Measles in Europe

We describe characteristics of an ongoing measles outbreak in Wallonia, Belgium, and difficulties in control measures implementation. As at 12 March 2017, 177 measles cases were notified, of which 50% were 15 years and older, 49% female. Atypical clinical presentation and severe complications, mainly among adults, in combination with late notification, low or unknown vaccination coverage of contacts, infected healthcare workers and increased workload due to contact tracing, are the main concerns for outbreak management.

We report 52 cases of measles linked to music and arts festivals in England and Wales, between mid-June and mid-October 2016. Nearly half were aged 15 to 19 years. Several individuals who acquired measles at one festival subsequently attended another festival while infectious, resulting in multiple interlinked outbreaks. Transmission within festivals resulted in a geographical spread of cases nationally as well as internationally, which presents particular challenges for measles control.

We report an outbreak of measles which started in April 2016 and which, by 13 June, has resulted in 22 confirmed and five probable measles cases occurring in four regions of Ireland. Genotype B3 was identified. We describe the identification, ongoing investigation and control measures being implemented. This outbreak occurs during a period of very low measles transmission in Ireland, with only one confirmed case (imported) notified in 2016 before this event.

This report describes a joint measles outbreak investigation between public health officials in the United Kingdom (UK) and the Netherlands following detection of a measles cluster with a unique measles virus strain. From 1 February to 30 April 2014, 33 measles cases with a unique measles virus strain of genotype B3 were detected in the UK and the Netherlands, of which nine secondary cases were epidemiologically linked to an infectious measles case travelling from the Philippines. Through a combination of epidemiological investigation and sequence analysis, we found that measles transmission occurred in flight, airport and household settings. The secondary measles cases included airport workers, passengers in transit at the same airport or travelling on the same flight as the infectious case and also household contacts. This investigation highlighted the particular importance of measles genotyping in identifying transmission networks and the need to improve vaccination, public health follow-up and management of travellers and airport staff exposed to measles.

Despite the introduction of safe, effective vaccines decades ago and joint global public health efforts to eliminate measles, this vaccine-preventable disease continues to pose threats to children’s health worldwide. During 2013 and 2014, measles virus was introduced into Denmark through several independent importations. This resulted in a number of secondary cases (n = 7), with two clusters in 2013 and one in 2014. In total, there were 44 cases of measles. Most cases (n = 41) were laboratory confirmed by detection of measles virus genome by real-time reverse transcription (RT)-PCR and IgM antibodies. The viruses from confirmed cases were genotyped by sequencing. Only one genotype circulated each year, i.e. D8 and B3, respectively. Sequencing of measles virus from different clinical specimens from the same patients revealed that sequence variants of measles viruses might co-exist and co-transmit during an outbreak. The majority of the cases were unvaccinated (n = 27) or recipients of one dose of measles-mumps-rubella (MMR) vaccine (n = 7). In addition, two fully vaccinated adult cases were reported in 2014. We demonstrate the transmission of measles virus in a population in which the two-dose MMR vaccination coverage rate was 80% and how even vaccinated individuals may be at risk of contracting measles once transmission has been established.