Incidence of sinus thrombosis with thrombocytopenia-A nation-wide register study.

Safe vaccination is essential for mitigation of the COVID-19 pandemic. Two adenoviral vector vaccines, ChAdOx1 nCov-19 (AstraZeneca) and Ad26.COV2.S (Johnson&Johnson/Janssen) have shown to be effective and they are distributed globally, but reports on serious cerebral venous sinus thrombosis (CVST) associated with thrombocytopenia, have emerged. Our objective was to evaluate the background incidence of CVST with thrombocytopenia and to compare it to incidences following COVID-19 vaccines. We conducted a register-based nation-wide cohort study in Finland, including all 5.5 million individuals alive in Finland, 1 Jan 2020. COVID-19 vaccinations registered in the National Vaccination Register served as the exposure. We detected CVST admissions or hospital visits recorded in the hospital discharge register from Jan 1, 2020 through April 2, 2021. We confirmed the diagnosis of CVST and thrombocytopenia (platelet count <150,000 per cubic millimeter) using radiology reports and laboratory data. By Poisson regression, we compared the baseline incidences to the risks within four weeks after COVID-19 vaccinations. Out of the 167 CVST episodes identified in the registers, 117 were confirmed as CVST, 18 of which coincided with thrombocytopenia (baseline incidence 0.18 per 28 days per million persons). We found 2 episodes of CVST with thrombocytopenia within 28 days of the first ChAdOx1 nCov-19 vaccination (among 200,397 vaccinated, aged 16 or above). No cases were found following the first mRNA vaccine dose among 782,604 vaccinated. The background incidence of CVST combined with thrombocytopenia was minuscule compared to the incidence during the weeks following the ChAdOx1 nCov-19 vaccination. Accurate estimation of the baseline incidence is essential in the critical appraisal of the benefit-risk of any vaccination program.

Sudden Hearing Loss Following Vaccination Against COVID-19.

Importance: Spontaneous adverse reaction reports of sudden hearing loss have been observed, and a population-based cohort study conducted in Israel showed an increase in the incidence of sudden sensorineural hearing loss (SSNHL) following vaccination with messenger RNA COVID-19 vaccine BNT162b2 (Pfizer-BioNTech). However, in this setting, the possibility of confounding remained. Objective: To assess a potential association between COVID-19 vaccinations and SSNHL. Design, Setting, and Participants: This register-based country-wide retrospective cohort study of 5.5 million Finnish residents was conducted from January 1, 2019, to April 20, 2022, and included all individuals who were identified from the population information system who were alive or born during the study period except individuals who had SSNHL during 2015 to 2018 according to specialized care derived diagnosis codes for SSNHL (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code H91.2) as a primary or secondary diagnosis. Exposures: The a priori primary risk period was 0 to 54 days following each COVID-19 vaccination. The risk periods for different vaccine doses did not overlap so that a later vaccine exposure ended the previous risk period. The secondary risk period was from 55 days following each COVID-19 vaccination until a subsequent COVID-19 vaccination. A secondary analysis included a risk time from 0 to 54 days following a positive polymerase chain reaction test result for SARS-CoV-2. Main Outcomes and Measures: The incidences of SSNHL following COVID-19 vaccination were compared with the incidences before the COVID-19 epidemic in Finland. The Poisson regression model included calendar time, age, sex, diabetes, cardiovascular disease, other chronic diseases, and the number of visits in primary health care. Results: For the 5.5 million Finnish residents included in the study, the comparison time comprised 6.5 million person-years, the primary risk time of 1.7 million person-years, and the secondary risk time of 2.1 million person-years. Before the COVID-19 epidemic in Finland, 18.7/100 000 people received a diagnosis of SSNHL annually. The study data suggested no increased risk for SSNHL following any COVID-19 vaccination. In particular, adjusted incidence rate ratios with 95% confidence intervals for the BNT162b2 vaccine's 3 doses were 0.8 (95% CI, 0.6-1.0), 0.9 (95% CI, 0.6-1.2), and 1.0 (95% CI, 0.7-1.4), respectively. There was no association between SARS-CoV-2 infection and an increased incidence of SSNHL. Conclusions and Relevance: The results of this cohort study show no evidence of an increased risk of SSNHL following COVID-19 vaccination. The study accounted for previous disease and other potential confounding factors. These results are based on diagnosis codes in specialized care but still need to be verified in settings that are capable of evaluating the degree of hearing loss.

