Sensitivity and specificity of nested and real-time PCR for the detection of Pneumocystis jiroveci in clinical specimens.
A polymerase chain reaction (PCR)-based test for Pneumocystis jiroveci (formerly Pneumocystis carinii f. sp. hominis) might be an alternative to histologic diagnoses of P. jiroveci pneumonia (PCP). However, previously developed nested PCR methods tend to have low specificities (high false-positive rates). In this study, nested and quantitative real-time PCR methods for the amplification of the P. jiroveci DHPS (dihydropteroate synthase) gene were evaluated in a variety of stored clinical samples from Spain, South Africa, and Brazil. The sensitivities of both assays were high, ranging from 62.5% to 100% depending on the type of specimen. In a subset of 71 microscopically confirmed PCP cases and 70 negative cases, the sensitivities and specificities were 94% and 81% for nested PCR and 94% and 96% for real-time PCR, respectively. Real-time PCR has a statistically significantly better specificity than nested PCR (P = .015) and is likely to generate fewer false positives.
Alvarez-Martínez
Míriam J
MJ
Microbiology Department, Hospital Clínic--IDIBAPS, Universitat de Barcelona, Barcelona 08036, Spain.
Miró
José M
JM
Valls
Maria Eugenia
ME
Moreno
Asunción
A
Rivas
Paula V
PV
Solé
Manel
M
Benito
Natividad
N
Domingo
Pere
P
Muñoz
Carmen
C
Rivera
Esteban
E
Zar
Heather J
HJ
Wissmann
Gustavo
G
Diehl
Ada R S
AR
Prolla
João C
JC
de Anta
Maria Teresa Jiménez
MT
Gatell
José M
JM
Wilson
Paul E
PE
Meshnick
Steven R
SR