ABSTRACT
In Portugal, measles vaccination coverage and population immunity are high, and no endemic measles cases had been reported since 2004. The World Health Organization classified measles as eliminated in the country in 2015 and 2016, based on data from the previous 3 years. However, in a context of increasing incidence in several European countries in 2016 and 2017, Portugal experienced two simultaneous measles outbreaks with a total of 27 laboratory-confirmed cases (0.3 cases/100,000 population) in two health regions between February and May 2017. Nineteen cases (70.1%) were adults, of whom 12 were healthcare workers. Overall, 17 cases (63.0%) were not vaccinated, of whom five were infants younger than 12 months of age. One unvaccinated teenager died. Genotype B3 was identified in 14 cases from both regions. Measles virus sequencing identified different possible origins of the virus in each region affected. Although measles transmission was stopped in less than 2 months from the first case being notified, these outbreaks represent an opportunity to reinforce awareness of measles diagnosis. We highlight the intensity of the control measures taken and their impact on the rapid control of the outbreaks and also the fact that high vaccination coverage was crucial to stop transmission.
Subject(s)
Disease Outbreaks/prevention & control , Measles Vaccine/administration & dosage , Measles virus/genetics , Measles virus/isolation & purification , Measles/diagnosis , Adolescent , Adult , Child , Child, Preschool , Disease Notification , Female , Genotype , Health Personnel/statistics & numerical data , Humans , Infant , Infant, Newborn , Male , Mandatory Reporting , Measles/epidemiology , Measles/prevention & control , Measles/transmission , Measles/virology , Measles virus/immunology , Middle Aged , Occupational Exposure , Polymerase Chain Reaction , Population Surveillance , Portugal/epidemiology , Vaccination/statistics & numerical data , Vaccination Coverage , Young AdultABSTRACT
We report a measles outbreak in two Portuguese health regions (Algarve and Lisbon and the Tagus Valley) since February 2017, and which by 31 May resulted in 28 confirmed cases, of which 16 were unvaccinated. Thirteen cases were healthcare workers. One unvaccinated teenager died. Genotype B3 was identified in 14 cases from both regions. This outbreak occurs after 12 years without endemic measles transmission, and in a context of high measles vaccination coverage and immunity.
Subject(s)
Measles Vaccine/administration & dosage , Measles virus/genetics , Measles/epidemiology , Measles/prevention & control , Vaccination , Disease Outbreaks/prevention & control , Genotype , Health Personnel/statistics & numerical data , Humans , Male , Measles/virology , Measles virus/immunology , Measles virus/isolation & purification , Portugal/epidemiology , Vaccination/statistics & numerical dataABSTRACT
Human adenoviruses (AdVs) typically cause mild illnesses in otherwise healthy hosts. We investigated a pediatric outbreak of acute respiratory infection with fatal outcomes that occurred in Lisbon, Portugal, in 2004. Biological specimens were collected from 83 children attending two nurseries, a kinesiotherapy clinic, and the household of a nanny. Adenovirus infection was confirmed in 48 children by PCR and virus isolation. Most (96%) isolates were classified as being of subspecies B1. Phylogenetic analysis of fiber and hexon gene sequences revealed that most infants were infected with AdV serotype 3 (AdV3) strains. Infants attending one nursery harbored a new recombinant strain containing an AdV serotype 7 hexon and serotype 3 fiber (AdV7/3). Both the AdV3 and the AdV7/3 strains caused fatal infections. Two different serotype 3 strains were circulating in Lisbon in 2004, and the new AdV7/3 recombinant type originated from only one of those strains. These results demonstrate that recombination leads to the emergence of new adenovirus strains with epidemic and lethal potential.
