Predictors of influenza among older adults in the emergency department

Developing and validating clinical features-based machine learning algorithms to predict influenza infection in influenza-like illness patients

BACKGROUND

Seasonal influenza poses a significant risk, and patients can benefit from early diagnosis and treatment. However, underdiagnosis and undertreatment remain widespread. We developed and compared clinical feature-based machine learning (ML) algorithms that can accurately predict influenza infection in emergency departments (EDs) among patients with influenza-like illness (ILI).

MATERIAL AND METHODS

We conducted a prospective cohort study in five EDs in the US and Taiwan from 2015 to 2020. Adult patients visiting the EDs with symptoms of ILI were recruited and tested by real-time RT-PCR for influenza. We evaluated seven ML algorithms and compared their results with previously developed clinical prediction models.

RESULTS

Out of the 2189 enrolled patients, 1104 tested positive for influenza. The eXtreme Gradient Boosting achieved superior performance with an area under the receiver operating characteristic curve of 0.82 (95% confidence interval [CI] = 0.79-0.85), with a sensitivity of 0.92 (95% CI = 0.88-0.95), specificity of 0.89 (95% CI = 0.86-0.92), and accuracy of 0.72 (95% CI = 0.69-0.76) in the testing set over cut-offs of 0.4, 0.6 and 0.5, respectively. These results were superior to those of previously proposed clinical prediction models. The model interpretation revealed that body temperature, cough, rhinorrhea, and exposure history were positively associated with and the days of illness and influenza vaccine were negatively associated with influenza infection. We also found the week of the influenza season, pulse rate, and oxygen saturation to be associated with influenza infection.

CONCLUSIONS

The clinical feature-based ML model outperformed conventional models for predicting influenza infection.

Vaccine promotion strategies in community pharmacy addressing vulnerable populations: a scoping review

CONTEXT

Social determinants of health are drivers of vaccine inequity and lead to higher risks of complications from infectious diseases in under vaccinated communities. In many countries, pharmacists have gained the rights to prescribe and administer vaccines, which contributes to improving vaccination rates. However, little is known on how they define and target vulnerable communities.

OBJECTIVE

The purpose of this study is to describe how vulnerable communities are targeted in community pharmacies.

METHODS

We performed a systematic search of the Embase and MEDLINE database in August 2021 inspired by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocols (PRISMA ScR). Articles in English, French or Spanish addressing any vaccine in a community pharmacy context and that target a population defined as vulnerable were screened for inclusion.

RESULTS

A total of 1039 articles were identified through the initial search, and 63 articles met the inclusion criteria. Most of the literature originated from North America (n = 54, 86%) and addressed influenza (n = 29, 46%), pneumococcal (n = 14, 22%), herpes zoster (n = 14, 22%) or human papilloma virus vaccination (n = 14, 22%). Lifecycle vulnerabilities (n = 48, 76%) such as age and pregnancy were most often used to target vulnerable patients followed by clinical factors (n = 18, 29%), socio-economical determinants (n = 16, 25%) and geographical vulnerabilities (n = 7, 11%). The most frequently listed strategy was providing a strong recommendation for vaccination, promotional posters in pharmacy, distributing leaflet/bag stuffers and providing staff training. A total of 24 barriers and 25 facilitators were identified. The main barriers associated to each vulnerable category were associated to effective promotional strategies to overcome them.

CONCLUSION

Pharmacists prioritize lifecycle and clinical vulnerability at the expense of narrowing down the definition of vulnerability. Some vulnerable groups are also under targeted in pharmacies. A wide variety of promotional strategies are available to pharmacies to overcome the specific barriers experienced by various groups.

Epidemiological and Clinical Characteristics of Influenza Outbreaks Among Children in Chongqing, China

Influenza is a global serious public health threat. Seasonal influenza among children in Chongqing has been a heavy health burden. To date, few studies have examined the spatial and temporal characteristics of influenza. This research sheds new light on correlating them with influenza outbreaks with data of over 5 years (2014–2018). All cluster outbreaks among preschool and school-age children reported in Chongqing were collected through the Public Health Emergency Management Information System. The demographical, epidemiological, and clinical data of the cases were analyzed. From 2014 to 2018, a total of 111 preschool- and school-based influenza-like illness outbreaks involving 3,549 cases were identified. Several clinical symptoms that were analyzed in this study showed significant contrast between influenza A and B. Spatial autocorrelation analysis over the 5-year data detected Xiushan district being the most likely cluster. The exploration of the spatial distribution and clinical characteristics of influenza cluster of children in Chongqing could help the effective implementation of health policies. Future studies should be conducted to monitor the outbreaks of influenza among children.

Symptom- and Prevention-Based Testing of COVID-19 in Nursing Home Residents: A Retrospective Cohort Study

Nursing homes (NH) residents with COVID-19 can either be tested because of presence of core symptoms (S-based) or because of transmission prevention (TP-based). The investigated study sample included all NH residents who underwent SARS-CoV-2 RT-PCR testing between March 16, 2020 and May 31, 2020 (n = 380). Clinical symptoms, temperature, and oxygen saturation were extracted from medical records, 7 days before to 14 days after testing. COVID-19 was confirmed in 81 (21%) residents; 36 (44%) S-based and 45 (56%) TP-based: 45. Cycle threshold (CT) values did not differ between the groups. In the 7 days prior to the test falling (32%), somnolence (25%) and fatigue (21%) occurred in both groups. Two days before the test, we observed a stronger decrease in oxygen saturation and an increase in temperature for the S-based group compared to the T-based group that remained up to 10 days after testing. Residents within the S-based group were 2.5 times more likely to increased mortality within 30 days than residents in the TP-based group (HR, 2.56; 95% 1.3–5.2). Although, 73% of the T-based group did eventually develop core symptoms. Thus, attention to falling and daily measures of temperature and oxygen saturation can contribute to earlier detection.

