Reducing the Burden of Influenza-Associated Complications with Antiviral Therapy

Effect of School-Based Education Intervention on Knowledge and Attitude Regarding Seasonal Influenza Vaccine Uptake Among Secondary Schoolgirl Students in Al-Ahsa, Saudi Arabia: A Quasi-experimental Study

Background School-based educational interventions are critical because they provide an opportunity to strengthen preventive measures by educating students about the importance of vaccination and promoting healthy practices within the community. Aim The study aimed to assess the effectiveness of influenza vaccination education in terms of knowledge and attitudes among secondary schoolgirl students in Al-Ahsa, Saudi Arabia. Methods This open-label, parallel-group, quasi-experimental study included 419 secondary school girls in Al-Ahsa, Saudi Arabia. The control group comprised 199 participants, while the intervention group comprised 220 participants. Both groups were administered a self-administered Arabic questionnaire prior to the study to collect information on participants' demographics, knowledge, attitudes, and practices regarding seasonal influenza and its vaccine. Subsequently, the intervention group was presented with a brief educational video and evaluated via a post-test. The primary outcomes were the students' knowledge and attitudes about seasonal influenza vaccines. The secondary outcomes were the participants' practices and reasons for not receiving the vaccine for seasonal influenza. Results Following an educational intervention about seasonal influenza and its vaccine, there was a statistical increase in knowledge and attitudes among students compared to a pre-intervention baseline. However, in both intervention and control groups, only a small proportion of participants had received the influenza vaccine, either once or on more than one occasion. Most participants employed additional preventive measures beyond vaccines; however, the majority also believed that vaccines were ineffective or perceived influenza as a relatively minor illness. Conclusion Implementing an influenza vaccination education program effectively enhances the knowledge and attitudes of secondary school female students in Al-Ahsa, Saudi Arabia. Nevertheless, further measures need to be taken to enhance the low vaccination uptake among the target population.

Knowledge, attitude, and practice of seasonal influenza and influenza vaccine immunization among people visiting primary healthcare centers in Riyadh, Saudi Arabia

Influenza infection continues to be a hazard to the Saudi population, resulting in high death rates and illness prevalence; it also places a substantial financial burden on the government. The government takes several strategies and approaches through the Ministry of Health has shown great success in curbing the disease. Vaccination is considered the most appropriate control measure; unfortunately, most Saudi residents, particularly in the city of Riyadh, do not consider vaccination a safe health practice. As a result, many have not participated in the influenza vaccine immunisation programme. Therefore, this study aimed to assess the knowledge, attitudes, and practices (KAPs) of seasonal influenza and influenza vaccine immunisation among clients visiting primary healthcare centers in Riyadh, Saudi Arabia. Furthermore, the study investigated the relationship between participants’ demographics and their KAPs regarding influenza vaccination. A cross-sectional, descriptive, correlational study was conducted among 611 individuals who visited four of Riyadh’s primary healthcare centers: Alsylimania, Alwady, Alyasmin, and Alsahafah. A self-reported questionnaire was used to assess the KAPs of participants, with questions regarding seasonal influenza and influenza vaccine immunisation. The scores of participants’ knowledge showed that the majority had good knowledge regarding seasonal flu (64.5%) and the flu vaccine (73.3%). Furthermore, only 52% of participants had a positive attitude score towards the seasonal influenza vaccination. Despite that, significant knowledge gaps and mistaken beliefs regarding certain aspects of influenza were noted in participants, resulting in negative attitudes and perceptions as well as a reduced likelihood of being vaccinated. In this study, 43.7% of participants (267 out of 611) had ever received a flu vaccine. Participants with a history of previous vaccination had a significantly higher level of knowledge and more positive attitudes, which resulted in increased vaccination coverage. Therefore, educational strategies to improve knowledge regarding influenza in Riyadh are recommended.

Management of community-acquired pneumonia in immunocompetent adults: updated Swedish guidelines 2017

Based on expert group work, Swedish recommendations for the management of community-acquired pneumonia in adults are here updated. The management of sepsis-induced hypotension is addressed in detail, including monitoring and parenteral therapy. The importance of respiratory support in cases of acute respiratory failure is emphasized. Treatment with high-flow oxygen and non-invasive ventilation is recommended. The use of statins or steroids in general therapy is not found to be fully supported by evidence. In the management of pleural infection, new data show favourable effects of tissue plasminogen activator and deoxyribonuclease installation. Detailed recommendations for the vaccination of risk groups are afforded.

Impact of patient characteristics and treatment procedures on hospitalization cost and length of stay in Japanese patients with influenza: A structural equation modelling approach

OBJECTIVES

Little is known about the economic burden of influenza-related hospitalizations in Japan. This study sought to identify the factors that contribute to the total healthcare costs (THCs) associated with hospitalizations due to influenza in the Japanese population.

STUDY DESIGN

A retrospective cross-sectional database analysis study.

METHODS

A structural equation modelling approach was used to analyse a nationwide Japanese hospital claims data. This study included inpatients with at least 1 confirmed diagnosis of influenza and with a hospital stay of at least 2 days, who were admitted between April 2014 and March 2015.

RESULTS

A total of 5261 Japanese inpatients with a diagnosis of influenza were included in the final analysis. The elderly (≥65 years) and the young (≤15 years) comprised more than 85% of patients. The average length of stay (LOS) was 12.5 days, and the mean THC was 5402 US dollars (US$) per hospitalization. One additional hospital day increased the THC by 314 US$. Intensive care unit hospitalizations were linked to higher costs (+4957 US$) compared to regular hospitalizations. The biggest procedure-related cost drivers, which were also impacted by LOS, were blood transfusions (+6477 US$), tube feedings (+3501 US$) and dialysis (+2992 US$).

