卡氏肺孢子虫肺炎是由卡氏肺孢子虫(Pneumocystis carinii)引起的急性肺炎。对本病的系统认识始于本世纪40～50年代,当时在早产儿或营养不良的婴儿中曾发生地方性流行。但其后更常见于因淋巴增殖性肿瘤、器官移植或胶原一血管病而长期接受激素治疗者,以及近年发现的获得性免疫缺陷综合征患者。在获得性免疫缺陷综合征病人中卡氏肺孢子虫肺炎是最常见的机会感染。 Pneumocystis carinii pneumonia is an acute pneumonia caused by Pneumocystis carinii. Systematic understanding of the disease began in the 40s and 50s of this century, when endemic prevalent or malnourished infants had been endemic. But later became more commonly treated with hormonal therapies due to lymphoproliferative neoplasms, organ transplants or collagen-1 vasculopathy, as well as patients with acquired immunodeficiency syndrome found in recent years. Pneumocystis carinii pneumonia is the most common opportunistic infection in patients with acquired immunodeficiency syndrome.