Influenza

Seasonal influenza epidemics of variable severity pose challenges to public health. Annual vaccination is the primary way to prevent influenza, and a wide range of vaccines are available, including inactivated or live attenuated standard-dose, recombinant vaccines, as well as adjuvanted or high-dose vaccines for persons aged 65 years or older. Persons at increased risk for influenza complications include young children, persons with underlying medical conditions, and older adults. Prompt diagnosis of influenza can facilitate early initiation of antiviral treatment that provides the greatest clinical benefit. This article summarizes recommendations for providers on influenza vaccination, diagnostic testing, and antiviral treatment.

Contribution of Nanotechnologies to Vaccine Development and Drug Delivery against Respiratory Viruses

According to the Center for Disease Control and Prevention (CDC), the coronavirus disease 2019, a respiratory viral illness linked to significant morbidity, mortality, production loss, and severe economic depression, was the third-largest cause of death in 2020. Respiratory viruses such as influenza, respiratory syncytial virus, SARS-CoV-2, and adenovirus, are among the most common causes of respiratory illness in humans, spreading as pandemics or epidemics throughout all continents. Nanotechnologies are particles in the nanometer range made from various compositions. They can be lipid-based, polymer-based, protein-based, or inorganic in nature, but they are all bioinspired and virus-like. In this review, we aimed to present a short review of the different nanoparticles currently studied, in particular those which led to publications in the field of respiratory viruses. We evaluated those which could be beneficial for respiratory disease-based viruses; those which already have contributed, such as lipid nanoparticles in the context of COVID-19; and those which will contribute in the future either as vaccines or antiviral drug delivery systems. We present a short assessment based on a critical selection of evidence indicating nanotechnology's promise in the prevention and treatment of respiratory infections.

Effects of Heat-Killed Levilactobacillus brevis KB290 in Combination with β-Carotene on Influenza Virus Infection in Healthy Adults: A Randomized Controlled Trial

Influenza, a seasonal acute respiratory disease caused primarily by the influenza virus A or B, manifests with severe symptoms leading to considerable morbidity and mortality and is a major concern worldwide. Therefore, effective preventive measures against it are required. The aim of this trial was to evaluate the preventive effects of heat-killed Levilactobacillus brevis KB290 (KB290) in combination with β-carotene (βC) on influenza virus infections in healthy Japanese subjects aged between 20 and 59 y throughout the winter season. We performed a randomized, double-blind, placebo-controlled, parallel-group trial from 16 December 2019 to 8 March 2020, comparing KB290 + βC beverage with placebo beverage. The primary endpoint was the incidence of influenza based on a doctor’s certificate. The incidence of influenza was not significantly different between the two groups. However, the subgroup analysis showed a significant difference between the two groups (influenza incidence: the KB290 + βC group 1.9%, and the placebo group 3.9%) in the subgroup of subjects aged ˂40 y, but not in the subgroup of subjects aged ≥40 y. The results of this trial suggest that the combination of KB290 and βC might be a possible candidate supplement for protection against the seasonal influenza virus infection in humans aged <40 y, although further clinical studies are needed to confirm the concrete preventive effect of this combination on influenza.

Viral community acquired pneumonia at the emergency department: Report from the pre COVID-19 age

The role of viruses in community acquired pneumonia (CAP) has been largely underestimated in the pre‐coronavirus disease 2019 age. However, during flu seasonal early identification of viral infection in CAP is crucial to guide treatment and in‐hospital management. Though recommended, the routine use of nasopharyngeal swab (NPS) to detect viral infection has been poorly scaled‐up, especially in the emergency department (ED). This study sought to assess the prevalence and associated clinical outcomes of viral infections in patients with CAP during peak flu season. In this retrospective, observational study adults presenting at the ED of our hospital (Rome, Italy) with CAP from January 15th to February 22th, 2019 were enrolled. Each patient was tested on admission with Influenza rapid test and real time multiplex assay. Seventy five consecutive patients were enrolled. 30.7% (n = 23) tested positive for viral infection. Of these, 52.1% (n = 12) were H1N1/FluA. 10 patients had multiple virus co‐infections. CAP with viral infection did not differ for any demographic, clinic and laboratory features by the exception of CCI and CURB‐65. All intra‐ED deaths and mechanical ventilations were recorded among CAP with viral infection. Testing only patients with CURB‐65 score ≥2, 10 out of 12 cases of H1N1/FluA would have been detected saving up to 40% tests. Viral infection occurred in one‐third of CAP during flu seasonal peak 2019. Since not otherwise distinguishable, NPS is so far the only reliable mean to identify CAP with viral infection. Testing only patients with moderate/severe CAP significantly minimize the number of tests.

This study stresses the incidence of viral pneumonia during the flu season and underlies the role of viral infection screening at the ED regardless of the current COVID‐19 pandemic.

Age-Related Changes in Clinical Presentation of Covid-19: the EPICOVID19 Web-Based Survey

BACKGROUND

The influence of aging and multimorbidity on Covid-19 clinical presentation is still unclear.

