Effectiveness of one and two doses of acellular pertussis vaccines against laboratory-confirmed pertussis requiring hospitalisation in infants: Results of the PERTINENT sentinel surveillance system in six EU/EEA countries, December 2015 - December 2019.

BACKGROUND: Monitoring effectiveness of pertussis vaccines is necessary to adapt vaccination strategies. PERTINENT, Pertussis in Infants European Network, is an active sentinel surveillance system implemented in 35 hospitals across six EU/EEA countries. We aim to measure pertussis vaccines effectiveness (VE) by dose against hospitalisation in infants aged <1 year. METHODS: From December 2015 to December 2019, participating hospitals recruited all infants with pertussis-like symptoms. Cases were vaccine-eligible infants testing positive for Bordetella pertussis by PCR or culture; controls were those testing negative to all Bordetella spp. For each vaccine dose, we defined an infant as vaccinated if she/he received the corresponding dose >14 days before symptoms. Unvaccinated were those who did not receive any dose. We calculated (one-stage model) pooled VE as 100*(1-odds ratio of vaccination) adjusted for country, onset date (in 3-month categories) and age-group (when sample allowed it). RESULTS: Of 1,393 infants eligible for vaccination, we included 259 cases and 746 controls. Median age was 16 weeks for cases and 19 weeks for controls (p < 0.001). Median birth weight and gestational age were 3,235 g and week 39 for cases, 3,113 g and week 39 for controls. Among cases, 119 (46 %) were vaccinated: 74 with one dose, 37 two doses, 8 three doses. Among controls, 469 (63 %) were vaccinated: 233 with one dose, 206 two doses, 30 three doses. Adjusted VE after at least one dose was 59 % (95 %CI: 36-73). Adjusted VE was 48 % (95 %CI: 5-71) for dose one (416 eligible infants) and 76 % (95 %CI: 43-90) for dose two (258 eligible infants). Only 42 infants were eligible for the third dose. CONCLUSIONS: Our results suggest moderate one-dose and two-dose VE in infants. Larger sample size would allow more precise estimates for dose one, two and three.

Effectiveness of Influenza Vaccination and Early Antiviral Treatment in Reducing Pneumonia Risk in Severe Influenza Cases.

INTRODUCTION: Influenza vaccination may be effective in preventing influenza infection and may reduce the risk of influenza-associated pneumonia. The study aim was to evaluate the effect of influenza vaccination in preventing pneumonia when it failed to prevent influenza hospitalization. METHODS: This was a case-control study comparing hospitalized cases of influenza with and without pneumonia in patients aged ≥18 years in 16 hospitals in Catalonia over 10 influenza seasons (2010-11 to 2019-20). Data on sociodemographic, virological characteristics, comorbidities, vaccination history, and antiviral treatment were collected and analysed. The crude odds ratio (OR) and adjusted OR (aOR) with the corresponding 95% confidence interval (CI) values were calculated. RESULTS: In total, 5080 patients hospitalized for severe influenza were included, 63.5% (3224/5080) of whom had pneumonia-mostly men (56.8%; 1830/3224) and mostly in the ≥75 age group (39.3%; 1267/3224)-and of whom 14.0% died (451/3224). Virus A and virus B accounted for 78.1% (2518/3224) and 21.9% (705/3224) of influenza types, respectively. Starting antiviral treatment ≤48 h after symptom onset (aOR = 0.69; 95%CI: 0.53-0.90) and a history of seasonal influenza vaccination (aOR = 0.85; 95%CI: 0.72-0.98) were protective factors in developing pneumonia. CONCLUSIONS: Adherence to seasonal influenza vaccination and starting antiviral treatment within 48 h of symptom onset can reduce pneumonia risk in severe influenza cases.

Impact of SARS-CoV-2 infection in pregnant women and their babies: clinical and epidemiological features.

