Viral genetic clustering and transmission dynamics of the 2022 mpox outbreak in Portugal.

Pathogen genome sequencing during epidemics enhances our ability to identify and understand suspected clusters and investigate their relationships. Here, we combine genomic and epidemiological data of the 2022 mpox outbreak to better understand early viral spread, diversification and transmission dynamics. By sequencing 52% of the confirmed cases in Portugal, we identified the mpox virus sublineages with the highest impact on case numbers and fitted them into a global context, finding evidence that several international sublineages probably emerged or spread early in Portugal. We estimated a 62% infection reporting rate and that 1.3% of the population of men who have sex with men in Portugal were infected. We infer the critical role played by sexual networks and superspreader gatherings, such as sauna attendance, in the dissemination of mpox virus. Overall, our findings highlight genomic epidemiology as a tool for the real-time monitoring and control of mpox epidemics, and can guide future vaccine policy in a highly susceptible population.

Circulation of pertussis and poor protection against diphtheria among middle-aged adults in 18 European countries.

Reported incidence of pertussis in the European Union (EU) and the European Economic Area (EEA) varies and may not reflect the real situation, while vaccine-induced protection against diphtheria and tetanus seems sufficient. We aimed to determine the seroprevalence of DTP antibodies in EU/EEA countries within the age groups of 40-49 and 50-59 years. Eighteen countries collected around 500 samples between 2015 and 2018 (N = 10,302) which were analysed for IgG-DTP specific antibodies. The proportion of sera with pertussis toxin antibody levels ≥100 IU/mL, indicative of recent exposure to pertussis was comparable for 13/18 countries, ranging between 2.7-5.8%. For diphtheria the proportion of sera lacking the protective level (<0.1 IU/mL) varied between 22.8-82.0%. For tetanus the protection was sufficient. Here, we report that the seroprevalence of pertussis in these age groups indicates circulation of B. pertussis across EU/EEA while the lack of vaccine-induced seroprotection against diphtheria is of concern and deserves further attention.

Report of simultaneous measles outbreaks in two different health regions in Portugal, February to May 2017: lessons learnt and upcoming challenges.

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.

Challenging measles case definition: three measles outbreaks in three Health Regions of Portugal, February to April 2018.

We report three simultaneous measles outbreaks with 112 confirmed cases in three Health Regions of Portugal, from February to April 2018. The mean age of cases was 30 years, 79% worked in a healthcare setting and 87% were vaccinated. Genotype B3 was identified in 84 cases from the three outbreaks. Primary cases in each outbreak were imported. Several cases presented with modified measles, highlighting the importance of rethinking the measles case definition for vaccinated cases.

Measles outbreak after 12 years without endemic transmission, Portugal, February to May 2017.

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.

Mumps Outbreak among Highly Vaccinated Teenagers and Children in the Central Region of Portugal, 2012-2013.

INTRODUCTION: Mumps vaccine was introduced in the National Immunization Program in Portugal in 1987, rapidly reaching a national coverage > 92%, with important reduction in the annual incidence of the disease. We report a mumps outbreak in the Central Region of Portugal, occurred in the winter 2012-13. MATERIAL AND METHODS: Cases of salivary-gland swelling and other symptoms compatible with mumps were investigated. Geodemographics, clinical, laboratory and vaccination data were analyzed. RESULTS: Over six months, 148 outbreak-related cases were reported: 87.8% occurred in three of the 16 affected counties and 78.4% had a known epidemiological link. Median age was 14.5 years (2-62) and 70.3% were 11-20 years old; 61.5% were male. The mean duration of disease was seven days (2-20). The disease was generally mild; 80.4% had fever and in 55.4% there was unilateral involvement of the parotid gland. Seven cases had orchitis, one oophoritis and one had nephritis. Two cases were hospitalized. School transmission predominated and class attack rates were < 30%. Most of the cases occurred in vaccinated individuals (92%) of whom 86.8% had received 2 doses; 17.7% had received one dose of the vaccine containing the Rubini strain. Mumps virus genotype G was identified in 4 cases. DISCUSSION: This mumps outbreak among a highly vaccinated population, occurring mostly in teenagers at school, could be due to the partial effectiveness of the vaccine against the disease (particularly in the group vaccinated with Rubini strain), waning immunity overtime and genotype mismatch. CONCLUSIONS: This outbreak report shows the importance of discussion about the need of more booster dose of the actual vaccine or new vaccine including more genotypes to improve immunogenicity.

Introdução: A vacina contra o sarampo, parotidite epidémica e rubéola foi introduzida no Programa Nacional de Vacinação em 1987, atingindo rapidamente uma cobertura vacinal > 92% para duas doses, com redução importante da incidência anual da doença. Reportamos um surto de parotidite na Região Centro de Portugal ocorrido entre outubro de 2012 e março de 2013. Material e Métodos: Foram investigados os casos de tumefação de glândulas salivares e sintomas compatíveis com parotidite. Para cada caso foram analisados dados demográficos, clínicos, laboratoriais e vacinais. Resultados: Ao longo de seis meses foram notificados 148 casos: 87,8% ocorreram em três dos 16 concelhos afetados e 78,4% tinham uma relação epidemiológica conhecida. A idade mediana foi de 14,5 anos (2-62) e 70,3% tinham entre 11 e 20 anos; 61,5% eram do sexo masculino. Na maioria dos casos a doença foi ligeira, com uma duração média de sete dias (2-20). A febre ocorreu em 80,4% e a glândula parótida apresentou envolvimento unilateral em 55,4%; sete casos tiveram orquite, um ooforite e uma nefrite. Dois doentes foram internados. A transmissão da doença ocorreu predominantemente em ambiente escolar, com taxas de ataque < 30%. A maioria dos casos ocorreu em indivíduos vacinados (92%), dos quais 86,8% com duas doses. Em 17,7% foi identificada uma dosede vacina contendo a estirpe Rubini. Foi identificado o genótipo G do vírus da parotidite em quatro casos. Discussão: Este surto de parotidite numa população com coberturas vacinais elevadas, atingindo principalmente adolescentes em meio escolar, poderá dever-se à efetividade parcial da vacina contra a doença (especialmente no grupo vacinado com a estirpe Rubini), à perda de imunidade ao longo do tempo ou ainda à discordância entre os genótipos vacinal e circulante causador de doença. Conclusões: O relato deste surto releva a importância da discussão sobre a necessidade de mais doses de reforço da vacina atual ou de uma nova vacina incluindo mais genótipos para melhorar a imunogenicidade.