Programa d'eliminació del xarampió, la rubèola i la parotiditis a Catalunya : vigilància epidemiològica i estratègies de vacunació

El xarampió, la rubèola i la parotiditis són malalties transmissibles que tenen les característiques idònies per ser considerades malalties eliminables d’un territori: reservori humà, es disposa de proves diagnòstiques precises i d’una vacuna, la vacuna triple vírica (TV), que és eficaç, segura i que confereix immunitat duradora. Catalunya ha establert les estratègies d’eliminació de la transmissió autòctona del xarampió i de la rubèola, així com del control de la parotiditis. Les estratègies fonamentals són: la vacunació amb dues dosis de vacuna TV amb cobertures ≥95% i un sistema de vigilància d’elevada qualitat que sigui sensible i prou específic per detectar, confirmar i classificar els casos sospitosos d’aquestes malalties. Objectiu: Investigar l’evolució del xarampió, la rubèola i la parotiditis a Catalunya en relació als programes d’eliminació d’aquestes malalties durant el període 2006-2011. Metodologia: Estudis observacionals (descriptius o cohorts retrospectives). La població van ser els casos notificats d’aquestes malalties al registre de malalties de declaració obligatòria (MDO) de Catalunya. Les definicions de cas van les establertes per l'OMS. Les dades descriptives de la malaltia i dels antecedents vacunals es van obtenir mitjançant interrogatori amb el pacient, per part dels professionals sanitaris de vigilància epidemiològica. L’efectivitat vacunal (EV) es va calcular segons la metodologia de Orenstein. Resultats rellevants: Xarampió: * En els infants de ≥15 mesos d’edat assistents a centres d’educació infantil, l’EV de la vacuna TV com a mesura de preexposició va ser del 95% per a una dosi de vacuna i del 100% per a dues dosis. * L’estratègia d’avançar la primera dosi dels 15 mesos als 12 mesos establerta a l’any 2008 va ser efectiva, ja que en el brot del 2010-2011 hi va haver un 88% menys de casos en infants de 12-14 mesos que en el brot 2006-2007. * En el període 2010-2011 van circular 5 genotips diferents del virus. El més detectat va ser el genotip B3 (65%), seguit pel genotip D4 (29%). En el brot 2006-2007, el genotip detectat va ser el D4. * En infants contactes susceptibles que van assistir a centres d’educació infantil de 1e i 2n cicle, l’EV d’una dosi de vacuna TV administrada dins de les 72 hores de l’inici de l’exantema del cas índex va ser del 90,5%. Rubèola postnatal: * L’estudi de la sensibilitat dels diferents registres de notificació durant el període 2002-2011 va mostrar que el sistema MDO urgent va ser el que va mostrar un percentatge més elevat (32,5%). El VPP més elevat el va obtenir el registre de cribratge d'altres virus del programa d'eliminació del xarampió amb un 77%. Parotiditis: * Durant el període 2007-2011, la prevalença de detecció d’altres virus en pacients amb sospita clínica va ser del 51%. El virus Epstein-Barr va ser el més detectat (25%), seguit pels virus parainfluença 3 i 2, i per l’adenovirus. Aquests virus podrien ser l’etiologia de la tumefacció parotídia dels pacients..

Norovirus outbreaks in long-term care facilities in Catalonia from 2017 to 2018

Norovirus is the leading cause of outbreaks of acute viral gastroenteritis. We carried out this study to investigate outbreaks in long-term care facilities reported in 2017 and 2018 in Catalonia (Spain). The characteristics of the centers, exposed persons and the genogroups responsible were analyzed. Viral loads were estimated. The attack rate (AR) of the outbreaks studied, and the rate ratio (RR) and the odds ratio (OR) and their 95% confdence intervals as measures of association were calculated. The mean cycle thresholds were compared using the t-test for independent means. We included 30 outbreaks (4631 exposed people). The global AR was 25.93%. The RR of residents vs. staf was 2.28 (95% CI 2.0-2.6). The RR between AR in residents with total or severe dependence vs. residents with moderate, low or no-dependence was 1.23 (95% CI 1.05-1.45). The AR were higher in smaller centers than in larger ones (38.47% vs. 19.25% and RR 2; 95% CI 1.82-2.2). GII was responsible for 70% of outbreaks. No association was found between the genogroup and presenting symptoms (OR 0.96; 95% CI 0.41-2.26). Viral loads were higher in symptomatic than in asymptomatic patients (p = 0.001)

