Seasonal influenza in adults and children--diagnosis, treatment, chemoprophylaxis, and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America

Correlation Between the Interval of Influenza Virus Infectivity and Results of Diagnostic Assays in a Ferret Model

BACKGROUND

The relationship between influenza virus infectivity and virus shedding, based on different diagnostic methods, has not been defined.

METHODS

Three donor ferrets infected with 2009 pandemic influenza A(H1N1) underwent daily quantitative culture, antigen-detection testing, and real-time reverse transcription-polymerase chain reaction (RT-PCR). Eight contacts were sequentially cohoused with each of the donors for 24 hours during days 3-10 after inoculation.

RESULTS

Transmission was observed until day 5 after inoculation, corresponding to high culture titers and positive results of antigen-detection tests. Real-time RT-PCR showed no relation to the cessation of transmission.

CONCLUSIONS

Antigen-detection testing and virus culture but not real-time RT-PCR identified the end of the infectious period.

Can newly developed, rapid immunochromatographic antigen detection tests be reliably used for the laboratory diagnosis of influenza virus infections?

Five years ago, the Point-Counterpoint series was launched. The initial article asked about the role of rapid immunochromatographic antigen testing in the diagnosis of influenza A virus 2009 H1N1 infection (D. F. Welch and C. C. Ginocchio, J Clin Microbiol 48:22-25, 2010, http://dx.doi.org/10.1128/JCM.02268-09). Since that article, not only have major changes been made in immunochromatographic antigen detection (IAD) testing for the influenza viruses, but there has also been rapid development of commercially available nucleic acid amplification tests (NAATs) for influenza virus detection. Further, a novel variant of influenza A, H7N9, has emerged in Asia, and H5N1 is also reemergent. In that initial article, the editor of this series, Peter Gilligan, identified two issues that required further consideration. One was how well IAD tests worked in clinical settings, especially in times of antigen drift and shift. The other was the role of future iterations of influenza NAATs and whether this testing would be available in a community hospital setting. James Dunn, who is Director of Medical Microbiology and Virology at Texas Children's Hospital, has extensive experience using IAD tests for diagnosing influenza. He will discuss the application and value of these tests in influenza diagnosis. Christine Ginocchio, who recently retired as the Senior Medical Director, Division of Infectious Disease Diagnostics, North Shore-LIJ Health System, and now is Vice President for Global Microbiology Affairs at bioMérieux, Durham, NC, wrote the initial counterpoint in this series, where she advocated the use of NAATs for influenza diagnosis. She will update us on the commercially available NAAT systems and explain what their role should be in the diagnosis of influenza infection.

Inducing Herd Immunity against Seasonal Influenza in Long-Term Care Facilities through Employee Vaccination Coverage: A Transmission Dynamics Model

Introduction. Vaccinating healthcare workers (HCWs) in long-term care facilities (LTCFs) may effectively induce herd immunity and protect residents against influenza-related morbidity and mortality. We used influenza surveillance data from all LTCFs in New Mexico to validate a transmission dynamics model developed to investigate herd immunity induction. Material and Methods. We adjusted a previously published transmission dynamics model and used surveillance data from an active system among 76 LTCFs in New Mexico during 2006-2007 for model validation. We used a deterministic compartmental model with a stochastic component for transmission between residents and HCWs in each facility in order to simulate the random variation expected in such populations. Results. When outbreaks were defined as a dichotomous variable, our model predicted that herd immunity could be induced. When defined as an attack rate, the model demonstrated a curvilinear trend, but insufficiently strong to induce herd immunity. The model was sensitive to changes in the contact parameter β but was robust to changes in the visitor contact probability. Conclusions. These results further elucidate previous studies' findings that herd immunity may not be induced by vaccinating HCWs in LTCFs; however, increased influenza vaccination coverage among HCWs reduces the probability of influenza infection among residents.

Wheezing exacerbations in early childhood: evaluation, treatment, and recent advances relevant to the genesis of asthma

Children who begin wheezing during early childhood are frequently seen by health care providers in primary care, in hospitals, and in emergency departments, and by allergists and pulmonologists. When a young child, such as the 2 year-old patient presented here, is evaluated for wheezing, a frequent challenge for clinicians is to determine whether the symptoms represent transient, viral-induced wheezing or whether sufficient risk factors are present to suspect that the child may experience recurrent wheezing and develop asthma. Most factors that influence prognosis are not mutually exclusive, are interrelated (ie, cofactors), and often represent gene-environment interactions. Many of these risk factors have been, and continue to be, investigated in prospective studies to decipher their relative importance with the goal of developing new therapies and interventions in the future. The etiologies of wheezing in young children, diagnostic methods, treatment, prognostic factors, and potential targets for prevention of the development of asthma are discussed.

Review of Non-Bacterial Infections in Respiratory Medicine: Viral Pneumonia

Although bacteria are the main pathogens involved in community-acquired pneumonia, a significant number of community-acquired pneumonia are caused by viruses, either directly or as part of a co-infection. The clinical picture of these different pneumonias can be very similar, but viral infection is more common in the pediatric and geriatric populations, leukocytes are not generally elevated, fever is variable, and upper respiratory tract symptoms often occur; procalcitonin levels are not generally affected. For years, the diagnosis of viral pneumonia was based on cell culture and antigen detection, but since the introduction of polymerase chain reaction techniques in the clinical setting, identification of these pathogens has increased and new microorganisms such as human bocavirus have been discovered. In general, influenza virus type A and syncytial respiratory virus are still the main pathogens involved in this entity. However, in recent years, outbreaks of deadly coronavirus and zoonotic influenza virus have demonstrated the need for constant alert in the face of new emerging pathogens. Neuraminidase inhibitors for viral pneumonia have been shown to reduce transmission in cases of exposure and to improve the clinical progress of patients in intensive care; their use in common infections is not recommended. Ribavirin has been used in children with syncytial respiratory virus, and in immunosuppressed subjects. Apart from these drugs, no antiviral has been shown to be effective. Prevention with anti-influenza virus vaccination and with monoclonal antibodies, in the case of syncytial respiratory virus, may reduce the incidence of pneumonia.