OBJECTIVE: Assess the risk associated with COVID-19 in pregnant women on maternal and neonatal outcomes in Catalonia (Spain) in 2020, before the beginning of COVID-19 vaccination campaign. METHOD: Cross-sectional descriptive study with all pregnant women (41,560) and their live newborns (42,097) (1st March to 31st December 2020). Women were classified: positive and negative COVID-19 diagnosis during pregnancy. The outcomes analysed were complications during pregnancy, gestational age, admission of newborns to neonatal intensive care unit (NICU) and birth weight. Associations among positive COVID-19 and maternal and infant variables were measured with logistic regression models. Results were expressed as odds ratios and 95% confidence intervals. Models were adjusted for nationality, maternal age, socioeconomic status, type of pregnancy and type of centre where the delivery occurred (public or private management hospital). RESULTS: A total of 696 women (1.7%) were diagnosed with COVID-19 during pregnancy. Women with COVID-19 were 4.37 times more likely to have complications during pregnancy (4.37; 3.52-5.40). A total of 713 newborns (1.7%) were from mothers with COVID-19. A positive diagnosis of COVID-19 increased the risk of preterm birth (1.41; 1.03-1.89), admission to NICU (1.40; 1.06-1.82) and low birth weight (1.35; 0.99-1.80) in babies. CONCLUSIONS: Pregnant women with COVID-19 had higher risk of developing complications during pregnancy and their newborns were more likely to be admitted to NICU and had prematurity.

Epidemiology and antimicrobial resistance profile of Neisseria gonorrhoeae in Catalonia, Spain, 2016-2019.

Antimicrobial resistance data for Neisseria gonorrhoeae is globally sparse and resistant strains are emerging in Catalonia. We aim to describe epidemiological and antimicrobial resistance in all patients infected with N. gonorrhoeae during the period from 2016 to 2019, using available antimicrobial susceptibility data. We retrospectively analysed confirmed N. gonorrhoeae cases notified to Catalonia's microbiological reporting system. Antibiotic susceptibility testing (azithromycin, cefixime, ceftriaxone, ciprofloxacin, penicillin, spectinomycin, and tetracycline) was assessed using clinical breakpoints published by the European Committee on Antimicrobial Susceptibility Testing. Incidence rates were calculated and proportions were compared using the χ2 test or Fisher's exact test, and analysed using the Statistical Package for Social Sciences (SPSS 18.0). A total of 14,251 confirmed cases of N. gonorrhoeae were notified. Incidence increased from 30.7 cases/100,000 person-years (p < 0.001) in 2016 to 64.7 in 2019. Culture was available in 6,292 isolates (44.2%), of which 5,377 (85.5%) were resistant to at least one of the antibiotics tested. Azithromycin resistance rose from 6.1% in 2016 to 16% in 2019 (p < 0.001). Only 1.0% (45 cases) were resistant to ceftriaxone. Multidrug-resistant N. gonorrhoeae increased from 0.25% in 2016 to 0.42% in 2019 (p = 0.521). One case presented extensively drug-resistant N. gonorrhoeae. In Catalonia, 10% of the N. gonorrhoeae isolates were resistant to azithromycin in the 2016-2019 period. According to World Health Organization guidelines, resistance above 5% indicates an alert to review treatment guidelines. Antimicrobial susceptibility testing in clinical practice followed by surveillance and interventions are essential to monitor trends and prevent the spread of antimicrobial resistance.

Impact of SARS-CoV-2 infection in pregnant women and their babies:clinical and epidemiological features / Infección por SARS-CoV-2 en mujeres embarazadas y sus recién nacidos: características clínicas y epidemiológicas

Objective: Assess the risk associated with COVID-19 in pregnant women on maternal and neonatal outcomes in Catalonia (Spain) in 2020, before the beginning of COVID-19 vaccination campaign. Method: Cross-sectional descriptive study with all pregnant women (41,560) and their live newborns (42,097) (1st March to 31st December 2020). Women were classified: positive and negative COVID-19 diagnosis during pregnancy. The outcomes analysed were complications during pregnancy, gestational age, admission of newborns to neonatal intensive care unit (NICU) and birth weight. Associations among positive COVID-19 and maternal and infant variables were measured with logistic regression models. Results were expressed as odds ratios and 95% confidence intervals. Models were adjusted for nationality, maternal age, socioeconomic status, type of pregnancy and type of centre where the delivery occurred (public or private management hospital). Results: A total of 696 women (1.7%) were diagnosed with COVID-19 during pregnancy. Women with COVID-19 were 4.37 times more likely to have complications during pregnancy (4.37; 3.52-5.40). A total of 713 newborns (1.7%) were from mothers with COVID-19. A positive diagnosis of COVID-19 increased the risk of preterm birth (1.41; 1.03-1.89), admission to NICU (1.40; 1.06-1.82) and low birth weight (1.35; 0.99-1.80) in babies. Conclusions: Pregnant women with COVID-19 had higher risk of developing complications during pregnancy and their newborns were more likely to be admitted to NICU and had prematurity.(AU)

