Adjunctive therapies and immunomodulatory agents in the management of severe influenza

Analysis of risk factors of fungal superinfections in viral pneumonia patients: A systematic review and meta-analysis

BACKGROUND

Infections with fungi, such as Aspergillus species, have been found as common complications of viral pneumonia. This study aims to determine the risk factors of fungal superinfections in viral pneumonia patients using meta-analysis.

OBJECTIVE

This study aims to determine the risk factors of fungal infection s in viral pneumonia patients using meta-analysis.

METHODS

We reviewed primary literature about fungal infection in viral pneumonia patients published between January 1, 2010 and September 30, 2020, in the Chinese Biomedical Literature, Chinese National Knowledge Infrastructure, Wanfang (China), Cochrane Central Library, Embase, PubMed, and Web of Science databases. These studies were subjected to an array of statistical analyses, including risk of bias and sensitivity analyses.

RESULTS

In this study, we found a statistically significant difference in the incidence of fungal infections in viral pneumonia patients that received corticosteroid treatment as compared to those without corticosteroid treatment (p < .00001). Additionally, regarding the severity of fungal infections, we observed significant higher incidence of invasive pulmonary aspergillosis (IPA) in patients with high Acute Physiology and Chronic Health Evaluation (APACHE) II scores (p < .001), tumors (p = .005), or immunocompromised patients (p < .0001).

CONCLUSIONS

Our research shows that corticosteroid treatment was an important risk factor for the development of fungal infection in patients with viral pneumonia. High APACHE II scores, tumors, and immunocompromised condition are also important risk factors of developing IPA. The diagnosis of fungal infection in viral pneumonia patients can be facilitated by early serum galactomannan (GM) testing, bronchoalveolar lavage fluid Aspergillus antigen testing, culture, and biopsy.

The active GLP-1 analogue liraglutide alleviates H9N2 influenza virus-induced acute lung injury in mice

Influenza virus is responsible for significant morbidity and mortality worldwide. Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is the major cause of death in influenza virus infected patients. Recent studies indicated that active glucagon like peptide-1 (GLP-1) encoded by glucagon (GCG) gene exerts anti-inflammatory functions. The aim of this study was to determine the potential role of active GLP-1 in H9N2 influenza virus-induced ALI/ARDS in mice. First, we uncovered that GCG mRNA expression levels and GCG precursor protein levels were significantly increased, but total GLP-1 and active GLP-1 levels were decreased in the lungs of H9N2-infected mice. Next, liraglutide, an active GLP-1 analogue, was used to treat infected mice and to observe its effects on H9N2 virus-induced ALI. Liraglutide treatment ameliorated the declined body weight, decreased food intake and mortality observed in infected mice. It also alleviated the severity of lung injury, including lowering lung index, decreasing inflammatory cell infiltration and lowing total protein levels in bronchoalveolar lavage fluid (BALF). In addition, liraglutide did not influence viral titers in infected lungs, but decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-α in BALF. These results indicated that liraglutide alleviated H9N2 virus-induced ALI in mice most likely due to lower levels of pro-inflammatory cytokines.

Case Report: Adrenal Pathology Findings in Severe COVID-19: An Autopsy Study

Although high mortality has been reported in many COVID-19 studies, very limited postmortem information from complete autopsies is available. We report the findings in the adrenal glands in 28 autopsies with confirmed SARS-CoV-2 infection. Microscopic lesions were identified in the adrenal glands in 12/28 patients (46%). Seven cases showed necrosis, generally ischemic; four showed cortical lipid degeneration; two showed hemorrhage; and one unspecific focal adrenalitis. Vascular thrombosis in one patient and focal inflammation in association with other findings in three patients were observed. No case presented adrenal insufficiency. In conclusion, adrenal lesions are frequent in patients with severe COVID-19. The lesions are mild but could contribute to the lethal outcome.

Efficacy of clarithromycin-naproxen-oseltamivir combination therapy versus oseltamivir alone in hospitalized pediatric influenza patients

PURPOSE

This study aimed to compare the safety and efficacy of clarithromycin-naproxen-oseltamivir combination therapy to that of oseltamivir therapy alone in hospitalized pediatric influenza patients.

METHODS

This prospective, single-blind study included children aged 1-18 years hospitalized with influenza, in MacKay Children's Hospital, Taiwan, between December 2017 and December 2019. The primary outcomes were the time to defervescence and decrease of the Pediatric Respiratory Severity Score (PRESS) during hospitalization. The secondary outcomes were serial changes in virus titers, measured using real-time polymerase chain reaction.

RESULTS

Fifty-four patients were enrolled (28 in the control group and 26 in the combination group) in total. There were no differences in the patients' baseline characteristics between the groups. The time to defervescence was significantly shorter in the combination group than the oseltamivir group (13.2 h vs. 32.1 h, p = 0.002). The decrease in the virus titer from days 1-3 (log Δ13) was more pronounced in the combination group than the oseltamivir group. (39% vs. 19%, p = 0.001). There were no differences in adverse effects such as vomiting, diarrhea, and abdominal pain during the study or within 30 days after antiviral therapy.

