Highlights • Analysis of community-based surveillance data provided timely estimates of influenza VE. • Influenza VE was 58% in children 6m–5y of age, 45% in children 6–17y, 36% in adults 18–50y and ...34% in adults >50y. • Comparability of these estimates with other studies supports the feasibility of this approach for routine monitoring of influenza VE.
Parainfluenza viruses (PIV) have been shown to contribute substantially to pediatric hospitalizations in the United States. However, to date, there has been no systematic surveillance to estimate the ...burden among pediatric outpatients.
From August 2010 through July 2014, outpatient health care providers with enumerated patient populations in 13 states and jurisdictions participating in the Influenza Incidence Surveillance Project conducted surveillance of patients with influenza-like illness (ILI). Respiratory specimens were collected from the first 10 ILI patients each week with demographic and clinical data. Specimens were tested for multiple respiratory viruses, including PIV1-4, using reverse transcriptase-polymerase chain reaction assays. Cumulative incidence was calculated using provider patient population size as the denominator.
PIVs 1-3 were detected in 8.0% of 7716 ILI-related outpatient specimens: 30% were PIV1, 26% PIV2 and 44% PIV3. PIV circulation varied noticeably by year and type, with PIV3 predominating in 2010-2011 (incidence 110 per 100,000 children), PIV1 in 2011-2012 (89 per 100,000), dual predominance of PIV2 and PIV3 (88 and 131 per 100,000) in 2012-2013 and PIV3 (100 per 100,000) in 2013-2014. The highest incidence of PIV detections was among patients aged <5 years (259-1307 per 100,000). The median age at detection for PIV3 (3.4 years) was significantly lower than the median ages for PIV1 (4.5 years) and PIV2 (7.0 years; P < 0.05).
PIVs 1-3 comprise a substantial amount of medically attended pediatric ILI, particularly among children aged <5 years. Distinct seasonal circulation patterns as well as significant differences in rates by age were observed between PIV types.
Despite a longstanding Israel Ministry of Health recommendation that all healthcare personnel (HCP) receive a seasonal influenza vaccine, vaccine uptake among HCP remains below the country’s target ...of 60% coverage. To understand factors related to vaccine hesitancy, we used data from a prospective three-year (2016–2019) influenza vaccine effectiveness study among Israeli HCP to examine knowledge, attitudes, and practices (KAP) about influenza vaccination and their association with vaccine uptake.
At the start of each influenza season, all participating HCP completed a questionnaire that included questions about socio-demographic and occupational characteristics, health status, and KAP related to seasonal influenza vaccination. We extracted vaccination history from electronic medical records and employee vaccination registries. We used logistic regression models to identify demographic and occupational factors, and KAP about influenza vaccination, associated with receipt of vaccination.
A total of 2,126 HCP were enrolled and had available data on vaccination history. Their median age was 42 years IQR 35–52, and 73 % self-identified as female. Influenza vaccine uptake in 2016, 2017 and 2018 was 46 %, 48 % and 47 %, respectively. Overall, 36 % of HCP had received an influenza vaccine in ≥ 4 of the eight years prior. HCP aged 35–49 years were less likely to receive influenza vaccine compared to HCP aged ≥ 50 years (OR: 0.81 95 % CI: 0.67–0.98). Nurses and allied personnel were less likely to receive influenza vaccine compared to physicians (OR: 0.63 95 % CI: 0.50–0.78 and OR: 0.53 95 % CI: 0.40–0.70, respectively). The emotional benefit of vaccination (e.g., anticipating regret if not vaccinated) and the perception of vaccine safety were factors associated with vaccine uptake (OR: 7.60 95 % CI: 6.27–9.22 and OR: 3.43 95 % CI:2.91–4.03, respectively).
Among HCP at two hospitals in Israel, less than half received an annual influenza vaccine. Older HCP, physicians, and those who reported the emotional benefit of vaccination or agreed that influenza vaccines are safe were more likely to be vaccinated. Future influenza vaccination campaigns could focus on these demographic groups and tailor messages emphasizing the emotional benefits of vaccination and vaccine safety to increase seasonal influenza vaccine uptake among HCP in Israel.