CONCLUSIONS

In Japan, the economic burden due to influenza-related hospitalizations for both children and the elderly is considerable and is further impacted by associated comorbidities, diagnostic tests and procedures that prolong the LOS.

Incidence and Risk Factors of Pneumonia in Hospitalized Patients with Seasonal Influenza A or B

BACKGROUND

Most patients with influenza recover spontaneously or following treatment with an anti-viral agent, but some patients experience pneumonia requiring hospitalization. We conducted a retrospective review to determine the incidence and risk factors of pneumonia in hospitalized patients with influenza A or B.

METHODS

A total of 213 patients aged 18 years or older and hospitalized with influenza between January 2012 and January 2015 were included in this study. A reverse-transcriptase polymerase chain reaction assay was used to detect the influenza A or B virus in the patients' sputum samples. We collected demographic and laboratory data, combined coexisting diseases, and radiologic findings.

RESULTS

The incidence of pneumonia was higher in patients in the influenza A group compared to those in the influenza B group (68.6% vs. 56.9%), but this difference was not statistically significant. The presence of underlying respiratory disease was significantly associated with pneumonia in the influenza A group (adjusted odds ratio [OR], 3.975; 95% confidence interval [CI], 1.312-12.043; p=0.015). In the influenza B group, the white blood cell count (adjusted OR, 1.413; 95% CI, 1.053-1.896; p=0.021), platelet count (adjusted OR, 0.988; 95% CI, 0.978-0.999; p=0.027), and existence of an underlying medical disease (adjusted OR, 15.858; 95% CI, 1.757-143.088; p=0.014) were all significantly associated with pneumonia in multivariate analyses.

CONCLUSION

The incidence of pneumonia was 65.7% in hospitalized patients with influenza A or B. The risk factors of pneumonia differed in hospitalized patients with influenza A or B.

Oseltamivir for influenza infection in children: risks and benefits

Influenza is a common disease affecting many children each year. In a number of cases, particularly in children <2 years old and in those with severe chronic underlying disease, influenza can be complicated by lower respiratory tract infections, acute otitis media, rhinosinusitis, febrile seizures, dehydration or encephalopathy. Oseltamivir is the influenza virus drug that is most commonly studied in children for both the treatment and prevention of influenza. To avoid the risk that children with mild influenza or patients suffering from different viral infections receive oseltamivir, oseltamivir treatment should be recommended only in severe influenza cases, especially if confirmed by reliable laboratory tests. However, therapy must be initiated considering the risk of complications and the presence of severe clinical manifestations at age- and weight-appropriate doses. Because the vaccine remains the best option for preventing influenza and its complications, prophylaxis using oseltamivir should only be considered in select patients.

Pneumonia and influenza, and respiratory and circulatory hospital admissions in Belgium: a retrospective database study

Background

Influenza infections can lead to viral pneumonia, upper respiratory tract infection or facilitate co-infection by other pathogens. Influenza is associated with the exacerbation of chronic conditions like diabetes and cardiovascular disease and consequently, these result in acute hospitalizations. This study estimated the number, proportions and costs from a payer perspective of hospital admissions related to severe acute respiratory infections.

Methods

We analyzed retrospectively, a database of all acute inpatient stays from a non-random sample of eleven hospitals using the Belgian Minimal Hospital Summary Data. Codes from the International Classification of Diseases, Ninth Revision, Clinical Modification was used to identify and diagnose cases of pneumonia and influenza (PI), respiratory and circulatory (RC), and the related complications.

Results

During 2002–2007, we estimated relative hospital admission rates of 1.69% (20960/1237517) and 21.79% (269634/1237517) due to primary PI and RC, respectively. The highest numbers of hospital admissions with primary diagnosis as PI were reported for the elderly patient group (n = 10184) followed by for children below five years of age (n = 3451).

Of the total primary PI and RC hospital admissions, 56.14% (11768/20960) and 63.48% (171172/269634) of cases had at least one possible influenza-related complication with the highest incidence of complications reported for the elderly patient group. Overall mortality rate in patients with PI and RC were 9.25% (1938/20960) and 5.51% (14859/269634), respectively. Average lengths of hospital stay for PI was 11.6 ± 12.3 days whereas for RC it was 9.1 ± 12.7 days. Annual average costs were 20.2 and 274.6 million Euros for PI and RC hospitalizations. Average cost per hospitalization for PI and RC were 5779 and 6111 Euros (2007), respectively. These costs increased with the presence of complications (PI: 7159, RC: 7549 Euros).

Conclusion

The clinical and economic burden of primary influenza hospitalizations in Belgium is substantial. The elderly patient group together with children aged <18 years were attributed with the majority of all primary PI and RC hospitalizations.

Trial registration

Not applicable.

