Background: Data on influenza incidence during pregnancy in China are limited. Methods: From October 2015–September 2018, we conducted active surveillance for acute respiratory illness (ARI) among women during pregnancy. Nurses conducted twice weekly phone and text message follow-up upon enrollment until delivery to identify new episodes of ARI. Nasal and throat swabs were collected ≤10 days from illness onset to detect influenza. Results: In total, we enrolled 18,724 pregnant women median aged 28yo, 37% in first trimester, 48% in second trimester and 15% in third trimester, with 7 self-reported vaccination during pregnancy. In the 18-week epidemic period during October 2015–September 2016, influenza incidence was 0.7/100 person-months (95% CI:0.5–0.9). In the 29-week epidemic during October 2016–September 2017, influenza incidence was 1.0/100 person-months (95% CI:0.8–1.2). In the 11-week epidemic period during October 2017–September 2018, influenza incidence was 2.1/100 person-months (95% CI:1.9–2.4). Influenza incidence was similar by trimester. More than half of the total influenza illnesses had no elevated temperature and cough. Most influenza-associated ARIs were mild, and <5.1% required hospitalization. Conclusions: Influenza illness in all trimesters of pregnancy was common. These data may help inform decisions regarding the use of influenza vaccine to prevent influenza during pregnancy.
Objectives Possibility of reinfection with SARS-CoV-2 changes our view on herd immunity and vaccination, and can impact worldwide quarantine policies. We performed RT-PCR follow-up studies on recovered patients to assess possible development of reinfections and re-positivity. Method During a 6-month period, 202 PCR-confirmed recovering COVID-19 patients entered this study. Follow-up RT-PCR tests and symptoms assessment were performed one month after the initial Positive results. patients who tested negative were tested again one and three months later. The Serum IgG and IgM levels were measured in the last follow-up session. Results In the first two follow-up sessions, 82 patients continued their participation, of which four patients tasted positive. In the second follow-up 44 patients participated, three of whom tested positive. None of the patients who tested positive in the first and second follow-up session were symptomatic. In the last session, 32 patients were tested and four patients were positive, three of them were mildly symptomatic and all of them were positive for IgG. Conclusion A positive RT-PCR in a recovering patient may represent reinfection. While we did not have the resources to prove reinfection by genetic sequencing of the infective viruses, we believe presence of mild symptoms in the three patients who tested positive over 100 days after becoming asymptomatic, can be diagnosed as reinfection. The IgG may have abated the symptoms of the reinfection, without providing complete protection.
Since the start of the SARS-CoV-2 pandemic, it has been difficult to differentiate between SARS-CoV-2 re-infection and prolonged RNA shedding. In this report, we identified patients with positive rtPCR results for SARS-CoV-2 ≥70 days apart. Clinical and laboratory data were collected and criteria were applied to discern whether the presentation was consistent with SARS-CoV-2 re-infection or prolonged viral RNA shedding. Eleven individuals met the initial testing criteria, of which, seven met at least one criteria for re-infection and four were consistent with prolonged RNA shedding. These data demonstrate the need for criteria to differentiate SARS-CoV-2 re-infection from prolonged RNA shedding.
Background: Standard dose seasonal influenza vaccines often produce modest immunogenic responses in adults ≥65 years old. MF59 is intended to elicit a greater magnitude and increased breadth of immune response. Objective: To determine the effectiveness of seasonal MF59-adjuvanted trivalent/quadrivalent influenza vaccine (aTIV/aQIV) relative to no vaccination or vaccination with standard or high dose egg-based influenza vaccines among people ≥65 years old. Methods: Cochrane methodological standards and PRISMA-P guidelines were followed. Real-world evidence from non-interventional studies published in peer reviewed journals and grey literature from 1997 through to July 15, 2020, including cluster-randomized trials, were eligible. Two reviewers independently extracted data and risk of bias was assessed using the ROBINS-I tool. Results: Twenty-one studies conducted during the 2006/07-2019/20 influenza seasons were included in the qualitative review; 16 in the meta-analyses. Meta-analysis of test-negative studies found that aTIV reduced medical encounters due to lab-confirmed influenza with pooled estimates of 40.7% (95% CI: 21.9, 54.9; I2=0%) for general practitioner visits and 58.5% (40.7, 70.9; I2=52.9%) for hospitalized patients. The pooled estimate of VE from case-control studies was 51.3% (39.1, 61.1; I2=0%) against influenza- or pneumonia-related hospitalization. The pooled estimates for the relative VE of aTIV for the prevention of influenza related medical encounters were 13.9% (4.2, 23.5; I2=95.9%) compared with TIV, 13.7% (3.1, 24.2; I2=98.8%) compared with QIV, and 2.8% (-2.9, 8.5; I2=94.5%) compared with HD TIV. Conclusions: Among adults ≥65 years aTIV demonstrated significant absolute VE, improved relative VE compared to non-adjuvanted standard-dose TIV/QIV, and comparable relative VE to high-dose TIV.