Messenger RNA (mRNA) BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) COVID-19 vaccines have been shown to be effective in preventing symptomatic COVID-19 in randomized placebo-controlled Phase III ...trials (1,2); however, the benefits of these vaccines for preventing asymptomatic and symptomatic SARS-CoV-2 (the virus that causes COVID-19) infection, particularly when administered in real-world conditions, is less well understood. Using prospective cohorts of health care personnel, first responders, and other essential and frontline workers* in eight U.S. locations during December 14, 2020-March 13, 2021, CDC routinely tested for SARS-CoV-2 infections every week regardless of symptom status and at the onset of symptoms consistent with COVID-19-associated illness. Among 3,950 participants with no previous laboratory documentation of SARS-CoV-2 infection, 2,479 (62.8%) received both recommended mRNA doses and 477 (12.1%) received only one dose of mRNA vaccine.
Among unvaccinated participants, 1.38 SARS-CoV-2 infections were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) per 1,000 person-days.
In contrast, among fully immunized (≥14 days after second dose) persons, 0.04 infections per 1,000 person-days were reported, and among partially immunized (≥14 days after first dose and before second dose) persons, 0.19 infections per 1,000 person-days were reported. Estimated mRNA vaccine effectiveness for prevention of infection, adjusted for study site, was 90% for full immunization and 80% for partial immunization. These findings indicate that authorized mRNA COVID-19 vaccines are effective for preventing SARS-CoV-2 infection, regardless of symptom status, among working-age adults in real-world conditions. COVID-19 vaccination is recommended for all eligible persons.
Abstract Background There are limited data on whether hybrid immunity differs by count and order of immunity-conferring events (infection with severe acute respiratory syndrome coronavirus 2 ...SARS-CoV-2 or vaccination against coronavirus disease 2019 COVID-19). From a multi-site cohort of frontline workers, we examined the heterogeneity of the effect of hybrid immunity on SARS-CoV-2 antibody levels. Methods Exposures included event count and event order, categorized into 7 permutations. Outcome was level of serum antibodies against receptor-binding domain (RBD) of the ancestral SARS-CoV-2 spike protein (total RBD-binding immunoglobulin). Means were examined up to 365 days after each of the first to seventh events. Results Analysis included 5793 participants measured from 7 August 2020 to 15 April 2023. Hybrid immunity from infection before 1 or 2 vaccine doses elicited modestly superior antibody responses after the second and third events (compared with infections or vaccine doses alone). This superiority was not repeated after additional events. Among adults infected before vaccination, adjusted geometric mean ratios (95% confidence interval CI) of anti-RBD early response (versus vaccinated only) were 1.23 (1.14–1.33), 1.09 (1.03–1.14), 0.87 (.81–.94), and 0.99 (.85–1.15) after the second to fifth events, respectively. Post-vaccination infections elicited superior responses; adjusted geometric mean ratios (95% CI) of anti-RBD early response (versus vaccinated only) were 0.93 (.75–1.17), 1.11 (1.06–1.16), 1.17 (1.11–1.24), and 1.20 (1.07–1.34) after the second to fifth events, respectively. Conclusions Evidence of heterogeneity in antibody levels by permutations of infection and vaccination history could inform COVID-19 vaccination policy.