Viral Etiology of Chronic Obstructive Pulmonary Disease Exacerbations during the A/H1N1pdm09 Pandemic and Postpandemic Period

Viral infections are one of the main causes of acute exacerbations of chronic obstructive pulmonary disease (AE-COPD). Emergence of A/H1N1pdm influenza virus in the 2009 pandemic changed the viral etiology of exacerbations that were reported before the pandemic. The aim of this study was to describe the etiology of respiratory viruses in 195 Spanish patients affected by AE-COPD from the pandemic until the 2011-12 influenza epidemic. During the study period (2009–2012), respiratory viruses were identified in 48.7% of samples, and the proportion of viral detections in AE-COPD was higher in patients aged 30–64 years than ≥65 years. Influenza A viruses were the pathogens most often detected during the pandemic and the following two influenza epidemics in contradistinction to human rhino/enteroviruses that were the main viruses causing AE-COPD before the pandemic. The probability of influenza virus detection was 2.78-fold higher in patients who are 30–64 years old than those ≥65. Most respiratory samples were obtained during the pandemic, but the influenza detection rate was higher during the 2011-12 epidemic. There is a need for more accurate AE-COPD diagnosis, emphasizing the role of respiratory viruses. Furthermore, diagnosis requires increased attention to patient age and the characteristics of each influenza epidemic.

Predictors of Influenza Diagnosis Among Patients With Laboratory-Confirmed Influenza

OBJECTIVE

This study was performed to determine predictors of clinical influenza diagnosis among patients with laboratory-confirmed influenza.

METHODS

Prospective, laboratory-confirmed surveillance for influenza was conducted among patients of all ages who were hospitalized or presented to the emergency department with fever and respiratory symptoms during 2009-2013. We evaluated all enrolled persons who had influenza confirmed by viral culture and/or polymerase chain reaction and received any discharge diagnosis. The primary outcome, clinical influenza diagnosis, was defined as (1) a discharge diagnosis of influenza, (2) a prescription of neuraminidase inhibitor, or (3) a rapid test positive for influenza virus. Bivariate analyses and multiple logistic regression modeling were performed.

RESULTS

Influenza was diagnosed for 29% of 504 enrolled patients with laboratory-confirmed influenza and for 56% of 236 patients with high-risk conditions. Overall, clinical influenza diagnosis was predicted by race/ethnicity, insurance status, year, being hospitalized, having high-risk conditions, and receiving no diagnosis of bacterial infection. Being diagnosed with a bacterial infection reduced the odds of receiving an influenza diagnosis by >3-fold for all patients and for patients with high-risk conditions.

CONCLUSIONS

Many influenza virus-positive patients, including those with high-risk conditions, do not receive a clinical diagnosis of influenza. The pattern of clinical diagnoses among influenza virus-positive patients suggests preferential consideration of bacterial diseases as a diagnosis.

Antiviral treatment among older adults hospitalized with influenza, 2006-2012

Objective

To describe antiviral use among older, hospitalized adults during six influenza seasons (2006—2012) in Davidson County, Tennessee, USA.

Methods

Among adults ≥50 years old hospitalized with symptoms of respiratory illness or non-localizing fever, we collected information on provider-initiated influenza testing and nasal/throat swabs for influenza by RT-PCR in a research laboratory, and calculated the proportion treated with antivirals.

Results

We enrolled 1753 adults hospitalized with acute respiratory illness. Only 26% (457/1753) of enrolled patients had provider-initiated influenza testing. Thirty-eight patients had a positive clinical laboratory test, representing 2.2% of total patients and 8.3% of tested patients. Among the 38 subjects with clinical laboratory-confirmed influenza, 26.3% received antivirals compared to only 4.5% of those with negative clinical influenza tests and 0.7% of those not tested (p<0.001). There were 125 (7.1%) patients who tested positive for influenza in the research laboratory. Of those with research laboratory-confirmed influenza, 0.9%, 2.7%, and 2.8% received antivirals (p=.046) during pre-pandemic, pandemic, and post-pandemic influenza seasons, respectively. Both research laboratory-confirmed influenza (adjusted odds ratio [AOR] 3.04 95%CI 1.26-7.35) and clinical laboratory-confirmed influenza (AOR 3.05, 95%CI 1.07-8.71) were independently associated with antiviral treatment. Severity of disease, presence of a high-risk condition, and symptom duration were not associated with antiviral use.

Conclusions

In urban Tennessee, antiviral use was low in patients recognized to have influenza by the provider as well as those unrecognized to have influenza. The use of antivirals remained low despite recommendations to treat all hospitalized patients with confirmed or suspected influenza.

Clinical diagnosis of influenza in the ED

BACKGROUND

Timely and accurate diagnosis of influenza remains a challenge but is critical for patients who may benefit from antiviral therapy. This study determined the test characteristics of provider diagnosis of influenza, final ED electronic medical record (EMR) diagnosis of influenza, and influenza-like illness (ILI) in patients recommended to receive antiviral treatment according to Centers for Disease Control and Prevention (CDC) guidelines. In addition, we evaluated the compliance with CDC antiviral guidelines.

METHODS

A prospective cohort of adults presenting to a tertiary care ED with an acute respiratory illness who met CDC criteria for recommended antiviral treatment were enrolled and tested for influenza. A clinical diagnosis of influenza was assessed by asking the clinician: "Do you think this patient has influenza?" Influenza-like illness was defined according to current CDC criteria.

RESULTS

In this cohort of 270 subjects, 42 (16%; 95% confidence interval [CI], 11%-20%) had influenza. Clinician diagnosis had a sensitivity of 36% (95% CI, 22%-52%) and specificity of 78% (95% CI, 72%-83%); EMR final ED diagnosis had a sensitivity of 26% (95% CI, 14%-42%) and specificity of 97% (95% CI, 94%-99%); ILI had a sensitivity of 31% (95% CI, 18%-47%) and specificity of 88% (95% CI, 83%-92%). Only 15 influenza-positive patients (36%) received antiviral treatment.

