General practitioner visits after SARS-CoV-2 omicron compared with the delta variant in children in Norway: a prospective nationwide registry study.

BACKGROUND: SARS-CoV-2 infection in children is followed by an immediate increase in primary care utilisation. The difference in utilisation following infection with the delta and omicron virus variants is unknown. OBJECTIVES: To study whether general practitioner (GP) contacts were different in children infected with the omicron versus delta variant for up to 4 weeks after the week testing positive. SETTING: Primary care. PARTICIPANTS: All residents in Norway aged 0-10. After excluding 47 683 children with a positive test where the virus variant was not identified as delta or omicron and 474 children who were vaccinated, the primary study population consisted of 613 448 children. MAIN OUTCOME MEASURES: GP visits. METHODS: We estimated the difference in the weekly share visiting the GP after being infected with the delta or omicron variant to those in the study population who were either not tested or who tested negative using an event study design, controlling for calendar week of consultation, municipality fixed effects and sociodemographic factors in multivariate logistic regressions. RESULTS: Compared with preinfection, increased GP utilisation was found for children 1 and 2 weeks after testing positive for the omicron variant, with an OR of 6.7 (SE: 0.69) in the first week and 5.5 (0.72) in the second week. This increase was more pronounced for children with the delta variant, with an OR of 8.2 (0.52) in the first week and 7.1 (0.93) in the second week. After 2 weeks, the GP utilisation returned to preinfection levels. CONCLUSION: The omicron variant appears to have resulted in less primary healthcare interactions per infected child compared with the delta variant.

Transmission of SARS-CoV-2 in Norwegian schools during academic year 2020-21: population wide, register based cohort study.

Objective: To assess the risk of transmission of SARS-CoV-2 in schools in Norway mainly kept open during the covid-19 pandemic in the academic year 2020-21. Design: Population wide, register based cohort study. Setting: Primary and lower secondary schools in Norway open during the academic year 2020-21, with strict infection prevention and control measures in place, such as organisation of students into smaller cohorts. Contact tracing, quarantine, and isolation were also implemented, and testing of students and staff identified as close contacts. Participants: All students and educational staff in primary and lower secondary schools in Norway, from August 2020 to June 2021. Main outcome measures: Overall attack rate of SARS-CoV-2 transmission (AR14) was defined as the number of individuals (among students, staff, or both) in the school with covid-19, detected within 14 days of the index case, divided by the number of students and staff members in the school. AR14 to students (attack rates from all index cases to students only) and AR14 to school staff (attack rates from all index cases to staff members only) were also calculated. These measures for student and school staff index cases were also calculated separately to explore variation in AR14 based on the characteristics of the index case. Results: From August 2020 to June 2021, 4078 index cases were identified; 3220 (79%) students and 858 (21%) school staff. In most (2230 (55%)) schools with an index case, no subsequent individuals with covid-19 were found within 14 days; in 631 (16%) schools, only one more individual with covid-19 within 14 days was found. Overall, AR14 was 0.33% (95% confidence interval 0.32% to 0.33%). When restricting index cases and subsequent individuals with covid-19 to students born in the same year, AR14 to students (0.56-0.78%) was slightly higher. Conclusions: Regarding the number of people infected with SARS-CoV-2 among students and staff, these results suggest that schools were not an important setting for transmission of the virus in Norway during the covid-19 pandemic in the academic year 2020-21.

Transmission of SARS-CoV-2 into and within immigrant households: nationwide registry study from Norway.

