Community-acquired pneumonia caused by Legionella pneumophila (“Legionnaire's Disease”): a brief overview and clinical observation

“Legionnaire's Disease” is an acute infectious disease caused by Legionella of the Legionellaceae family. Clinical forms of legionellosis are diverse, but the risk of severe community-acquired pneumonia (СAP) is the main clinical significance. Unfortunately, as technological progress increases, epidemiological risks of foci of infection associated with artificial water systems (favorable habitat for Legionella) are increasing, which has led to numerous epidemic outbreaks and group cases of legionellosis infection recorded in the world recently. There are no pathognomonic symptoms and signs that allow it to be reliably differentiated from CAP by another etiology for “Legionnaire's disease”. An important role in the early verification of the disease is assigned to taking into account known risk factors of infection (a recent trip accompanied by possible contact with a water spray of a centralized air conditioning system) – age over 40 years, male sex, smoking, chronic concomitant diseases (diabetes mellitus, etc.), immunosuppression and timely laboratory diagnosis. The most accessible and convenient methods of primary diagnostics of community-acquired legionellosis are tests based on the detection of soluble antigen L. pneumophila serogroup-1 in urine. The treatment of Legionellosis CAP is based on antibacterial therapy, levofloxacine and macrolides are the drugs of choice. In this article, a series of clinical observations (2017 – 2019) in one of the multidisciplinary hospitals of Moscow is given as a confirmation of the clinical significance of legionella in the etiology of CAP in hospitalized patients and the need for timely diagnosis of the disease. 

1. Diederen B.M.W. Legionella spp. and Legionnaires’ disease. J. Infect. 2008; 56 (1): 1–12. DOI: 10.1016/j.jinf.2007.09.010.

2. Tartakovskiy I.S., Sinopal'nikov A.I. [Legionellosis: the role in human infectious diseases]. Klinicheskaya mikrobiologiya i antimikrobnaya khimioterapiya. 2007; 3 (9): 219–233 (in Russian).

3. Tartakovskiy I.S., Gruzdeva O.A. [Legionellosis (Legionnaire's disease, Pontiac fever)]. In: Briko N.I., Onishchenko G.G., Pokrovskiy V.I., eds. [Guidelines for the Epidemiology of Infectious Diseases]. Moscow: MIA; 2019. V. 2: 477–495 (in Russian).

4. Tartakovskiy I.S., Gruzdeva O.A., Galstyan G.M., Karpova T.I. [Prevention, Diagnosis and Treatment of Legionellosis.]. Moscow: MDV; 2013 (in Russian).

5. Joseph C., Ricketts C. The epidemiology of Legionnaires disease. In: Heuner K., Swanson M., eds. Legionella: Molecular Biology. Norfolk: Caster Akademic Press; 2008: 35–52.

6. Hamilton K.A., Prussin A.J., Ahmed F., Haas C.N. Outbreaks of Legionnairesʹ disease and Pontiac fever 2006-2017. Curr. Environ. Health Rep. 2018; 5 (2): 263–271. DOI: 10.1007/s40572-018-0201-4.

7. Vergis E.N., Akbas E., Yu V.L. Legionella as a cause of severe pneumonia. Semin. Respir. Crit. Care Med. 2000; 21 (4): 295–304. DOI: 10.1055/s-2000-9862.

8. Zakharenkov I., Rachina S., Kozlov R. et al. Etiology and antibiotic resistance patterns in adults with severe community-acquired pneumonia in Russia. Eur. Respir. J. 2019; 54 (Suppl. 63): PA290.

9. Rachina S.A., Bobylev A.A. [Atypical pathogens of community-acquired pneumonia: epidemiology, diagnosis, and treatment]. Prakticheskaya pul'monologiya. 2016; (2): 20–28 (in Russian).

10. Chuchalin A.G., Sinopal'nikov A.I., Kozlov R.S. et al. [Russian Respiratory Society, Interregional association on clinical microbiology and antimicrobial chemotherapy. Clinical guidelines on diagnosis, treatment and prevention of severe community-acquired pneumonia in adults]. Pul'monologiya. 2014; (4): 13–48. DOI: 10.18093/0869-0189-2014-0-4-13-48 (in Russian).

11. Bartram J. et al., eds. Legionella and the prevention of legionellosis. World Health Organization; 2007. Available at: https://www.who.int/water_sanitation_health/emerging/legionella.pdf

12. Stout J.E., Yu V.L. Hospital-acquired Legionnairesʹ disease: new developments. Curr. Opin. Infect. Dis. 2003; 16 (4): 337–341. DOI: 10.1097/00001432-200308000-00005.

13. Tartakovskiy I.S., Gruzdeva O.A., Gabrielyan N.I. [Current aspects of nosocomial legionellosis profilaxis].Vestnik transplantologii i iskusstvennykh organov 2010; 12 (4): 61–71 (in Russian).

14. Chuchalin A.G., Sinopal'nikov A.I., Tartakovskiy I.S. et al. [Guidelines on diagnosis and treatment of Legionella pneumophila serogroup 1 infection]. Klinicheskaja mikrobiologija i antimikrobnaja himioterapija. 2009; 11 (1): 4–13 (in Russian).

15. Tartakovskiy I.S., Novokshonova I.V., Marinenko O.V. et al. [Rate and level of contamination of potentially dangerous water supply facilities in Moscow region by Legionella pneumophila]. Zhurnal mikrobiologii, jepidemiologii i immunobiologii. 2010; (6): 21–26 (in Russian).

16. Gruzdeva O.A., Tartakovskiy I.S. [Organization of prevention of legionellosis]. Zdravoohranenie Rossijskoy Federacii. 2011; (1): 26–28 (in Russian).

17. Gruzdeva O.A., Tartakovskiy I.S., Karpova T.I., Marinenko O.V. [Features of epidemiology and prevention methods of nosocomial legionellosis]. Jepidemiologiya i vakcinoprofilaktika. 2014; 1 (74): 19–23 (in Russian).

18. Mercante J.W., Winchell J.M. Current and emerging legionella diagnostic for laboratory and outbreak investigations. Clin. Microbiol. Rev. 2015; 28 (1): 95–133. DOI: 10.1128/CMR.00029-14.

19. Legionellosis – United States, 2000–2009. Am. J. Transplant. 2012; 12 (1): 250–253. DOI: 10.1111/j.1600-6143.2011.03938.x.

20. Rachina S.A., Kozlov R.S., Dehnich N.N. et al. [Antibiotic therapy for severe community-acquired pneumonia in adults: a review of guidelines and clinical examples.]. Arhiv vnutrenney mediciny. 2015; 3 (23): 63–74 (in Russian).