Pneumocystis jirovecii Pneumonia: A Revisit to the Old Malady

Abstract

Pneumocystis jirovecii Pneumonia (PJP) was previously called as Pneumocystis carinii Pneumonia (PCP), it is one of the most common opportunistic fungal infection in immuno-compromised individuals. Patients may present clinical symptoms such as fever, non-productive cough, chills, weight loss, dyspnoea, shortness of breath and respiratory failures in severe cases. Clinical samples such as Sputum, Induced sputum, Bronchio Alveolar Lavage fluid (BAL), Pleural fluid and Lung tissue are used for identification of Pneumocystis infection. Diagnosis of Pneumocystis jirovecii is done by staining, serology, in-vitro cultivation and molecular methods. Different types of Polymerase Chain Reaction (PCR) assays can be used for different gene targets for detection of Pneumocystis. PCR assays are most sensitive and specific methods which can be useful for detection of P. jirovecii from infected individuals, recurrent PJP patients. Treatment of PJP infection is based on the severity of the illness and diagnosis. Evidence based guidelines should be followed for giving proper treatment. If treatment is not given, the patient will die with PJP infection. Trimethoprim/Sulfamethoxazole (TMP-SMZ) is given as an early treatment prophylaxis in patients with PJP. If side effects are severe with TMP-SMZ, other drugs include Pentamidine, Trimetrexate, Atovaquone, clindamycin and primaquine combined with leucovorin, dapsone and Caspofungin combined with clindamycin can be given as alternative drug regimen to the patients with PJP infection. Wide spread and long term usage of PJP prophylaxis can lead to rising new cases of dihydropteroate synthetase (DHPS) mutant strains. Extensive utilisation of TMP-SMZ and dapsone in Human Immunodeficiency Virus (HIV) and other immuno-compromised individuals can lead to sulfa (sulfonamide or sulfone) drug resistance. Evaluation of drug resistance is complicated in HIV patients and finally further advance research is required for strategies development as well as to stop the further increase of resistant strains. New diagnostic methods and usage of non-invasive respiratory specimens such as oral washes for diagnosis of PJP should be expanded. PCR is the most sensitive method compared to other conventional and serological methods. Using PCR and Sequence analysis can be helpful for estimation of prevalence of disease as well as epidemiological purposes. There is an urgent need to develop newer drugs and vaccines to eradicate the PJP disease burden. This review of literature gives recent information on PJP by highlighting epidemiology, taxonomy, pathophysiology, mortality, present situation, recent diagnostic methods, recommended immuno-prophylaxis and recent advances.

Keywords

• andhra pradesh
• human immunodeficiency virus
• immuno-compromised