Two-dose measles vaccine effectiveness remains high over time: A French observational study, 2017-2019.

BACKGROUND: From 2008 to 2019, France has experienced a resurgence of measles epidemics. Surveillance data have shown that the proportion of cases vaccinated with two doses of measles-containing vaccine (MCV) increased with age, raising concerns about the duration of vaccine protection. Our objectives were to investigate age-stratified vaccine effectiveness (VE) for the second dose of MCV (MCV2) and to quantify protection levels over time. METHODS: We analyzed data on measles cases aged 2-31 years, reported via mandatory notification to the French measles surveillance system from October 2017 to September 2019. We estimated an age-stratified VE for MCV2 using the screening method, which compares the vaccination status of cases with that of the general population. We improved this method by accounting for natural immunity, exploring four scenarios with four possible levels of natural immunity in the population. In addition, we quantified the decay rate of protection over time, by fitting an exponential decay model among individuals vaccinated in early life. RESULTS: In the baseline analysis (absence of natural immunity), VE estimates were high in all age groups and decreased with age, from 99.6 % (95 % confidence interval: 99.3-99.8) in 2-5 years old to 91.4 % (85.1-95.0) in 26-31 years old. Accounting for natural immunity increased VE in the older age group to 93.2-99.2 % depending on the scenario. We estimated that VE was slowly decreasing over time, with an exponential decay rate of 0.0022/year (0.0017-0.0028), leading to VE of 96.7 % (96.0-97.4) 16 years after MCV2 vaccination. This decline was most compatible with scenario 2, a scenario of 4.4 % naturally immunized, non-vaccinated individuals in the 26-31 years old. CONCLUSION: Our study confirms the continued high effectiveness of two doses of MCV with only slight degradation, decades after immunization. These findings support the importance of achieving a very high vaccination coverage with 2 doses of MCV.

Experiences with regular testing of students for SARS-CoV-2 in primary and secondary schools: results from a cross-sectional study in two Norwegian counties, autumn 2021.

BACKGROUND: To allow for normal school attendance during the COVID-19 pandemic, regular testing of students was introduced in the autumn 2021 in Norway to manage COVID-19 transmission. We mapped the experiences of five stakeholders (parents, students, school staff and administration, contact tracing teams) regarding the implementation of regular testing in primary and secondary schools in Oslo and Viken counties, to assess the acceptability through different indicators and improve future guidelines. METHODS: A cross-sectional survey was conducted between October and November 2021 to explore experiences of implementation, compliance, satisfaction, difficulties, concerns, confidence in regular testing, quality of teaching and school attendance. Five stakeholder groups were invited to participate: contact tracing teams; school administrators and employees in primary, lower secondary, and upper-secondary school; students in upper-secondary school and parents of primary and lower secondary students. Bivariate analyses were performed for students, parents, and school employees groups. Descriptive analyses were done for contact tracing teams and school administrators. RESULTS: Four thousand five hundred sixty-five participants were included in our study. School attendance increased for most of the students in primary and lower secondary schools in Oslo and Viken after the implementation of regular testing. Students across all school levels reported high testing compliance and satisfaction with the implementation. Compliance was significantly associated with an increasing number of weekly tests across all school levels up to two weekly tests. Contact tracing teams were less satisfied with the cooperation with the educational authorities compared to the school employees. Higher educational level of parents was significantly associated with decreased concern of their children getting infected at school after regular testing implementation. Concerned parents were more likely to keep children at home from school, to protect all household members from becoming infected. Lack of time and communication were reported as challenging factors to implementation. CONCLUSION: Compliance, satisfaction, and confidence in regular testing of COVID-19 were high among stakeholders. An acceptable testing regime for a future regular testing implementation would be a home-based, bi-weekly test. Increased awareness of the importance of school attendance, safety of regular testing along with good communication and role clarification should be prioritized for stakeholders involved in regular testing.

Clinical outcomes of antimicrobial resistance in cancer patients: a systematic review of multivariable models.

