91
Test
Culture
• The clinical and environmental
isolates can be compared.
• Detects all the species and
serogroups.
• 100% specific.
• Technically difficult.
• Response time: 3 to 7 days to
obtain the result.
• Sensitivity highly dependent on
technical capacity that can vary
from < 10 to 80%.
• Can be affected by treatment
with antibiotics.
Search of the
antigen in
urine
• Specificity >99%.
• Rapid execution (results in less
than 1 hour).
• Detects only
L.pneumophila
serogroup (Lp1).
Serology
• Less affected by the treatment
with antibiotics.
• Specificity > 95%.
• Sensitivity 80-90%
• The serum samples must be
paired.
• Response time from 3 to 10
weeks.
• 5-10% of the population has
titer 1:≥256.
• Antibody titers of individual
acute phase of 1:≥256 do not
discriminate among the cases of
Legionnaires’ disease and other
causes of community-acquired
pneumonia.
Direct Immu-
nofluorescence
(DFA)
• Specificity >95%.
• 25-75% sensitive
• Very hard technique and
dependent on specific
professional qualification.
PCR
• Rapid response time (< 4 hours).
• Tests vary according to the
laboratory.
Advantages
Disadvantages
The table 01 below summarizes the main advantages and disadvantages of
laboratory tests available for laboratory diagnosis of Legionellosis.
Table 01 – Advantages and disadvantages of the laboratory tests available for
laboratory diagnosis of Legionellosis.
