Pneumocystis jirovecii in hiv patients and suspected pneumonia: A problematic diagnosis in caracas, venezuela

Abstract

Pneumocystis jirovecii pneumonia (PCP) is one of the most frequent opportunistic infections in immunocompromised patients. The objective of this study was to know the P. jirovecii epidemiology in Venezuelan patients with Human Immunodeficiency Virus (HIV) infection and suspected pneumonia, through passive surveillance at a national reference laboratory during six years. Laboratory records of patients with HIV infection, who were hospitalized with acute lower respiratory tract infection (ALRTI), and presumptive clinical diagnosis of PCP, were reviewed between January 2007 and December 2012, at the Mycology Department of the Instituto Nacional de Higiene Rafael Rangel. Several respiratory specimens were received and the direct immunofluorescence assay (DIF) and nested polymerase chain reaction (nPCR) diagnostic techniques were used. One hundred and sixty-one respiratory samples were processed and P. jirovecii was detected in 76 samples by DIF and in 20 by nPCR. PCP’s frequency in Venezuelan patients with HIV is high and it has been sustained throughout time. Colonization by P. jirovecii has uncertain clinical significance, but this study provides evidence that the state of advanced immunosuppression increases the probability of colonization. DIF and nPCR are very useful techniques for PCP diagnosis, but are of limited access in many hospital centers, especially in developing countries. We recommend the use of DIF with spontaneous sputum specimens as the first diagnostic line for PCP in patients with HIV infection. The results obtained by nPCR should be interpreted with caution, taking into account the patient’s clinical symptoms.