CONCLUSION

The clarithromycin-naproxen-oseltamivir combination group experienced a more rapid defervescence and a more rapid decline of influenza virus titer than the group treated with oseltamivir alone. Further consideration should be given to whether the overall benefits of combination therapy in hospitalized pediatric influenza patients outweigh the risks.

Successful treatment of a centenarian with coronavirus disease 2019 (COVID-19) using convalescent plasma

Background

Because treatment options for coronavirus disease 2019 (COVID-19) are very limited, the use of convalescent plasma has bee explored.

Case presentation and treatment

A male centenarian with cough and dyspnea for 2 months was diagnosed with COVID-19. Without effective treatments and with the increased risks of antiviral therapy for the elderly, this patient was given convalescent plasma. The viral load, complete blood count, inflammatory indicators, vital signs, and clinical symptoms were observed before and after COVID-19 convalescent plasma transfusion.

Results

After convalescent plasma transfusion, significant improvement was observed on laboratory indicators and clinical symptoms of the patient. Concurrently, SARS-CoV-2 viral load decreased sharply after the first transfusion (from 2.55 × 104 to 1.39 × 103 copies/mL) and became undetectable after the second transfusion.

Conclusions

With the substantial increase of COVID-19 in recent months,treatment for elderly patients has become restricted in some countries. The successful treatment of this 100-year-old patient using convalescent plasma suggests that we should consider adding convalescent plasma in th management of the elderly.

Assessment of efficacy of Oseltamivir-Azithromycin combination therapy in prevention of Influenza-A (H1N1)pdm09 infection complications and rapidity of symptoms relief

Objectives: This study aimed to assess the efficacy of oseltamivir-Azithromycin combination therapy for prevention of Influenza-A (H1N1)pdm09 infection associated complications and early relief of influenza symptoms.Methods: In a retrospective observational cohort study, Influenza-A (H1N1)pdm09 infection hospitalized patients were identified and divided into two groups based on the initial therapy. Group-AV patients were initiated on Oseltamivir without any antibiotic in treatment regimen while Group-AV+AZ patients were initiated on Oseltamivir and Azithromycin combination therapy for at least 3-5 days. Patients were evaluated for different clinical outcomes.Results: A total of 227 and 102 patients were identified for Group-AV and Group-AV+AZ respectively. Multivariate regression analysis showed that incidences of secondary bacterial infections were significantly less frequent (23.4% vs 10.4%; P-value = 0.019) in Group-AV+AZ patients. Group-AV+AZ patients were associated with shorter length of hospitalization (6.58 vs 5.09 days; P-value = <0.0001) and less frequent incidences of respiratory support (38.3% vs 17.6%; P-value = 0.016). Overall influenza symptom severity score was statistically significant less for Group-AV+AZ patients on Day-5 (10.68 ± 2.09; P-value = 0.001) of hospitalization.Conclusion: Oseltamivir-Azithromycin combination therapy was found to be more efficacious as compared to oseltamivir alone in rapid recovery and prevention of Influenza associated complications especially in high risk patients.

Recommended hospital preparations for future cases and outbreaks of novel influenza viruses

Introduction: Seasonal influenza epidemics and periodic pandemics are important causes of morbidity and mortality. Influenza transmits predominantly by respiratory droplets and fomites but opportunistic airborne transmission may occur in the hospital setting due to overcrowding, poor compliance with infection control measures, and performance of aerosol-generating procedures.Areas covered: This article reviews the risk factors of nosocomial influenza outbreaks and discusses clinical, diagnostic, and treatment aspects of seasonal and avian influenza to facilitate hospital preparations for future influenza outbreaks. Literature search was conducted through PubMed of relevant peer-reviewed full papers in English journals with inclusion of relevant publications by the WHO and US CDC.Expert opinion: Accurate and rapid identification of an influenza outbreak is important to facilitate patient care and prevent nosocomial transmission. Timely treatment with a neuraminidase inhibitor (NAI) for adults hospitalized with severe influenza is associated with lower mortality and better clinical outcomes. Baloxavir, a polymerase endonuclease inhibitor, offers a new treatment alternative and its role in combination with NAI for treatment of severe influenza is being investigated. High-dose systemic corticosteroids are associated with worse outcomes in patients with severe influenza. It is important to develop more effective antiviral and immuno-modulating therapies for the treatment of influenza infections.

Delayed oseltamivir plus sirolimus treatment attenuates H1N1 virus-induced severe lung injury correlated with repressed NLRP3 inflammasome activation and inflammatory cell infiltration

Severe influenza A virus infection causes high mortality and morbidity worldwide due to delayed antiviral treatment and inducing overwhelming immune responses, which contribute to immunopathological lung injury. Sirolimus, an inhibitor of mammalian target of rapamycin (mTOR), was effective in improving clinical outcomes in patients with severe H1N1 infection; however, the mechanisms by which it attenuates acute lung injury have not been elucidated. Here, delayed oseltamivir treatment was used to mimic clinical settings on lethal influenza A (H1N1) pdm09 virus (pH1N1) infection mice model. We revealed that delayed oseltamivir plus sirolimus treatment protects mice against lethal pH1N1 infection by attenuating severe lung damage. Mechanistically, the combined treatment reduced viral titer and pH1N1-induced mTOR activation. Subsequently, it suppressed the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated secretion of interleukin (IL)-1β and IL-18. It was noted that decreased NLRP3 inflammasome activation was associated with inhibited nuclear factor (NF)-κB activation, reduced reactive oxygen species production and increased autophagy. Additionally, the combined treatment reduced the expression of other proinflammatory cytokines and chemokines, and decreased inflammatory cell infiltration in lung tissue and bronchioalveolar lavage fluid. Consistently, it inhibited the mTOR-NF-κB-NLRP3 inflammasome-IL-1β axis in a lung epithelial cell line. These results demonstrated that combined treatment with sirolimus and oseltamivir attenuates pH1N1-induced severe lung injury, which is correlated with suppressed mTOR-NLRP3-IL-1β axis and reduced viral titer. Therefore, treatment with sirolimus as an adjuvant along with oseltamivir may be a promising immunomodulatory strategy for managing severe influenza.