Objetivo: Evaluar el riesgo asociado de COVID-19 y los resultados en mujeres embarazadas y sus recién nacidos en Cataluña (España) antes del inicio de la campaña de vacunación. Método: Estudio descriptivo transversal de mujeres gestantes (41.560) y sus recién nacidos (42.097) (del 1 de marzo al 31 de diciembre de 2020). Las gestantes fueron clasificadas según diagnóstico COVID-19 positivo o negativo durante el embarazo. Los resultados analizados fueron complicaciones gestacionales, semana gestacional, ingreso del recién nacido en la unidad de cuidados intensivos neonatales (UCIN) y bajo peso al nacer. Las asociaciones entre COVID-19 positivo y variables maternas y perinatales se midieron con regresión logística. Los resultados se expresaron con odds ratio e intervalo de confianza del 95%. Los modelos se ajustaron por nacionalidad, edad materna, nivel socioeconómico, tipo de embarazo y titularidad (pública o privada) del hospital donde se dio a luz. Resultados: Un total de 696 gestantes (1,7%) fueron diagnosticadas de COVID-19 durante el embarazo. Las gestantes con COVID-19 presentaron 4,37 veces mayor probabilidad de tener complicaciones durante el embarazo (4,37; 3,52-5,40). Hubo 713 recién nacidos (1,7%) de gestantes con COVID-19. El diagnóstico positivo de COVID-19 incrementó el riesgo de prematuridad (1,41; 1,03-1,89), ingreso en UCIN (1,40; 1,06-1,82) y bajo peso al nacer (1,35; 0,99-1,80) de los recién nacidos. Conclusiones: Las gestantes con COVID-19 presentaron mayor riesgo de desarrollar complicaciones durante el embarazo y sus hijos tuvieron mayor probabilidad de ingreso en la UCIN y de prematuridad.(AU)

Effectiveness of pertussis vaccination in pregnancy to prevent hospitalisation in infants aged <2 months and effectiveness of both primary vaccination and mother's vaccination in pregnancy in infants aged 2-11 months.

BACKGROUND: PERTINENT is an active hospital-based surveillance system for pertussis in infants. In 2019, four of the six participating European countries recommended pertussis vaccination in pregnancy. Among infants aged <2 months, we measured the vaccine effectiveness (VE) in pregnancy; among infants aged 2-11 months, VE of vaccination in pregnancy and of primary vaccination (PV). METHODS: From December 2015 to 2019, we included all infants aged <1 year presenting with pertussis-like symptoms. Using a test-negative-design, cases were infants testing positive for Bordetella pertussis by PCR or culture. Controls were those testing negative for all Bordetella species. Vaccinated mothers were those who received vaccine in pregnancy. Vaccinated infants were those who received ≥1 dose of PV > 14 days before symptom onset. We excluded infants with unknown maternal or PV status or with mothers vaccinated ≤14 days before delivery. We calculated pooled VE as 100 * (1-odds ratio of vaccination) adjusted for study site, onset date in quarters and infants' age group. RESULTS: Of 829 infants presenting with pertussis-like symptoms, 336 (41%) were too young for PV. For the VE in pregnancy analysis, we included 75 cases and 201 controls. Vaccination in pregnancy was recorded for 9 cases (12%) and 92 controls (46%), adjusted VE was between 75% [95%CI: 35-91%] and 88% [95%CI: 57-96%]. Of 493 infants eligible for PV, we included 123 cases and 253 controls. Thirty-one cases and 98 controls recorded both PV with ≥ 1 dose and vaccination in pregnancy, adjusted VE was between 74% [95%CI: 33-90] and 95% [95%CI: 69-99]; 27 cases and 53 controls recorded PV only, adjusted VE was between 68% [95%CI: 27-86] and 94% [95%CI: 59-99]. CONCLUSION: Our findings suggest that vaccination in pregnancy reduces pertussis incidence in infants too young for PV. In infants aged 2-11 months, PV only and both PV and vaccination in pregnancy provide significant protection against severe pertussis.

