P. carini causes infection primarily in?: (A) Rats, (B) Guinea pig, (C) Rabbits, (D) Humans
Answer is A. Pneumocystis jirovecii causes infection Primarily in Rats. Pneumocystis jirovecii (previously P. carinii) is the causative organism of Pneumocystis pneumonia paicularly among immunocompromised hosts. P. jiroveci causes PCP in human with HIV if, their CD4+ cells count below 200/uL.