The severity and lethality of influenza A virus infection are frequently aggravated by virus-induced tissue destruction and overwhelming immune responses. Combined therapy with antiviral medications and immunomodulators, which not only inhibit viral replication, but also reduce the damaging consequences of host immune responses, will be beneficial in the treatment of severe influenza. In the present study, we revealed that pH1N1-induced activation of mTOR promotes lung immunopathological injury, which is correlated with upregulated NF-κB activity and increased reactive oxygen species production. Subsequently, it induces NLRP3 inflammasome activation and the secretion of IL-1β and IL-18. Combined treatment with oseltamivir and the mTOR inhibitor sirolimus (as an adjuvant) not only blocks viral replication, but also suppresses mTOR-NLRP3-IL-1β axis-mediated immune damage, thus protecting mice against lethal pH1N1 infection. Our findings provide the theoretical and experimental basis for the clinical investigation of sirolimus as an adjunct treatment for severe influenza.

Safety and efficacy of N-acetyl-cysteine for prophylaxis of ventilator-associated pneumonia: a randomized, double blind, placebo-controlled clinical trial

Ventilator-associated-pneumonia (VAP) is characterized by morbidity, mortality, and prolonged length of stay in intensive care unit (ICU). The present study aimed to examine the effect of N-acetyl-cysteine (NAC) in preventing VAP in patients hospitalized in ICU. We performed a prospective, randomized, double-blind, placebo-controlled trial of 60 mechanically ventilated patients at high risk of developing VAP. NAC (600 mg/twice daily) and placebo (twice daily) were administered to NAC group (n = 30) and control group (n = 30), respectively, through the nasogastric tube in addition to routine care. The clinical response was considered as primary (incidence of VAP) and secondary outcomes. Twenty-two (36.6%) patients developed VAP. Patients treated with NAC were significantly less likely to develop clinically confirmed VAP compared with patients treated with placebo (26.6% vs. 46.6%; P = 0.032). Patients treated with NAC had significantly less ICU length of stay (14.36 ± 4.69 days vs. 17.81 ± 6.37 days, P = 0.028) and less hospital stay (19.23 ± 5.54 days vs. 24.61 ± 6.81 days; P = 0.03) than patients treated with placebo. Time to VAP was significantly longer in the NAC group (9.42 ± 1.9 days vs. 6.46 ± 2.53 days; P = 0.002). The incidence of complete recovery was significantly higher in the NAC group (56.6% vs. 30%; P = 0.006). No adverse events related to NAC were identified. NAC is safe and effective to prevent and delay VAP, and improve its complete recovery rate in a selected, high-risk ICU population.

The role of adjuvant immunomodulatory agents for treatment of severe influenza

A severe inflammatory immune response with hypercytokinemia occurs in patients hospitalized with severe influenza, such as avian influenza A(H5N1), A(H7N9), and seasonal A(H1N1)pdm09 virus infections. The role of immunomodulatory therapy is unclear as there have been limited published data based on randomized controlled trials (RCTs). Passive immunotherapy such as convalescent plasma and hyperimmune globulin have some studies demonstrating benefit when administered as an adjunctive therapy for severe influenza. Triple combination of oseltamivir, clarithromycin, and naproxen for severe influenza has one study supporting its use, and confirmatory studies would be of great interest. Likewise, confirmatory studies of sirolimus without concomitant corticosteroid therapy should be explored as a research priority. Other agents with potential immunomodulating effects, including non-immune intravenous immunoglobulin, N-acetylcysteine, acute use of statins, macrolides, pamidronate, nitazoxanide, chloroquine, antiC5a antibody, interferons, human mesenchymal stromal cells, mycophenolic acid, peroxisome proliferator-activated receptors agonists, non-steroidal anti-inflammatory agents, mesalazine, herbal medicine, and the role of plasmapheresis and hemoperfusion as rescue therapy have supportive preclinical or observational clinical data, and deserve more investigation preferably by RCTs. Systemic corticosteroids administered in high dose may increase the risk of mortality and morbidity in patients with severe influenza and should not be used, while the clinical utility of low dose systemic corticosteroids requires further investigation.