OBJECTIVES

We investigated whether the association between symptoms (or cluster of symptoms) and positive SARS-CoV-2 nasopharyngeal swab (NPS) was different according to patients' age and presence of multimorbidity.

METHODS

The study included 6680 participants in the EPICOVID19 web-based survey, who reported information about symptoms from February to June 2020 and who underwent at least one NPS. Symptom clusters were identified through hierarchical cluster analysis. The associations between symptoms (and clusters of symptoms) and positive NPS were investigated through multivariable binary logistic regression in the sample stratified by age (<65 vs ≥65 years) and number of chronic diseases (0 vs 1 vs ≥2).

RESULTS

The direct association between taste/smell disorders and positive NPS was weaker in older and multimorbid patients than in their younger and healthier counterparts. Having reported no symptoms reduced the chance of positive NPS by 86% in younger (95%CI: 0.11-0.18), and by 46% in older participants (95%CI: 0.37-0.79). Of the four symptom clusters identified (asymptomatic, generic, flu-like, and combined generic and flu-like symptoms), those associated with a higher probability of SARS-CoV-2 infection were the flu-like for older people, and the combined generic and flu-like for the younger ones.

CONCLUSIONS

Older age and pre-existing chronic diseases may influence the clinical presentation of Covid-19. Symptoms at disease onset tend to aggregate differently by age. New diagnostic algorithms considering age and chronic conditions may ease Covid-19 diagnosis and optimize health resources allocation.

TRIAL REGISTRATION

NCT04471701 (ClinicalTrials.gov).

Short-term effects of ambient air pollution on the incidence of influenza in Wuhan, China: A time-series analysis

BACKGROUND

Evidence suggests that air pollution is associated with many adverse health outcomes such as cardiovascular diseases (CVD), respiratory diseases, cancer, and birth defects. Yet few studies dig into the relationship between air pollution and airborne infectious diseases.

METHODS

Daily data on influenza incidence were obtained from Hubei Provincial Center for Disease Control and Prevention (Hubei CDC). Data on air pollutants including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ground-level ozone (O₃), particulate matter (PM) with aerodynamic diameter ≤ 2.5 μm (PM_2.5), and PM with aerodynamic diameter ≤ 10 μm (PM₁₀) were retrieved from ten national air sampling stations located at Wuhan. We applied generalized additive model (GAM) to estimate the associations between air pollution and the risk of influenza in Wuhan, China during 2015-2017.

RESULTS

In the single-day lag model, the largest effect estimates were observed at lag 0. An increased relative risk (RR) of influenza was significantly associated with a 10 μg/m³ increase in SO₂ (RR: 1.099; 95% confidence interval [CI]: 1.011-1.195), NO₂ (RR: 1.039; 95% CI: 1.013-1.065), and O₃ (RR: 1.005; 95% CI: 0.994-1.016), respectively. In the multi-day lag model, concentrations of SO₂, NO₂, and O₃ were statistically significantly associated with the risk of influenza at lag 0-1. The seasonal analysis suggests that the influence of air pollution on influenza is greater in the cold season as compared in the warm season in the early lag days. The multi-pollutant model indicates that NO₂ may be a potential confounder for co-pollutants.

CONCLUSIONS

Our study shows that air pollution may be associated with the risk of influenza in a broad sense. Therefore, when formulating policies to deal with influenza outbreaks in the future, factors regarding air pollution should be taken into consideration.

Impact of Rapid Influenza Molecular Testing on Management in Pediatric Acute Care Settings

OBJECTIVES

To measure the impact of rapid influenza real-time qualitative reverse transcriptase polymerase chain reaction (RT-PCR) on patient management in busy pediatric emergency department (ED) and urgent care clinic settings.

STUDY DESIGN

We developed a brief, elective survey that clinicians completed when an influenza RT-PCR order was placed in the ED or urgent care clinic between February 18, 2019, and March 13, 2019. We captured the clinical suspicion for influenza, intended management plans, and actual management plans once influenza RT-PCR results were available.

RESULTS

We evaluated 339 encounters, of which 164 (48.4%) had a positive influenza RT-PCR. Clinical suspicion for influenza was a nonsignificant predictor for influenza PT-PCR positivity (P = .126). After rapid influenza RT-PCR results were available, clinicians changed their original plans in 44.5% of influenza RT-PCR positive vs 92.6% of influenza RT-PCR negative cases (P < .0001). Change in plans for antiviral use was observed in 26% of influenza positive vs 77% of influenza negative cases (P < .0001). A total of 135 antiviral prescriptions were avoided in patients with negative influenza RT-PCR.

CONCLUSIONS

Implementation of a rapid and accurate influenza RT-PCR in the acute care setting is important to systematically diagnose influenza in children and improve outpatient management decisions, because clinical suspicion for influenza is inaccurate. A negative influenza RT-PCR decreases unnecessary antiviral use and has the potential for significant cost savings.

Early cases of SARS-CoV-2 infection in Uganda: epidemiology and lessons learned from risk-based testing approaches - March-April 2020

BACKGROUND

On March 13, 2020, Uganda instituted COVID-19 symptom screening at its international airport, isolation and SARS-CoV-2 testing for symptomatic persons, and mandatory 14-day quarantine and testing of persons traveling through or from high-risk countries. On March 21, 2020, Uganda reported its first SARS-CoV-2 infection in a symptomatic traveler from Dubai. By April 12, 2020, 54 cases and 1257 contacts were identified. We describe the epidemiological, clinical, and transmission characteristics of these cases.