CONCLUSION

Clinician diagnosis, final ED EMR diagnosis, and ILI have low sensitivity for diagnosing influenza, and there is overall poor compliance with CDC antiviral treatment recommendations. Improved methods of influenza diagnosis are needed to help guide management in the clinical setting.

Postexposure management of healthcare personnel to infectious diseases

Healthcare personnel (HCP) are at risk of exposure to various pathogens through their daily tasks and may serve as a reservoir for ongoing disease transmission in the healthcare setting. Management of HCP exposed to infectious agents can be disruptive to patient care, time-consuming, and costly. Exposure of HCP to an infectious source should be considered an urgent medical concern to ensure timely management and administration of postexposure prophylaxis, if available and indicated. Infection control and occupational health departments should be notified for management of exposed HCP, identification of all contacts of the index case, and application of immediate infection control measures for the index case and exposed HCP, if indicated. This article reviews the main principles of postexposure management of HCP to infectious diseases, in general, and to certain common infections, in particular, categorized by their route of transmission, in addition to primary prevention of these infections.

Detection of influenza A and B with the Alere ™ i Influenza A & B: a novel isothermal nucleic acid amplification assay

Background

Rapid influenza diagnostic tests (RIDTs) have an important role in clinical decision-making; however, the performances of currently available assays vary widely.

Objectives

We evaluated the performance of the Alere™ i Influenza A&B (Alere™ iNAT), a rapid isothermal nucleic acid amplification assay that has recently received FDA clearance, for the detection of influenza A and B viruses during the Australian influenza season of 2013. Results were compared to two other RIDTs tested in parallel; Quidel Sofia® Influenza A+B fluorescent immunoassay (FIA) and Alere™ BinaxNOW® Influenza A & B immunochromatographic (ICT) assay.

Methods

A total of 202 paired nasopharyngeal swabs collected from patients ≥16 years old with an influenza-like illness (ILI) were eluted in 2 ml of universal transport medium (UTM) that was used to perform all three RIDTs in parallel. Reverse-transcription polymerase chain reaction (RT-PCR) was used as the reference standard.

Results

Compared to RT-PCR, Alere™ iNAT detected 77·8% influenza A positive samples versus 71·4% and 44·4% for the Quidel Sofia® Influenza A+B FIA and BinaxNOW® Influenza A & B ICT assay, respectively. For influenza B, Alere™ iNAT detected 75% of those positive by RT-PCR, versus 33·3% and 25·0% for Sofia® and BinaxNOW®, respectively. The specificity of Alere™ iNAT was 100% for influenza A and 99% for influenza B.

Conclusions

Alere™ i Influenza A&B is a promising new rapid influenza diagnostic assay with potential point-of-care applications.

Use of influenza antiviral medications among outpatients at high risk for influenza-associated complications during the 2013-2014 influenza season

During the 2013-2014 influenza season, we analyzed data from 6004 outpatients aged ≥6 months with acute respiratory illness (ARI). Among the 2786 ARI patients at higher risk for influenza complications, 835 (30%) presented to care ≤2 days from symptom onset; among those, 126 (15%) were prescribed an antiviral medication.

Optimizing antiviral therapy for influenza: understanding the evidence

Influenza is an important cause of annual epidemics of respiratory viral infection associated with significant morbidity and mortality. Three classes of drugs, the M2 ion channel, neuraminidase and RNA-dependent RNA polymerase inhibitors, are approved for the prevention and treatment of influenza. Due to widespread resistance to the class, the M2 ion channel inhibitors are not recommended currently for therapy. The only polymerase inhibitor, favipiravir, is approved only in Japan and its use is highly restricted. Despite significant data to support the early use of the neuraminidase inhibitors, their use in all patient populations is suboptimal. The data to support the early use of neuraminidase inhibitors will be reviewed, as will current data on the utilization rates in ambulatory and hospitalized populations.

Use of neuraminidase inhibitors in primary health care during pandemic and seasonal influenza between 2009 and 2013

BACKGROUND

In a context of controversy about influenza antiviral treatments, this study assessed primary health-care physicians' prescription of neuraminidase inhibitors (NIs) in France during pandemic and seasonal influenza between 2009 and 2013.

METHODS

This observational study, using data recorded in three national databases, estimated the rate of NI prescription among influenza-like illness (ILI) patients seen in GP and paediatrician consultations, and determined factors associated with this prescription according to a multivariate analysis. NI delivery by pharmacists was also evaluated.

RESULTS

Rates of NI prescription were estimated to be 61.1% among ILI patients with a severe influenza risk factor seen in GP consultation during the A(H1N1)pdm2009 pandemic versus an average rate of 25.9% during the three following seasonal influenza epidemics. Factors associated with NI prescription were a chronic disease in patients under 65 years (OR 14.85; 95% CI 13.00, 16.97) and in those aged 65 and older (OR 7.54; 5.86, 9.70), an age ≥65 years in patients without chronic disease (OR 1.35; 1.04, 1.74), a pregnancy (OR 10.63; 7.67, 15.76), obesity (OR 4.67; 3.50, 6.22) and a consultation during the pandemic A(H1N1)pdm2009 (OR 3.19; 2.93, 3.48). The number of antiviral treatments delivered by pharmacists during the A(H1N1)pdm2009 pandemic was 835 per 100,000 inhabitants, and an average of 275 per 100,000 inhabitants during the three following seasonal influenza epidemics.

CONCLUSIONS

Although physicians seem to follow the recommended indications for NIs in primary health-care practice, this study confirms the low rate of NI prescription to ILI patients with a severe influenza risk factor, especially during seasonal epidemics.

Evaluation of a new, rapid, simple test for the detection of influenza virus

BACKGROUND

Influenza virus infections are responsible for significant morbidity and mortality in both pediatric and adult populations worldwide. Rapid and accurate diagnosis of influenza is necessary for appropriate patient management during the influenza season and for optimal utilization of anti-influenza therapy. We prospectively tested the accuracy of a simple and rapid diagnostic method.