The value of neuraminidase inhibitors for the prevention and treatment of seasonal influenza: a systematic review of systematic reviews

Controversy has arisen regarding the effectiveness of neuraminidase inhibitors (NIs), especially against influenza-related complications. A literature search was performed to critically assess the evidence collected by the available systematic reviews (SRs) regarding the benefits and disadvantages of NIs (oseltamivir, zanamivir) compared to placebos in healthy and at-risk individuals of all ages for prophylaxis and treatment of seasonal influenza. A SR was done using the Cochrane Database of Systematic Reviews, Health Technology Assessment Database, Database of Abstracts of Reviews of Effects, and Medline (January 2006-July 2012). Two reviewers selected SRs based on randomized clinical trials, which were restricted to intention-to-treat results, and they assessed review (AMSTAR) and study quality indicators (GRADE). The SRs included (N = 9) were of high quality. The efficacy of NIs in prophylaxis ranged from 64% (16-85) to 92% (37-99); the absolute risk reduction ranged from 1.2% to 12.1% (GRADE moderate to low). Clinically relevant treatment benefits of NIs were small in healthy adults and children suffering from influenza-like illness (GRADE high to moderate). Oseltamivir reduced antibiotic usage in healthy adults according to one SR, but this was not confirmed by other reviews (GRADE low). Zanamivir showed a preventive effect on antibiotic usage in children (95% (77-99);GRADE moderate) and on the occurrence of bronchitis in at-risk individuals (59% (30-76);GRADE moderate). No evidence was available on the treatment benefits of NIs in elderly and at-risk groups and their effects on hospitalization and mortality. In oseltamivir trials, nausea, vomiting and diarrhea were significant side-effects. For zanamivir trials, no adverse effects have been reported. The combination of diagnostic uncertainty, the risk for virus strain resistance, possible side effects and financial cost outweigh the small benefits of oseltamivir or zanamivir for the prophylaxis and treatment of healthy individuals. No relevant benefits of these NIs on complications in at-risk individuals have been established.

Annual all-cause healthcare costs among influenza patients with and without influenza-related complications: analysis of a United States managed care database

BACKGROUND

Several studies have reported that patients with influenza have a high risk of developing complications such as secondary infections, exacerbation of cardiovascular conditions and asthma. However, limited data exists on the healthcare cost burden for influenza patients with and without influenza-related complications.

OBJECTIVE

We compared healthcare utilization and costs among influenza patients with related complications versus patients without complications.

METHODS

In this retrospective database analysis (LifeLink database: 1998-2009) of a US managed care database, we selected patients diagnosed with influenza during influenza seasons and categorized them as complicated or uncomplicated based on the presence or absence of a diagnosis for a related complication in the year following their influenza diagnosis. Multivariable regression analyses were conducted to compare all-cause utilization and costs (adjusted to 2009 US dollars) between the two groups.

RESULTS

We identified 54,469 patients of which ~65 % had evidence for at least one complication. Patients with complicated influenza had a 1.5-fold higher rate of inpatient utilization compared with uncomplicated cases (p < 0.001). Significantly higher covariate-adjusted predicted mean annual costs were also observed among complicated influenza patients across all care (p-values <0.001 for all comparisons).

CONCLUSION

Healthcare costs were twice as high among influenza patients with complications versus those without, with inpatient and outpatient services being the primary cost drivers. Now with the universal recommendation for seasonal influenza vaccination for all individuals ≥6 months of age, improvement in coverage rates may help reduce the healthcare utilization and costs associated with influenza and associated complications.

Early childhood infections and risk of schizophrenia

The association between early childhood infections and the risk of schizophrenia is not clear, and this study aimed to investigate the association between childhood infections and the risk of schizophrenia in a population-based Australia male cohort. A population-based cohort of males born between 1980 and 1984 in Western Australia was identified using birth registry records and followed-up until December 31st, 2009 or death using linked health data available through the Western Australian Data Linkage System. The associations between hospitalized infections occurring during 0-3yr of age and risk of schizophrenia were assessed with stratified analysis and multivariate logistic regression models. Analysis was further repeated to assess the effect of hospitalized intestinal infections (gastroenteritis) and respiratory infections. It was observed that male participants with two or more hospitalizations for infections before the age of three had an 80% higher risk of schizophrenia, and these findings remained when the analysis was limited to intestinal infections and acute respiratory infections. These findings support the hypothesis that infections during early childhood may lead to the onset of schizophrenia in later life.

Swedish guidelines on the management of community-acquired pneumonia in immunocompetent adults--Swedish Society of Infectious Diseases 2012

This document presents the 2012 evidence based guidelines of the Swedish Society of Infectious Diseases for the in- hospital management of adult immunocompetent patients with community-acquired pneumonia (CAP). The prognostic score 'CRB-65' is recommended for the initial assessment of all CAP patients, and should be regarded as an aid for decision-making concerning the level of care required, microbiological investigation, and antibiotic treatment. Due to the favourable antibiotic resistance situation in Sweden, an initial narrow-spectrum antibiotic treatment primarily directed at Streptococcus pneumoniae is recommended in most situations. The recommended treatment for patients with severe CAP (CRB-65 score 2) is penicillin G in most situations. In critically ill patients (CRB-65 score 3-4), combination therapy with cefotaxime/macrolide or penicillin G/fluoroquinolone is recommended. A thorough microbiological investigation should be undertaken in all patients, including blood cultures, respiratory tract sampling, and urine antigens, with the addition of extensive sampling for more uncommon respiratory pathogens in the case of severe disease. Recommended measures for the prevention of CAP include vaccination for influenza and pneumococci, as well as smoking cessation.

