Anti-TNF therapy and the risk for Legionella pneumophila

We don't ordinarily think of Legionella pneumophila as an opportunist but findings of a recent study indicate that patients undergoing anti-TNF therapy are at special risk. The paper concludes:

The incidence rate of legionellosis for patients receiving TNF-α antagonists is high, and the risk is higher for patients receiving anti-TNF-α monoclonal antibodies than soluble TNF-receptor therapy. In case of pneumonia occurring during TNF-α antagonist therapy, specific urine antigen detection should be performed and antibiotic therapy should cover legionellosis.

The CAP guidelines recommend legionella coverage for all patients. Urinary antigen testing, however, is only recommended for select groups (e.g. ICU admissions, outpatient treatment failure) with no mention made of anti-TNF treatment status.