METHODS

Ninety-eight samples (nasal and pharyngeal swabs) from patients with upper respiratory tract infection symptoms who presented to primary healthcare centres in Barcelona (Spain) were prospectively analyzed. The samples were collected as part of influenza surveillance program. Samples that had enough volume to make the new test after aliquoting the amount needed to perform routine tests were included. None of the samples were pre-selected as a result of their status in relation to influenza virus. Samples were analyzed by in-house real-time PCR and Alere i Influenza A & B (Alere i), which uses isothermal amplification of nucleic acids for the qualitative detection of influenza A and B in nasal swabs transported in viral transport media. The two techniques were compared by positive percent agreement (PPA) and negative percent agreement (NPA). Statistical analysis was performed with Stata.

RESULTS

Of the 98 samples analysed 90 were concordant; 46 (46.9%) were positive and 44 (44.9%) were negative. Five samples showed invalid results with the Alere i test and could be not re-tested due to insufficient sample volume and were not included in the final statistical analysis. In the 93 remaining samples, the Alere i test showed 97% of accuracy having correctly classified 90 samples. We obtained discordant results in 3 samples (3%). The PPA was 93.8% for influenza A and 94.1% for influenza B, and NPA was 100% for influenza A and influenza B virus. In addition, the Alere i was very rapid (15 minutes or less) and extremely easy to use.

CONCLUSIONS

The Alere i test provided a good correlation compared to the real-time PCR test for the diagnosis of influenza. Since this method can be performed in minutes, it allows immediate, accurate clinical decisions to prescribe appropriate antiviral treatment or isolation of patients.

Vaccinations for pregnant women

In the United States, eradication and reduction of vaccine-preventable diseases through immunization has directly increased life expectancy by reducing mortality. Although immunization is a public priority, vaccine coverage among adult Americans is inadequate. The Institute of Medicine, the Community Preventive Services Task Force, and other public health entities have called for the development of innovative programs to incorporate adult vaccination into routine clinical practice. Obstetrician-gynecologists are well suited to serve as vaccinators of women in general and more specifically pregnant women. Pregnant women are at risk for vaccine-preventable disease-related morbidity and mortality and adverse pregnancy outcomes, including congenital anomalies, spontaneous abortion, preterm birth, and low birth weight. In addition to providing direct maternal benefit, vaccination during pregnancy likely provides direct fetal and neonatal benefit through passive immunity (transplacental transfer of maternal vaccine-induced antibodies). This article reviews: 1) types of vaccines; 2) vaccines specifically recommended during pregnancy and postpartum; 3) vaccines recommended during pregnancy and postpartum based on risk factors and special circumstances; 4) vaccines currently under research and development for licensure for maternal-fetal immunization; and 5) barriers to maternal immunization and available patient and health care provider resources.

Utilization of the respiratory virus multiplex reverse transcription-polymerase chain reaction test for adult patients at a Korean tertiary care center

BACKGROUND/AIMS

Respiratory viruses (RVs) are considered to be important respiratory pathogens in adult patients, and the multiplex reverse transcription-polymerase chain reaction (RT-PCR) test is used frequently in adult patients with respiratory infections. However, clinical data regarding utilization of the multiplex RT-PCR test for RVs are lacking.

METHODS

We investigated the utilization of the multiplex RT-PCR test for RVs at Chung-Ang University Hospital in Seoul, Korea, between January 2012 and April 2013.

RESULTS

During the study period, the multiplex RT-PCR test was performed for 291 adult patients. The test frequency was 4.9% of rapid influenza antigen detection tests and 0.8% of respiratory bacterial culture studies. A turnaround time of < 48 hours was observed in 25.9% of positive tests. Most of the tests were performed for admitted patients (97.9%) with a community-acquired infection (84.2%) during the flu season (82.5%). RVs were detected in 81 of 291 cases (27.8%). The RV positivity rates for community- and hospital-acquired infections did not differ (28.6% vs. 23.9%, p = 0.52). Of 166 patients with pneumonia, 44 (26.5%) had a viral infection. Among the patients with RV-associated pneumonia, an RV other than influenza was detected in 20 patients (45.4%).

CONCLUSIONS

The multiplex RT-PCR test for RVs was infrequently performed at a tertiary care center, and the test results were often reported late. The test was most often performed for admitted adult patients with community-acquired infections during the flu season. The utilization of multiplex RT-PCR testing for RVs in current clinical practice should be improved.

Efficacy and safety of clearing heat and detoxifying injection in the treatment of influenza: a randomized, double-blinded, placebo-controlled trial

Objective. To evaluate the efficacy and safety of CHDI in the treatment of influenza infection. Method. A randomized double-blind, double dummy trial was conducted. Influenza patients with a positive influenza A rapid test diagnosis were randomized to receive CHDI or oseltamivir. Primary outcome was assessed by the median fever alleviation time and clearance time, and secondary outcome was total scores of influenza symptoms. Results. One hundred thirty-nine participants were screened and 34 had a RT-PCR laboratory confirmation of influenza virus infection. Fever alleviation time was 2.5 and 5 hours in CHDI and oseltamivir, respectively, and fever clearance time was 32.5 and 49 hours. The HR of fever alleviation and clearance time shows no significant difference between two groups. Total scores of influenza symptoms descended significantly in both groups after treatment and descended more in CHDI than oseltamivir on day 2. Similar to total symptoms severity score, fever severity score descend more significantly in CHDI than oseltamivir on day 2, and there were no differences on other symptoms. Conclusions. CHDI have a similar effect to oseltamivir in reducing the duration of influenza illness. CHDI was well tolerated, with no serious adverse events noted during the study period.

Quantitative RT-PCR evaluation of a rapid influenza antigen test for efficient diagnosis of influenza virus infection

Influenza virus infection is diagnosed in most cases using a rapid influenza antigen diagnostic test (RIDT). However, false-negative results are a major concern. By contrast, the nucleic acid amplification test offers high sensitivity and therefore can aid the interpretation of negative RIDT results. In this study, influenza viral loads were quantified with quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using viral suspensions left over after RIDT, and the performance of both methods was evaluated. qRT-PCR detected as few as 10(3)copies/mL of influenza viruses A and B, whereas RIDT showed negative results for viral loads less than 10(7) and 10(5)copies/mL of influenza viruses A and B, respectively. These results indicate that small quantities of the virus that cause false-negative RIDT results can be detected efficiently with qRT-PCR follow-up. In addition, influenza A virus subtype was determined using qRT-PCR.