Background. The Influenza Incidence Surveillance Project (IISP) monitored outpatient acute respiratory infection (ARI; denned as the presence of ≥2 respiratory symptoms not meeting ILI criteria) and ...influenza-like illness (ILI) to determine the incidence and contribution of associated viral etiologies. Methods. From August 2010 through July 2011, 57 outpatient healthcare providers in 12 US sites reported weekly the number of visits for ILI and ARI and collected respiratory specimens on a subset for viral testing. The incidence was estimated using the number of patients in the practice as the denominator, and the virus-specific incidence of clinic visits was extrapolated from the proportion of patients testing positive. Results. The age-adjusted cumulative incidence of outpatient visits for ARI and ILI combined was 95/1000 persons, with a viral etiology identified in 58% of specimens. Most frequently detected were rhinoviruses/enteroviruses (RV/EV) (21%) and influenza viruses (21%); the resulting extrapolated incidence of outpatient visits was 20 and 19/1000 persons respectively. The incidence of influenza virus-associated clinic visits was highest among patients aged 2-17 years, whereas other viruses had varied patterns among age groups. Conclusions. The IISP provides a unique opportunity to estimate the outpatient respiratory illness burden by etiology. Influenza virus infection and RV/EV infection(s) represent a substantial burden of respiratory disease in the US outpatient setting, particularly among children.
Background
Influenza viruses pose significant disease burdens through seasonal outbreaks and unpredictable pandemics. Existing surveillance programs rely heavily on reporting of medically attended ...influenza (MAI). Continuously monitoring cause‐specific school absenteeism may identify local acceleration of seasonal influenza activity. The Oregon Child Absenteeism Due to Respiratory Disease Study (ORCHARDS; Oregon, WI) implements daily school‐based monitoring of influenza‐like illness‐specific student absenteeism (a‐ILI) in kindergarten through Grade 12 schools and assesses this approach for early detection of accelerated influenza and other respiratory pathogen transmission in schools and surrounding communities.
Methods
Starting in September 2014, ORCHARDS combines automated reporting of daily absenteeism within six schools and home visits to school children with acute respiratory infection (ARI). Demographic, epidemiological, and symptom data are collected along with respiratory specimens. Specimens are tested for influenza and other respiratory viruses. Household members can opt into a supplementary household transmission study. Community comparisons are possible using a pre‐existing and highly effective influenza surveillance program, based on MAI at five family medicine clinics in the same geographical area.
Results
Over the first 5 years, a‐ILI occurred on 6634 (0.20%) of 3,260,461 student school days. Viral pathogens were detected in 64.5% of 1728 children with ARI who received a home visit. Influenza was the most commonly detected virus, noted in 23.3% of ill students.
Conclusion
ORCHARDS uses a community‐based design to detect influenza trends over multiple seasons and to evaluate the utility of absenteeism for early detection of accelerated influenza and other respiratory pathogen transmission in schools and surrounding communities.
Please cite this paper as: Fowlkes et al. (2012) Estimating influenza incidence and rates of influenza‐like illness in the outpatient setting. Influenza and Other Respiratory Viruses DOI: ...10.1111/irv.12014.
Background: Estimating influenza incidence in outpatient settings is challenging. We used outpatient healthcare practice populations as a proxy to estimate community incidence of influenza‐like illness (ILI) and laboratory‐confirmed influenza‐associated ILI.
Methods: From October 2009 to July 2010, 38 outpatient practices in seven jurisdictions conducted surveillance for ILI (fever with cough or sore throat for patients ≥2 years; fever with ≥1 respiratory symptom for patients <2 years). From a sample of patients with ILI, respiratory specimens were tested for influenza.
Results: During the week of peak influenza activity (October 24, 2009), 13% of outpatient visits were for ILI and influenza was detected in 72% of specimens. For the 10‐month surveillance period, ILI and influenza‐associated ILI incidence were 20·0 (95% CI: 19·7, 20·4) and 8·7/1000 (95% CI: 8·2, 9·2) persons, respectively. Influenza‐associated ILI incidence was highest among children aged 2–17 years. Observed trends were highly correlated with national ILI and virologic surveillance.
Conclusions: This is the first multistate surveillance system demonstrating the feasibility of using outpatient practices to estimate the incidence of medically attended influenza at the community level. Surveillance demonstrated the substantial burden of pandemic influenza in outpatient settings and especially in children aged 2–17 years. Observed trends were consistent with established syndromic and virologic systems.
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