Norovirus outbreaks in long-term care facilities in Catalonia from 2017 to 2018

Norovirus is the leading cause of outbreaks of acute viral gastroenteritis. We carried out this study to investigate outbreaks in long-term care facilities reported in 2017 and 2018 in Catalonia (Spain). The characteristics of the centers, exposed persons and the genogroups responsible were analyzed. Viral loads were estimated. The attack rate (AR) of the outbreaks studied, and the rate ratio (RR) and the odds ratio (OR) and their 95% confidence intervals as measures of association were calculated. The mean cycle thresholds were compared using the t-test for independent means. We included 30 outbreaks (4631 exposed people). The global AR was 25.93%. The RR of residents vs. staff was 2.28 (95% CI 2.0–2.6). The RR between AR in residents with total or severe dependence vs. residents with moderate, low or no-dependence was 1.23 (95% CI 1.05–1.45). The AR were higher in smaller centers than in larger ones (38.47% vs. 19.25% and RR 2; 95% CI 1.82–2.2). GII was responsible for 70% of outbreaks. No association was found between the genogroup and presenting symptoms (OR 0.96; 95% CI 0.41–2.26). Viral loads were higher in symptomatic than in asymptomatic patients (p = 0.001).This study was funded by Instituto de Salud Carlos III through the project PI16/02005 (Co-funded by European Regional Development Fund “Investing in your future”) and the Catalan Agency for the Management of Grants for University (AGAUR Grant No. 2017/SGR 1342). The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication

Mumps: MMR vaccination and genetic diversity of mumps virus, 2007-2011 in Catalonia, Spain

Background: Mumps is a vaccine-preventable disease but outbreaks have been reported in persons vaccinated with two doses of MMR vaccine. The objective was to describe the demographic features, vaccination effectiveness and genetic mumps virus diversity among laboratory-confirmed cases between 2007 and 2011 in Catalonia. Methods: Cases and outbreaks of mumps notified to the notifiable diseases system of Catalonia between 2007 and 2011 retrospectively registered were included. Public health care centres provided written immunization records to regional public health staff to determine the vaccination history. Saliva and serum specimens were collected from suspected cases for laboratory-confirmation using real-time reverse-transcriptase PCR (rtRT-PCR) or serological testing. Phylogenetic analysis of the complete SH gene (316 nucleotides) and complete coding HN protein (1749 nucleotides) sequences was made. Categorical variables were compared using the Chi-square or Fisher's tests and continuous variables using the Student test. Vaccination effectiveness by number of MMR doses was estimated using the screening method. Results: During the study period, 581 confirmed cases of mumps were notified (incidence rate 1.6 cases/100,000 persons-year), of which 60% were male. Three hundred sixty-four laboratory-confirmed cases were reported, of which 44% were confirmed by rtRT-PCR. Of the 289 laboratory-confirmed cases belonging to vaccination cohorts, 33.5% (97) had received one dose of MMR vaccine and 50% (145) two doses. Based on phylogenetic analyses of 316-nucleotide and 174-nucleotide SH sequences, the viruses belonging to viral genotypes were: genotype G (126), genotype D (23), genotype H (2), genotype F (2), genotype J (1), while one remained uncharacterized. Amino acid differences were detected between circulating strains and the Jeryl Lynn vaccine strains, although the majority of amino acid substitutions were genotype-specific. Fifty-one outbreaks were notified that included 324 confirmed mumps cases. Genotype G was the most frequent genotype detected. The family (35%), secondary schools (25%) and community outbreaks (18%) were the most frequent settings. Conclusions: Our study shows that genotype G viruses are the most prevalent in Catalonia. Most cases occurred in people who had received two doses of MMR, suggesting inadequate effectiveness of the Jeryl Lynn vaccine strain. The possible factors related are discussed

Involvement of workers in closed and semiclosed institutions in outbreaks of acute gastroenteritis due to norovirus