Background: Seasonal influenza is a burden for emergency departments. The aim of this study was to investigate whether point-of-care (POC) PCR testing can be used to reduce staff sick days and improve diagnostic and therapeutic procedures. Methods: Using a cross-over design, the cobas® Liat® Influenza A/B POC PCR test (Liat) was compared to standard clinical practice during the 2019/2020 influenza season. All adult patients (aged ≥18 years) with fever (≥38°C) and respiratory symptoms were included. Primary endpoints were prevalence of influenza infections in the ED and staff sick days. Secondary endpoints were frequency of antiviral and antibacterial therapy, time between admission and test result or treatment initiation, patient disposition, ED length of stay (LOS) and for in-patients mortality and LOS. Nurses were interviewed about handling and integration of POC testing. The occurrence of SARS-CoV-2 infections coincided with the second half of the study. Results: A total of 828 patients were enrolled in the study. All 375 patients of the intervention group were tested with Liat, 103 of them (27.6%) tested positive. During the intervention period staff sick days were reduced by 34.4% (p=0.023). Significantly more patients in the intervention group received antiviral therapy with neuraminidase-inhibitors (7.2% vs. 3.8%, p=0.028) and tested patients received antibiotics more frequently (40.0% vs. 31.6%, p=0.033). Patients with POC test were transferred to external hospitals significantly more often (5.6% vs. 1.3%, p=0.01). Conclusion: We conclude that POC testing for influenza is useful in the ED, especially if it is heavily frequented by patients with respiratory symptoms.
Abstract: Objectives: Our work assessed the prevalence of co-infections in patients with SARS-CoV-2. Methods: All patients hospitalized in a Parisian hospital during the first wave of COVID-19 were tested by mPCR if they presented ILI symptoms. Results: A total of 806 patients (21%) were positive for SARS-CoV-2, 755 (20%) were positive for other respiratory viruses. Among the SARS-CoV-2 positive patients, 49 (6%) had viral co-infections. They presented similar age, symptoms, except for fever (p=0.013) and headaches (p=0.048), than single SARS-CoV-2 infections. Conclusions: SARS-CoV-2 infected patients presenting viral co-infections had similar clinical characteristics and prognosis than patients solely infected with SARS-CoV-2.
Background Physical distancing and facemask use are worldwide recognized as effective non-pharmaceutical interventions (NPIs) against the coronavirus disease 2019 (COVID-19). Since January 2020, Taiwan has introduced both NPIs but their effectiveness on non-COVID-19 respiratory viruses (NCRVs) remain underexplored. Methods This retrospective observational study examined electronic records at a tertiary hospital in northern Taiwan from pre-COVID (January–December 2019) to post-COVID period (January–May 2020). Patients with respiratory syndromes were tested for both enveloped (e.g. influenza virus and seasonal coronavirus) and non-enveloped RVs (e.g. enterovirus and rhinovirus) using multiplex reverse-transcription polymerase chain reaction assays. Monthly positivity rates of NCRVs among adult and pediatric patients were analyzed with comparison between pre- and post-COVID periods. Results A total of 9693 patients underwent 12127 multiplex RT-PCR tests. The average positivity rate of NCRVs reduced by 11.2% (25.6% to 14.4%) after nationwide PHIs. Despite the COVID-19 pandemic, the most commonly identified enveloped and non-enveloped viruses were influenza virus and enterovirus/rhinovirus, respectively. Observed reduction in NCRV incidence was predominantly contributed by enveloped NCRVs including influenza viruses. We did not observe epidemiological impacts of NPIs on non-enveloped viruses but an increasing trend in enterovirus/rhinovirus test positivity rate among pediatric patients. Our data were validated using Taiwan’s national notification database. Conclusions Our frontline investigation suggests that the current NPIs in Taiwan might not effectively control the transmission of non-enveloped respiratory viruses, despite their protective effects against influenza and seasonal coronavirus. Hydrogen peroxide or chloride-based disinfectants should be integrated into national preventative strategies against respiratory viral infections in the post-COVID-19 era.
