Atypical pathogens including and are increasingly recognized as important causes of community-acquired pneumonia (CAP). accounts for 20-40% of all CAP and is responsible for 3-15% of cases. The paucity of data from India in this regard prompted us to conduct this prospective multicentric analysis to detect the prevalence of and in our geographical region. A total of 453 patients with symptoms of pneumonia and 90 controls with no history of lower respiratory tract infections were included in the study. A duplex polymerase chain reaction (PCR) targeting 543 bp region of gene of and 375 bp region of gene of was standardized for simultaneous detection of these atypical pathogens. Respiratory secretions, blood, and urine samples were collected from each patient and control and were subjected to duplex PCR, culture and serology for and. Urine samples were subjected for detecting antigen. Among the 453 patients investigated for, 52 (11.4%) were positive for IgM antibodies, 17 were positive by culture, and seven tested positive by PCR ( gene). Similarly for , 50 cases (11%) were serologically positive for IgM antibodies, one was positive by PCR ( gene) and urine antigen detection. A total of eight samples were positive by duplex PCR for gene ( = 7) and gene ( = 1). Of the 90 controls, two samples (2.2%) showed IgM positivity, and 15 (16.7%) showed IgG positivity for . For, three samples (3.3%) tested positive for IgM, and 12 (13.3%) tested positive for IgG antibodies. The study findings indicate the presence of and in our geographical region, and a combination of laboratory approaches including PCR, culture, and serology is required for effective detection of these agents.
Proactive environmental surveillance for Legionella pneumophila in hospitals that treat immunocompromised patients is a useful strategy for preventing nosocomial Legionnaires’ disease. We report the presence of L. pneumophila serogroup 1 in 15.2% of the water systems of our tertiary healthcare center, which should prompt health officials to formulate mitigation policies.
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.
Legionella pneumophila infection may become fatal in immunocompromised state. We report here the first known fatal case from India due to Legionella pneumophila infection complicated by renal failure in a patient undergoing treatment for Sarcoidosis. Sarcoidosis is an idiopathic systemic inflammatory disease involving multiple organs. Urine antigen detection and polymerase chain reaction targeting 16S rRNA gene could help in rapid diagnosis of the infection and thereby start specific therapy. Clinical awareness along with availability of rapid diagnostic tests and institution of specific therapy may reduce morbidity and mortality associated with this infection especially in immunocompromised state.
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