Epidemiologic data and pathogen genome sequences: a powerful synergy for public health

Epidemiologists aim to inform the design of public health interventions with evidence on the evolution, emergence and spread of infectious diseases. Sequencing of pathogen genomes, together with date, location, clinical manifestation and other relevant data about sample origins, can contribute to describing nearly every aspect of transmission dynamics, including local transmission and global spread. The analyses of these data have implications for all levels of clinical and public health practice, from institutional infection control to policies for surveillance, prevention and treatment. This review highlights the range of epidemiological questions that can be addressed from the combination of genome sequence and traditional ‘line lists’ (tables of epidemiological data where each line includes demographic and clinical features of infected individuals). We identify opportunities for these data to inform interventions that reduce disease incidence and prevalence. By considering current limitations of, and challenges to, interpreting these data, we aim to outline a research agenda to accelerate the genomics-driven transformation in public health microbiology.

Recommendations for prevention and control of influenza in children, 2014-2015

The purpose of this statement is to update recommendations for routine use of seasonal influenza vaccine and antiviral medications for the prevention and treatment of influenza in children. The American Academy of Pediatrics recommends annual seasonal influenza immunization for all people 6 months and older, including all children and adolescents. Highlights for the upcoming 2014-2015 season include the following:The influenza vaccine composition for the 2014-2015 season is unchanged from the 2013-2014 season.Both trivalent and quadrivalent influenza vaccines are available in the United States for the 2014-2015 season.Annual universal influenza immunization is indicated with either a trivalent or quadrivalent vaccine (no preference).Live attenuated influenza vaccine (LAIV) should be considered for healthy children 2 through 8 years of age who have no contraindications or precautions to the intranasal vaccine. If LAIV is not readily available, inactivated influenza vaccine (IIV) should be used; vaccination should not be delayed to obtain LAIV.The dosing algorithm for administration of influenza vaccine to children 6 months through 8 years of age reflects that virus strains in the vaccine have not changed from last season.As always, pediatricians, nurses, and all other health care personnel should be immunized themselves and should promote influenza vaccine use and infection control measures. In addition, pediatricians should promptly identify clinical influenza infections to enable rapid antiviral treatment, when indicated, to reduce morbidity and mortality.

Geriatric Fever Score: a new decision rule for geriatric care

BACKGROUND

Evaluating geriatric patients with fever is time-consuming and challenging. We investigated independent mortality predictors of geriatric patients with fever and developed a prediction rule for emergency care, critical care, and geriatric care physicians to classify patients into mortality risk and disposition groups.

MATERIALS AND METHODS

Consecutive geriatric patients (≥65 years old) visiting the emergency department (ED) of a university-affiliated medical center between June 1 and July 21, 2010, were enrolled when they met the criteria of fever: a tympanic temperature ≥37.2°C or a baseline temperature elevated ≥1.3°C. Thirty-day mortality was the primary endpoint. Internal validation with bootstrap re-sampling was done.

RESULTS

Three hundred thirty geriatric patients were enrolled. We found three independent mortality predictors: Leukocytosis (WBC >12,000 cells/mm3), Severe coma (GCS ≤ 8), and Thrombocytopenia (platelets <150 10(3)/mm3) (LST). After assigning weights to each predictor, we developed a Geriatric Fever Score that stratifies patients into two mortality-risk and disposition groups: low (4.0%) (95% CI: 2.3-6.9%): a general ward or treatment in the ED then discharge and high (30.3%) (95% CI: 17.4-47.3%): consider the intensive care unit. The area under the curve for the rule was 0.73.

CONCLUSIONS

We found that the Geriatric Fever Score is a simple and rapid rule for predicting 30-day mortality and classifying mortality risk and disposition in geriatric patients with fever, although external validation should be performed to confirm its usefulness in other clinical settings. It might help preserve medical resources for patients in greater need.

Targeting eicosanoid pathways in the development of novel anti-influenza drugs

The constant new emergence of life-threatening human respiratory viral pathogens presents new challenges to clinicians who are left with no available therapeutic interventions. Highly pathogenic strains of influenza A virus (IAV) share an enhanced capacity to propagate to the lower airways and paralyze alveolar macrophage antiviral capacity in order to replicate efficiently and cause pathologic inflammation. Following a century of using NSAIDs for the management of influenza symptoms, a number of studies have interrogated their function in the host response to IAV infection. We herein provide an overview of these studies as well as further insight of how pathogenic IAV hijacks the microsomal prostaglandin E synthase-1-dependent prostaglandin E2 pathway in order to evade host type I interferon-mediated antiviral immunity. We also reflect on the potential beneficial action of microsomal prostaglandin E synthase-1 inhibitory compounds in the treatment of IAV infections and potentially other RNA viruses.

High rate of A(H1N1)pdm09 infections among rural Thai villagers, 2009-2010

Background

Pandemic influenza A(H1N1)pdm09 emerged in Thailand in 2009. A prospective longitudinal adult cohort and household transmission study of influenza-like illness (ILI) was ongoing in rural Thailand at the time of emergence. Symptomatic and subclinical A(H1N1)pdm09 infection rates in the cohort and among household members were evaluated.

Methods

A cohort of 800 Thai adults underwent active community-based surveillance for ILI from 2008–2010. Acute respiratory samples from ILI episodes were tested for A(H1N1)pdm09 by qRT-PCR; acute and 60-day convalescent blood samples were tested by A(H1N1)pdm09 hemagglutination inhibition assay (HI). Enrollment, 12-month and 24-month follow-up blood samples were tested for A(H1N1)pdm09 seroconversion by HI. Household members of influenza A-infected cohort subjects with ILI were enrolled in household transmission investigations in which day 0 and 60 blood samples and acute respiratory samples were tested by either qRT-PCR or HI for A(H1N1)pdm09. Seroconversion between annual blood samples without A(H1N1)pdm09-positive ILI was considered as subclinical infection.