METHODS

A confirmed case was laboratory-confirmed SARS-CoV-2 infection during March 21-April 12, 2020 in a resident of or traveler to Uganda. We reviewed case-person files and interviewed case-persons at isolation centers. We identified infected contacts from contact tracing records.

RESULTS

Mean case-person age was 35 (±16) years; 34 (63%) were male. Forty-five (83%) had recently traveled internationally ('imported cases'), five (9.3%) were known contacts of travelers, and four (7.4%) were community cases. Of the 45 imported cases, only one (2.2%) was symptomatic at entry. Among all case-persons, 29 (54%) were symptomatic at testing and five (9.3%) were pre-symptomatic. Among the 34 (63%) case-persons who were ever symptomatic, all had mild disease: 16 (47%) had fever, 13 (38%) reported headache, and 10 (29%) reported cough. Fifteen (28%) case-persons had underlying conditions, including three persons with HIV. An average of 31 contacts (range, 4-130) were identified per case-person. Five (10%) case-persons, all symptomatic, infected one contact each.

CONCLUSION

The first 54 case-persons with SARS-CoV-2 infection in Uganda primarily comprised incoming air travelers with asymptomatic or mild disease. Disease would likely not have been detected in these persons without the targeted testing interventions implemented in Uganda. Transmission was low among symptomatic persons and nonexistent from asymptomatic persons. Routine, systematic screening of travelers and at-risk persons, and thorough contact tracing will be needed for Uganda to maintain epidemic control.

Developing a clinical screening tool for identifying COVID-19 infection in older people dwelling in residential aged care services

OBJECTIVE

To develop and conduct preliminary feasibility testing of a clinical screening instrument for early identification of COVID-19 infection in older people residing in residential aged care services (RACS).

METHODS

A qualitative study was conducted using a multi-modal approach involving examination of existing literature and national guidelines for COVID-19 clinical screening, formulation of a discussion document with peer review and feasibility testing of a prototype screening tool.

RESULTS

Existing COVID-19 clinical screening tools do not consider age-related impacts on clinical presentation. The qualitative analysis identified the important clinical elements to include were a lower threshold for temperature, occurrence of a recent fall and change in functional status. The new elements also had to be simple and feasible to implement. Overall feedback was positive with all participants recommending the use of the new tool.

CONCLUSION

A new screening tool for RACS residents was developed addressing the pathophysiological changes with ageing and atypical features of COVID-19 infection.

Risk prediction models to guide antibiotic prescribing: a study on adult patients with uncomplicated upper respiratory tract infections in an emergency department

BACKGROUND

Appropriate antibiotic prescribing is key to combating antimicrobial resistance. Upper respiratory tract infections (URTIs) are common reasons for emergency department (ED) visits and antibiotic use. Differentiating between bacterial and viral infections is not straightforward. We aim to provide an evidence-based clinical decision support tool for antibiotic prescribing using prediction models developed from local data.

METHODS

Seven hundred-fifteen patients with uncomplicated URTI were recruited and analysed from Singapore's busiest ED, Tan Tock Seng Hospital, from June 2016 to November 2018. Confirmatory tests were performed using the multiplex polymerase chain reaction (PCR) test for respiratory viruses and point-of-care test for C-reactive protein. Demographic, clinical and laboratory data were extracted from the hospital electronic medical records. Seventy percent of the data was used for training and the remaining 30% was used for validation. Decision trees, LASSO and logistic regression models were built to predict when antibiotics were not needed.

RESULTS

The median age of the cohort was 36 years old, with 61.2% being male. Temperature and pulse rate were significant factors in all 3 models. The area under the receiver operating curve (AUC) on the validation set for the models were similar. (LASSO: 0.70 [95% CI: 0.62-0.77], logistic regression: 0.72 [95% CI: 0.65-0.79], decision tree: 0.67 [95% CI: 0.59-0.74]). Combining the results from all models, 58.3% of study participants would not need antibiotics.

CONCLUSION

The models can be easily deployed as a decision support tool to guide antibiotic prescribing in busy EDs.

Coronavirus: the geriatric emergency of 2020. Joint document of the Section on Geriatric Cardiology of the Spanish Society of Cardiology and the Spanish Society of Geriatrics and Gerontology

SARS-CoV-2 infection, also known as COVID-19 (coronavirus infectious disease-19), was first identified in December 2019. In Spain, the first case of this infection was diagnosed on 31 January, 2020 and, by 15 April 2020, has caused 18 579 deaths, especially in the elderly. Due to the rapidly evolving situation regarding this disease, the data reported in this article may be subject to modifications. The older population are particularly susceptible to COVID-19 infection and to developing severe disease. The higher morbidity and mortality rates in older people have been associated with comorbidity, especially cardiovascular disease, and frailty, which weakens the immune response. Due to both the number of affected countries and the number of cases, the current situation constitutes an ongoing pandemic and a major health emergency. Because Spain has one of the largest older populations in the world, COVID-19 has emerged as a geriatric emergency. This document has been prepared jointly between the Section on Geriatric Cardiology of the Spanish Society of Cardiology and the Spanish Society of Geriatrics and Gerontology.