Respiratory virus circulation in children after relaxation of COVID-19 restrictions in fall 2021-A nationwide register study in Finland.

Social restrictions interrupted the normal respiratory virus circulation in Spring 2020. This report describes virus circulation in the pediatric population before and after the restrictions ended in Finland in September 2021. We used data from the Finnish Infectious Disease Register. Nationwide influenza A and B, rhinovirus, severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), and respiratory syncytial virus (RSV) findings from January 2018 to December 2021. Age stratified (0-4, 5-9, and 10-14 years) weekly incidences per 100 000 children were calculated. School and day-care closures interrupted completely the circulation of all other respiratory viruses than rhinovirus in spring 2020. After restrictions were relaxed in September 2021, SARS-Cov-2 detections increased majorly. We observed high RSV season atypically early. SARS-Cov-2 was detected in older children whereas RSV season peaked especially among children aged under 5. Influenza seemed to return to normal circulation. In conclusion, we report that the ending of social restrictions in September 2021 led to an increase in SARS-Cov-2 detections and high epidemic peaks of RSV and parainfluenza in atypical timing in children. Our results highlight the importance of continuous pathogen surveillance during the pandemic, as atypical surges of non-COVID-19 respiratory viruses were observed.

Record high parainfluenza season in children after relaxation of COVID-19 restrictions in fall 2021-A nationwide register study in Finland.

Social restrictions interrupted the circulation of common respiratory viruses among children in spring 2020. In the winter season 2020-2021, only rhinovirus spread in Finland. As the restrictions were ended in September 2021, we saw record high epidemic peak of parainfluenza. Typically, the epidemic peak is in springtime, but now, it started in the early fall 2021. The monthly incidence among children aged 0-4 years (120 per 100,000 children) was six times higher than the second highest reported monthly incidence (21 per 100,000 children) during the last 10 years. Our finding highlights the importance of active surveillance of viral respiratory pathogens during the pandemic.

Urinary tract infections decreased in Finnish children during the COVID-19 pandemic.

Social restrictions reduced the rates of respiratory infections in 2020, but studies on the rates of urinary tract infections (UTIs) during lockdown have had conflicting results. This study aimed to report UTI incidence during the first and second waves of COVID-19 pandemic in Finland. We conducted a retrospective register-based cohort study. The whole Finnish pediatric population (children under the age of 15 years, N = 860,000) was included. The yearly and monthly incidences of UTIs per 100,000 children in 2020 were compared to that of three previous years (2017-2019) by incidence rate ratios (IRRs) with 95% confidence intervals (CIs). A total of 10,757 cystitis and 4873 pyelonephritis cases were included. The yearly incidence of cystitis was 12% lower (IRR 0.88, CI 0.83-0.94) among children aged 1-6 in 2020 and 11% (IRR 0.89, CI 0.83-0.95) lower among children aged 7-14 in 2020 compared with previous years. The yearly incidence of pyelonephritis was 16% lower (IRR 0.84, CI 0.76-0.94) among children aged 1-6. No significant decrease were observed among children aged < 1 and 7-14. CONCLUSION: The incidence of cystitis and pyelonephritis during a period of social restrictions was lower than during 2017-2019, especially in children aged 1-6 years. These results raise the possibility of reducing the occurrence of urinary tract infections in children by improving hygiene measures. WHAT IS KNOWN: • Social restrictions have reduced the rate of common respiratory infections globally. • Previous studies have presented a decreased or unchanged incidence of urinary tract infections during the COVID-19 pandemic. WHAT IS NEW: • During the pandemic, there was a decrease in the incidence of urinary tract infections in Finnish children and the most prominent decrease was in daycare-aged children. • Improved hygiene measures and social restrictions may have influenced the transmission of uropathogens.

