Legionnaires’ Disease Cases at a Large Community Hospital—Common and Underdiagnosed

Abstract

Legionnaires’ disease (LD) is a severe pneumonia with a mortality rate of about 10%. The illness remains largely underdiagnosed with outbreaks occurring with alarming incidence. In this study, we assessed the frequency of Legionnaires’ disease among pneumonia cases treated at a large community hospital over a summer season. We invited all admitted patients diagnosed with pneumonia, able to provide a urine sample for an antigen test, presenting from May to October 2018, to enroll in our study; 35 patients were tested for the presence of Legionella. Out of 33 patients tested, 9 (28%) were positive for Legionella. Three sets of the 9 Legionella cases exhibited spatiotemporal clustering indicative of LD outbreaks. Only one of the 9 Legionella UAT-positive patients presented a sporadic case of LD. The number of pneumonia cases in our community confirmed to be LD was strikingly high (28%), compared to other survey studies that report between 3.7% and 14%. These results are consistent with previous knowledge that LD is underdiagnosed and support that routine testing should be considered for all possible LD cases, particularly in the summer months. Such testing is likely to prevent further cases of community acquired LD.

The Impact of Storms on Legionella pneumophila in Cooling Tower Water, Implications for Human Health

“…L. pneumophila outbreaks found to be from cooling tower sources have resulted in increased vigilance maintenance and control of existing cooling systems ( Nguyen et al, 2006 ; Ulleryd et al, 2012 ). Legionnaires’ disease cases often remain largely underdiagnosed with outbreaks not properly determined, due to the pneumonia-like symptoms mimicking other ailments, and lack of testing ( Spiegelman et al, 2020 ). In addition, while many biocides are available for water treatment and Legionella prevention, environmental aspects including other biota ( Orrison et al, 1983 ; McNealy et al, 2002 ), water chemistry ( Kim et al, 2002 ), and environmental factors can influence its survival and recalcitrance to biocides ( Mallison, 1980 ).…”

Case Report: Metagenomic Next-Generation Sequencing in Diagnosis of Legionella pneumophila Pneumonia in a Patient After Umbilical Cord Blood Stem Cell Transplantation

“…The most susceptible hosts of hospital-acquired Legionella pneumonia are immunocompromised patients, including organ transplant recipients (8) and cancer patients (9), as well as those receiving glucocorticoid therapy. Multiple studies have shown Legionella infections to be underdiagnosed and undertreated (1,10,11). In this case report, the patient was fortunate to be treated in time and was discharged from the hospital in good health.…”

Detection of Legionella pneumophila as the cause of atypical pneumonia in the water sources of the holy places of Makkah

“…Another published review article of respiratory tract infection during Hajj identified these infections as the most common cause of hospital admissions (Mandourah et al, 2012). Interestingly, a published study of formerly collected data, showed both water samples from different sources include water coolers, sprinkles, and storage tanks in Makah areas such as Arafat, Mona, Muzdaliphah, and nearby the Holy Mosque "Haram", and clinical specimens from pneumonia diagnosed patients admitted to five tertiary hospitals in Makkah and the findings showed that pneumonia was the major cause of sickness in pilgrims and recommended with more studies on water sources (Sreenath et al, 2020;Al-Tawfiq et al, 2013Spiegelman et al, 2020;Zahran et al, 2018). Absence of documented data on the isolation rates of this type of bacteria cause this disease in Saudi Arabia and in view of the results of previous studies during the Hajj season; the reason for the emergence of this type of bacteria may be due to the fact that these hotels use water from wells which can be the main source of these pathogenic bacterial strains.…”