Application of real‑time quantitative polymerase chain reaction assay to detect Legionella pneumophila in patients of community‑acquired pneumonia in a tertiary care hospital.

ABSTRACT

Legionella pneumophila is one of the important pathogen responsible for community –acquired pneumonia attributing for 1-5% of cases. Since early and accurate therapy reduces mortality, rapid and reliable diagnostic methods are needed. A total of 134 samples of blood, urine and respiratory tract fluids were collected. Blood was tested for IgG, IgM and IgA antibodies using commercially available kits. A total of 8 (6%) samples were found to be positive for L. pneumophila by quantitative reverse transcription polymerase chain reaction (qRT‑PCR), compared to conventional PCR where 6 (4.4%) samples were positive. Serology was positive in a total of 32 (23%) cases though only 3 (2.2%) of the PCR‑positive cases were positive by serology as well. These results suggest that real‑time PCR can detect Legionella infection early in the course of the disease before serological response develops.