Delay in diagnosis of influenza virus in an elderly hospitalized patient: a fatal outcome

Influenza is a well established cause of seasonal hospitalizations and deaths among older persons. However, influenza is frequently underdiagnosed by physicians, because its clinical presentations are often complex, particularly in elderly patients. We report the case of a 78-year-old woman admitted to the emergency department in January 2008 with fever, vomiting, and a history of asthenia and falls in the preceding three days. Diagnosis of influenza at admission was missed. Influenza was diagnosed by direct fluorescent antibody in a sputum specimen four days later, but the evolution was rapidly unfavorable with fatal respiratory distress syndrome. This case illustrates that, during the influenza season, influenza should be suspected in elderly patients admitted to hospital even if they do not present with classical symptoms. Immunofluorescence testing on sputum specimens can provide a rapid diagnosis and merits further evaluation.

Prevalence and risk factors of chronic rhinosinusitis in Korea

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common inflammatory diseases with multiple etiologies. Despite its high prevalence, risk factors influencing its prevalence have not been thoroughly revealed. Therefore, we investigated the prevalence and risk factors of CRS in Korea.

METHODS

The 4098 subjects that participated in the Korea National Health and Nutrition Examination Survey were included in the study. Risk factors were categorized into sociodemographic and personal medical factors. Univariate and multivariate analyses were performed to identify significant risk factors of CRS. In addition, population attributable risks of the significant factors were calculated to estimate the effect on the population level.

RESULTS

The prevalence of CRS in Korea was 6.95%. Among sociodemographic factors, male sex, old age, and heavy stress were significantly related with CRS. Influenza vaccination, septal deviation, and persistent allergic rhinitis were significant personal medical risk factors of CRS. Among these risk factors, persistent/moderate to severe allergic rhinitis was proven to be the most significant risk factor for CRS at the population level.

CONCLUSION

Although the prevalence and risk factors vary according to time, place, and diagnostic criteria, periodic epidemiological study on CRS is necessary to reduce socioeconomic expenditure and establish an improved national health care policy.

Oseltamivir in seasonal, pandemic, and avian influenza: a comprehensive review of 10-years clinical experience

Oseltamivir (Tamiflu®; F. Hoffmann-La Roche Ltd, Basel, Switzerland) is an orally administered antiviral for the treatment and prevention of influenza A and B infections that is registered in more than 100 countries worldwide. More than 83 million patients have been exposed to the product since its introduction. Oseltamivir is recommended by the World Health Organization (WHO) for use in the clinical management of pandemic and seasonal influenza of varying severity, and as the primary antiviral agent for treatment of avian H5N1 influenza infection in humans. This article is a nonsystematic review of the experience gained from the first 10 years of using oseltamivir for influenza infections since its launch in early 2000, emphasizing recent advances in our understanding of the product and its clinical utility in five main areas. The article reviews the pharmacokinetics of oseltamivir and its active metabolite, oseltamivir carboxylate, including information on special populations such as children and elderly adults, and the co-administration of oseltamivir with other agents. This is followed by a summary of data on the effectiveness of oseltamivir treatment and prophylaxis in patients with all types of influenza, including pandemic (H1N1) 2009 and avian H5N1 influenza. The implications of changes in susceptibility of circulating influenza viruses to oseltamivir and other antiviral agents are also described, as is the emergence of antiviral resistance during and after the 2009 pandemic. The fourth main section deals with the safety profile of oseltamivir in standard and special patient populations, and reviews spontaneously reported adverse event data from the pandemic and pre-pandemic periods and the topical issue of neuropsychiatric adverse events. Finally, the article considers the pharmacoeconomics of oseltamivir in comparison with vaccination and usual care regimens, and as a component of pandemic influenza mitigation strategies.

Otolaryngological Complications in Patients Infected with the Influenza A (H1N1) Virus

Objective. To describe bacterial upper respiratory infections in patients with influenza A (H1N1) virus during the 2009 pandemic.

Study Design. Case series with chart review.

Setting. May 17 to July 17, 2009, Clinica Las Condes, Santiago, Chile.

Subjects and Methods. Patients with clinical and/or laboratory diagnosis of influenza A (H1N1) who presented to the emergency department or other medical specialists with bacterial upper respiratory infection requiring antibiotic treatment within 2 months of influenza diagnosis.

Results. A total of 10,048 cases of influenza A (H1N1) were identified by the emergency department. All patients received oseltamivir. Fifty-four patients (0.55%) who presented with bacterial upper respiratory infection within 2 months after the diagnosis of influenza were selected. The median time to presentation with bacterial respiratory infection was 12 days. Median age was 12 years, and 51.8% were male. The most common bacterial upper respiratory infections were acute rhinosinusitis (46.4%; median age, 17 years), acute otitis media (33.9%; median age, 5 years), and pharyngotonsillitis (14.3%; median age, 17 years). Four patients were hospitalized: 3 with streptococcal tonsillitis with prolonged fever and 1 with acute otitis media who later developed pansinusitis and otomastoiditis. There were no deaths in this group of patients.

Conclusion. There were few bacterial upper respiratory infections associated with influenza A (H1N1) (0.55%). The most common infections were acute otitis media in young children and acute rhinosinusitis and pharyngotonsillitis in young adults. These complications were more often seen during the 2 months following the influenza infection than at the time of diagnosis with influenza. Outcome was favorable for all patients.

