Two years' performance of an in-house ELISA for diagnosis of Legionnaires' disease: Detection of specific IgM and IgG antibodies against Legionella pneumophila serogroup 1, 3 and 6 in human serum

This study confirms that the detection of IgG and IgM antibodies by ELISA is an important diagnostic tool, also during the initial phase of the disease. Furthermore, we showed that LD in Denmark with or without serum samples collected exhibits the same age and sex distribution and epidemiology, as in the rest of Europe, i.e., mostly men are infected, infections are mostly community acquired, followed by infection from travelling abroad. Apart from patients with notified LD, the patients investigated by serology were evenly distributed in all age groups; there was only a slightly higher ratio of men tested for “atypical pneumonia” in the serology laboratory.