A clinical approach to the threat of emerging influenza viruses in the Asia-Pacific region

Seasonal influenza epidemics and periodic pandemics are important causes of morbidity and mortality. Patients with chronic co‐morbid illness, those at the extremes of age and pregnant women are at higher risks of complications requiring hospitalization, whereas young adults and obese individuals were also at increased risk during the A(H1N1) pandemic in 2009. Avian influenza A(H5N1) and A(H7N9) viruses have continued to circulate widely in some poultry populations and infect humans sporadically since 1997 and 2013, respectively. The recent upsurge in human cases of A(H7N9) infections in Mainland China is of great concern. Sporadic human cases of avian A(H5N6), A(H10N8) and A(H6N1) have also emerged in recent years while there are also widespread poultry outbreaks due to A(H5N8) in many countries. Observational studies have shown that treatment with a neuraminidase inhibitor (NAI) for adults hospitalized with severe influenza is associated with lower mortality and better clinical outcomes, especially when administered early in the course of illness. Whether higher than standard doses of NAI would provide greater antiviral effects in such patients will require further investigation. High‐dose systemic corticosteroids were associated with worse outcomes in patients with severe influenza. There is an urgent need for developing more effective antiviral therapies for treatment of influenza infections.

Anti-inflammatory effects of adjunctive macrolide treatment in adults hospitalized with influenza: A randomized controlled trial

INTRODUCTION

- Macrolides can ameliorate inflammation in respiratory diseases, providing clinical benefits. Data in influenza is lacking.

METHOD

- A randomized, open-label, multicenter trial among adults hospitalized for laboratory-confirmed influenza was conducted. Study treatments of oseltamivir and azithromycin (500 mg/day), or oseltamivir alone, both for 5 days, were allocated at 1:1 ratio. The primary outcome was plasma cytokine/chemokine concentration change over time (Day 0-10); secondary outcomes were viral load and symptom score changes. Generalized Estimating Equation (GEE) models were used to analyze longitudinal data.

RESULTS

- Fifty patients were randomized to the oseltamivir-azithromycin or oseltamivir groups, with comparable baseline characteristics (age, 57 ± 18 years; A/H3N2, 70%), complications (72%), and viral load. Pro-inflammatory cytokines IL-6 (GEE: β -0.037, 95%CI-0.067,-0.007, P = 0.016; reduction from baseline -83.4% vs -59.5%), CXCL8/IL-8 (β -0.018, 95%CI-0.037,0.000, P = 0.056; -80.5% vs -58.0%), IL-17 (β -0.064, 95%CI-0.117,-0.012, P = 0.015; -74.0% vs -34.3%), CXCL9/MIG (β -0.010, 95%CI-0.020,0.000, P = 0.043; -71.3% vs -56.0%), sTNFR-1, IL-18, and CRP declined faster in the oseltamivir-azithromycin group. There was a trend toward faster symptom resolution (β -0.463, 95%CI-1.297,0.371). Viral RNA decline (P = 0.777) and culture-negativity rates were unaffected. Additional ex vivo studies confirmed reduced induction of IL-6 (P = 0.017) and CXCL8/IL-8 (P = 0.005) with azithromycin.

CONCLUSION

- We found significant anti-inflammatory effects with adjunctive macrolide treatment in adults with severe influenza infections. Virus control was unimpaired. Clinical benefits of a macrolide-containing regimen deserve further study. [ClinicalTrials.gov NCT01779570].

Epidemic and Emerging Coronaviruses (Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome)

Bats are the natural reservoirs of severe acute respiratory syndrome (SARS)-like coronaviruses (CoVs) and likely the reservoir of Middle East respiratory syndrome (MERS)-CoV. The clinical features of SARS-CoV infection and MERS-CoV infection are similar but MERS-CoV infection progresses to respiratory failure more rapidly. Although the estimated pandemic potential of MERS-CoV is lower than that of SARS-CoV, the case fatality rate of MERS is higher. The transmission route and the possibility of other intermediary animal sources remain uncertain among many sporadic primary cases. Clinical trial options for MERS-CoV infection include monotherapy and combination therapy.

Pandemic Influenza A H1N1 in Oman: Epidemiology, Clinical Features, and Outcome of Patients Admitted to Sultan Qaboos University Hospital in 2009

OBJECTIVES

Oman experienced the H1N1 pandemic in 2009 that initially started in Mexico and the United States. We present the epidemiology, clinical features, and outcome of cases admitted to Sultan Qaboos University Hospital.

METHODS

We retrospectively reviewed all patients admitted with confirmed influenza A H1N1 infection from August to December 2009. The study included adults and pediatric patients. We looked at the clinical and laboratory factors associated with increased length of hospital stay.

RESULTS

There were 68 patients admitted with influenza A H1N1 infection, and their median age was 23 years. The most common symptoms were fever (100%) and cough (79.4%). The most common reason for admission was the severity of illness (69.1%). Lymphopenia was the most common hematological abnormality (41.8%). All patients received treatment with oseltamivir. One patient died secondary to multi-organ failure. On multivariate analysis, severity of illness, use of steroids, anemia, lymphopenia, and abnormal alanine amino transferase levels were associated with increased length of stay.

CONCLUSIONS

The H1N1 pandemic in Oman followed the international trends in terms of clinical presentation and laboratory values for patients admitted to the hospital.

Prevalence of neutralizing antibodies to common respiratory viruses in intravenous immunoglobulin and in healthy donors in southern China

BACKGROUND

Acute respiratory infections (ARIs) are a leading cause of death among children under the age of 5. However, there are no effective drugs for most of these severe viral infections. Passive immunotherapy with convalescent plasma or hyperimmune intravenous immunoglobulin (H-IVIG) is a potential therapeutic option for serious viral infections. It is important to find a suitable source of convalescent plasma and of H-IVIG containing high titer neutralizing antibodies (NAbs).

