Antimicrobial strategy for severe community-acquired legionnaires' disease

Q: Doxycycline is a good choice of treatment in patients with Legionnaires' disease?

A) True

B) False

Answer: B

Tetracyclines like doxycycline are not a good choice to treat Legionnaires' disease as resistance is high. The two most effective antibiotics are levofloxacin and azithromycin. Both of these antibiotics are

• bactericidal
• achieve high intracellular concentrations
• penetrate lung tissue, and 
• active against all Legionella species

Alternatively, drugs from the same classes can be used.

Said that combining levofloxacin and azithromycin does not provide any added benefit. Similarly, adding rifampin also does not provide any benefit.

Tigecycline can be tried as a salvage therapy in refractory L. pneumophila infections.

#ID

#antibiotics

References:

1. Cecchini J, Tuffet S, Sonneville R, et al. Antimicrobial strategy for severe community-acquired legionnaires' disease: a multicentre retrospective observational study. J Antimicrob Chemother 2017; 72:1502.

2. Garcia-Vidal C, Sanchez-Rodriguez I, Simonetti AF, et al. Levofloxacin versus azithromycin for treating legionella pneumonia: a propensity score analysis. Clin Microbiol Infect 2017; 23:653.

3. Grau S, Antonio JM, Ribes E, et al. Impact of rifampicin addition to clarithromycin in Legionella pneumophila pneumonia. Int J Antimicrob Agents 2006; 28:249.

4. Bopp LH, Baltch AL, Ritz WJ, et al. Activities of tigecycline and comparators against Legionella pneumophila and Legionella micdadei extracellularly and in human monocyte-derived macrophages. Diagn Microbiol Infect Dis 2011; 69:86.