Isolate and identify Legionella sp.
Contamination with normal flora from respiratory tract should be avoided.
Transport to the laboratory within 24 hours of collection.
Refrigerated (preferred) - 24 hours
Culture on selective and nonselective media
No Legionella species isolated
Isolate and identify Legionella spAcute and convalescent sera for Legionella antibodies should also be considered to increase the chance of documenting the diagnosis. A fourfold rise to a titer of 1:128 is a diagnostic standard criterion. Seroconversion may be detected in many patients in the first weeks. Seroconversion 0-7 days after onset, 16%; 0-14 days, 52%; 0-21 days, 66%; 0-28 days, 71%. Twenty-five percent of patients did not have diagnostic titers.
Consult the laboratory regarding availability and selection of the most appropriate method. Nosocomial infections have been recognized with reservoirs in the water distribution systems, cooling systems, and hot water systems of hospitals being reported. Twenty species in the Legionellaceae family of bacteria have been discovered since Legionella pneumophila was first recognized. Thirteen species have been implicated as causes of human pneumonia.