Background Children are important in community-level influenza transmission. School-based monitoring may inform influenza surveillance. Methods We used reported weekly confirmed influenza in Allegheny County during the 2007, and 2010-2015 influenza seasons using Pennsylvania’s Allegheny County Health Department all-age influenza cases from health facilities, and all-cause and influenza-like illness (ILI)-specific absences from nine county school districts. Negative binomial regression predicted influenza cases using all-cause and illness-specific absence rates, calendar week, average weekly temperature and relative humidity, using four cross-validations. Results School districts reported 2,184,220 all-cause absences (2010-2015). Three one-season studies reported 19,577 all-cause and 3,012 ILI-related absences (2007, 2012, 2015). Over seven seasons, 11,946 confirmed influenza cases were reported. Absences improved seasonal model fits and predictions. Multivariate models using elementary school absences outperformed middle and high school models (relative mean absolute error (relMAE)=0.94, 0.98, 0.99). K-5 grade-specific absence models had lowest mean absolute errors (MAE) in cross-validations. ILI-specific absences performed marginally better than all-cause absences in two years, adjusting for other covariates, but markedly worse one year. Conclusions Our findings suggest seasonal models including K-5th grade absences predict all-age confirmed influenza and may serve as a useful surveillance tool.
Background: Adults with cardiopulmonary conditions are at increased risk for complications from influenza and respiratory syncytial virus (RSV) infection, but few data are available from middle-income countries. Methods: Using data from a prospective cohort study of influenza vaccine effectiveness among community-dwelling Thai adults aged ≥65 years, we estimated and compared the incidence of influenza and RSV in those with and without cardiopulmonary conditions. During May 2015-May 2017, older adults in a rural province in Thailand were followed weekly with year-round surveillance for acute respiratory illness (ARI), defined broadly as new onset or worsening of cough with or without fever, and hospitalized ARI. When ill, nasal self-swabs and/or nasopharyngeal swabs were collected for reverse-transcription polymerase chain reaction testing. We used Poisson regression to calculate incidence rate ratios (IRR), adjusting for age, sex, past healthcare-seeking behavior, weekly influenza activity, and influenza vaccination. Results: Overall, 3,220 adults with a median age of 71 years (IQR 68-76) were enrolled; 1,324 (41.1%) were male; and 313 (9.7%) had ≥1 underlying cardio-pulmonary condition, most commonly chronic obstructive pulmonary disease (131; 41.2%) or asthma (73; 23.3%). Compared to those without, participants with cardiopulmonary conditions had higher incidences of ARI, influenza, and RSV (Adjusted IRR: 1.83, 95% CI 1.63-2.05; 1.84, 95% CI 1.05-3.23; 2.02, 95% CI 1.10-3.72, respectively). Conclusion: Our findings show that older adults in rural Thailand with cardiopulmonary conditions have increased rates of ARI, influenza, and RSV infections, and support efforts to ensure this population has access to influenza vaccines and other respiratory illness prevention measures.
Global influenza virus circulation declined and has been below traditional seasonal levels during the COVID-19 pandemic.1-3 We reviewed WHO influenza surveillance outputs from May 1-December 31, 2020 (epidemiologic weeks 18-53) from tropical Asian countries. For each country we report influenza surveillance specimens tested, and the percentage positive for influenza, by type and subtype. We compared current data to historical data from 2015-2019 in order to place the current season in historical context. Twelve included countries tested 17,407 surveillance specimens, with 592 (3.4%) testing positive for influenza viruses. From April 27-July 26, 2020 (epidemiologic weeks 18-30), specimens tested decreased from an average of 14,102 per year in 2015-2019 to 3,969 (71.9% decrease) and influenza positivity from 22% to <1%. During weeks 31-53, specimens tested decreased from an average of 24,782 per year in 2015-2019 to 13,438 (45.8% decrease) and influenza positivity from 18% to 4%. In six countries that maintained testing of surveillance specimens for >90% of weeks, influenza circulation was unseasonably low, or absent, during weeks 18-30, 2020. However, during weeks 31-53, the percentage of surveillance specimens testing positive for influenza approached or reached positivity rates of 2015-2019 in Bangladesh and Cambodia; and increased but remained lower than historical positivity in Lao PDR and Viet Nam. The data presented here are a reminder that the low levels of influenza circulation in the northern hemisphere in summer 2020 may not necessarily persist into the upcoming influenza season, and influenza surveillance and prevention strategies should continue as planned and not be delayed.