Does knowing the influenza epidemic threshold has been reached influence the performance of influenza case definitions?

BACKGROUND: Disease surveillance using adequate case definitions is very important. The objective of the study was to compare the performance of influenza case definitions and influenza symptoms in the first two epidemic weeks with respect to other epidemic weeks. METHODS: We analysed cases of acute respiratory infection detected by the network of sentinel primary care physicians of Catalonia for 10 seasons. We calculated the diagnostic odds ratio (DOR) and 95% confidence intervals (CI) for the first two epidemic weeks and for other epidemic weeks. RESULTS: A total of 4,338 samples were collected in the epidemic weeks, of which 2,446 (56.4%) were positive for influenza. The most predictive case definition for laboratory-confirmed influenza was the WHO case definition for influenza-like illness (ILI) in the first two epidemic weeks (DOR 2.10; 95% CI 1.57-2.81) and in other epidemic weeks (DOR 2.31; 95% CI 1.96-2.72). The most predictive symptom was fever. After knowing that epidemic threshold had been reached, the DOR of the ILI WHO case definition in children aged <5 years and cough and fever in this group increased (190%, 170% and 213%, respectively). CONCLUSIONS: During influenza epidemics, differences in the performance of the case definition and the discriminative ability of symptoms were found according to whether it was known that the epidemic threshold had been reached or not. This suggests that sentinel physicians are stricter in selecting samples to send to the laboratory from patients who present symptoms more specific to influenza after rather than before an influenza epidemic has been declared.

SARS-CoV-2 Catalonia contact tracing program: evaluation of key performance indicators.

BACKGROUND: Guidance on SARS-CoV-2 contact tracing indicators have been recently revised by international public health agencies. The aim of the study is to describe and analyse contact tracing indicators based on Catalonia's (Spain) real data and proposing to update them according to recommendations. METHODS: Retrospective cohort analysis including Catalonia's contact tracing dataset from 20 May until 31 December 2020. Descriptive statistics are performed including sociodemographic stratification by age, and differences are assessed over the study period. RESULTS: We analysed 923,072 contacts from 301,522 SARS-CoV-2 cases with identified contacts (67.1% contact tracing coverage). The average number of contacts per case was 4.6 (median 3, range 1-243). A total of 403,377 contacts accepted follow-up through three phone calls over a 14-day quarantine period (84.5% of contacts requiring follow-up). The percentage of new cases declared as contacts 14 days prior to diagnosis evolved from 33.9% in May to 57.9% in November. All indicators significantly improved towards the target over time (p < 0.05 for all four indicators). CONCLUSIONS: Catalonia's SARS-CoV-2 contact tracing indicators improved over time despite challenging context. The critical revision of the indicator's framework aims to provide essential information in control policies, new indicators proposed will improve system delay's follow-up. The study provides information on COVID-19 indicators framework experience from country's real data, allowing to improve monitoring tools in 2021-2022. With the SARS-CoV-2 pandemic being so harmful to health systems and globally, is important to analyse and share contact tracing data with the scientific community.

Estimation of the incidence of invasive meningococcal disease using a capture-recapture model based on two independent surveillance systems in Catalonia, Spain.

OBJECTIVES: Invasive meningococcal disease (IMD) is an urgent notifiable disease and its early notification is essential to prevent cases. The objective of the study was to assess the sensitivity of two independent surveillance systems and to estimate the incidence of IMD. DESIGN: We used capture-recapture model based on two independent surveillance systems, the statutory disease reporting (SDR) system and the microbiological reporting system (MRS) of the Public Health Agency of Catalonia, between 2011 and 2015. The capture-recapture analysis and 95% CIs were calculated using the Chapman formula. Multivariate vector generalised linear model was performed for adjusted estimation. MEASURES: The variables collected were age, sex, year of report, size of municipality (<10 000 and ≥10 000), clinical form, death, serogroup, country of birth and type of reporting centre (private and public). RESULTS: The sensitivity of the two combined surveillance systems was 88.5% (85.0-92.0). SDR had greater sensitivity than the MRS (67.9%; 62.7-73.1 vs 64.7%; 59.4-70.0). In 2014-2015, the sensitivity of both systems was higher (80.6%; 73.2-87.9 vs 73.4%; 65.2-81.6) than in 2011-2013 (59.3%; 52.6-66.0 vs 58.3%; 51.6-65.1). In private centres, the sensitivity was higher for SDR than for MRS (100%; 100-100 vs 4.8%; -4.4-13.9). The adjusted estimate of IMD cases was lower than that obtained using the Chapman formula (279; 266-296 vs 313; 295-330). The estimated adjusted incidence of IMD was 0.7/100 000 persons-year. CONCLUSIONS: The sensitivity of enhanced surveillance through the combination of two complementary sources was higher than for the sources individually. Factors associated with under-reporting in different systems should be analysed to improve IMD surveillance.