[Coronavirus: the geriatric emergency of 2020. Joint document of the Section on Geriatric Cardiology of the Spanish Society of Cardiology and the Spanish Society of Geriatrics and Gerontology]

SARS-CoV-2 infection, also known as COVID-19 (coronavirus infectious disease-19), was first identified in December 2019. In Spain, the first case of this infection was diagnosed on 31 January, 2020 and, by 15 April 2020, has caused 18 579 deaths, especially in the elderly. Due to the rapidly evolving situation regarding this disease, the data reported in this article may be subject to modifications. The older population are particularly susceptible to COVID-19 infection and to developing severe disease. The higher morbidity and mortality rates in older people have been associated with comorbidity, especially cardiovascular disease, and frailty, which weakens the immune response. Due to both the number of affected countries and the number of cases, the current situation constitutes an ongoing pandemic and a major health emergency. Because Spain has one of the largest older populations in the world, COVID-19 has emerged as a geriatric emergency. This document has been prepared jointly between the Section on Geriatric Cardiology of the Spanish Society of Cardiology and the Spanish Society of Geriatrics and Gerontology.

Presymptomatic SARS-CoV-2 Infections and Transmission in a Skilled Nursing Facility

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can spread rapidly within skilled nursing facilities. After identification of a case of Covid-19 in a skilled nursing facility, we assessed transmission and evaluated the adequacy of symptom-based screening to identify infections in residents.

METHODS

We conducted two serial point-prevalence surveys, 1 week apart, in which assenting residents of the facility underwent nasopharyngeal and oropharyngeal testing for SARS-CoV-2, including real-time reverse-transcriptase polymerase chain reaction (rRT-PCR), viral culture, and sequencing. Symptoms that had been present during the preceding 14 days were recorded. Asymptomatic residents who tested positive were reassessed 7 days later. Residents with SARS-CoV-2 infection were categorized as symptomatic with typical symptoms (fever, cough, or shortness of breath), symptomatic with only atypical symptoms, presymptomatic, or asymptomatic.

RESULTS

Twenty-three days after the first positive test result in a resident at this skilled nursing facility, 57 of 89 residents (64%) tested positive for SARS-CoV-2. Among 76 residents who participated in point-prevalence surveys, 48 (63%) tested positive. Of these 48 residents, 27 (56%) were asymptomatic at the time of testing; 24 subsequently developed symptoms (median time to onset, 4 days). Samples from these 24 presymptomatic residents had a median rRT-PCR cycle threshold value of 23.1, and viable virus was recovered from 17 residents. As of April 3, of the 57 residents with SARS-CoV-2 infection, 11 had been hospitalized (3 in the intensive care unit) and 15 had died (mortality, 26%). Of the 34 residents whose specimens were sequenced, 27 (79%) had sequences that fit into two clusters with a difference of one nucleotide.

CONCLUSIONS

Rapid and widespread transmission of SARS-CoV-2 was demonstrated in this skilled nursing facility. More than half of residents with positive test results were asymptomatic at the time of testing and most likely contributed to transmission. Infection-control strategies focused solely on symptomatic residents were not sufficient to prevent transmission after SARS-CoV-2 introduction into this facility.

Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility - King County, Washington, March 2020

Older adults are susceptible to severe coronavirus disease 2019 (COVID-19) outcomes as a consequence of their age and, in some cases, underlying health conditions (1). A COVID-19 outbreak in a long-term care skilled nursing facility (SNF) in King County, Washington that was first identified on February 28, 2020, highlighted the potential for rapid spread among residents of these types of facilities (2). On March 1, a health care provider at a second long-term care skilled nursing facility (facility A) in King County, Washington, had a positive test result for SARS-CoV-2, the novel coronavirus that causes COVID-19, after working while symptomatic on February 26 and 28. By March 6, seven residents of this second facility were symptomatic and had positive test results for SARS-CoV-2. On March 13, CDC performed symptom assessments and SARS-CoV-2 testing for 76 (93%) of the 82 facility A residents to evaluate the utility of symptom screening for identification of COVID-19 in SNF residents. Residents were categorized as asymptomatic or symptomatic at the time of testing, based on the absence or presence of fever, cough, shortness of breath, or other symptoms on the day of testing or during the preceding 14 days. Among 23 (30%) residents with positive test results, 10 (43%) had symptoms on the date of testing, and 13 (57%) were asymptomatic. Seven days after testing, 10 of these 13 previously asymptomatic residents had developed symptoms and were recategorized as presymptomatic at the time of testing. The reverse transcription-polymerase chain reaction (RT-PCR) testing cycle threshold (Ct) values indicated large quantities of viral RNA in asymptomatic, presymptomatic, and symptomatic residents, suggesting the potential for transmission regardless of symptoms. Symptom-based screening in SNFs could fail to identify approximately half of residents with COVID-19. Long-term care facilities should take proactive steps to prevent introduction of SARS-CoV-2 (3). Once a confirmed case is identified in an SNF, all residents should be placed on isolation precautions if possible (3), with considerations for extended use or reuse of personal protective equipment (PPE) as needed (4).

Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility - King County, Washington, March 2020

Older adults are susceptible to severe coronavirus disease 2019 (COVID-19) outcomes as a consequence of their age and, in some cases, underlying health conditions (1). A COVID-19 outbreak in a long-term care skilled nursing facility (SNF) in King County, Washington that was first identified on February 28, 2020, highlighted the potential for rapid spread among residents of these types of facilities (2). On March 1, a health care provider at a second long-term care skilled nursing facility (facility A) in King County, Washington, had a positive test result for SARS-CoV-2, the novel coronavirus that causes COVID-19, after working while symptomatic on February 26 and 28. By March 6, seven residents of this second facility were symptomatic and had positive test results for SARS-CoV-2. On March 13, CDC performed symptom assessments and SARS-CoV-2 testing for 76 (93%) of the 82 facility A residents to evaluate the utility of symptom screening for identification of COVID-19 in SNF residents. Residents were categorized as asymptomatic or symptomatic at the time of testing, based on the absence or presence of fever, cough, shortness of breath, or other symptoms on the day of testing or during the preceding 14 days. Among 23 (30%) residents with positive test results, 10 (43%) had symptoms on the date of testing, and 13 (57%) were asymptomatic. Seven days after testing, 10 of these 13 previously asymptomatic residents had developed symptoms and were recategorized as presymptomatic at the time of testing. The reverse transcription-polymerase chain reaction (RT-PCR) testing cycle threshold (Ct) values indicated large quantities of viral RNA in asymptomatic, presymptomatic, and symptomatic residents, suggesting the potential for transmission regardless of symptoms. Symptom-based screening in SNFs could fail to identify approximately half of residents with COVID-19. Long-term care facilities should take proactive steps to prevent introduction of SARS-CoV-2 (3). Once a confirmed case is identified in an SNF, all residents should be placed on isolation precautions if possible (3), with considerations for extended use or reuse of personal protective equipment (PPE) as needed (4).

Influenza surveillance case definitions miss a substantial proportion of older adults hospitalized with laboratory-confirmed influenza: A report from the Canadian Immunization Research Network (CIRN) Serious Outcomes Surveillance (SOS) Network

OBJECTIVE

Older adults often have atypical presentation of illness and are particularly vulnerable to influenza and its sequelae, making the validity of influenza case definitions particularly relevant. We sought to assess the performance of influenza-like illness (ILI) and severe acute respiratory illness (SARI) criteria in hospitalized older adults.

DESIGN

Prospective cohort study.

SETTING

The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network undertakes active surveillance for influenza among hospitalized adults.

METHODS

Data were pooled from 3 influenza seasons: 2011/12, 2012/13, and 2013/14. The ILI and SARI criteria were defined clinically, and influenza was laboratory confirmed. Frailty was measured using a validated frailty index.

RESULTS

Of 11,379 adult inpatients (7,254 aged ≥65 years), 4,942 (2,948 aged ≥65 years) had laboratory-confirmed influenza. Their median age was 72 years (interquartile range [IQR], 58-82) and 52.6% were women. The sensitivity of ILI criteria was 51.1% (95% confidence interval [CI], 49.6-52.6) for younger adults versus 44.6% (95% CI, 43.6-45.8) for older adults. SARI criteria were met by 64.1% (95% CI, 62.7-65.6) of younger adults versus 57.1% (95% CI, 55.9-58.2) of older adults with laboratory-confirmed influenza. Patients with influenza who were prefrail or frail were less likely to meet ILI and SARI case definitions.

CONCLUSIONS

A substantial proportion of older adults, particularly those who are frail, are missed by standard ILI and SARI case definitions. Surveillance using these case definitions is biased toward identifying younger cases, and does not capture the true burden of influenza. Because of the substantial fraction of cases missed, surveillance definitions should not be used to guide diagnosis and clinical management of influenza.

The effects of age on clinical characteristics, hospitalization and mortality of patients with influenza-related illness at a tertiary care centre in Malaysia

Background

Age is an established risk factor for poor outcomes in individuals with influenza‐related illness, and data on its influence on clinical presentations and outcomes in the South‐East Asian settings are scarce. The aim of this study was to determine the above among adults with influenza‐related upper respiratory tract infection at a teaching hospital in Malaysia.

Methods

A retrospective case‐note analysis was conducted on a cohort of 3935 patients attending primary care at the University Malaya Medical Centre, Malaysia from February 2012 till May 2014 with URTI symptoms. Demographics, clinical characteristics, medical and vaccination history were obtained from electronic medical records, and mortality data from the National Registration Department. Comparisons were made between those aged <25, ≥25 to <65 and ≥65 years.

Results

470 (11.9%) had PCR‐confirmed influenza virus infection. Six (1.3%) received prior influenza vaccination. Those aged ≥65 years were more likely to have ≥2 comorbidities (P < .001) and were less likely to present with fever (P = .004). One‐third of those aged ≥65 years experienced hospitalization, intensive care admission or death within a year compared to 10% in the ≥25 to <65 years. Age ≥65 years was an independent predictor of hospitalization and death (OR = 9.97; 95% CI = 3.11‐31.93) compared to those aged <25 years.

Conclusion

Older patients in our cohort were more likely to have comorbidities and present with atypical features, with older age being an independent predictor of poor health outcomes. Our findings will now inform future health policies on older persons and economic modelling of adult vaccination programmes.

Demographic, clinical, and virological characteristics of patients with a laboratory-confirmed diagnosis of influenza during three consecutive seasons, 2015/2016-2017/18, in the Islamic Republic of Iran

BACKGROUND

There are minimal data on the differences in demographics, clinical presentations and outcomes for patients with different types and sub-types of influenza in the Middle East.

OBJECTIVES

To use population-based data from Iran to investigate factors associated with unfavorable disease outcome.

