Hospitalization following influenza infection and pandemic vaccination in multiple sclerosis patients: a nationwide population-based registry study from Norway

Under embargo until: 2020-12-23Patients with multiple sclerosis (MS) are at increased risk of infections and related worsening of neurological function. Influenza infection has been associated with increased risk of various neurological complications. We conducted a population-based registry study to investigate the risk of acute hospitalization of MS patients in relation to influenza infection or pandemic vaccination in Norway. The entire Norwegian population in the years 2008–2014 was defined as our study population (N = 5,219,296). Information on MS diagnosis, influenza infection and vaccination were provided by Norwegian national registries. The self-controlled case series method was used to estimate incidence rate ratios (IRRs) with 95% confidence intervals (95% CI) in defined risk periods. 6755 MS patients were identified during the study period. Average age at first registration of an MS diagnosis was 51.8 years among men and 49.9 years among females (66.9%). The IRR for emergency hospitalization among MS patients the first week after an influenza diagnosis was 3.4 (95% CI 2.4–4.8). The IRR was 5.6 (95% CI 2.7–11.3) after pandemic influenza, and 4.8 (95% CI 3.1–7.4) after seasonal influenza. Pandemic vaccination did not influence risk of hospitalization [IRR within the first week: 0.7 (95% CI 0.5–1.0)]. Among MS patients, influenza infection was associated with increased risk for acute hospitalization while no increased risk was observed after pandemic vaccination. Influenza vaccination could prevent worsening of MS-related symptoms as well as risk of hospitalization.acceptedVersio

Lutte étagée ciblée et pulvérisation à très bas volume. Une protection insecticide du cotonnier moins onéreuse et plus respectueuse de l'environnement

La lutte étagée ciblée consiste à évaluer le niveau des populations de ravageurs la veille du traitement. Les insectes observés sont les chenilles des capsules ou des feuilles, les acariens, les aleurodes et les pucerons. Les niveaux de population sont confrontés à des seuils d'intervention et les résultats obtenus guident les choix des doses et des types d'insecticides utilisés. En 1995, 1 519 postes d'observateurs saisonniers ont été créés, pour une rémunération globale de 56 millions de francs CFA. Prévulgariséesur 407 ha en 1990, la lutte étagée ciblée a été vulgarisée sur 85 000 ha en 1995. Cette innovation nécessite la mise en oeuvre d'importants moyens dans le domaine de la formation et du suivi. La pulvérisation à très bas volume (TBV) épand 10 litres de bouillie aqueuse par hectare. Les insecticides utilisés sont des concentrés émulsionnables, moins chers que les insecticides pour ultra bas volume. A dose de matière active égale, un traitement TBV est 20 % moins cher qu'un traitement ULV. Les anciens appareils de traitement ultra bas volume ont été adaptés pour la pulvérisation TBV par un changement de buse et l'adjonction d'un réservoir auxiliaire. L'utilisation de la pulvérisation TBV a réduit les risques d'intoxication des opérateurs par inhalation (nuage de pulvérisation moins volatile) et par contact (bouillies insecticides aqueuses et moins concentrées). En permettant des économies de matières actives atteignant 30 à 40 %, la lutte étagée ciblée a permis de limiter les effets néfastes potentiels de la protection insecticide sur l'environnement. En 1992, la protection insecticide coûtait 9 005 francs CFA à l'hectare. En 1995, malgré la dévaluation, elle a coûté 10 700 francs CFA à l'hectare. En francs CFA constants, le coût de la protection insecticide a chuté de 41 % entre 1992 et 1995. Pour la campagne agricole 1995, l'économie réalisée a dépassé 900 millions de francs CFA

Comorbidities treated in primary care in children with chronic fatigue syndrome

Background: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a complex condition. Causal factors are not established, although underlying psychological or immunological susceptibility has been proposed. We studied primary care diagnoses for children with CFS/ME, with children with another hospital diagnosis (type 1 diabetes mellitus [T1DM]) and the general child population as comparison groups. Methods: All Norwegian children born 1992–2012 constituted the study sample. Children with CFS/ME (n = 1670) or T1DM (n = 4937) were identified in the Norwegian Patient Register (NPR) (2008-2014). Children without either diagnosis constituted the general child population comparison group (n = 1337508). We obtained information on primary care diagnoses from the Norwegian Directorate of Health. For each primary care diagnosis, the proportion and 99 % confidence interval (CI) within the three groups was calculated, adjusted for sex and age by direct standardization. Results: Children with CFS/ME were more often registered with a primary care diagnosis of weakness/general tiredness (89.9 % [99 % CI 88.0 to 91.8 %]) than children in either comparison group (T1DM: 14.5 % [99 % CI: 13.1 to 16.0 %], general child population: 11.1 % [99 % CI: 11.0 to 11.2 %]). Also, depressive disorder and anxiety disorder were more common in the CFS/ME group, as were migraine, muscle pain, and infections. In the 2 year period prior to the diagnoses, infectious mononucleosis was registered for 11.1 % (99 % CI 9.1 to 13.1 %) of children with CFS/ ME and for 0.5 % (99 % CI (0.2 to 0.8 %) of children with T1DM. Of children with CFS/ME, 74.6 % (1292/1670) were registered with a prior primary care diagnosis of weakness / general tiredness. The time span from the first primary care diagnosis of weakness / general tiredness to the specialist health care diagnosis of CFS/ME was 1 year or longer for 47.8 %. Conclusions: This large nationwide registry linkage study confirms that the clinical picture in CFS/ME is complex. Children with CFS/ME were frequently diagnosed with infections, supporting the hypothesis that infections may be involved in the causal pathway. The long time span often observed from the first diagnosis of weakness / general tiredness to the diagnosis of CFS/ME might indicate that the treatment of these patients is sometimes not optimal.publishedVersio