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.

Surveillance of SARS-CoV-2 virus circulation using Acute Respiratory Infections sentinel system of Catalonia (PIDIRAC) during the 2019-2020 season: A retrospective observational study.

BACKGROUND: In the context of COVID-19 pandemic in Catalonia (Spain), the present study analyses respiratory samples collected by the primary care network using Acute Respiratory Infections Sentinel Surveillance System (PIDIRAC) during the 2019-2020 season to complement the pandemic surveillance system in place to detect SARS-CoV-2. The aim of the study is to describe whether SARS-CoV-2 was circulating before the first confirmed case was detected in Catalonia, on February 25th, 2020. METHODS: The study sample was made up of all samples collected by the PIDIRAC primary care network as part of the Influenza and Acute Respiratory Infections (ARI) surveillance system activities. The study on respiratory virus included coronavirus using multiple RT-PCR assays. All positive samples for human coronavirus were subsequently typed for HKU1, OC43, NL63, 229E. Every respiratory sample was frozen at-80°C and retrospectively studied for SARS-CoV-2 detection. A descriptive study was performed, analysing significant differences among variables related to SARS-CoV- 2 cases comparing with rest of coronaviruses cases through a bivariate study with Chi-squared test and statistical significance at 95%. RESULTS: Between October 2019 and April 2020, 878 respiratory samples from patients with acute respiratory infection or influenza syndrome obtained by PIDIRAC were analysed. 51.9% tested positive for influenza virus, 48.1% for other respiratory viruses. SARS-CoV-2 was present in 6 samples. The first positive SARS-CoV-2 case had symptom onset on 2 March 2020. These 6 cases were 3 men and 3 women, aged between 25 and 50 years old. 67% had risk factors, none had previous travel history nor presented viral coinfection. All of them recovered favourably. CONCLUSION: Sentinel Surveillance PIDIRAC enhances global epidemiological surveillance by allowing confirmation of viral circulation and describes the epidemiology of generalized community respiratory viruses' transmission in Catalonia. The system can provide an alert signal when identification of a virus is not achieved in order to take adequate preparedness measures.

SARS-CoV-2 seroprevalence in blood donors before and after the first wave in Catalonia (Spain).

BACKGROUND: Due to the COVID-19 pandemic, a national lockdown was applied in Spain from March to May 2020. It is uncertain when SARS-CoV-2 started to circulate in Catalonia, and only a few cases were diagnosed in this period. We assessed the SARS-CoV-2 seroprevalence in blood donors before and after the first wave and compared it with public health service (PHS) data. MATERIALS AND METHODS: Retrospective archive or prospective fresh blood samples were obtained from blood donors aged 18 to 70 and anonymized after demographic data had been recorded (gender, age, place of residence, blood collection date). Two CE-marked enzyme-linked immunosorbent assays were used to test for anti-SARS-CoV-2. A SARS-CoV-2 IgM test was additionally performed in positive samples. Individuals aged 18 to 70 from among the general population diagnosed as having SARS-CoV-2 by the PHS were included for comparison with blood donor results. RESULTS: A total of 10,170 blood donations were included in the first period, between 24 February and 9 March 2020, and 6,829 in the second period, between 16 May and 17 June 2020. The observed SARS-CoV-2 seroprevalence among blood donors rose from 0.27% (95% CI: 0.18-0.39) before the first wave to 5.55% (95% CI: 5.03-6.12) after it, and was even higher (6.90% [95% CI: 5.64-8.41]) among blood donors aged 18 to 29. The seroprevalence among blood donors was higher in more populated areas (Barcelona: 7.69%). A comparison of blood donor data with officially diagnosed cases showed a global 87.44% underestimation of SARS-CoV-2 in June 2020. DISCUSSION: We analyzed the explosive 3-month increase in blood donor SARS-CoV-2 seroprevalence (from 0.27% to 5.55%) and show that more than 87% of cases went undiagnosed, despite the unprecedented deployment of testing measures. SARS-CoV-2 IgM results suggest that the virus was circulating among blood donors in February 2020. Blood donors are definitively proven to be a valuable resource for emerging disease surveillance studies.