Parasite-mediated upregulation of NK cell-derived gamma interferon protects against severe highly pathogenic H5N1 influenza virus infection

Outbreaks of influenza A viruses are associated with significant human morbidity worldwide. Given the increasing resistance to the available influenza drugs, new therapies for the treatment of influenza virus infection are needed. An alternative approach is to identify products that enhance a protective immune response. In these studies, we demonstrate that infecting mice with the Th1-inducing parasite Toxoplasma gondii prior to highly pathogenic avian H5N1 influenza virus infection led to decreased lung viral titers and enhanced survival. A noninfectious fraction of T. gondii soluble antigens (STAg) elicited an immune response similar to that elicited by live parasites, and administration of STAg 2 days after H5N1 influenza virus infection enhanced survival, lowered viral titers, and reduced clinical disease. STAg administration protected H5N1 virus-infected mice lacking lymphocytes, suggesting that while the adaptive immune response was not required for enhanced survival, it was necessary for STAg-mediated viral clearance. Mechanistically, we found that administration of STAg led to increased production of gamma interferon (IFN-γ) from natural killer (NK) cells, which were both necessary and sufficient for survival. Further, administration of exogenous IFN-γ alone enhanced survival from H5N1 influenza virus infection, although not to the same level as STAg treatment. These studies demonstrate that a noninfectious T. gondii extract enhances the protective immune response against severe H5N1 influenza virus infections even when a single dose is administered 2 days postinfection.

[Influenza : clinical symptoms, diagnostics and therapy]

Influenza infections have important socio-economic consequences. Risk groups identified so far include small children and elderly adults with comorbidities. In recent years in addition to seasonal influenza an outbreak of avian influenza occurred in 2005 and the new H1N1 pandemic occurred in 2009. For the latter other at risk groups were affected and a different clinical course has been documented. The focus of this article is to give an overview on the epidemiology, clinical characteristics, diagnosis and therapy of influenza infections.

Body mass index and the incidence of influenza-associated pneumonia in a UK primary care cohort

Please cite this paper as: Blumentals WA. et al. (2012) Body mass index and the incidence of influenza‐associated pneumonia in a UK primary care cohort. Influenza and Other Respiratory Viruses 6(1), 28–36.

Background  Accumulating data suggest an association between increased BMI/obesity and morbidity in patients with pandemic (H1N1) 2009 influenza. Information on metabolic status and prognosis in seasonal influenza is lacking, however.

Methods  A retrospective cohort study was carried out using the UK General Practice Research Database. Patients aged ≥18 with ≥1 recorded BMI in the 12–58 kg/m² range between January 1, 2000, and December 31, 2007, were observed for an influenza‐associated pneumonia diagnosis after the date of baseline BMI, including ‘influenza with pneumonia’ or a diagnosis of ‘pneumonia’ up to 30 days after a diagnosis of ‘influenza’.

Results  A total of 1 074 315 patients were included, of whom 73·2% were within the reference BMI range or overweight and 2·2% were underweight (<18·5 kg/m²). Pneumonia rates were 32·33–37·48/100 000 in all BMI categories except the underweight (98·29/100 000). Relative to patients with acceptable weight, those who were underweight had an increased pneumonia rate [adjusted IRR = 2·32 (95% CI 1·80–2·94)], while being overweight (BMI = 25·0–29·9 kg/m²) or obese (BMI ≥ 30·0 kg/m²) was associated with a decreased pneumonia rate [adjusted IRR = 0·77 (95% CI 0·68–0·86) and 0·85 (95% CI 0·73–1·00), respectively]. On the other hand, women and obese women with type 2 diabetes had increased pneumonia rates [adjusted IRR = 1·37 (95% CI 1·08–1·72) and 1·47 (95%CI 1·01–2·06), respectively].

Conclusions  In contrast to initial data from pandemic influenza, influenza pneumonia, and pneumonia following influenza were the most common in underweight persons, and an apparent decreased rate of pneumonia was noted with increasing BMI categories. Women with type 2 diabetes had increased rates of pneumonia.

Safety of oseltamivir in pregnancy: a review of preclinical and clinical data

Pregnant women with influenza are at increased risk of morbidity, particularly due to respiratory complications. A high excess mortality rate among pregnant women has been observed in previous influenza pandemics and healthcare agencies have provided recommendations on the use of oseltamivir to treat pregnant women who are infected with the pandemic (H1N1) 2009 virus. This article reviews pre-clinical and clinical data to assess the safety of oseltamivir administered during pregnancy, in the context of the effects of influenza on adverse pregnancy outcomes and fetal malformations. The effects of influenza during pregnancy, whether mediated directly by the virus or by fever or other events secondary to the underlying infection, are not yet well understood, but some data indicate an increased risk of birth defects in women infected with influenza during the first trimester. Animal and toxicology studies do not suggest that clinically effective dosages of oseltamivir have the potential to produce adverse effects on fetal development. Additionally, transplacental transfer of the drug and its active metabolite was very limited and not detectable at normal therapeutic doses in an ex vivo human placenta model. To investigate the safety of oseltamivir in pregnancy, the Roche oseltamivir safety database was searched for all exposures to oseltamivir during pregnancy in the 9 years up to 14 December 2008. In addition, a search of the literature was carried out. Of 232 maternal exposures to oseltamivir in the Roche database, pregnancy outcomes were known for 115 of these exposures. The incidence of adverse pregnancy outcomes was as follows: spontaneous abortions 6.1% (7/115), therapeutic abortions 11.3% (13/115) and pre-term deliveries 2.1% (2/94 live births), values that are not higher than background incidence rates. Fetal outcomes were known in 100 of the 232 exposures. For the nine cases of birth defect that were reported, the timing of oseltamivir exposure in relation to the sensitive period for inducing the birth defect was analysed. Two cases of ventricular septal defect, a more common birth defect, and one case of anophthalmos, an uncommon birth defect, were consistent with exposure to oseltamivir during the sensitive period for these birth defects. For other birth defects, there was either no exposure to oseltamivir during the sensitive period for the defect or insufficient information for assessment. These findings were consistent with other reports in the published literature, including a series of 79 Japanese women exposed to oseltamivir during the first trimester. Together with the other evidence reviewed herein, review of the company safety database suggests that oseltamivir is unlikely to cause adverse pregnancy or fetal outcomes, but available data are limited. Clinicians who use oseltamivir in pregnant women should consider the available safety information, the pathogenicity of the circulating influenza virus strain, the woman's general health and the guidance provided by health authorities. Roche will continue to monitor all reports of oseltamivir use during pregnancy.