Systemic antibiotics and asthma medicines dispensed to 0-12 year olds significantly decreased during the COVID-19 pandemic in 2020.

AIM: Nationwide lockdowns and social restrictions during the COVID-19 pandemic have reduced childhood infections. We assessed how many items of systemic antibiotics and asthma medicines were dispensed to children aged 0-12 years in Finland before and during the pandemic and analysed the reimbursement costs. METHODS: The data came from the national Finnish register of reimbursable prescriptions, which is maintained by the country's Social Insurance Institution. It included all prescriptions for antibiotics and asthma medicines dispensed to children aged 0-12 years in 2019 and 2020. Prescription rates per 1000 children were calculated for each quarter and compared using rate ratios and 95% confidence intervals (95% CI). RESULTS: Overall dispensing for antibiotics decreased by 55.3% and was most prominent for macrolides for children aged 0-5 years (59.6%, 95% CI 60.9%-58.2%). Asthma medicines decreased by 19.8%, and the most prominent reduction was in short-acting beta-agonists for children aged 0-5 years (35.2%, 95% CI 36.1%-34.2%). These reduced reimbursement costs by 3.4 million Euros from 2019 to 2020. CONCLUSION: This nationwide study showed that the number of antibiotics and asthma medicines decreased by 59.6% and 19.8% respectively from 2019 to 2020, generating a cost saving of 3.4 million Euros.

Tympanostomies and tonsillar surgery in children during the COVID-19 pandemic in Finland.

OBJECTIVE: To assess the impact of social restrictions due to COVID-19 on the number of tympanostomies and tonsillar surgeries in children. METHODS: Incidences were calculated per 100 000 children for tonsillar surgery and tympanostomies in 2020 and compared to the mean incidence of referral years 2017 to 2019 by incidence rate ratios (IRR) with 95% confidence intervals (CIs). Median waiting times were also compared. RESULTS: Before the lockdown, tonsillar surgery incidence was 33.4/100000 (IRR 1.14, CI 0.76-1.71) in February 2020. After the lockdown began, the incidence of tonsillar surgery was 1.4/100000 (IRR 0.04, CI 0.01-0.15) in April. In June, tonsillar operation incidence started to increase (20.4 per 100 000). The incidence of tympanostomies was 81% lower (IRR 0.19, CI 0.09-0.39) in April 2020 and 61% lower (IRR 0.39, CI 0.22-0.69) in August 2020 than in 2017-2019. These incidence rates remained lower all year (December 2020 IRR 0.13, CI 0.05-0.33). Median waiting time for tonsillar surgery was 3.3 months in 2020 and 1.6 months in 2017 to 2019; P <.001, and for tympanostomies 1.3 months in 2020 and 1.0 months in 2017 to 2019, P <.001. The referral rate to otorhinolaryngology during the severest restrictions was 35% lower in April and May 2020 compared with the reference years. CONCLUSION: This study suggests that the restrictions against COVID-19 reduced the incidence rates of tonsil surgery and tympanostomies in children. Also, the lockdown and cancellations of elective operations in spring 2020 led to increased waiting times. These findings may help in preparing for future pandemics.Level of evidence: Level 3.

Rhinovirus spread in children during the COVID-19 pandemic despite social restrictions-A nationwide register study in Finland.

Social restrictions during the coronavirus disease 2019 pandemic strongly affected the epidemiology of influenza and respiratory syncytial virus (RSV). As rhinovirus seemed to spread despite the restrictions, we aimed to analyze rhinovirus epidemiology in children during the pandemic. This register-based study used data from the Finnish Infectious Disease Register. Nationwide rhinovirus findings from July 2015 to March 2021 were included and stratified by age (0-4, 5-9, and 10-14). Cumulative 14-day incidence per 100000 children was calculated. Four thousand five hundred and seventy six positive rhinovirus findings were included, of which 3788 (82.8%) were among children aged 0-4. The highest recorded incidence was 36.2 among children aged 0-4 in October 2017. The highest recorded incidence during the pandemic period was 13.6 in November 2020. The impact of the restrictions was mostly seen among children aged 0-4 years of age in weeks 14-22 in 2020. The incidence has since remained near reference levels in all age groups. Strict restrictions temporarily interrupted the circulation of rhinovirus in spring 2020. Rhinovirus incidence returned to normal levels soon after the harsh restrictions were lifted. These looser social restrictions prevented RSV and influenza seasons but failed to prevent the spread of rhinovirus.