METHODS

Sera from 96 healthy adult donors in southern China and commercially available IVIG were analyzed for the titers of NAb to several most common respiratory viruses including respiratory syncytial virus (RSV), seasonal influenza A (InfA), enterovirus 71 (EV71), coxsackievirus A16 (CA16), adenovirus type 3 (Ad3) and a recent epidemic adenovirus type 55 (Ad55) by microneutralization test.

RESULTS

A high proportion of samples from healthy adult donors were positive for NAbs (>16) to all the viruses except Ad55. A different proportion of these samples had high NAb titers (>512) for InfA (25%), Ad3 (17.71%), RSV (9.38%), EV71 (1.04%), CA16 (3.13%), and Ad55 (4.17%). Commercially available IVIG had high NAb titers to InfA and Ad3 (>1,000) and lower NAb titers to RSV [320], EV71 [160], and CA16 [160]. Strikingly, IVIG also had a high NAb titer to Ad55 (>1,000).

CONCLUSIONS

Convalescent plasma could be screened from healthy blood volunteers to establish blood banks and to prepare specific H-IVIG for treating severe ARIs caused by common respiratory viruses.

The risk of new onset depression in association with influenza--A population-based observational study

IMPORTANCE

Case-reports provided evidence that influenza infections, particularly severe episodes, may exert neuronal damage in the CNS and thereby increase the risk of depression.

OBJECTIVE

It was the aim of this study to analyse the association between influenza infections and the risk of developing incident depression.

DESIGN

We conducted a case-control analysis between 2000 and 2013 using the large UK-based primary care database Clinical Practice Research Datalink (CPRD).

SETTING

This database contains anonymous longitudinal data from primary care. At present, it contains over 100 million person-years of data from some 10 million active patients.

PARTICIPANTS

We encompassed 103307 patients below the age of 80 years with an incident major depression diagnosis between 2000 and 2013, and matched each case to one control patient on age, sex, general practice, number of medical encounters, and years of history in the CPRD prior to the index date.

EXPOSURE

Major depression diagnosis was identified by READ-codes based on ICD-10 codes (F32), with a minimum of three prescriptions for antidepressant drugs recorded after the diagnosis.

MAIN OUTCOME

We calculated relative risk estimates of developing depression in association with previous influenza infections, stratified by the number, timing and severity of such events, and we adjusted for a variety of comorbidities, smoking status, alcohol intake, body mass index, use of oral corticosteroids, and benzodiazepines.

RESULTS

Patients with a previous influenza infection had an increased risk of developing depression (OR 1.30, 95%CI 1.25-1.34) compared to patients with no history of influenza infections. A recent influenza infection recorded within 30-180 days prior to the index date yielded an adjusted 1.57 (95%CI 1.36-1.81), and an increasing number of previous influenza infections was associated with increasing odds ratios (⩾ 3 recorded influenza infections, adjusted OR 1.48, 95%CI 1.22-1.81).

CONCLUSION

This study suggests that influenza infections are associated with a moderately increased risk of developing depression.

NADPH Oxidase 1 Is Associated with Altered Host Survival and T Cell Phenotypes after Influenza A Virus Infection in Mice

The role of the reactive oxygen species-producing NADPH oxidase family of enzymes in the pathology of influenza A virus infection remains enigmatic. Previous reports implicated NADPH oxidase 2 in influenza A virus-induced inflammation. In contrast, NADPH oxidase 1 (Nox1) was reported to decrease inflammation in mice within 7 days post-influenza A virus infection. However, the effect of NADPH oxidase 1 on lethality and adaptive immunity after influenza A virus challenge has not been explored. Here we report improved survival and decreased morbidity in mice with catalytically inactive NADPH oxidase 1 (Nox1*/Y) compared with controls after challenge with A/PR/8/34 influenza A virus. While changes in lung inflammation were not obvious between Nox1*/Y and control mice, we observed alterations in the T cell response to influenza A virus by day 15 post-infection, including increased interleukin-7 receptor-expressing virus-specific CD8+ T cells in lungs and draining lymph nodes of Nox1*/Y, and increased cytokine-producing T cells in lungs and spleen. Furthermore, a greater percentage of conventional and interstitial dendritic cells from Nox1*/Y draining lymph nodes expressed the co-stimulatory ligand CD40 within 6 days post-infection. Results indicate that NADPH oxidase 1 modulates the innate and adaptive cellular immune response to influenza virus infection, while also playing a role in host survival. Results suggest that NADPH oxidase 1 inhibitors may be beneficial as adjunct therapeutics during acute influenza infection.

Plasma therapy against infectious pathogens, as of yesterday, today and tomorrow

Plasma therapy consists in bringing to a patient in need – in general suffering a severe, resistant to current therapy, and even lethal infection – plasma or specific, fractioned, antibodies, along with other immunoglobulins and possibly healing factors that can be obtained from immunized blood donors; donors (voluntary and benevolent) can be either actively immunized individuals or convalescent persons. Plasma therapy has been used since the Spanish flu in 1917–1918, and regularly then when viral epidemics threatened vulnerable populations, the last reported occurrence being the 2013–2015 Ebola virus outbreak in West Africa. The precise action mechanism of plasma therapy is not fully delineated as it may function beyond purified, neutralizing antibodies.