Oseltamivir in seasonal, avian H5N1 and pandemic 2009 A/H1N1 influenza: pharmacokinetic and pharmacodynamic characteristics

Oseltamivir is the ester-type prodrug of the neuraminidase inhibitor oseltamivir carboxylate. It has been shown to be an effective treatment for both seasonal influenza and the recent pandemic 2009 A/H1N1 influenza, reducing both the duration and severity of the illness. It is also effective when used preventively. This review aims to describe the current knowledge of the pharmacokinetic and pharmacodynamic characteristics of this agent, and to address the issue of possible therapeutic drug monitoring. According to the currently available literature, the pharmacokinetics of oseltamivir carboxylate after oral administration of oseltamivir are characterized by mean ± SD bioavailability of 79 ± 12%, apparent clearance of 25.3 ± 7.0 L/h, an elimination half-life of 7.4 ± 2.5 hours and an apparent terminal volume of distribution of 267 ± 122 L. A maximum plasma concentration of 342 ± 83 μg/L, a time to reach the maximum plasma concentration of 4.2 ± 1.1 hours, a trough plasma concentration of 168 ± 32 μg/L and an area under the plasma concentration-time curve from 0 to 24 hours of 6110 ± 1330 μg · h/L for a 75 mg twice-daily regimen were derived from literature data. The apparent clearance is highly correlated with renal function, hence the dosage needs to be adjusted in proportion to the glomerular filtration rate. Interpatient variability is moderate (28% in apparent clearance and 46% in the apparent central volume of distribution); there is no indication of significant erratic or limited absorption in given patient subgroups. The in vitro pharmacodynamics of oseltamivir carboxylate reveal wide variation in the concentration producing 50% inhibition of influenza A and B strains (range 0.17-44 μg/L). A formal correlation between systemic exposure to oseltamivir carboxylate and clinical antiviral activity or tolerance in influenza patients has not yet been demonstrated; thus no formal therapeutic or toxic range can be proposed. The pharmacokinetic parameters of oseltamivir carboxylate after oseltamivir administration (bioavailability, apparent clearance and the volume of distribution) are fairly predictable in healthy subjects, with little interpatient variability outside the effect of renal function in all patients and bodyweight in children. Thus oseltamivir carboxylate exposure can probably be controlled with sufficient accuracy by thorough dosage adjustment according to patient characteristics. However, there is a lack of clinical study data on naturally infected patients. In addition, the therapeutic margin of oseltamivir carboxylate is poorly defined. The usefulness of systematic therapeutic drug monitoring in patients therefore appears to be questionable; however, studies are still needed to extend the knowledge to particular subgroups of patients or dosage regimens.

Nursing home-acquired pneumonia: a review of risk factors and therapeutic approaches

OBJECTIVE

To review the risk factors, etiologic profile, treatment approaches, and guidelines for the management of nursing home-acquired pneumonia (NHAP).

RESEARCH DESIGN AND METHODS

A search of the current literature was conducted using the MEDLINE and Embase databases. This search, limited to studies performed in humans and published in English between January 1, 1990 and October 31, 2009, included the terms 'acquired pneumonia', 'associated pneumonia', 'nursing home', 'long-term care', 'institution', and 'healthcare'.

RESULTS

Older age, male gender, swallowing difficulty, and inability to take oral medications are all significant risk factors for pneumonia. Medications such as antipsychotics and anticholinergics, histamine receptor blockers and proton pump inhibitors have also been linked to higher risk of pneumonia. The etiology of NHAP overlaps with that of community-acquired pneumonia (CAP), with Streptococcus pneumoniae and Haemophilus influenzae as predominant pathogens in long-term care facilities. In patients who require hospitalization, Chlamydophila pneumoniae, Staphylococcus aureus, and influenza virus have also been identified. In contrast, the etiology of severe NHAP overlaps with that of hospital-acquired pneumonia (HAP), with S. aureus, including methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, and enteric Gram-negative bacilli as important causative pathogens. Therapy is dependent on disease severity and, on the treatment setting. Respiratory fluoroquinolones or β-lactams plus a macrolide are recommended in patients with NHAP. Patients hospitalized with severe NHAP may require triple combination therapy that covers both MRSA and P. aeruginosa. However, there is little evidence of the clinical superiority of one regimen over another, making it challenging to establish guidelines for the treatment of NHAP in the nursing home setting.

CONCLUSION

There is a pressing need for clinical trials of antibiotic therapy in nursing home patients that would help establish uniform guidelines to standardize therapy in the nursing home setting.

