Molecular Detection by PCR and Sequencing<<Return to Laboratory
Molecular detection of Borrelia species causing relapsing fever including, but not limited to; B. hermsii and B. miyamotoi in clinical specimens.
- Relapsing fever
Serum is a low-yield specimen type for the detection of these organisms and will be rejected.
Collect blood in EDTA tubes. Do not centrifuge. Minimum volume required is 5 mL.
Store whole blood refrigerated up to 5 days. Ship with freezer packs.
Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.
For additional guidance on the transport of infectious substances in other languages, please click on the link below.
Appropriate clinical symptoms with potential exposure to ticks or lice while travelling to endemic areas.
Clinical manifestations include recurring episodes of fever, headache, neck stiffness, arthralgia, myalgia, ecchymosis, epistaxis, and petechiae. Some individuals present with symptoms similar to Lyme disease, including fever, headache, fatigue, chills, myalgia, joint and muscle pain, loss of appetite, nausea, disorientation or memory loss, lack of coordination, as well as more severe conditions of neurological disease, headache, muscle and joint aches, and nausea.
There are two types of relapsing fever; Tick-borne relapsing fever (TBRF) and Louse-borne relapsing fever (LBRF).
Tick-borne relapsing fever is spread by multiple tick species, each of which has a preferred habitat and set of hosts. Hard-bodied (Ixodes) ticks are vectors of B. miyamotoi, which causes TBRF in North America, Eastern Europe, Russia and Japan. In addition, TBRF can also be due to other Borrelia species such as B. hermsii, which are transmitted by various soft-bodied (Ornithodoros) ticks. These ticks are found in the western and south-western United States as well as in discrete areas throughout the world, including plateau regions of Mexico, Central and South America, the Mediterranean, Central Asia, and much of Africa.
Louse-borne relapsing fever is caused by B. recurrentis and is transmitted by the human body louse. This illness is generally associated with refugee settings where over-crowding and limited washing facilities exist. It is endemic in north-eastern Africa.
Completed Requisition for Molecular Testing for Selected Zoonotic with recent travel history. If possible, include the clinical history and lab results performed at local or provincial laboratories.
Specimens may be subject to rejection if they are not the appropriate sample type, have insufficient volume, or are not accompanied by relevant patient information.
THIS TEST IS PERFORMED FOR INVESTIGATIONAL OR RESEARCH PURPOSES ONLY
Extracted DNA is screened by a real-time PCR assay that detects Borrelia species. If positive in the screening assay, samples are further tested by RFB-specific real-time PCR, as well as conventional PCR and sequencing for confirmation of species.
Initiation of antibiotic treatment prior to testing may result in decreased bacterial genome which will affect the outcome of PCR testing.
21 calendar days.
- Courtney, J.W., Kostelnik, L.M., Zeidner, N.S., Massung, R.F. 2004. Multiplex real-time PCR for detection of Anaplasma phagocytophilum and Borrelia burgdorferi.J. Clin. Micro. 42(7):3164-3168.
- Scott, J.C., Wright, D.J., and Cutler, S.J. 2005. Typing African Relapsing Fever Spirochetes. Emerging Infectious Diseases, 11(11), 1722–1729. http://doi.org/10.3201/eid1111.050483et al., 2005. Typing African Relapsing Fever Spirochetes. Emerg. Inf. Dis. 11(11):1722-1729.
- Bunikis J., Tsao J., Garpmo U., Berglund J., et al., 2004. Typing of Borrelia relapsing fever group strains. Emerg. Inf. Dis. 10:1661–1664.
- Elbir, H., Henry, M., Diatta, G., Mediannikov, O., et al. 2013. Multiplex Real-Time PCR Diagnostic of Relapsing Fevers in Africa. PLoS Neg. Trop. Dis. 7(1), e2042.