Table 1 Summary of 7 key management recommendations for severe Legionnaire’s disease (LD)

1

Early appropriate antibiotic therapy (within 24 h of hospital admission and 8 h of ICU admission) is associated with better outcomes

2

Use a bactericidal agent with good lung penetration, active against all species causing human infection achieving high intracellular concentrations. Either intravenous levofloxacin or azithromycin are the preferred agents for severe LD. Newer macrolides (clarithromycin, spiramycin) are alternative options

3

Consider combining levofloxacin and macrolides if vasoactive agents are required, for immunocompromised patients or in case of monotherapy treatment failure. Adding rifampin does not appear to improve outcomes but increase adverse events. CS therapy should not be recommended

4

Severe pneumonia often requires above 10 days of therapy and immunocompromised hosts require longer duration than 14 days

5

Utility of procalcitonin in patients with LD is not well-established

6

Consider superinfection, empyema (lung ultrasound assessment) and causes of non-resolving pneumonia if delayed resolution

7

Alert public health authorities to find the source of contamination or in the case of nosocomial cases