Norovirus outbreaks frequently occur in closed or semiclosed institutions. Recent studiesin Catalonia and various countries indicate that, during outbreaks in these institutions, norovirus isdetected in between 23% and 60% of workers, and the prevalence of infection in asymptomatic workersinvolved in outbreaks ranges from 17% to 40%. In this work, we carried out a prospective studyto investigate the involvement of workers in closed and semiclosed institutions during outbreaks.The attack rates (ARs) and the rate ratios (RRs) were calculated according to the type of transmissionand occupational category. The RRs and 95% confidence intervals (CIs) between workers and userswere calculated. The mean cycle of quantification (Cq) values were compared according to thegenogroup and the presence of symptoms. ARs were higher in person-to-person transmission thanin common vehicle outbreaks, and 38.8% of workers were symptomatic. The RR between workersand users was 0.46 (95% CI 0.41-0.52). The ARs in workers were high, particularly in workers withcloser contact with users. The mean Cq was lower in patients than in asymptomatic infected persons,although the difference was only significant for genogroup I (GI). The frequency of asymptomaticinfected persons suggests that personal hygiene measures should be followed by all workers in thecenters affected

Impact of the COVID-19 pandemic on contact tracing of patients with pulmonary tuberculosis

Background: The COVID-19 pandemic could have negative effects on tuberculosis (TB) control. The objective was to assess the impact of the pandemic in contact tracing, TB and latent tuberculosis infection (LTBI) in contacts of patients with pulmonary TB in Catalonia (Spain). Methods: Contact tracing was carried out in cases of pulmonary TB detected during 14 months in the pre-pandemic period (1 January 2019 to 28 February 2020) and 14 months in the pandemic period (1 March 2020 to 30 April 2021). Contacts received the tuberculin skin test and/or interferon gamma release assay and it was determined whether they had TB or LTBI. Variables associated with TB or LTBI in contacts (study period and sociodemographic variables) were analyzed using adjusted odds ratio (aOR) and the 95% confidence intervals (95% CI). Results: The pre-pandemic and pandemic periods showed, respectively: 503 and 255 pulmonary TB reported cases (reduction of 50.7%); and 4676 and 1687 contacts studied (reduction of 36.1%). In these periods, the proportion of TB cases among the contacts was 1.9% (84/4307) and 2.2% (30/1381) (P = 0.608); and the proportion of LTBI was 25.3% (1090/4307) and 29.2% (403/1381) (P < 0.001). The pandemic period was associated to higher LTBI proportion (aOR = 1.3; 95% CI 1.1–1.5), taking into account the effect on LTBI of the other variables studied as sex, age, household contact and migrant status. Conclusions: COVID-19 is affecting TB control due to less exhaustive TB and LTBI case detection. An increase in LTBI was observed during the pandemic period. Efforts should be made to improve detection of TB and LTBI among contacts of TB cases.This study was supported by the Ministry of Science and Innovation, Institute of Health Carlos III (Project PI18/01751) and Fondo Europeo de Desarrollo Regional (FEDER-Una manera de hacer Europa)

Arbovirus surveillance: first dengue virus detection in local Aedes albopictus mosquitoes in Europe, Catalonia, Spain, 2015

Dengue has emerged as the most important viral mosquito-borne disease globally. The current risk of dengue outbreaks in Europe appeared with the introduction of the vector Aedes albopictus mosquito in Mediterranean countries. Considering the increasing frequency of dengue epidemics worldwide and the movement of viraemic hosts, it is expected that new autochthonous cases will occur in the future in Europe. Arbovirus surveillance started in Catalonia in 2015 to monitor imported cases and detect possible local arboviral transmission. During 2015, 131 patients with a recent travel history to endemic countries were tested for dengue virus (DENV) and 65 dengue cases were detected. Twenty-eight patients with a febrile illness were viraemic, as demonstrated by a positive real-time RT-PCR test for DENV in serum samples. Entomological investigations around the viraemic cases led to the detection of DENV in a pool of local Ae. albopictus captured in the residency of one case. The sequence of the DENV envelope gene detected in the mosquito pool was identical to that detected in the patient. Our results show how entomological surveillance conducted around viraemic travellers can be effective for early detection of DENV in mosquitoes and thus might help to prevent possible autochthonous transmission