Results

The 2-yr cumulative incidence of A(H1N1)pdm09 infection in the cohort in 2009/2010 was 10.8% (84/781) with an annual incidence of 1.2% in 2009 and 9.7% in 2010; 83.3% of infections were subclinical (50% in 2009 and 85.9% in 2010). The 2-yr cumulative incidence was lowest (5%) in adults born ≤1957. The A(H1N1)pdm09 secondary attack rate among household contacts was 47.2% (17/36); 47.1% of these infections were subclinical. The highest A(H1N1)pdm09 secondary attack rate among household contacts (70.6%, 12/17) occurred among children born between 1990 and 2003.

Conclusion

Subclinical A(H1N1)pdm09 infections in Thai adults occurred frequently and accounted for a greater proportion of all A(H1N1)pdm09 infections than previously estimated. The role of subclinical infections in A(H1N1)pdm09 transmission has important implications in formulating strategies to predict and prevent the spread of A(H1N1)pdm09 and other influenza virus strains.

Socioeconomic impact of seasonal (epidemic) influenza and the role of over-the-counter medicines

The substantial economic impact of influenza on society results primarily from lost work time and reduced productivity of patients and caregivers and increased use of medical resources. Additionally, since the 1980s, aging of the US population has meant rising influenza-related morbidity and mortality. According to the most current published data on this topic, in 2003 the total economic burden of influenza epidemics in the USA across all age groups was US$87.1 billion. As of February 2013, overall vaccine effectiveness for the 2012/2013 season was estimated to be 56 %. The Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases has concluded that more effective vaccines and vaccination strategies are needed. Moderate efficacy of the influenza vaccine, continued questions regarding the value of treatment with antivirals, and a growing self-care movement have led to increased use of over-the-counter (OTC) medicines, which play a vital role in managing symptoms associated with mild to moderate influenza and provide an estimated US$102 billion in annual savings for the US healthcare system. A primary benefit to society of using OTC medicines to manage influenza is decreased use of the healthcare system, thereby mitigating the socioeconomic burden of influenza. Considering the stresses placed on the US healthcare system and the substantial productivity losses resulting from seasonal influenza as well as the growing self-care movement, OTC medicines will play an important role in the course of future influenza epidemics.

Effectiveness of seasonal influenza vaccinations against laboratory-confirmed influenza-associated infections among Singapore military personnel in 2010-2013

BACKGROUND

Limited information is available about seasonal influenza vaccine effectiveness (VE) in tropical communities.

OBJECTIVES

Virus subtype-specific VE was determined for all military service personnel in the recruit camp and three other non-recruit camp in Singapore's Armed Forces from 1 June 2009 to 30 June 2012.

METHODS

Consenting servicemen underwent nasal washes, which were tested with RT-PCR and subtyped. The test positive case and test negative control design was used to estimate the VE. To estimate the overall effect of the programme on new recruits, we used an ecological time series approach.

RESULTS

A total of 7016 consultations were collected. The crude estimates for the VE of the triavalent vaccine against both influenza A(H1N1)pdm09 and influenza B were 84% (95% CI 78-88%, 79-86%, respectively). Vaccine efficacy against influenza A(H3N2) was markedly lower (VE 33%, 95% CI -4% to 57%). An estimated 70% (RR = 0.30; 95% CI 0.11-0.84), 39% (RR = 0.61;0.25-1.43) and 75% (RR = 0.25; 95% CI 0.11-0.50) reduction in the risk of influenza A(H1N1)pdm09, influenza A(H3N2) and influenza B infections, respectively, in the recruit camp during the post-vaccination period compared with during the pre-vaccination period was observed.

CONCLUSIONS

Overall, the blanket influenza vaccine programme in Singapore's Armed Forces has had a moderate to high degree of protection against influenza A(H1N1)pdm09 and influenza B, but not against influenza A(H3N2). Blanket influenza vaccination is recommended for all military personnel.

Healthcare workers under a mandated H1N1 vaccination policy with employment termination penalty: a survey to assess employee perception

The ethical debate over mandatory healthcare worker (HCW) influenza vaccination is a heated one. Our study hospital instituted a mandatory employee influenza vaccination policy for the 2009-2010 influenza season during the highly publicized pandemic of the H1N1 "Swine Flu." Under this mandate there was no informed declination option, and termination of employment was the consequence for noncompliance. Our objective was to examine HCW perceptions of the H1N1 influenza virus, the vaccine, and the strict mandated vaccination policy. A survey was designed, distributed, and anonymously collected. In total, 202 completed questionnaires were obtained via accidental sampling by the investigators achieving a 100% response rate. Data analysis showed that 31.7% of surveyed HCWs felt the mandate was an infringement on their rights and 3.5% of HCWs would electively seek employment elsewhere. Significantly more nurses and clerks/technicians were opposed to the mandate compared to other types of employees. 96% felt that the mandating hospital should be liable should a significant adverse effect occur from receiving the vaccine. While the mandate helped to increase HCW influenza vaccination rates dramatically, the strict consequence of employment termination created negative feelings of coercion. Adopting a policy that includes a declination option with mandatory masking during influenza season might be a more widely acceptable and still adequate approach.

Acute respiratory viral infections in pediatric cancer patients undergoing chemotherapy

OBJECTIVE

to estimate the prevalence of infection by respiratory viruses in pediatric patients with cancer and acute respiratory infection (ARI) and/or fever.

METHODS

cross-sectional study, from January 2011 to December 2012. The secretions of nasopharyngeal aspirates were analyzed in children younger than 21 years with acute respiratory infections. Patients were treated at the Grupo em Defesa da Criança Com Câncer (Grendacc) and University Hospital (HU), Jundiaí, SP. The rapid test was used for detection of influenza virus (Kit Biotrin, Inc. Ireland), and real-time multiplex polymerase chain reaction (FTD, Respiratory pathogens, multiplex Fast Trade Kit, Malta) for detection of influenza virus (H1N1, B), rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus, human parechovirus, bocavirus, metapneumovirus, and human coronavirus. The prevalence of viral infection was estimated and association tests were used (χ(2) or Fisher's exact test).