Background: Following the first detection of SARS-CoV-2 in passengers arriving from Europe on 19 March 2020, Madagascar took several mitigation measures to limit the spread of the virus in the country. Methods: Nasopharyngeal and/or oropharyngeal swabs were collected from travellers to Madagascar, suspected SARS-CoV-2 cases, and contact of confirmed cases. Swabs were tested at the national reference laboratory using real-time RT-PVR. Data collected from patients were entered in an electronic database for subsequent statistical analysis. All distribution of laboratory confirmed cases were mapped and six genomes of viruses were fully sequenced. Results: Overall, 26,415 individuals were tested for SARS-CoV-2 between 18 March and 18 September 2020, of whom 21.0% (5,553/26,145) returned positive. Among laboratory-confirmed SARS-CoV-2 positive patients, the median age was 39 years (CI95%: 28-52), and 56.6% (3,311/5,553) were asymptomatic at the time of sampling. The probability of testing positive increased with age with the highest adjusted odds ratio of 2.2 [95% CI: 1.9-2.5] for individuals aged 49 years and more. Viral strains sequenced belong to clades 19A, 20A, and 20B in favour of several independent introduction of viruses. Conclusions. Our study describes the first wave of the COVID-19 in Madagascar. Despite early strategies in place Madagascar could not avoid the introduction and spread of the virus. More studies are needed to estimate the true burden of disease and make public health recommendations for a better preparation to another wave.
Background Claims of influenza vaccination increasing COVID-19 risk are circulating. Within the I-MOVE-COVID-19 primary care multicentre study, we measured the association between 2019–20 influenza vaccination and COVID-19. Methods We conducted a multicentre test-negative case-control study at primary care level, in study sites in five European countries, from March–August 2020. Patients presenting with acute respiratory infection were swabbed, with demographic, 2019–20 influenza vaccination and clinical information documented. Using logistic regression we measured the adjusted odds ratio (aOR), adjusting for study site and age, sex, calendar time, presence of chronic conditions. The main analysis included patients swabbed ≤7 days after onset from the three countries with <15% of missing influenza vaccination. In secondary analyses, we included five countries, using multiple imputation with chained equations to account for missing data. Results We included 257 COVID-19 cases and 1631 controls in the main analysis (three countries). The overall aOR between influenza vaccination and COVID-19 was 0.93 (95% CI: 0.66–1.32). The aOR was 0.92 (95% CI: 0.58–1.46) and 0.92 (95%CI: 0.51–1.67) among those aged 20–59 and ≥60 years, respectively. In secondary analyses, we included 6457 cases and 69272 controls. The imputed aOR was 0.87 (95% CI: 0.79–0.95) among all ages and any delay between swab and symptom onset. Conclusions There was no evidence that COVID-19 cases were more likely to be vaccinated against influenza than controls. Influenza vaccination should be encouraged among target groups for vaccination. I-MOVE-COVID-19 will continue documenting influenza vaccination status in 2020-21, in order to learn about effects of recent influenza vaccination.
Background: Tens of thousands of Australians become ill with influenza annually, causing thousands of severe infections that require hospitalisation. However, only 40% of adults receive the annual influenza vaccine. We surveyed Australian adults to provide up-to-date data on the predictors and barriers of seasonal influenza vaccination. Methods: We administered an online survey to a nationally representative sample of Australian adults. We designed survey questions using the constructs of the health belief model. Using simple and multivariable Poisson regression, we identified attitudes and beliefs associated with influenza vaccination in 2019. Results: Among 1,444 respondents, 51.7% self-reported influenza vaccination in 2019. We estimated vaccine coverage to be 44% for adults under 45, 46% for adults aged 45 to 64, and 77% for adults aged 65 and over. The strongest individual predictors of self-reported vaccination were believing the vaccine is effective at preventing influenza (APR = 3.71; 95% CI = 2.87-4.80), followed by recalling their doctor recommending the vaccine (APR = 2.70; 95%CI = 2.31-3.16). Common perceived barriers that predicted self-reported vaccination included believing the vaccine could give you influenza (APR = 0.59; 95% CI = 0.52-0.67), believing the vaccine can make you ill afterwards (APR = 0.68; 95% CI = 0.62-0.74), and preferring to develop immunity “naturally” (APR = 0.38; 95% CI = 0.32-0.45). Conclusion: Although vaccine uptake in 2019 appears to be higher than previous years, there are perceived barriers which may limit uptake among Australians. Tailored interventions are needed to combat widespread influenza vaccine hesitancy, particularly among high risk grou
Background: Although the burden of influenza is well characterized, the burden of community-onset non-influenza respiratory viruses has not been systematically assessed. Understanding the severity and seasonality of non-influenza viruses, including human coronaviruses, will provide a better understanding of the overall disease burden from respiratory viruses that could better inform resource utilization for hospitals and highlight the value of preventative strategies, including vaccines. Methods: From October 2017 to September 2019, a retrospective study was performed in a pre-defined catchment area to estimate the population-based incidence of community-onset respiratory viruses associated with hospitalization. Included patients were >18 years old, resided in New York City, were hospitalized for >24 hours, and had a respiratory virus detected within 3 calendar-days of admission. Disease burden was measured by hospital length of stay (LOS), intensive care unit (ICU) admissions, and in-hospital mortality and compared among those with laboratory-confirmed influenza versus those with laboratory-confirmed non-influenza viruses (human coronaviruses, parainfluenza viruses, respiratory syncytial virus, human metapneumovirus, and adenovirus). Results: During the study period, 4,232 eligible patients were identified of whom 50.9% were >65 years of age. For each virus, the population-based incidence was highest for those >80 years of age. When compared to those with influenza viruses detected, those with non-influenza respiratory viruses detected (combined) had higher population-based incidence, significantly more ICU admissions, and higher in-house mortality. Conclusions: The burden of non-influenza respiratory viruses for hospitalized adults is substantial. Prevention and treatment strategies are needed for non-influenza respiratory viruses, particularly for older adults.