Emerging respiratory tract viral infections

PURPOSE OF REVIEW

This article reviews the clinical and treatment aspects of avian influenza viruses and the Middle East Respiratory Syndrome coronavirus (MERS-CoV).

RECENT FINDINGS

Avian influenza A(H5N1) and A(H7N9) viruses have continued to circulate widely in some poultry populations and infect humans sporadically. Sporadic human cases of avian A(H5N6), A(H10N8) and A(H6N1) have also emerged. Closure of live poultry markets in China has reduced the risk of A(H7N9) infection. Observational studies have shown that oseltamivir treatment for adults hospitalized with severe influenza is associated with lower mortality and better clinical outcomes, even as late as 4-5 days after symptom onset. Whether higher than standard doses of neuraminidase inhibitor would provide greater antiviral effects in such patients requires further investigation. High-dose systemic corticosteroids were associated with worse outcomes in patients with A(H1N1)pdm09 or A(H5N1). MERS-CoV has continued to spread since its first discovery in 2012. The mortality rates are high in those with comorbid diseases. There is no specific antiviral treatment or vaccine available. The exact mode of transmission from animals to humans remains unknown.

SUMMARY

There is an urgent need for developing more effective antiviral therapies to reduce morbidity and mortality of these emerging viral respiratory tract infections.

Peptidomimetic furin inhibitor MI-701 in combination with oseltamivir and ribavirin efficiently blocks propagation of highly pathogenic avian influenza viruses and delays high level oseltamivir resistance in MDCK cells

Antiviral medication is used for the treatment of severe influenza infections, of which the neuraminidase inhibitors (NAIs) are the most effective drugs, approved so far. Here, we investigated the antiviral efficacy of the peptidomimetic furin inhibitor MI-701 in combination with oseltamivir carboxylate and ribavirin against the infection of highly pathogenic avian influenza viruses (HPAIV) that are activated by the host protease furin. Cell cultures infected with the strains A/Thailand/1(KAN-1)/2004 (H5N1) and A/FPV/Rostock/1934 (H7N1) were treated with each agent alone, or in double and triple combinations. MI-701 alone achieved a concentration-dependent reduction of virus propagation. Double treatment of MI-701 with oseltamivir carboxylate and triple combination with ribavirin showed synergistic inhibition and a pronounced delay of virus propagation. MI-701 resistant mutants were not observed. Emergence of NA mutation H275Y conferring high oseltamivir resistance was significantly delayed in the presence of MI-701. Our data indicate that combination with a potent furin inhibitor significantly enhances the therapeutic efficacy of conventional antivirals drugs against HPAIV infection.

Do corticosteroids reduce the mortality of influenza A (H1N1) infection? A meta-analysis

Introduction

Corticosteroids are used empirically in influenza A (H1N1) treatment despite lack of clear evidence for effective treatment. This study aims to assess the efficacy of corticosteroids treatment for H1N1 infection.

Methods

Systematic review and meta-analysis were used to estimate the efficacy of corticosteroids for the prevention of mortality in H1N1 infection. Databases searched included MEDLINE, EMBASE, PubMed, Cochrane Central Register of Controlled Clinical Trials and so on, and bibliographies of retrieved articles, from April 2009 to October 2014. We included both cohort studies and case-control studies reported in English or Chinese that compared treatment effects between corticosteroids and non-corticosteroids therapy in inpatients with H1N1 virus infection. Cohort studies employed mortality as outcome, and case-control studies employed deaths as cases and survivors as controls; both were assessed in this meta-analysis.

Results

In total twenty-three eligible studies were included. Both cohort studies (nine studies, n = 1,405) and case-control studies (14 studies, n = 4,700) showed a similar trend toward increased mortality (cohort studies relative risk was 1.85 with 95% confidence interval (CI) 1.46 to 2.33; case-control studies odds ratio was 4.22 with 95% CI 3.10 to 5.76). The results from both subgroup analyses and sensitive analyses were consistent with each other, showing that steroid treatment is associated with mortality. However, considering the fact that corticosteroids were tend to be used in sickest case-patients and heterogeneity was observed between studies, we cannot make a solid conclusion.

Conclusions

Available evidence did not support the use of corticosteroids as standard care for patients with severe influenza. We conclude that further research is required.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0764-5) contains supplementary material, which is available to authorized users.

