Wednesday, 18 September 2013

MERS-CoV WHO testing guidelines: September update

The World Health Organization has updates its laboratory testing guidelines. They can be accessed here.

Some key points:

  • Lower respiratory tract samples are recommended since there are data to support higher viral loads (better detectability using PCR) from these samples
  • The upE real-time reverse transcriptase polymerase chain reaction (RT-rtPCR) assay of Corman et al is considered highly sensitive and is recommended for screening
  • The ORF1a screening assay is of equal sensitivity and the ORF1b slightly less sensitive than upE
  • RdRp and N gene assay are suitable for genotyping
  • Antibody testing assays are described and some seem to be very sensitive. none have been validated against a large panel of known MERS-CoV POS sera and result interpretation is still without consensus
  • Laboratories should notify their local public health authorities as soon as they receive a specimen for MERS-CoV testing and all results should also be passed along to these authorities.
  • Member States are asked to immediately notify WHO of initially POS laboratory results even before confirmatory testing is complete.
Pretty clear and straightforward really.