BACKGROUND: Minority groups and immigrants have been hit disproportionally hard by COVID-19 in many developed countries, including Norway. METHODS: Using individual-level registry data of all Norwegian residents, we compared infections across all multiperson households. A household with at least one member born abroad was defined as an immigrant household. In households where at least one person tested positive for SARS-CoV-2 from 1 August 2020 to 1 May 2021, we calculated secondary attack rates (SARs) as the per cent of other household members testing positive within 14 days. Logistic regression was used to adjust for sex, age, household composition and geography. RESULTS: Among all multiperson households in Norway (n=1 422 411), at least one member had been infected in 3.7% of the 343 017 immigrant households and 1.4% in the 1 079 394 households with only Norwegian-born members. SARs were higher in immigrant (32%) than Norwegian-born households (20%). SARs differed considerably by region, and were particularly high in households from West Asia, Eastern Europe, Africa and East Asia, also after adjustment for sex and age of the secondary case, household composition and geography. CONCLUSION: SARS-CoV-2 is more frequently introduced into multiperson immigrant households than into households with only Norwegian-born members, and transmission within the household occurs more frequently in immigrant households. The results are likely related to living conditions, family composition or differences in social interaction, emphasising the need to prevent introduction of SARS-CoV-2 into these vulnerable households.

Impacts of mild COVID-19 on elevated use of primary and specialist health care services: A nationwide register study from Norway.

AIM: To explore the temporal impact of mild COVID-19 on need for primary and specialist health care services. METHODS: In all adults (≥20 years) tested for SARS-CoV-2 in Norway March 1st 2020 to February 1st 2021 (N = 1 401 922), we contrasted the monthly all-cause health care use before and up to 6 months after the test (% relative difference), for patients with a positive test for SARS-CoV-2 (non-hospitalization, i.e. mild COVID-19) and patients with a negative test (no COVID-19). RESULTS: We found a substantial short-term elevation in primary care use in all age groups, with men generally having a higher relative increase (men 20-44 years: 522%, 95%CI = 509-535, 45-69 years: 439%, 95%CI = 426-452, ≥70 years: 199%, 95%CI = 180-218) than women (20-44 years: 342, 95%CI = 334-350, 45-69 years = 375, 95%CI = 365-385, ≥70 years: 156%, 95%CI = 141-171) at 1 month following positive test. At 2 months, this sex difference was less pronounced, with a (20-44 years: 21%, 95%CI = 13-29, 45-69 years = 38%, 95%CI = 30-46, ≥70 years: 15%, 95%CI = 3-28) increase in primary care use for men, and a (20-44 years: 30%, 95%CI = 24-36, 45-69 years = 57%, 95%CI = 50-64, ≥70 years: 14%, 95%CI = 4-24) increase for women. At 3 months after test, only women aged 45-70 years still had an increased primary care use (14%, 95%CI = 7-20). The increase was due to respiratory- and general/unspecified conditions. We observed no long-term (4-6 months) elevation in primary care use, and no elevation in specialist care use. CONCLUSION: Mild COVID-19 gives an elevated need for primary care that vanishes 2-3 months after positive test. Middle-aged women had the most prolonged increased primary care use.

SARS-CoV-2 in health and care staff in Norway, 2020. / SARS-CoV-2 blant ansatte i helse- og omsorgstjenesten.

BACKGROUND: The COVID-19 pandemic is placing considerable pressure on health services around the world. In Norway, the incidence rate among the working-age population (20-69 years) for the whole of 2020 was 1.11 %. In this study, we describe diagnosed infection among staff in the health service, based on register data. MATERIAL AND METHOD: From the emergency preparedness register, Beredt C19, we identified 382 332 persons employed in selected occupational groups in the health service in week 9 of 2020, and investigated incidence and testing activity for diagnosed SARS-CoV-2 according to occupation, age, sex, country of birth, place of residence and place of work, for the whole of 2020. RESULTS: The incidence in the health service for the entire period was 1.48 % (5673/382 332). Diagnosed infection was highest among ambulance personnel and nursing home staff, with an incidence of 1.83 % (95/5203) and 1.86 % (1534/82 776), respectively. Doctors were tested most frequently (1.45 tests per person), and the proportion of positive tests was highest among cleaners (2.78 %) and ambulance personnel (1.57 %). Imported infection was highest for dentists (14.3 %), psychologists (12.8 %) and doctors (10.8 %). INTERPRETATION: There are variations in the incidence of diagnosed infections among employees in the health service. Some of this can likely be viewed in connection with high testing activity, imported infection, age and sex distribution, place of residence and country of birth, and outbreaks in different health services. More research and data are needed to ascertain whether occupational practice is associated with increased risk of SARS-CoV-2 infection.