STUDY DESIGN

Clinical data were compiled from the Iranian Ministry of Health for patients of all ages who fulfilled the severe acute respiratory infections (SARI) definition according to World Health Organization criteriatested for any reason and found to have and had laboratory proven influenza September 21, 2015 through March 20, 2018. Pulmonary, cardiac, renal, hematologic and neurologic complications were recorded. Results were compared by type, age, gender and health status. Multivariate analysis was used to analyze risk factors for complications and death.

RESULTS

Of 11,080 enrolled patients, 10,046 (90.7 %) were inpatients, 2254 (20.4 %) were children, 8403 (75.8 %) had influenza A, 2599 (23.5 %) had influenza B, and 78 (0.7 %) had unidentified types. Fever was less common in older patients (OR 0.99; 95 % CI 0.98-0.99, p < 0.001 and in those with comorbidity (OR 0.87; 95 % CI 0.77-0.97, p = 0.013). Although the rate of complications was lower with A(H1N1) pdm09 influenza than with A(H3N2) infection (12.8 % versus 15.6 %, p = 0.001), the mortality rate was higher (7.0 % versus 3.0 %, p < 0.001). Complications occurred more often during late versus early influenza season (OR 1.22; 95 % CI 1.08-1.37, p = 0.002). Patients with type B influenza (OR 0.85; 95 % CI 0.74-0.98, p = 0.025), or who presented with sore throat (OR 0.74; 95 % CI 0.65-0.84, p < 0.001) were less likely to develop complications. The risk of developing complications was increased in patients who had chronic heart disease (OR 1.51; 95 % CI 1.29-1.76, p < 0.001), chronic pulmonary disease (OR 1.62; 95 % CI 1.37-1.91, p < 0.001), diabetes (OR 1.24; 95 % CI 1.03-1.50, p = 022), or epilepsy (OR 1.55; 95 % CI 1.17-2.05). Older age and male gender increased the risk of death but not of complications.

CONCLUSIONS

The clinical features, complications and outcomes of influenza vary by age and by viral type and sub-type. Comorbidites appear to be more important than age in predicting complications.

Effect of four neuraminidase inhibitors on influenza in Osaka, Japan: An eight-year survey

BACKGROUND

After the A/H1N1 influenza pandemic in 2009, two new drugs against influenza, namely laninamivir and peramivir, were released in 2010 in Japan. We investigated prescription trends of four neuraminidase inhibitors (NAIs), which are laninamivir, peramivir, oseltamivir, and zanamivir, and assessed clinical data related to influenza for 8 years.

METHODS

Patients living in Osaka Prefecture and diagnosed with influenza responded to a postcard questionnaire that collected data regarding their demographic characteristics, symptoms including fever, prescribed drugs, and influenza type.

RESULTS

Laninamivir was most prescribed to patients aged ≥ 10 years, and oseltamivir was most prescribed to patients aged < 10 years. All four NAIs had similar effects on influenza. Patients with type A influenza experienced fever alleviation earlier than those with type B influenza. Older patients tended to have lower fever. Most seasons had similar results.

CONCLUSIONS

Our descriptive epidemiologic study revealed the status of patients with influenza and their medication use.

Clinical Characteristics of Influenza in Season 2017/2018 in a German Emergency Department: A Retrospective Analysis

Introduction:

Influenza infection is a viral disease with significant morbidity and mortality during the cold months. Clinical presentation typically includes cough, fever, and pain. Influenza disease is hardly diagnosed only on the basis of clinical symptoms due to similar clinical presentation of other diseases such as a typical cold or other flu-like diseases. We evaluated patients with proven influenza who presented at an emergency department of internal medicine in a university hospital according to the clinical presentation and different age groups.

Materials and Methods:

From October 2017 to April 2018, 723 reverse transcription-polymerase chain reaction (RT-PCR) tests for influenza were performed in the emergency department on patients with suspected influenza diagnosed clinically. A total of 240 influenza-positive patients were retrospectively assessed for documented main symptoms, vital parameters, risk factors for an unfavorable course, hospitalization, and death.

Results:

The mean age of influenza patients was 65 years. Overall, 30 patients were aged 18 to 39 years, 48 patients 40 to 59 years, and 162 patients ⩾60 years. Influenza B in 168 (70%) was predominant to 72 influenza A (mostly H1N1). In only 30% of the patients all three typical symptoms (cough, fever, and headache/myalgia) were documented. Headache or myalgia (with 34%) was rather uncommon in influenza B. Sudden onset was cited in only 5.4%; 57% of all influenza patients were in hospital for a mean of 7.1 days, and 5.8% of all influenza patients died. Patients aged above 60 years had more risk factors, showed typical symptoms less frequently, and were hospitalized longer than younger patients (<60 and <40 years).

Conclusions:

At an emergency department of internal medicine, influenza-diseased patients are of higher age, show an increased number of comorbidities, and are more likely to have milder symptoms documented. Elderly patients with influenza have a higher hospitalization rate with a longer hospital stay as compared with younger patients.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Factors Associated With Influenza in an Emergency Department Setting

BACKGROUND

Emergency departments (EDs) become more overcrowded during peak respiratory virus season. Distinguishing influenza from other viruses is crucial to implement social distancing practices, early treatment, and prompt disposition.

OBJECTIVES

We sought to determine factors associated with influenza among a prospective cohort of consecutive ED patients with acute respiratory illness (ARI).

