Korean J healthc assoc Infect Control Prev.  2022 Dec;27(2):134-140. 10.14192/kjicp.2022.27.2.134.

Epidemiological Investigation and Control Measures of a Case of Nosocomial Legionella Pneumonia in a Pediatric Hematopoietic Stem Cell Transplantation Unit

• Yang J
• Cho SY
• Shin L
• Kim DM
• Jeong JS
• Chung DR

• KMID: 2537074
• DOI: http://doi.org/10.14192/kjicp.2022.27.2.134

Abstract

Background
Nosocomial legionellosis is associated with high mortality. Here, we present the results of an epidemiological investigation and the control measures undertaken for a case of nosocomial Legionella pneumonia at a pediatric hematopoietic stem cell transplantation (HSCT) unit.
Methods
A 22-month-old boy developed nosocomial Legionella pneumonia while at a pediatric HSCT unit. A multidisciplinary team conducted an environmental assessment of the hospital water system and collected water and swab samples from faucets and shower heads from the index patient rooms and nurse stations for Legionella culture.
Results
Legionella was isolated from two swab samples and four water samples out of a total of 24 environmental samples. Follow-up cultures were conducted after replacing the faucets or shower heads which tested positive on Legionella cultures, and point-of-use filters were additionally installed on the sites where Legionella were still isolated. When the water temperature was measured in 20 patient areas, the hot water from the four areas was 50°C or less. Based on the results of the investigation, several interventions including water temperature increase (60°C or higher), flushing out hot water in all patient rooms monthly, cleaning and disinfecting faucets and shower heads monthly, and expanding sampling sites for surveillance were implemented. After the implementation of the control measures, no cases of nosocomial legionellosis occurred, and Legionella was not detected in environmental samples.
Conclusion
Conducting multidisciplinary collaboration and investigation, even for a single nosocomial legionellosis, is important to identify the source and to prevent further transmission. Hospitals should maintain comprehensive water management programs and ensure that control measures are implemented through continuous monitoring.

Keyword

Infection control; Legionella; Pneumonia; Surveillance

Figure

• 

  Fig. 1 Chest computed tomography showed multiple mass-like, confluent consolidative lesions in both lungs.

• 

  Fig. 2 (A) Schematic representation of the water supplying system at the study hospital (blue line: cold water, red line: hot water, yellow box: water heater and grey box: water tank). (B) Floor plan and water flow of the 8th floor where the case patients was hospitalized (red line and blue arrow: hot water flow and black circle: sampling point of Legionella culture).

• 

  Fig. 3 Reinforced cleaning, disinfection and maintenance of water system components.

Reference

1. Soda EA, Barskey AE, Shah PP, Schrag S, Whitney CG, Arduino MJ, et al. 2017; Vital signs: health care-associated Legionnaires' disease surveillance data from 20 states and a large metropolitan area - United States, 2015. MMWR Morb Mortal Wkly Rep. 66:584–9. DOI: 10.15585/mmwr.mm6622e1. PMID: 28594788. PMCID: PMC5720245.

2. Cunha BA, Burillo A, Bouza E. 2016; Legionnaires' disease. Lancet. 387:376–85. DOI: 10.1016/S0140-6736(15)60078-2. PMID: 26231463.

3. Korea Disease Control. Guidelines for the management of respiratory infectious diseases, 2022. https://www.kdca.go.kr/board/board.es?mid=a20507020000&bid=0019&act=view&list_no=718910. Updated on 7 March 2022.

4. Kanamori H, Weber DJ, Rutala WA. 2016; Healthcare outbreaks associated with a water reservoir and infection prevention strategies. Clin Infect Dis. 62:1423–35. DOI: 10.1093/cid/ciw122. PMID: 26936670.

5. Kessler MA, Osman F, Marx J Jr, Pop-Vicas A, Safdar N. 2021; Hospital-acquired Legionella pneumonia outbreak at an academic medical center: lessons learned. Am J Infect Control. 49:1014–20. DOI: 10.1016/j.ajic.2021.02.013. PMID: 33631307.

6. Campins M, Ferrer A, Callís L, Pelaz C, Cortés PJ, Pinart N, et al. 2000; Nosocomial Legionnaire's disease in a children's hospital. Pediatr Infect Dis J. 19:228–34. DOI: 10.1097/00006454-200003000-00011. PMID: 10749465.

7. Bauer M, Mathieu L, Deloge-Abarkan M, Remen T, Tossa P, Hartemann P, et al. 2008; Legionella bacteria in shower aerosols increase the risk of Pontiac fever among older people in retirement homes. J Epidemiol Community Health. 62:913–20. DOI: 10.1136/jech.2007.063784. PMID: 18791050.

8. Gattuso G, Rizzo R, Lavoro A, Spoto V, Porciello G, Montagnese C, et al. 2022; Overview of the clinical and molecular features of Legionella pneumophila: focus on novel surveillance and diagnostic strategies. Antibiotics (Basel). 11:370. DOI: 10.3390/antibiotics11030370. PMID: 35326833. PMCID: PMC8944609.

9. ECDC. European technical guidelines for the prevention, control and investigation of infections caused by Legionella species. https://www.ecdc.europa.eu/en/publications-data/european-technical-guidelines-prevention-control-and-investigation-infections. Updated on June 2017.

10. Francois Watkins LK, Toews KE, Harris AM, Davidson S, Ayers-Millsap S, Lucas CE, et al. 2017; Lessons from an outbreak of Legionnaires' disease on a hematology-oncology unit. Infect Control Hosp Epidemiol. 38:306–13. DOI: 10.1017/ice.2016.281. PMID: 27919312. PMCID: PMC5887123.

11. Laganà P, Facciolà A, Palermo R, Delia S. 2019; Environmental surveillance of legionellosis within an Italian university hospital-results of 15 years of analysis. Int J Environ Res Public Health. 16:1103. DOI: 10.3390/ijerph16071103. PMID: 30925660. PMCID: PMC6480113.

12. CDC. Water management program validation. https://www.cdc.gov/legionella/wmp/healthcare-facilities/water-mgmt-validation.html. Updated on 25 March 2021.

13. Quaranta G, DI Pumpo M, LA Milia DI, Wachocka M, Pattavina F, Vincenti S, et al. 2021; A management model for Hospital Hygiene Unit: evidence-based proactive surveillance of potential environmental sources of infection in order to prevent patient's risk. J Prev Med Hyg. 61:E628–35. DOI: 10.15167/2421-4248/jpmh2020.61.4.1587. PMID: 33628970. PMCID: PMC7888400.