The investigation of Pneumocystis jirovecii colonization in adult individuals of Turkish population

Abstract

Pneumocystis jirovecii previously known Pneumocystis carinii is the cause of opportunistic infections in the lower respiratory tract of immunocompromised hosts mainly among patients with HIV infected, hematologic malignancies, congenital immunodeficiency, organ transplant recipients, and patients receiving immunosuppressive drugs.1 The organism was considered as one of the most leading causes of morbidity and mortality among HIV patients before the introduction of antiretroviral therapy. However, Pneumocystis pneumonia (PCP) is associated with significant mortality and morbidity rates among non-HIV patients.2 The mechanism of Pneumocystis transmission was debating. Although previously it was thought that PCP infection is a reactivation of latent infection acquired during childhood, recently it has been recognized to be de novo exposure from either environment or individuals with PCP or colonized with Pneumocystis.3 Pneumocystis colonization has been defined as the presence of P. jirovecii in respiratory specimens of persons without signs or symptoms of acute pneumonia3 Pneumocystis jirovecii can colonize in lower respiratory tract without causing signs and symptoms and PCP may develop in these colonized individuals. Thus, Pneumocystis colonized individuals could also be a problem for public health since they could play a role as a major reservoir of Pneumocystis jirovecii and a source of infection for susceptible subjects.4 Furthermore, patients at risk for PCP who receive long term anti-pneumocystis prophylactic treatments may be colonized with drug mutated pneumocystis species. In addition, colonization may stimulate a host inflammatory response leading to lung damage and progression of lung disease such as chronic obstructive pulmonary disease (COPD).1,3 Therefore, we planned a prospective study and aimed to investigate the colonization prevalence and related risk factors among adult population in our region.