METHODS

Between December 2016 and March 2017, trained research assistants screened consecutive ED patients with ARI symptoms. ARI criteria included measured fever at home or in the ED >38°C and a cough, sore throat, or rhinorrhea with a duration of symptoms >12 hours and <1 week. After consent, research assistants collected demographics and clinical history using a standardized data form, and patients had a polymerase chain reaction-based assay that is nearly 100% sensitive for influenza. Univariate analysis was conducted on all predictor variables. Significant variables were entered into a multivariate logistic regression model to find factors that were independently associated with influenza.

RESULTS

One hundred nineteen patients consented to enrollment and 31% were found to be positive for influenza. Myalgia, the absence of gastrointestinal symptoms (no diarrhea or vomiting), sore throat, chills, headache, and oxygen saturation ≥97% were significant on univariate analysis and were entered into the multivariate model. Myalgia (adjusted odds ratio [AOR] 3.9), the absence of gastrointestinal symptoms (AOR 4.7), and oxygen saturation ≥97% (AOR 2.8) were significant independent factors of influenza.

CONCLUSION

The presence of myalgia, the absence of gastrointestinal symptoms, and oxygen saturation ≥97% are factors that can help distinguish influenza from other acute respiratory illnesses in the ambulatory ED population.

Using a novel rapid viral test to improve triage of emergency department patients with acute respiratory illness during flu season

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Seasonal viral respiratory illnesses overburden emergency department resources.

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Current viral testing practices are ineffective for patient management in the ED.

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Triage viral testing can reduce transmission risk & optimize antimicrobial therapy.

Background

Acute respiratory illnesses (ARI) are mostly viral in etiology and cause significant morbidity and mortality. Point of care PCR (POC-PCR) is a promising new technology for rapid virus identification but utility in the Emergency Department (ED) is not yet defined.

Objectives

Primarily, to investigate the value of POC-PCR in rapidly identifying RSV and influenza in the setting of ED triage. Additionally, to assess whether rapid knowledge of accurate test results would improve patient management by preventing nosocomial transmission and optimizing the prescription of antimicrobials for ARIs.

Study Design

A prospective cohort study of consecutive ED patients with ARI symptoms during peak flu season was conducted. Patient nasopharyngeal swabs were collected and tested using a POC-PCR device; physicians and patients were blinded to results. Virus positive and negative groups were compared by ED patient room placement and antimicrobial therapy ordered. Specificity and sensitivity were calculated using laboratory-PCR as the gold standard.

Results

Of 119 participants, 52.9% were POC-PCR positive - Influenza A (42.9%), RSV (41.3%), influenza B (15.9%). Nearly 70% of virus positive patients were placed rooms shared with non-ARI patients. Antibiotics were prescribed for 27.3% of virus positive patients, and 77.8% of oseltamivir-eligible patients did not receive therapy. POC-PCR was 100% sensitive (95% CI, 80.5–100.0%) and 95.2% specific (95% CI, 76.2–99.9%).

Conclusions

Rapid POC-PCR for influenza and RSV in ED triage has excellent sensitivity and specificity and the potential to improve social distancing practices through better triage and increase appropriate prescription of antimicrobials.

Underdiagnosis of Influenza Virus Infection in Hospitalized Older Adults

OBJECTIVES

To describe factors associated with provider-ordered influenza testing in hospitalized older adults.

DESIGN

Information on participant demographics, symptoms, and provider-ordered influenza testing were collected by questionnaire and chart review. We conducted prospective laboratory-based surveillance using reverse-transcriptase polymerase chain reaction (RT-PCR), the criterion standard for diagnosis of influenza, to determine how participant characteristics and provider-ordered testing affected accurate influenza diagnosis.

SETTING

One academic and three community hospitals in Davidson County, Tennessee.

PARTICIPANTS

Adults aged 18 and older with acute respiratory illness or nonlocalizing fever (N=1,422).

MEASUREMENTS

We compared characteristics of participants with and without provider-ordered testing for influenza using the Wilcoxon test and Pearson chi-square test. Multivariable logistic regression models were used to identify factors predictive of provider-ordered influenza testing.

RESULTS

Twenty-eight percent (399/1,422) of participants had provider-ordered influenza testing. Participants who were tested were younger than those not tested (58 ± 18 vs 66 ± 15, p<.001) and more likely to have influenza-like illness (ILI) (71% vs 49%, p<.001). ILI decreased with increasing age (aged 18-49, 63%; aged 50-64, 60%; aged ≥65, 48%). ILI and younger age were independent predictors of provider-ordered testing. Of the 136 participants with influenza confirmed using RT-PCR, ILI was the only significant predictor of provider-ordered testing (adjusted odds ratio=3.43, 95% confidence interval=1.22-9.70).

CONCLUSION

Adults aged 65 and older hospitalized with fever or respiratory symptoms during influenza season are less likely to undergo a provider-ordered influenza test than younger adults. Some, but not all, of this disparity is due to a lower likelihood of ILI. Further strategies are needed to increase clinician awareness and testing in this vulnerable group.

Influenza

Influenza is an acute viral respiratory disease that affects persons of all ages and is associated with millions of medical visits, hundreds of thousands of hospitalizations, and thousands of deaths during annual winter epidemics of variable severity in the United States. Elderly persons have the highest influenza-associated hospitalization and mortality rates. The primary method of prevention is annual vaccination. Early antiviral treatment has the greatest clinical benefit; otherwise, management includes adherence to recommended infection prevention and control measures as well as supportive care of complications.