Epidemiological Outbreaks of Pneumocystis jirovecii Pneumonia Are Not Limited to Kidney Transplant Recipients: Genotyping Confirms Common Source of Transmission in a Liver Transplantation Unit

Abstract

j Over a 5-month period, four liver transplant patients at a single hospital were diagnosed with Pneumocystis jirovecii pneumonia (PCP). This unusually high incidence was investigated using molecular genotyping. Bronchoalveolar lavage fluids (BALF) obtained from the four liver recipients diagnosed with PCP were processed for multilocus sequence typing (MLST) at three loci (SOD, mt26s, and CYB). Twenty-four other BALF samples, which were positive for P. jirovecii and collected from 24 epidemiologically unrelated patients with clinical signs of PCP, were studied in parallel by use of the same method. Pneumocystis jirovecii isolates from the four liver recipients all had the same genotype, which was different from those of the isolates from all the epidemiologically unrelated individuals studied. These findings supported the hypothesis of a common source of contamination or even cross-transmission of a single P. jirovecii clone between the four liver recipients. Hospitalization mapping showed several possible encounters between these four patients, including outpatient consultations on one particular date when they all possibly met. This study demonstrates the value of molecular genotyping of P. jirovecii isolated from clinical samples for epidemiological investigation of PCP outbreaks. It is also the first description of a common source of exposure to a single P. jirovecii clone between liver transplant recipients and highlights the importance of prophylaxis in such a population.

Single‐center outbreak of Pneumocystis jirovecii pneumonia in heart transplant recipients

“…5 Nosocomial clusters of PJP have been previously described. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] By associating the study of patient contacts and the molecular identification of PJ genotypes, they strongly support the theory of an interhuman PJP transmission. Following solid organ transplantation, the risk for PJP is higher in the first 6 months, in patients with prolonged leukopenia or receiving increased immunosuppression (eg, graft rejection) and during invasive cytomegalovirus (CMV) infection.…”

Combination of β‐(1, 3)‐D‐glucan testing in serum and qPCR in nasopharyngeal aspirate for facilitated diagnosis of Pneumocystis jirovecii pneumonia

“…PjP infection occurs mostly in immunocompromised patients, such as subjects infected with human immunodeficiency virus (HIV) or those suffering from haematological malignancies . It has been also largely described in solid‐organ transplant recipients or in individuals receiving immunosuppressive therapy for autoimmune or inflammatory diseases . Clinical signs of PjP infection are not specific; they include fever, thoracic pain and cough, and they can misleadingly mimic other lung infections, mostly those caused by viruses …”

“…3,4 It has been also largely described in solid-organ transplant recipients or in individuals receiving immunosuppressive therapy for autoimmune or inflammatory diseases. 5 Clinical signs of PjP infection are not specific; they include fever, thoracic pain and cough, and they can misleadingly mimic other lung infections, mostly those caused by viruses. 2,4 Because P jirovecii is not easy to grow in vitro, 6 the biological diagnosis of PjP remains complex 7 and is usually based on direct observation of the fungus and/or detection of its DNA in respiratory fluids.…”

Healthcare related transmission of Pneumocystis pneumonia: From key insights toward comprehensive prevention

“…Despite accumulating knowledge of P. jirovecii and PCP, comprehensive infection control recommendations for handling inpatient or outpatient immunocompromised children or adults with proven or suspected PCP have not been issued. Articles reporting outbreaks or clusters of PCP continue to appear in the medical literature, affecting diverse immunosuppressed populations and raising the concern about this issue among infection control teams and a wide spectrum of clinical specialists . Even more worrisome is the high mortality still associated with PCP, which is variably reported between 10% and 40% .…”

“…specialists. [21][22][23] Even more worrisome is the high mortality still associated with PCP, which is variably reported between 10% and 40%. 24 The management of a PCP-case with regard to prevention of transmission encompasses multiple considerations and respective actions that will be reviewed here.…”