Platelet-activating factor receptor plays a role in lung injury and death caused by Influenza A in mice

Influenza A virus causes annual epidemics which affect millions of people worldwide. A recent Influenza pandemic brought new awareness over the health impact of the disease. It is thought that a severe inflammatory response against the virus contributes to disease severity and death. Therefore, modulating the effects of inflammatory mediators may represent a new therapy against Influenza infection. Platelet activating factor (PAF) receptor (PAFR) deficient mice were used to evaluate the role of the gene in a model of experimental infection with Influenza A/WSN/33 H1N1 or a reassortant Influenza A H3N1 subtype. The following parameters were evaluated: lethality, cell recruitment to the airways, lung pathology, viral titers and cytokine levels in lungs. The PAFR antagonist PCA4248 was also used after the onset of flu symptoms. Absence or antagonism of PAFR caused significant protection against flu-associated lethality and lung injury. Protection was correlated with decreased neutrophil recruitment, lung edema, vascular permeability and injury. There was no increase of viral load and greater recruitment of NK1.1⁺ cells. Antibody responses were similar in WT and PAFR-deficient mice and animals were protected from re-infection. Influenza infection induces the enzyme that synthesizes PAF, lyso-PAF acetyltransferase, an effect linked to activation of TLR7/8. Therefore, it is suggested that PAFR is a disease-associated gene and plays an important role in driving neutrophil influx and lung damage after infection of mice with two subtypes of Influenza A. Further studies should investigate whether targeting PAFR may be useful to reduce lung pathology associated with Influenza A virus infection in humans.

Influenza virus causes disease that affects people from different age, gender or social conditions. The illness spreads easily and affects millions of people every year. Vaccines are effective preventive approaches, but the high degree of viral antigenic drift requires annual formulation. Anti-viral drugs are used as therapy, but are only effective at the very early stages of disease. The main symptoms that lead to hospitalizations and deaths are associated with the severe inflammatory host immune response triggered by the virus infection. Our approach was to decrease the inflammatory events associated with the viral infection by targeting a molecule, Platelet Activating Factor receptor (PAFR), known to induce several inflammatory events, including leukocyte recruitment and leakage. We found that PAFR deficient mice or wild type mice treated with a PAFR antagonist had less pulmonary inflammation, pulmonary injury and lethality rates when infected by two subtypes of Influenza A virus. In contrast, the immune response against the virus, as assessed by viral loads and specific antibodies, were not decreased. Our findings concur with the idea that severe inflammation plays an important role in flu morbidity and mortality and show that PAFR is a major driver of the exacerbated inflammation in mice infected with Influenza A virus.

Decision making with regard to antiviral intervention during an influenza pandemic

BACKGROUND

Antiviral coverage is defined by the proportion of the population that takes antiviral prophylaxis or treatment. High coverage of an antiviral drug has epidemiological and evolutionary repercussions. Antivirals select for drug resistance within the population, and individuals may experience adverse effects. To determine optimal antiviral coverage in the context of an influenza outbreak, we compared 2 perspectives: 1) the individual level (the Nash perspective), and 2) the population level (utilitarian perspective).

METHODS

We developed an epidemiological game-theoretic model of an influenza pandemic. The data sources were published literature and a national survey. The target population was the US population. The time horizon was 6 months. The perspective was individuals and the population overall. The interventions were antiviral prophylaxis and treatment. The outcome measures were the optimal coverage of antivirals in an influenza pandemic.

RESULTS

At current antiviral pricing, the optimal Nash strategy is 0% coverage for prophylaxis and 30% coverage for treatment, whereas the optimal utilitarian strategy is 19% coverage for prophylaxis and 100% coverage for treatment. Subsidizing prophylaxis by $440 and treatment by $85 would bring the Nash and utilitarian strategies into alignment. For both prophylaxis and treatment, the optimal antiviral coverage decreases as pricing of antivirals increases. Our study does not incorporate the possibility of an effective vaccine and lacks probabilistic sensitivity analysis. Our survey also does not completely represent the US population. Because our model assumes a homogeneous population and homogeneous antiviral pricing, it does not incorporate heterogeneity of preference.

CONCLUSIONS

The optimal antiviral coverage from the population perspective and individual perspectives differs widely for both prophylaxis and treatment strategies. Optimal population and individual strategies for prophylaxis and treatment might be aligned through subsidization.

A cross-sectional survey to evaluate knowledge, attitudes and practices (KAP) regarding seasonal influenza vaccination among European travellers to resource-limited destinations

BACKGROUND

Influenza is one of the most common vaccine-preventable diseases in travellers. By performing two cross-sectional questionnaire surveys during winter 2009 and winter 2010 among European travellers to resource-limited destinations, we aimed to investigate knowledge, attitudes and practices (KAP) regarding seasonal influenza vaccination.

METHODS

Questionnaires were distributed in the waiting room to the visitors of the University of Zurich Centre for Travel' Health (CTH) in January and February 2009 and January 2010 prior to travel health counselling (CTH09 and CTH10). Questions included demographic data, travel-related characteristics and KAP regarding influenza vaccination. Data were analysed by using SPSS version 14.0 for Windows. Differences in proportions were compared using the Chi-square test and the significance level was set at p <or = 0.05. Predictors for seasonal and pandemic influenza vaccination were determined by multiple logistic regression analyses.

