Should Legionella urinary antigen test be applied in any case of community-acquired pneumonia?

Abstract number: O33

Pedro-Botet M.L., Sopena N., Tudela P., Roure S., Mateu L., Heras E., Rey-Joly C., Sabrià M.

Objectives: Despite the availability of a simple and rapid test such as Legionella urinary antigen (LUA), that allows the diagnosis of up 80% of infections caused by L. pneumophila sg 1, its systematic use in community-acquired pneumonia (CAP) is controversial. In this study we evaluated the incidence of Legionella infection observed during periods of routine and non routine use of the LUA test in our hospital.

Methods: Four different periods were evaluated (Table 1). During period I the LUA test was never applied. In period II a prospective study on the aetiology of CAP was carried out and the LUA test was used in almost all cases of CAP. At the end of this study the use of the LUA test decreased and was limited to patients with epidemiologically or clinically suspected LD (period III). From February 1998 to October 2006, the use of the LUA test was included in the hospital CAP guidelines and routinely performed (period IV).

Results: Table 1 shows the number of diagnoses of CAP by Legionella in each period related to the cases of CAP admitted to the hospital during the same period.

Conclusions: As observed in this study, the incidence of CAP by Legionella rose notably when doctors considered this entity because of an ongoing investigation or a hospital policy that considered the use of LUA when pneumonia is diagnosed. To the contrary, when Legionella infection was considered a rare entity (period I) or it was only investigated when clinical data was suggestive of LD the incidence declined significantly (period III). When extrapolating these data to all the cases of CAP, this figure would increase considerably and probably thousands of patients would not be diagnosed with LD worldwide.

Table 1. Periods studied and cases of Legionnaires disease (LD)

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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