR and GMS stain were 20.3% and 10.2% respectively (P < 0.05). Of 236 BALF specimens, P. jirovecii positive rates of PCR and GMS stain were 32.6% and 25.5% respectively (P > 0.05). Of the total 851 pneumonia cases, 123 (14.5%) were GMS positive for P. jirovecii cyst and 202 cases (23.7%) were PCR positive for P. jirovecii DNA. In those immuno-suppressed patient group including patients with connective tissue diseases, organ transplant recipients, nephrotic, hematologic diseases and malignant tumor, P. jirovecii positive rate appeared the highest, 28.2% for GMS stain and 39.4% for PCR. There were also PCP patients in the immuno-competent pneumonia patient groups including senile patients with chronic diseases and patients without clear predisposing immuno-deficiencies. The positive rates of P. jirovecii GMS were 8.7% and 10.9%, respectively and 17.5% and 19.6% for P. jirovecii under PCR.

PCR assay seemed sensitive for the detection of P. jirovecii in the sputum specimens and could be used for screening PCP patients without HIV infection. Our data showed that there was high risk of PCP in non-HIV infected patients in China.