Molecular Detection (RT-PCR)

Molecular detection of the measles virus by RT-PCR.

Urine, nasopharyngeal (NP) swab, throat swab. All specimens should be collected as soon as possible after rash onset (within 7 days for urine and 4 days for NP/throat swabs). Note: specimens collected later will still be accepted however the assay sensitivity will not be optimal. Viral isolates may also be sent.

Prélever 50 mL (minimum 10 mL) d’urine dans un contenant stérile. Pour les écouvillonnages, utiliser des écouvillons stériles approuvés pour l’isolement des virus pour le prélèvement des cellules épithéliales de la gorge ou des voies nasales. Placer les écouvillons de gorge et nasopharyngés dans 2-3 mL de milieu de transport viral (MTV) pendant au moins 1 heure. Pour l’isolat viral, prélever les cellules infectées et le milieu, et soumettre au moins 1,0 mL.

Process urine by centrifuging at 2500 x g for 15 minutes at 4°C. Resuspend the sediment in 1-2 mL VTM. For NP and throat swabs, remove the swab. Store at 4°C and ship on wet ice for arrival at the NML within 48 hours of collection. Otherwise, freeze at -70°C and ship frozen on dry ice. Viral Isolates should be shipped frozen (-70°C) on dry ice.

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.

Suspected cases of measles. Refer to reference 1 for case definitions.

Completed Measles, Mumps, and Rubella requisition form. Include date of rash onset, date of fever onset, date of last measles vaccination (if recent), travel history and/or MARS identifier (from the Measles and Rubella Surveillance application on CNPHI) or case number if available.

Measles genotyping is automatically performed on measles RT-PCR positive samples. It is important to provide a complete patient history (including travel) for accurate genotype surveillance. This test is accredited to CAN-P-4E (ISO/IEC 17025) standards. The NML is a WHO/PAHO accredited Measles and Rubella Regional Reference Laboratory.

Extracted RNA from samples is tested by real-time RT-PCR for the measles Nucleoprotein (N) gene and measles Hemagglutinin (H) gene (4). Positive RT-PCR result is laboratory confirmation of measles infection.

7 calendar days. Stat testing available upon request.

1. Measles and Rubella Elimination Working Group, Health Canada, Public Health Agency of Canada. Guidelines for the prevention and control of measles outbreaks in Canada. CCDR. 2013; 39:ACS-3. Available at http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/13vol39/acs-dcc-3/index-eng.php#appa.
2. Tipples G, J Hiebert. Detection of measles, mumps and rubella viruses. Methods Mol Biol. 2011; 665: 183-193.
3. World Health Organization. Manual for the laboratory diagnosis of measles and rubella virus infection. 2007. WHO/IVB/07.01
4. Hummel KB, Lowe L, Bellini WJ, Rota PA. Development of quantitative gene-specific real-time RT-PCR assays for the detection of measles virus in clinical specimens. J Virol Methods. 2006; 132:166-73.