RESULTS

With a response rate of 96.6%, 906 individuals were enrolled and 868 (92.5%) provided complete data. Seasonal influenza vaccination coverage was 13.7% (n = 119). Only 43 (14.2%) participants were vaccinated against pandemic influenza A/H1N1, mostly having received both vaccines simultaneously, the seasonal and pandemic one. Job-related purposes (44, 37%), age > 64 yrs (25, 21%) and recommendations of the family physician (27, 22.7%) were the most often reported reasons for being vaccinated. In the multiple logistic regression analyses of the pooled data increasing age (OR = 1.03, 95% CI 1.01 - 1.04), a business trip (OR = 0.39, 95% CI 0.17 - 0.92) and seasonal influenza vaccination in the previous winter seasons (OR = 12.91, 95% CI 8.09 - 20.58) were independent predictors for seasonal influenza vaccination in 2009 or 2010.Influenza vaccination recommended by the family doctor (327, 37.7%), travel to regions with known high risk of influenza (305, 35.1%), and influenza vaccination required for job purposes (233, 26.8%) were most frequently mentioned to consider influenza vaccination.

CONCLUSIONS

Risk perception and vaccination coverage concerning seasonal and pandemic influenza was very poor among travellers to resource-limited destinations when compared to traditional at-risk groups. Previous access to influenza vaccination substantially facilitated vaccinations in the subsequent year. Information strategies about influenza should be intensified and include health professionals, e.g. family physicians, travel medicine practitioners and business enterprises.

Bench-to-bedside review: bacterial pneumonia with influenza - pathogenesis and clinical implications

Seasonal and pandemic influenza are frequently complicated by bacterial infections, causing additional hospitalization and mortality. Secondary bacterial respiratory infection can be subdivided into combined viral/bacterial pneumonia and post-influenza pneumonia, which differ in their pathogenesis. During combined viral/bacterial infection, the virus, the bacterium and the host interact with each other. Post-influenza pneumonia may, at least in part, be due to resolution of inflammation caused by the primary viral infection. These mechanisms restore tissue homeostasis but greatly impair the host response against unrelated bacterial pathogens. In this review we summarize the underlying mechanisms leading to combined viral/bacterial infection or post-influenza pneumonia and highlight important considerations for effective treatment of bacterial pneumonia during and shortly after influenza.

Oseltamivir in seasonal influenza: cumulative experience in low- and high-risk patients

Seasonal influenza viruses cause annual disease epidemics that affect individuals at low and high risk for secondary illnesses. Influenza vaccines are widely used in high-risk patients to prevent infection, but the protection afforded varies by population; uptake is also limited in some groups. Antiviral drugs for influenza are now readily available. Oseltamivir is the most widely used antiviral for the treatment and prophylaxis of seasonal influenza, and its efficacy and safety are now well established in a variety of populations. In addition to decreasing the severity and duration of the symptoms of influenza, clinical and epidemiological studies demonstrate that oseltamivir significantly reduces the frequency of secondary illnesses and exacerbation of underlying conditions; survival is also significantly improved in seriously ill patients who are hospitalized with severe influenza. Resistant viruses are isolated with a low frequency during oseltamivir treatment (0.33% in adults and 4.0% in children among almost 2000 oseltamivir-treated patients enrolled onto Roche-sponsored clinical trials of oseltamivir treatment during the oseltamivir development programme). However, an oseltamivir-resistant influenza A (H1N1) virus emerged in Europe during the 2007-08 season and circulated in the southern and northern hemispheres in 2008-09. No link with oseltamivir usage could be detected, and the clinical impact of these viruses was limited. Oseltamivir-susceptible pandemic (H1N1) 2009 viruses now predominate in many countries. Oseltamivir is generally well tolerated, with a similar adverse event profile to placebo.

Lymphocyte to monocyte ratio as a screening tool for influenza

In fall 2009 the emergency department of a clinic in Greece with increased patient visits due to influenza-like illness observed a particular pattern in the complete blood count (CBC) of these patients. In 90% of all patients with probable influenza, lymphopenia and/or monocytosis were present. Relative lymphopenia with or without monocytosis appears to be a laboratory marker for H1N1 virus infection, a finding that could play a major role in early identifying and treating patients with new influenza A. A ratio of lymphocytes to monocytes below 2 is proposed as a screening tool for influenza infection instead of rapid tests.

The novel influenza A (H1N1) virus pandemic: An update

In the 4 months since it was first recognized, the pandemic strain of a novel influenza A (H1N1) virus has spread to all continents and, after documentation of human-to-human transmission of the virus in at least three countries in two separate World Health Organization (WHO) regions, the pandemic alert was raised to level 6. The agent responsible for this pandemic, a swine-origin influenza A (H1N1) virus (S-OIV), is characterized by a unique combination of gene segments that has not previously been identified among human or swine influenza A viruses. As of 31th July 2009, 168 countries and overseas territories/communities have each reported at least one laboratory-confirmed case of pandemic H1N1 infection. There have been a total of 162,380 reported cases and 1154 associated deaths. Influenza epidemics usually take off in autumn, and it is important to prepare for an earlier start this season. Estimates from Europe indicate that 230 millions Europe inhabitants will have clinical signs and symptoms of S-OIV this autumn, and 7- 35% of the clinical cases will have a fatal outcome, which means that there will be 160,000- 750,000 H1N1-related deaths. A vaccine against H1N1 is expected to be the most effective tool for controlling influenza A (H1N1) infection in terms of reducing morbidity and mortality and limiting diffusion. However, there are several issues with regard to vaccine manufacture and approval, as well as production capacity, that remain unsettled. We searched the literature indexed in PubMed as well as the websites of major international health agencies to obtain the material presented in this update on the current S-OIV pandemic.