RESULTS

104 samples of nasopharyngeal aspirate and blood were analyzed. The median age was 12 ± 5.2 years, 51% males, 68% whites, 32% had repeated ARIs, 32% prior antibiotic use, 19.8% cough, and 8% contact with ARIs. A total of 94.3% were in good general status. Acute lymphocytic leukemia (42.3%) was the most prevalent neoplasia. Respiratory viruses were detected in 50 samples: rhinoviruses (23.1%), respiratory syncytial virus AB (8.7%), and coronavirus (6.8%). Co-detection occurred in 19% of cases with 2 viruses and in 3% of those with 3 viruses, and was more frequent between rhinovirus and coronavirus 43. Fever in neutropenic patients was observed in 13%, of which four (30.7) were positive for viruses. There were no deaths.

CONCLUSIONS

the prevalence of respiratory viruses was relevant in the infectious episode, with no increase in morbidity and mortality. Viral co-detection was frequent in patients with cancer and ARIs.

Inaccurate ascertainment of morbidity and mortality due to influenza in administrative databases: a population-based record linkage study

BACKGROUND

Historically, counting influenza recorded in administrative health outcome databases has been considered insufficient to estimate influenza attributable morbidity and mortality in populations. We used database record linkage to evaluate whether modern databases have similar limitations.

METHODS

Person-level records were linked across databases of laboratory notified influenza, emergency department (ED) presentations, hospital admissions and death registrations, from the population (∼6.9 million) of New South Wales (NSW), Australia, 2005 to 2008.

RESULTS

There were 2568 virologically diagnosed influenza infections notified. Among those, 25% of 40 who died, 49% of 1451 with a hospital admission and 7% of 1742 with an ED presentation had influenza recorded on the respective database record. Compared with persons aged ≥65 years and residents of regional and remote areas, respectively, children and residents of major cities were more likely to have influenza coded on their admission record. Compared with older persons and admitted patients, respectively, working age persons and non-admitted persons were more likely to have influenza coded on their ED record. On both ED and admission records, persons with influenza type A infection were more likely than those with type B infection to have influenza coded. Among death registrations, hospital admissions and ED presentations with influenza recorded as a cause of illness, 15%, 28% and 1.4%, respectively, also had laboratory notified influenza. Time trends in counts of influenza recorded on the ED, admission and death databases reflected the trend in counts of virologically diagnosed influenza.

CONCLUSIONS

A minority of the death, hospital admission and ED records for persons with a virologically diagnosed influenza infection identified influenza as a cause of illness. Few database records with influenza recorded as a cause had laboratory confirmation. The databases have limited value for estimating incidence of influenza outcomes, but can be used for monitoring variation in incidence over time.

Effect of nitazoxanide in adults and adolescents with acute uncomplicated influenza: a double-blind, randomised, placebo-controlled, phase 2b/3 trial

Background

Influenza is an important cause of morbidity and mortality worldwide. Treatment options are scarce, and new drugs with novel mechanisms of action are needed. We aimed to assess the efficacy and safety of nitazoxanide, a thiazolide anti-infective, for treatment of acute uncomplicated influenza.

Methods

We did a double-blind, randomised, placebo-controlled, phase 2b/3 trial in 74 primary care clinics in the USA between Dec 27, 2010, and April 30, 2011. We enrolled participants aged 12–65 years with fever, at least one respiratory symptom, and one constitutional symptom of influenza within 48 h of symptom onset. We randomly assigned participants to receive either nitazoxanide 600 mg, nitazoxanide 300 mg, or placebo twice daily for 5 days, (ratio 1:1:1) and followed them up for 28 days. Randomisation lists were computer generated and done in blocks of three. Sponsor, investigators, study monitors, patients, and laboratory personnel were all masked to treatment allocation in the study. The primary endpoint was the time from first dose to alleviation of symptoms. The primary analysis was by intention-to-treat for participants with influenza infection confirmed by RT-PCR or culture at baseline. This trial is registered with ClinicalTrials.gov, number NCT01227421.

Findings

Of 650 participants screened, 624 (96%) were enrolled. Of these, 212 were randomly assigned to receive placebo twice a day, 201 to receive nitazoxanide 300 mg twice a day, and 211 to receive nitazoxanide 600 mg a day. The median duration of symptoms for participants receiving placebo was 116·7 h (95% CI 108·1–122·1) compared with 95·5 h (84·0–108·0; p=0·0084) for those receiving 600 mg nitazoxanide and 109·1 h (96·1–129·5, p=0·52) for those receiving 300 mg nitazoxanide. Adverse events were similar between the three groups, the most common being headache reported by 24 (11%) of 212 patients enrolled in placebo group, 12 (6%) of 201 patients in the low-dose group, and 17 (8%) of 211 patients in the high-dose group, or diarrhoea, reported by seven (3%) patients in the placebo group, four (2%) patients enrolled in the low-dose group, and 17 (8%) patients in the high-dose group.

Interpretation

Treatment with nitazoxanide 600 mg twice daily for 5 days was associated with a reduction of the duration of symptoms in participants with acute uncomplicated influenza. Further studies are warranted to confirm these findings and to assess efficacy of the drug alone or in combination with existing drugs in seriously ill patients and those at risk of influenza complications.

Funding

Romark Laboratories LC.

Evaluation of the Sofia Influenza A + B fluorescent immunoassay for the rapid diagnosis of influenza A and B

Rapid influenza diagnostic tests (RIDTs) can facilitate the appropriate prescription of antivirals for influenza, obviate the need for unnecessary testing and antibacterial agents and allow the implementation of infection control measures. However, the reported sensitivities and specificities of different RIDTs vary widely in clinical settings, as does assay ability to distinguish between influenza types and subtypes. To evaluate the performance of the Sofia Influenza A + B fluorescent immunoassay (FIA) for the detection of influenza A and B during the 2013 Southern Hemisphere influenza season, a total of 209 consecutive respiratory tract swabs from adult patients with an influenza-like illness were tested by both Sofia Influenza A + B and an in-house real-time, reverse transcription-polymerase chain reaction (RT-PCR) assay. Compared to RT-PCR, the sensitivity and specificity of the Sofia Influenza A + B FIA for detection of influenza A was 72.4% and 98.3%, respectively. Too few influenza B positive samples were available during the study to accurately assess the Sofia's performance for influenza B detection. The sensitivity of Sofia Influenza A + B FIA for both influenza A and B detection correlated with the amount of influenza RNA present in the sample as indicated indirectly by the RT-PCR cycle threshold (Ct ). In conclusion, the Sofia Influenza A + B FIA continues to perform well as a RIDT with the circulating influenza strains of the 2013 Southern Hemisphere influenza season.

