Investigation of outbreaks of Pneumocystis jirovecii pneumonia in two Scottish renal units

Abstract

Pneumocystis jirovecii is recognized as an opportunistic pathogen. In recent years, human-to-human transmission of P. jirovecii has been demonstrated. However, outbreaks of P. jirovecii infections are not well defined because the epidemiological setting that facilitates transmission is not fully understood. This article describes two outbreaks of P. jirovecii pneumonia (PCP) in renal transplant patients in the West of Scotland. In total, 25 patients in two geographically contiguous locations were affected. Allele B was identified as the dominant type, along with allele A3. It was not possible to determine the exact reason for clustering of cases, although the outpatient clinic setting featured in one of the outbreaks. The outbreaks ceased with the use of trimethoprim-sulphamethoxazole prophylaxis; the target populations that received prophylaxis were different in the two outbreaks. Infection control teams should be alert to the possibility of outbreaks of PCP.

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.…”

“…CMV viremia at PJP hospitalization, n (%) protein, mg/dL, median (Q1-Q3) a 26(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) SD, standard deviation; BMI, body mass index; IQR, interquartile range; PJP, Pneumocystis Jirovecii Pneumonia; CMV, cytomegalovirus; WBC, white blood cells, BUN, blood urea nitrogen; AST, aspartate aminotransferase; ALT, alanine aminotransferase; NT-proBNP, N-terminal pro b-type natriuretic peptide. a Reference range, 0.0-0.5 mg/dL.TA B L E 2 Clinical presentation, treatment and outcomes of heart transplant patients hospitalized for Pneumocystis jirovecii pneumonia Peak viral load -CMV PCR (copies/mL), deviation; pAO2, partial pressure of oxygen; CT, computed tomography; BAL, bronchoalveolar lavage; IV TMP-SMX, intravenous trimethoprim-sulfamethoxazole; ICU, intensive care unit; CMV, cytomegalovirus; PCR, polymerase chain reaction; WBC, white blood cells.…”

“…Chest CT scan (performed on day 1 and day 6 for case A and B, respectively) showed diffuse bilateral ground-glass opacity in less than 50% of the studies reporting PJP outbreaks. Despite differences in the selected PJ molecular typing, they provided additional evidence supporting interhuman nosocomial transmission by identifying either a single or predominant strain in each outbreak in most of the studies 5,21,22,29. A variety of typing methods have been used throughout the years.…”

Airborne Interindividual Transmission of Pneumocystis jirovecii

“…PCP outbreaks occurring in hospitals over the past 60 years favor the hypothesis of interindividual transmission of P. jirovecii. Between 1968 and 2019, almost 60 outbreaks were described worldwide, mainly in renal transplant recipients as well as in HIV-infected and cancer patients [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Although interindividual transmission of P. jirovecii was suggested, it remained hypothetical until 1998 due to the absence of genotyping methods.…”

Impact of Increased Duration of Trimethoprim-Sulfamethoxazole Prophylaxis for Pneumocystis Pneumonia After Renal Transplant

“…Prior to 2015, our unit prescribed 3 months of TMP-SMX 480 mg daily as prophylaxis. However, following an outbreak of PCP in 2015, the duration was increased to 6 months, with an additional 6-month prophylaxis following any treatment for acute rejection [9]. TMP-SMX has several important potential adverse effects which can lead to cessation of treatment.…”