The impact of the lockdown and the re-opening of schools and day cares on the epidemiology of SARS-CoV-2 and other respiratory infections in children - A nationwide register study in Finland.

BACKGROUND: Nationwide restrictions started in Finland in March to prevent the spread of COVID-19, leading to school and day care closures. The aim of this study is to describe the effect of closures and re-openings on the respiratory pathogen epidemiology. METHODS: Laboratory-confirmed cases of SARS-CoV-2; respiratory syncytial virus (RSV); influenza (A & B); parainfluenza-, adeno-, and rhinoviruses; Mycoplasma pneumoniae; and Streptococcus pneumoniae in children were collected from the National Infectious Disease Register over the period of 2017-2020. Weekly incidences (weeks 1 to 35) with 95% confidence intervals (CIs) were calculated per 100 000 children in 2020 and compared by incidence rate ratios (IRRs) to corresponding periods in 2017-2019. FINDINGS: The lockdown had immediate impact on the incidences of respiratory pathogens except SARS-CoV-2. Week after the lockdown began IRR was 0•3 (CI 0•3-0•4) and next week the IRR was 0•1 (0•1-0•2). The incidence of SARS-CoV-2 started to decline eight weeks after the lockdown began. The highest recorded weekly incidence of SARS-CoV-2 was 7•2/100 000 children. The effect of the lockdown lasted until late summer. Rhinovirus and SARS-CoV-2 began to increase before the schools or day cares opened in August. The re-opening of schools seemed to have no impact on the incidence of any pathogen. INTERPRETATION: Our results suggest that general social distancing, including school and day care closures, played a crucial role in reducing infections, and the effect lasted for several weeks. The re-opening of schools and day care centres seems to have had no immediate impact on the incidences of any respiratory pathogens. FUNDING: This study had no funding source.

Effect of Social Distancing Due to the COVID-19 Pandemic on the Incidence of Viral Respiratory Tract Infections in Children in Finland During Early 2020.

BACKGROUND: Social distancing measures are used to reduce the spreading of infection. Our aim was to assess the immediate effects of national lockdown orders due to coronavirus disease 2019 (COVID-19) on pediatric emergency room (ER) visits and respiratory tract infections in hospitals and nationwide in Finland. METHODS: This register-based study used hospital patient information systems and the Finnish national infectious disease register. The participants were all patients visiting pediatric ER in 2 Finnish hospitals (Kuopio University Hospital, Mikkeli Central Hospital) covering 1/5th of the Finnish children population, 4 weeks before and 4 weeks after the start of the nationwide lockdown on March 16, 2020. Nationwide weekly numbers of influenza (A + B) and respiratory syncytial virus (RSV) in children were assessed from the infectious disease register from 2015 to 2020. RESULTS: A major decrease in the rate of daily median pediatric ER visits was detected in both hospitals in the study during the nationwide lockdown compared with the study period before the lockdown (Mikkeli, 19 vs. 7, P < 0.001; Kuopio, 9 vs. 2,5, P < 0.001). The influenza season was shorter (8 weeks from peak to no cases), and the weekly rate of new cases decreased faster compared with the previous 4 influenza seasons (previously 15-20 weeks from peak to no cases). A similar decrease was also seen in RSV cases. No pediatric cases of COVID-19 were found in participating hospitals during the study period. CONCLUSION: These results strongly suggest that social distancing and other lockdown strategies are effective to slow down the spreading of common respiratory viral diseases and decreasing the need for hospitalization among children.