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).

Molecular Characterization of Imported and Autochthonous Dengue in Northeastern Spain.

Dengue is the most significant arbovirus worldwide and a public health threat to non-endemic areas in which Aedes vectors are present. Autochthonous dengue transmission has been reported in several European countries in the last decade. Infected travelers from endemic regions arriving to areas colonized by Aedes albopictus in Europe need to be monitored in surveillance and control programs. We aimed to perform molecular characterization of RT-PCR-positive dengue cases detected in Catalonia, northeastern Spain, from 2013 to 2018. The basic demographic information and the geographical regions of importation were also analyzed. One-hundred four dengue cases were studied (103 imported infections and the first autochthonous case in our region). The dengue virus strains detected were serotyped and genotyped using molecular methods, and phylogenetic analyses were conducted. All four dengue serotypes were detected in travelers, including up to 10 different genotypes, reflecting the global circulation of dengue in endemic areas. The primary travel-related case of the 2018 autochthonous transmission was not identified, but the molecular analysis revealed dengue serotype 1, genotype I of Asian origin. Our results highlight the diversity of imported dengue virus strains and the role of molecular epidemiology in supporting arbovirus surveillance programs.

Effectiveness of maternal pertussis vaccination in protecting newborn: A matched case-control study.

INTRODUCTION: The objective was to estimate the effectiveness of maternal pertussis vaccination in protecting infants aged < 2 months. METHODS: We performed a case-control study. Laboratory-confirmed cases aged <8 weeks at disease onset were identified and 2-4 matched-controls born within ± 15 days of the case were included. Information was obtained from healthcare providers and maternal interviews. Odds ratios (OR) were calculated using multivariable conditional logistic regression. Vaccine effectiveness (VE) was estimated as (1 - OR) × 100%. RESULTS: 47 cases and 124 controls were studied. The mean age (in days) (39.8 ± 12.7 vs. 40.8 ± 13.2), weeks of gestation (38.8 vs. 39.1, p = 0.43) and mean birth weight (3.309 vs. 3.253 kg, p = 0.55) were comparable between cases and controls. Mothers of cases were less frequently vaccinated in the third trimester (59.6% vs. 83.9%, p <0.001). The VE of maternal vaccination in pregnancy was 88.0% (95%CI 53.8% -96.5%), and was slightly higher in those vaccinated before the 32nd week of gestation (88.5% vs 87.8%). CONCLUSION: Pertussis vaccination in pregnancy is very effective in reducing pertussis in children aged < 2 months. Vaccination before and after the 32nd week of pregnancy are equally effective in reducing the risk of pertussis.

Influenza Vaccine Effectiveness in Preventing Severe Outcomes in Patients Hospitalized with Laboratory-Confirmed Influenza during the 2017-2018 Season. A Retrospective Cohort Study in Catalonia (Spain).

Seasonal influenza is a common cause of hospital admission, especially in older people and those with comorbidities. The objective of this study was to determine influenza vaccine effectiveness (VE) in preventing intensive care admissions and shortening the length of stay (LOS) in hospitalized laboratory-confirmed influenza cases (HLCI) in Catalonia (Spain). A retrospective cohort study was carried out during the 2017-2018 season in HLCI aged ≥18 years from 14 public hospitals. Differences in means and proportions were assessed using a t-test or a chi-square test as necessary and the differences were quantified using standardized effect measures: Cohen's d for quantitative and Cohen's w for categorical variables. Adjusted influenza vaccine effectiveness in preventing severity was estimated by multivariate logistic regression where the adjusted VE = (1 - adjusted odds ratio) · 100%; adjustment was also made using the propensity score. We analyzed 1414 HLCI aged ≥18 years; 465 (33%) were vaccinated, of whom 437 (94%) were aged ≥60 years, 269 (57.8%) were male and 295 (63.4%) were positive for influenza type B. ICU admission was required in 214 (15.1%) cases. There were 141/1118 (12.6%) ICU admissions in patients aged ≥60 years and 73/296 (24.7%) in those aged <60 years (p < 0.001). The mean LOS and ICU LOS did not differ significantly between vaccinated and unvaccinated patients. There were 52/465 (11.2%) ICU admissions in vaccinated cases vs. 162/949 (17.1%) in unvaccinated cases. Patients admitted to the ICU had a longer hospital LOS (mean: 22.4 [SD 20.3] days) than those who were not (mean: 11.1 [SD 14.4] days); p < 0.001. Overall, vaccination was associated with a lower risk of ICU admission. Taking virus types A and B together, the estimated adjusted VE in preventing ICU admission was 31% (95% CI 1-52; p = 0.04). When stratified by viral type, the aVE was 40% for type A (95% CI -11-68; p = 0.09) and 25% for type B (95% CI -18-52; p = 0.21). Annual influenza vaccination may prevent ICU admission in cases of HLCI. A non-significantly shorter mean hospital stay was observed in vaccinated cases. Our results support the need to increase vaccination uptake and public perception of the benefits of influenza vaccination in groups at a higher risk of hospitalization and severe outcomes.

