Retrospective study of Pneumocystis pneumonia over half a century in mainland China.

A retrospective study was performed on case reports of Pneumocystis pneumonia (PCP) from 1959 to 2009 in mainland China. The epidemiological characteristics of PCP over half a century were investigated over two time spans. The first was from 1959, when the first incidence of PCP was reported, to 1984, before the emergence of AIDS in mainland China. The second was from 1985, when the first AIDS case was reported in mainland China, to the end of 2009. A total of 2351 PCP cases were reported during these two time spans, covering a 51-year period. Only seven PCP cases were reported during the first time span. Six were diagnosed by autopsy, accordingly without treatment, whilst the other was diagnosed by open lung biopsy in a living patient who eventually recovered following treatment with sulfadiazine and pyrimethamine. The other 2344 PCP cases were reported during the second time span (1985-2009) from 21 provinces, four municipalities and three autonomous regions. Among the 2344 PCP cases, 70.22 % (1646/2344) were identified together with human immunodeficiency virus (HIV) infection or were in AIDS patients. The remaining 698 non-HIV-infected patients had undergone organ transplantation, had other underlying diseases such as malignancy or hypoimmunity, or had undetermined diagnosis. The results of statistical analysis indicated that AIDS was the most common underlying disease of PCP for patients <1 year and >14 years. For patients aged between 1 and 14 years, haematological malignancy was the most common underlying disease. The trend of the underlying diseases changed with time, showing that the number of PCP patients afflicted by HIV/AIDS increased dramatically, reaching almost threefold during the most recent 5 years compared with the level of the previous 10 years. The number of patients undergoing organ transplantation or with other underlying diseases rose constantly, but the number of malignancies tended to decline from 1995-2004 to 2005-2009. During the second time span (1995-2009), most of the patients (97.61 %) were diagnosed alive and only 56 cases (2.39 %) were identified by autopsy. The mortality of PCP patients treated with anti-Pneumocystis drugs was 14.61 % for those with HIV/AIDS and 15.84 % for those without HIV/AIDS. For the PCP patients without anti-Pneumocystis treatment, all (100 %) of the HIV/AIDS-associated PCP patients died, whilst 13.79 % (4/29) of non-HIV-infected PCP patients survived. These data from epidemiological investigation of PCP in China over a period of half a century may provide useful information for prevention and the development of treatment of PCP.