Neuraminidase inhibitors, superinfection and corticosteroids affect survival of influenza patients

We aimed to study factors influencing outcomes of adults hospitalised for seasonal and pandemic influenza.  Individual-patient data from three Asian cohorts (Hong Kong, Singapore and Beijing; N=2649) were analysed. Adults hospitalised for laboratory-confirmed influenza (prospectively diagnosed) during 2008-2011 were studied. The primary outcome measure was 30-day survival. Multivariate Cox regression models (time-fixed and time-dependent) were used. Patients had high morbidity (respiratory/nonrespiratory complications in 68.4%, respiratory failure in 48.6%, pneumonia in 40.8% and bacterial superinfections in 10.8%) and mortality (5.9% at 30 days and 6.9% at 60 days). 75.2% received neuraminidase inhibitors (NAI) (73.8% received oseltamivir and 1.4% received peramivir/zanamivir; 44.5% of patients received NAI ≤2 days and 65.5% ≤5 days after onset of illness); 23.1% received systemic corticosteroids. There were fewer deaths among NAI-treated patients (5.3% versus 7.6%; p=0.032). NAI treatment was independently associated with survival (adjusted hazard ratio (HR) 0.28, 95% CI 0.19-0.43), adjusted for treatment-propensity score and patient characteristics. Superinfections increased (adjusted HR 2.18, 95% CI 1.52-3.11) and chronic statin use decreased (adjusted HR 0.44, 95% CI 0.23-0.84) death risks. Best survival was shown when treatment started within ≤2 days (adjusted HR 0.20, 95% CI 0.12-0.32), but there was benefit with treatment within 3-5 days (adjusted HR 0.35, 95% CI 0.21-0.58). Time-dependent analysis showed consistent results of NAI treatment (adjusted HR 0.39, 95% CI 0.27-0.57). Corticosteroids increased superinfection (9.7% versus 2.7%) and deaths when controlled for indications (adjusted HR 1.73, 95% CI 1.14-2.62). Early NAI treatment was associated with shorter length of stay in a subanalysis. NAI treatment may improve survival of hospitalised influenza patients; benefit is greatest from, but not limited to, treatment started within 2 days of illness. Superinfections and corticosteroids increase mortality. Antiviral and non-antiviral management strategies should be considered.

Emerging novel and antimicrobial-resistant respiratory tract infections: new drug development and therapeutic options

The emergence and spread of antimicrobial-resistant bacterial, viral, and fungal pathogens for which diminishing treatment options are available is of major global concern. New viral respiratory tract infections with epidemic potential, such as severe acute respiratory syndrome, swine-origin influenza A H1N1, and Middle East respiratory syndrome coronavirus infection, require development of new antiviral agents. The substantial rise in the global numbers of patients with respiratory tract infections caused by pan-antibiotic-resistant Gram-positive and Gram-negative bacteria, multidrug-resistant Mycobacterium tuberculosis, and multiazole-resistant fungi has focused attention on investments into development of new drugs and treatment regimens. Successful treatment outcomes for patients with respiratory tract infections across all health-care settings will necessitate rapid, precise diagnosis and more effective and pathogen-specific therapies. This Series paper describes the development and use of new antimicrobial agents and immune-based and host-directed therapies for a range of conventional and emerging viral, bacterial, and fungal causes of respiratory tract infections.

Antiviral combinations for severe influenza

Observational data suggest that the treatment of influenza infection with neuraminidase inhibitors decreases progression to more severe illness, especially when treatment is started soon after symptom onset. However, even early treatment might fail to prevent complications in some patients, particularly those infected with novel viruses such as the 2009 pandemic influenza A H1N1, avian influenza A H5N1 virus subtype, or the avian influenza A H7N9 virus subtype. Furthermore, treatment with one antiviral drug might promote the development of antiviral resistance, especially in immunocompromised hosts and critically ill patients. An obvious strategy to optimise antiviral therapy is to combine drugs with different modes of action. Because host immune responses to infection might also contribute to illness pathogenesis, improved outcomes might be gained from the combination of antiviral therapy with drugs that modulate the immune response in an infected individual. We review available data from preclinical and clinical studies of combination antiviral therapy and of combined antiviral-immunomodulator therapy for influenza. Early-stage data draw attention to several promising antiviral combinations with therapeutic potential in severe infections, but there remains a need to substantiate clinical benefit. Combination therapies with favourable experimental data need to be tested in carefully designed aclinical trials to assess their efficacy.

Seasonal Human Influenza: Treatment Options

Seasonal influenza can be a self-limiting illness in healthy individuals but is associated with short-term morbidity and economic burden. Influenza can cause significant morbidity and mortality in young children, the elderly, pregnant and post-partum women, patients with co-morbidities and the immunocompromised. Neuraminidase inhibitors (NAIs) are the treatment of choice for influenza due to widespread resistance to the adamantanes. NAIs are efficacious for the treatment of influenza in ambulatory patients with mild illness, when initiated within 48 h of symptom onset. Early treatment with NAIs has been shown to reduce otitis media in children, and lower respiratory tract complications, resulting in antibiotic therapy, in adults. Evidence on the efficacy of NAIs for the prevention of influenza-related complications in at-risk populations, based on reviews of data from randomised trials is inconclusive. However, observational studies suggest that in hospitalised patients early treatment with NAIs has been associated with reduced mortality. NAIs should be initiated as soon as possible in patients at high-risk of influenza-related complications, with suspected or proven influenza, hospitalised patients and patients with severe or progressive disease. NAIs can be considered in previously healthy patients when therapy can be initiated within 48 h of symptom onset. In previously healthy patients, the therapeutic efficacy of oseltamivir is time-dependent, with maximal benefit observed when therapy is initiated within 48 h of symptom onset. However, several observational studies suggest therapeutic benefit beyond 48 h, in hospitalised patients, severe disease, and patients at high risk of complications, including pregnant women. NAIs should be considered in patients at high risk of influenza-related complications who present late. Further studies are needed to define the optimal timing of NAIs. Oseltamivir-resistant virus has been widely reported but is predominantly an issue in H1N1 seasonal influenza. Zanamivir-resistant influenza virus is rare, and inhaled or intravenous (IV) zanamivir is the treatment of choice in proven or suspected oseltamivir-resistant virus. Intubated patients with severe influenza can be treated with oseltamivir (suspension) administered via nasogastric tube. The commercial dry powder formulation of zanamivir should not be administered, via nebulisation, as it has been associated with ventilator malfunction and mortality. In intubated patients, when there are concerns about gastric absorption, IV zanamivir should be obtained under Emergency Investigational New Drug access schemes. Currently available evidence does not support the use of high-dose or extended-duration oseltamivir in patients with severe influenza, but does require further investigation. Extracorporeal membrane oxygenation has not been shown to be superior to conventional management in patients with influenza-associated acute respiratory distress syndrome and should be considered as salvage therapy. Corticosteriods should not be used in the treatment of severe influenza as this has been associated with increased risk of mortality and bacterial superinfection.