Human Astrovirus Outbreak in a Daycare Center and Propagation among Household Contacts.

We investigated an outbreak of acute gastroenteritis due to human astrovirus in a daycare center, describing the transmission mechanism, the most affected age groups, conditioning factors and the extent of the outbreak among household contacts of the daycare center attenders. Data were collected from persons exposed at the daycare center and their home contacts. Fecal samples from affected and non-affected daycare center attenders were analyzed for viruses causing acute gastroenteritis by RT-PCR. The percentage of households affected and the attack rates (AR) were calculated. The attack rates were compared using the rate ratio (RR) with 95% confidence intervals. Information was obtained from 245 people (76 attenders and 169 contacts) of whom 49 were clinical cases. Five HAstV-4, two HAstV-8 and three non-typable HAstV cases were identified (six from clinical cases and four from asymptomatic infected people). The global AR was 20% (41.2% in children aged < 2 years). Data were obtained from 67 households: 20 households of affected attenders and 47 of non-affected attendees. Household contacts of affected attenders had a higher AR (74.3%) than that of non-affected attendees (2.4%). We found asymptomatic infections amongst daycare attendees. The transmission of HAstV during the outbreak was not limited to the daycare center but extended to household contacts of both affected and non-affected attenders.

Behavior of hospitalized severe influenza cases according to the outcome variable in Catalonia, Spain, during the 2017-2018 season.

Influenza is an important cause of severe illness and death among patients with underlying medical conditions and in the elderly. The aim of this study was to investigate factors associated with ICU admission and death in patients hospitalized with severe laboratory-confirmed influenza during the 2017-2018 season in Catalonia. An observational epidemiological case-to-case study was carried out. Reported cases of severe laboratory-confirmed influenza requiring hospitalization in 2017-2018 influenza season were included. Mixed-effects regression analysis was used to estimate the factors associated with ICU admission and death. A total of 1306 cases of hospitalized severe influenza cases were included, of whom 175 (13.4%) died and 217 (16.6%) were ICU admitted. Age 65-74 years and ≥ 75 years and having ≥ 2 comorbidities were positively associated with death (aOR 3.19; 95%CI 1.19-8.50, aOR 6.95, 95%CI 2.76-1.80 and aOR 1.99; 95%CI 1.12-3.52, respectively). Neuraminidase inhibitor treatment and pneumonia were negatively associated with death. The 65-74 years and ≥ 75 years age groups were negatively associated with ICU admission (aOR 0.41; 95%CI 0.23-0.74 and aOR 0.30; 95%CI 0.17-0.53, respectively). A factor positively associated with ICU admission was neuraminidase inhibitor treatment. Our results support the need to investigate the worst outcomes of hospitalized severe cases, distinguishing between death and ICU admission.

Whole-Genome Analysis Surveillance of Influenza A Virus Resistance to Polymerase Complex Inhibitors in Eastern Spain from 2016 to 2019.

Molecular surveillance by whole-genome sequencing was used to monitor the susceptibility of circulating influenza A viruses to three polymerase complex inhibitors. A total of 12 resistance substitutions were found among 285 genomes analyzed, but none were associated with high levels of resistance. Natural resistance to these influenza A antivirals is currently uncommon.