BACKGROUND: Infections are major causes of disease in cancer patients and pose a major obstacle to the success of cancer care. The global rise of antimicrobial resistance threatens to make these obstacles even greater and hinder continuing progress in cancer care. To prevent and handle such infections, better models of clinical outcomes building on current knowledge are needed. This internally funded systematic review (PROSPERO registration: CRD42021282769) aimed to review multivariable models of resistant infections/colonisations and corresponding mortality, what risk factors have been investigated, and with what methodological approaches. METHODS: We employed two broad searches of antimicrobial resistance in cancer patients, using terms associated with antimicrobial resistance, in MEDLINE and Embase through Ovid, in addition to Cinahl through EBSCOhost and Web of Science Core Collection. Primary, observational studies in English from January 2015 to November 2021 on human cancer patients that explicitly modelled infection/colonisation or mortality associated with antimicrobial resistance in a multivariable model were included. We extracted data on the study populations and their malignancies, risk factors, microbial aetiology, and methods for variable selection, and assessed the risk of bias using the NHLBI Study Quality Assessment Tools. RESULTS: Two searches yielded a total of 27,151 unique records, of which 144 studies were included after screening and reading. Of the outcomes studied, mortality was the most common (68/144, 47%). Forty-five per cent (65/144) of the studies focused on haemato-oncological patients, and 27% (39/144) studied several bacteria or fungi. Studies included a median of 200 patients and 46 events. One-hundred-and-three (72%) studies used a p-value-based variable selection. Studies included a median of seven variables in the final (and largest) model, which yielded a median of 7 events per variable. An in-depth example of vancomycin-resistant enterococci was reported. CONCLUSIONS: We found the current research to be heterogeneous in the approaches to studying this topic. Methodological choices resulting in very diverse models made it difficult or even impossible to draw statistical inferences and summarise what risk factors were of clinical relevance. The development and adherence to more standardised protocols that build on existing literature are urgent.

Characterization of Non-Toxigenic Clostridioides difficile Strains Isolated from Preterm Neonates and In Vivo Study of Their Protective Effect.

In a previous monocentric study in preterm neonates (PN), we described a high Clostridioides difficile colonization rate (74%) with two uncommon non-toxigenic strains (NTCD) belonging to PCR-ribotype (RT) (CE)847 and (CE)032. To determine the extent of carriage of both NTCD in other spatio-temporal settings, strains isolated in PN stools from two multicenter cohorts were characterized by PCR-ribotyping, MLVA and MLST. We also evaluated the protective role of two NTCD from these RT against C. difficile infection in a hamster caecitis model. Animals were administered either each NTCD alone (n = 7), or followed by a 027 strain (n = 9). A control group received only the 027 strain (n = 8). Clinical activity and colonization by C. difficile in stools were monitored daily until death or sacrifice at D20. We isolated 18 RT(CE)032 (ST-83) strains and 2 RT(CE)847 (ST-26) strains among 247 PN from both cohorts. Within each RT, strains were genetically related. The survival rate was significantly increased when animals received a RT(CE)847 or (CE)032 strain before the 027 strain (4/9 deaths, p = 0.029; 1/9 death, p = 0.0004, respectively). We describe two predominant uncommon NTCD strains, in a PN population from different healthcare facilities. Both NTCD provide a potential protection against C. difficile infection.

Large concomitant outbreaks of acute gastroenteritis emergency visits in adults and food-borne events suspected to be linked to raw shellfish, France, December 2019 to January 2020.

On 27 December 2019, the French Public Health Agency identified a large increase in the number of acute gastroenteritis and vomiting visits, both in emergency departments and in emergency general practitioners' associations providing house-calls. In parallel, on 26 and 27 December, an unusual number of food-borne events suspected to be linked to the consumption of raw shellfish were reported through the mandatory reporting surveillance system. This paper describes these concomitant outbreaks and the investigations' results.