Protective effect of fluvastatin on influenza virus infection

Statins are 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and have pleiotropic effects. It has been suggested that statins may be a potential treatment during the next influenza pandemic. In a previous study we found that a statin/caffeine combination protects BALB/c mice against Influenza A, subtypes haemagglutinin type 5 and neuraminidase type 1 (H5N1), H3N2 and H1N1 infection. The effect of statins alone on influenza virus infection, however, is not known. In this study, it was investigated whether fluvastatin is capable of inhibiting influenza A virus replication in vitro. The results demonstrated that the synthesis of viral RNA and protein was affected by fluvastatin treatment. Virus production was markedly reduced when fluvastatin was administered simultaneously with the virus; however, a greater inhibition was observed when fluvastatin was added following viral adsorption. The selectivity index [SI; 50% cytotoxic concentration (CC50)/50% inhibition concentration (IC50)], however, was only 21. It was further demonstrated that fluvastatin protects host cells against influenza-induced inflammation by reducing the production of tumour necrosis factor-α, interleukin 8 and interferon γ. In conclusion, the results demonstrated that fluvastatin exerted a minor inhibitory effect on influenza virus infection, which involved anti-inflammatory activities.

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

Analysis of medical use of carbon adsorbents in China and additional possibilities in this field achieved in Ukraine

The review is devoted to analysis of the use of carbon sorbents for medicinal purposes in China and description of some innovative technologies in this field in Ukraine. The review underlines the presence of common roots of sorption therapy development in these two countries determined by pioneer works of Prof. T.M.S. Chang, created to the concept of artificial cells. High level of works of Chinese scientists on sorption purification of blood and combined extracorporeal methods has been mentioned. At the same time, by author's opinion, two other methods of sorption therapy, namely enterosorption and sorption therapy of wounds and burns, has not been properly developed in China. In the review, there are also described the essential results of Ukrainian scientists in the field of blood purification from protein-bound toxins and other harmful compounds what is important for treatment of many serious human pathologies, and also the important data on the use of oral sorbents and dressings from activated carbon materials, which could be considered as a useful addition to achievements of Chinese scientists in the field of the development and use of sorbents for medicinal purposes.

Severe acute respiratory syndrome (SARS): lessons learnt in Hong Kong

Many healthcare workers were infected while looking after the SARS patients on the medical wards in 2003. The high infectivity of the SARS coronavirus with peak viral load on day 10 of illness when patients were ill, overcrowding of the old medical wards with low air changes/hr (ACH), and aerosol-generating procedures while resuscitating the patients were the major factors. Procedures reported to present an increased risk of SARS transmission include tracheal intubation, non-invasive ventilation, tracheotomy and manual ventilation before intubation whereas oxygen therapy and bed distance <1 m were also implicated. Studies based on laser visualization technique with smoke particles as smokers in the human patient simulator has shown that oxygen therapy via Hudson mask and nasal cannula could disperse exhaled air of patients to 0.4 and 1 m respectively whereas jet nebulizer could disperse exhaled air >0.8 m from the patient. Bigger isolation rooms with 16 ACH are more effective than smaller isolation rooms with 12 ACH in removing exhaled air and preventing room contamination but at the expense of more noise and electricity consumption. Non-invasive ventilation via face masks and single circuit can disperse exhaled air from 0.4 to 1 m. Both higher inspiratory pressures and use of whisper swivel device (to facilitate carbon dioxide removal) could increase the exhaled air leakage and isolation room contamination during on-invasive ventilation. Addition of a viral-bacterial filter during manual ventilation by bagging may reduce the exhaled air leakage forward and yet increase the sideway leakage. N95 mask was more effective than surgical mask in preventing expelled air leakage during patient's coughing but there was still significant sideway leakage to 15 cm. Clinicians should be aware of air leakage from the various face masks and adopt strict infection control measures during resuscitation of patients with severe respiratory infections. Carefully designed clinical trials are required to determine the optimal timing and dosage of any antiviral agents, convalescent plasma, and immuno-modulating agents in the treatment of the possibly immune-mediated lung injury in SARS and newly emerged infection such as the Middle East Respiratory Syndrome.