Maternal Active and Passive Smoking and Hypertensive Disorders of Pregnancy: Risk with Trimester-Specific Exposures

The inverse association between prenatal smoking and preeclampsia is puzzling, given the increased risks of prematurity and low birthweight associated with both smoking and preeclampsia. We analyzed the Norwegian Mother and Child Birth Cohort (MoBa) to determine whether the associations varied by timing of prenatal smoking

Effectiveness of mRNA booster vaccination against mild, moderate, and severe COVID-19 caused by the Omicron variant in a large, population-based, Norwegian cohort

Background Understanding how booster vaccination can prevent moderate and severe illness without hospitalization is crucial to evaluate the full advantage of mRNA boosters. Methods We followed 85 801 participants (aged 31–81 years) in 2 large population-based cohorts during the Omicron BA.1/2 wave. Information on home testing, PCR testing, and symptoms of coronavirus disease 2019 (COVID-19) was extracted from biweekly questionnaires covering the period 12 January 2022 to 7 April 2022. Vaccination status and data on previous SARS-CoV-2 infection were obtained from national registries. Cox regression was used to estimate the effectiveness of booster vaccination compared to receipt of 2-dose primary series >130 days previously. Results The effectiveness of booster vaccination increased with increasing severity of COVID-19 and decreased with time since booster vaccination. The effectiveness against severe COVID-19 was reduced from 80.9% shortly after booster vaccination to 63.4% in the period >90 days after vaccination. There was hardly any effect against mild COVID-19. The effectiveness tended to be lower among subjects aged ≥60 years than those aged <50 years. Conclusions This is the first population-based study to evaluate booster effectiveness against self-reported mild, moderate, and severe COVID-19. Our findings contribute valuable information on duration of protection and thus timing of additional booster vaccinations.publishedVersio

Do Genetic Variants Modify the Effect of Smoking on Risk of Preeclampsia in Pregnancy?

Under embargo until: 2022-11-28Objective Maternal smoking is associated with as much as a 50% reduced risk of preeclampsia, despite increasing risk of other poor pregnancy outcomes that often co-occur with preeclampsia, such as preterm birth and fetal growth restriction. Researchers have long sought to understand whether this perplexing association is biologically based, or a result of noncausal mechanisms. We examined whether smoking-response genes modify the smoking-preeclampsia association to investigate potential biological explanations. Study Design We conducted a nested case–control study within the Norwegian Mother, Father and Child Birth Cohort (1999–2008) of 2,596 mother–child dyads. We used family-based log-linear Poisson regression to examine modification of the maternal smoking-preeclampsia relationship by maternal and fetal single nucleotide polymorphisms involved in cellular processes related to components of cigarette smoke (n = 1,915 with minor allele frequency ≥10%). We further investigated the influence of smoking cessation during pregnancy. Results Three polymorphisms showed overall (p < 0.001) multiplicative interaction between smoking and maternal genotype. For rs3765692 (TP73) and rs10770343 (PIK3C2G), protection associated with smoking was reduced with two maternal copies of the risk allele and was stronger in continuers than quitters (interaction p = 0.02 for both loci, based on testing 3-level smoking by 3-level genotype). For rs2278361 (APAF1) the inverse smoking-preeclampsia association was eliminated by the presence of a single risk allele, and again the trend was stronger in continuers than in quitters (interaction p = 0.01). Conclusion Evidence for gene–smoking interaction was limited, but differences by smoking cessation warrant further investigation. We demonstrate the potential utility of expanded dyad methods and gene–environment interaction analyses for outcomes with complex relationships between maternal and fetal genotypes and exposures.acceptedVersio

Perfluoroalkyl Substances During Pregnancy and Validated Preeclampsia Among Nulliparous Women in the Norwegian Mother and Child Cohort Study

Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003–2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)2), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure