Our Rickettsia testing includes the screening for rickettsia of the spotted fever group (SFG), typhus group (TG) and scrub typhus group (STG).
Although STG infections are caused by the genus Orientia, these organisms are closely related to the rickettsia and are hence found in the same cluster.
There are three tests offered for the diagnosis of these diseases:
- An Indirect microimmunofluorescence assay (IFA)
- Polymerase chain reaction (PCR)
For the IFA, clotted blood (serum) may be submitted for serological diagnosis. If possible a follow-up specimen should be sent a minimum of 7-10 days later to detect a change from negative to a positive antibody level (seroconversion) or if the first sample is positive, a significant increase in antibody levels will also confirm the diagnosis.
The PCR involves the detection of a specific DNA target of the bacterial genome.
The culture assay involves the isolation of the organism in cell culture and can take up to twelve weeks.