An interferometric reflectance imaging sensor for point of care viral diagnostics

The use of in vitro diagnostic devices is transitioning from the laboratory to the primary care setting to address early disease detection needs. Time critical viral diagnoses are often made without support due to the experimental time required in today's standard tests. Available rapid point of care (POC) viral tests are less reliable, requiring a follow-on confirmatory test before conclusions can be drawn. The development of a reliable POC viral test for the primary care setting would decrease the time for diagnosis leading to a lower chance of transmission and improve recovery. The single particle interferometric reflectance imaging sensor (SP-IRIS) has been shown to be a sensitive and specific-detection platform in serum and whole blood. This paper presents a step towards a POC viral assay through a SP-IRIS prototype with automated data acquisition and analysis and a simple, easy-to-use software interface. Decreasing operation complexity highlights the potential of SP-IRIS as a sensitive and specific POC diagnostic tool. With the integration of a microfluidic cartridge, this automated instrument will allow an untrained user to run a sample-to-answer viral assay in the POC setting.

Comparison of laboratory-confirmed influenza and noninfluenza acute respiratory illness in healthcare personnel during the 2010-2011 influenza season

OBJECTIVE

Compare the severity of illnesses associated with influenza and noninfluenza acute respiratory illness (ARI) in healthcare personnel (HCP).

DESIGN

Prospective observational cohort.

PARTICIPANTS

HCP at 2 healthcare organizations with direct patient contact were enrolled prior to the 2010-2011 influenza season.

METHODS

HCP who were fewer than 8 days from the start of fever/feverishness/chills and cough were eligible for real-time reverse-transcription polymerase chain reaction influenza virus testing of respiratory specimen. Illness severity was assessed by the sum of self-rated severity (0, absent; 3, severe) of 12 illness symptoms, subjective health (0, best health; 9, worst health), activities of daily living impairment (0, able to perform; 9, unable to perform), missed work, and duration of illness.

RESULTS

Of 1,701 HCP enrolled, 267 were tested for influenza, and 58 (22%) of these tested positive. Influenza compared with noninfluenza illnesses was associated with higher summed 12-symptom severity score (mean [standard deviation], 17.9 [5.4] vs 14.6 [4.8]; P < .001), worse subjective health (4.5 [1.8] vs 4.0 [1.8]; P <.05), greater impairment of activities of daily living (4.9 [2.5] vs 3.8 [2.5]; P < .01), and more missed work (12.1 [10.5] vs 7.8 [10.5] hours; P < .01). Differences in symptom severity, activities of daily living, and missed work remained significant after adjusting for illness and participant characteristics.

CONCLUSIONS

Influenza had a greater negative impact on HCP than noninfluenza ARIs, indicated by higher symptom severity scores, less ability to perform activities of daily living, and more missed work. These results highlight the importance of efforts to prevent influenza infection in HCP.

[Respiratory viriasis. Influenza]

Respiratory viriasis are acute infectious diseases with a usually favorable course. Influenza is the disease caused by influenza viruses A and B; it could cause seasonal periodical epidemics and influenza A is implicated in worlwide pandemias. Influenza complications usually are limited to older patients and to those with comorbilities, especially those with chronic respiratory or cardiovascular diseases. Anti-influenza therapy has an effect on the duration of the symptomatic period and vaccination efficiently decreases the incidence of the infection. Respiratory syncytial virus is the more frequent cause of the acute bronchiolitis in breastfeeding patients. Rinovirus and coronavirus are implicated in the common cold. Coronavirus was the etiological agent of the severe acute respiratory syndrome, described in 2002 in China. Parainfluenza virus is the cause of the laryngeal croup in infants.

Preventing and controlling influenza with available interventions

Influenza activity has been surging in the United States, and there are reports of critical illness and death in young and middle-aged adults. The predominant virus so far this season is influenza

Systematic review of evidence-based guidelines on medication therapy for upper respiratory tract infection in children with AGREE instrument

OBJECTIVES

To summarize recommendations of existing guidelines on the treatment of upper respiratory tract infections (URTIs) in children, and to assess the methodological quality of these guidelines.

METHODS

We searched seven databases and web sites of relevant academic agencies. Evidence-based guidelines on pediatric URTIs were included. AGREE II was used to assess the quality of these guidelines. Two researchers selected guidelines independently and extracted information on publication years, institutions, target populations, recommendations, quality of evidence, and strength of recommendations. We compared the similarities and differences of recommendations and their strength. We also analyzed the reasons for variation.

RESULTS

Thirteen guidelines meeting our inclusion criteria were included. Huge differences existed among these 13 guidelines concerning the categorization of evidence and recommendations. Nearly all of these guidelines lacked the sufficient involvement of stake holders. Further, the applicability of these guidelines still needs to be improved. In terms of recommendations, penicillin and amoxicillin were suggested for group A streptococcal pharyngitis. Amoxicillin and amoxicillin-clavulanate were recommended for acute bacterial rhinosinusitis (ABRS). An observation of 2-3 days prior to antibiotic therapy initiation for mild acute otitis media (AOM) was recommended with amoxicillin as the suggested first choice agent. Direct evidence to support strong recommendations on the therapy for influenza is still lacking. In addition, the antimicrobial durations for pharyngitis and ABRS were still controversial. No consensus was reached for the onset of antibiotics for ABRS in children.

CONCLUSIONS

Future guidelines should use a consistent grading system for the quality of evidence and strength of recommendations. More effort needs to be paid to seek the preference of stake holders and to improve the applicability of guidelines. Further, there are still areas in pediatric URTIs that need more research.