Measles and rubella laboratory network
The global measles and rubella laboratory network was developed based on the successful model of the global polio laboratory network. As of 2008, 679 laboratories have been established in 164 countries. Many of these laboratories are also responsible for laboratory-based surveillance of other vaccine preventable diseases in their countries.
Measles case confirmation is based on confirming suspected cases with the detection of measles specific IgM from a single serum sample collected from a suspected case at first contact with a health facility, anytime within 28 days of rash onset. Most national laboratories use standardized, validated ELISA IgM assays which are simple and rapid to perform, with results possible within 3-4 hours after a sample arrives in the laboratory. Measles virus detection is not used as a diagnostic tool due to the very short period of measles excretion following rash onset (～5 days). However viruses are collected from outbreaks wherever possible and sequencing these viruses is helpful for determining measles transmission patterns. In conjunction with epidemiological data, sequencing information can determine whether cases are due to indigenous or imported virus.
Rubella surveillance is often integrated with measles surveillance as the WHO measles case definition also captures rubella cases. Many countries administering rubella vaccine also take advantage of the combination vaccine presentation of measles and/or mumps. The confirmation of rubella cases is very similar to measles. The standard procedure recommends use of an IgM ELISA assay performed on a single serum sample. Most countries follow a procedure of testing measles negative samples for rubella. Rubella virus detection is more challenging than for measles, but when successful, sequence information can be utilized for the same molecular epidemiological purposes as for measles.