With the rapid increase of reported COVID-19 cases, German policymakers announced a 4-week “shutdown light” starting on Nov 2, 2020. Applying mathematical models, possible scenarios for the evolution of the outbreak in Germany are simulated. The results indicate that independent of the effectiveness of the current restrictive measures they might not be sufficient to mitigate the outbreak. Repeated shutdown periods or permanently applied measures over the winter could be successful alternatives.
Evaluation of population-based COVID-19 control measures informs strategies to quell the current pandemic and reduce the impact of those yet to come. Effective COVID-19 control measures may simultaneously reduce the incidence of other acute respiratory infections (ARIs) due to shared transmission modalities. To assess the impact of stay-at-home orders and other physical distancing measures on the prevalence of ARI-related symptoms, we compared symptoms reported by prospective college cohorts enrolled during two consecutive academic years. ARI-related symptoms declined following campus closure and implementation of stay-at-home orders, demonstrating the impact of population-based physical distancing measures on control of a broad range of respiratory infections.
Background Reliable diagnostics are key to identifying influenza infections. Our objectives were to describe detection of influenza among severe acute respiratory infection (SARI) cases, to compare test results from the FTD-33 kit for influenza detection to the Centers for Disease Control (CDC) human influenza virus detection and characterization panel, and to assess seasonality of influenza in Burkina Faso. Methods: Nasopharyngeal and oropharyngeal specimens from SARI cases (hospitalized patients with fever, cough, and onset in the previous 10 days) were tested using the FTD-33 kit and the CDC rRT-PCR influenza assays. We assessed sensitivity and specificity of the FTD-33 kit for detecting Influenza A, Influenza B, and the influenza A(H1N1)pdm09 strain using the CDC human influenza rRT-PCR panel as the gold standard. Results: From December 2016 to February 2019, 1706 SARI cases were identified, 1,511 specimens were tested, and 211 were positive for influenza A (14.0%) and 100 for influenza B (6.6%) by either assay. Higher influenza circulation occurred between November and April with varying peaks of influenza A and B. Sensitivity of the FTD-33 assay was 91.9% for influenza A, 95.7% for influenza B, and 93.8% for A(H1N1)pdm09 subtype. Specificity was over 99% for all three tests. Conclusions: Our study indicates that Burkina Faso has one peak of influenza each year which is similar to the Northern Hemisphere and differs from other countries in West Africa. We found high concordance of influenza results between the two assays indicating FTD-33 can be used to reliably detect influenza among SARI cases.
Abstract. The Controlled Human Infection Model and specifically the Human Viral Challenge Model are not dissimilar to standard clinical trials while adding another layer of complexity and safety considerations. The models deliberately infect volunteers, with an infectious challenge agent (CA) to determine the effect of the infection and the potential benefits of the experimental interventions. The Human Viral Challenge Model studies can shorten the time to assess the efficacy of a new vaccine or treatment by combining this with the assessment of safety. The newly emerging SARS-COV-2 virus is highly contagious and the cause pandemic disease COVID-19. An urgent race in is on to develop a new vaccine against this virus in a timeframe never attempted before. The use of the Human Viral Challenge Model has been proposed to accelerate the development of the vaccine. In the early 2000’s the authors successfully developed a pathogenic Human Viral Challenge Model for another virus for which there was no effective treatment and established it to evaluate potential therapies and vaccines against Respiratory Syncytial Virus. The authors feel that the experience gained in the development of that model can help with the development of a COVID-19 HVCM and describe it here. Word count: 197