title: Phylogenetic and epidemiological analysis of measles outbreaks in Denmark, 2013 to 2014.
abstract: 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.
authors.affiliation: Microbiological Diagnostics and Virology, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Lasse Dam
authors.initials: LD
authors.lastname: Rasmussen
authors.forename: Jannik
authors.initials: J
authors.lastname: Fonager
authors.forename: Lisbet Krause
authors.initials: LK
authors.lastname: Knudsen
authors.forename: Peter Henrik Senten
authors.initials: PH
authors.lastname: Andersen
authors.forename: Jesper
authors.initials: J
authors.lastname: Rønn
authors.forename: Mille Weismann
authors.initials: MW
authors.lastname: Poulsen
authors.forename: Kristina Træholt
authors.initials: KT
authors.lastname: Franck
authors.forename: Thea Kølsen
authors.initials: TK
authors.lastname: Fischer
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D004196:Disease Outbreaks; D062665:Epidemiological Monitoring; D005260:Female; D005838:Genotype; D060005:Genotyping Techniques / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology*; D008459:Measles virus / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D022542:Measles-Mumps-Rubella Vaccine / Q000008:administration & dosage; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D014611:Vaccination / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D022542:Measles-Mumps-Rubella Vaccine
keywords: Measles; epidemiology; genotyping; outbreaks; transmission