Rickettsia: PCR

Test description

• Real-time PCR for the detection of DNA of Rickettsia of the spotted fever group
• Real-time PCR for the detection of DNA of Rickettsia of the typhus group

The highest sensitivity is achieved when analysing material from the eschar at the level of the inoculation site. An alternative is a biopsy (possibly swab) of the skin rash, vesicles or petechiae. In the absence of skin lesions, examination of EDTA whole blood or serum may be potentially useful. However, PCR has low sensitivity on this material.

Purpose of the test

Diagnosis in the acute phase of the disease (up to 7-15 days after the onset of symptoms) (EDTA blood) or as long as cutaneous lesions are present (biopsy/scaffold).

Criteria for performing this test in the context of reference activities

• Clinical suspicion of recent infection
• Indicate the interval between symptom onset and sample collection on the request form
• Indicate clinical and epidemiological information on the request form

Instructions for samples

• Biopsy/rash of eschar/rash. Place biopsies immediately in sterile physiological water, keep scabs/rash dry and sterile
• Alternative: remove a sterile, dry ‘flocked swab’ by three twisting movements against the edge of the lesion (eschar/rash). Cool the swab immediately (4°C) and store dry
• EDTA blood (minimum volume 2 ml)
• Store all samples at 4°C
• For transport to the NRC of > 24 h, samples should be stored and shipped at -20°C

Instructions for transport

• Samples stored at 4°C, can be shipped at room temperature.
• Samples stored at -20°C, should be shipped on dry ice.
• Transit time should be kept as short as possible (avoid transportation during weekends or holidays).

Unacceptable requests

Analysis will not be performed in case of:

• Blood collection outside the acute phase of the disease (or date of onset of symptoms not communicated)
• Inappropriate or insufficient sample
• Improper transport or storage
• Application form not fully completed

Turn around time (and frequency of analysis)

Average: 12 days.

Reporting of test results

The report is sent by fax, post or e-mail.