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Background: We conducted double-blind, placebo-controlled trials assessing the efficacy and tolerability of favipiravir in acute influenza.Methods: Otherwise healthy adults with influenza-like symptoms and fever of ≤48 hours were randomized to favipiravir (1800 mg twice daily [BID] on day 1, 800 mg BID on days 2-5) or placebo tablets (1:1 in US316; 3:1 in US317). The primary efficacy endpoint was the time to illness alleviation when 6 influenza symptoms were self-rated as absent or mild and fever was absent in the intention-to-treat, influenza-infected participants.Results: In US316 (301 favipiravir, 322 placebo), favipiravir was associated with a 14.4-hour reduction (median, 84.2 vs 98.6 hours; P = .004) in time to illness alleviation vs placebo. In US317 (526 favipiravir, 169 placebo), favipiravir did not significantly reduce time to alleviation (median, 77.8 vs 83.9 hours). In both trials favipiravir was associated with reduced viral titers, RNA load area under the curve over days 1-5, and median times to cessation of virus detection (P < .001). Aside from asymptomatic hyperuricemia, no important differences in adverse events were found.Conclusions: This favipiravir dosing regimen demonstrated significant antiviral efficacy but inconsistent illness alleviation in uncomplicated influenza. Studies of higher doses and antiviral combinations for treating serious influenza and other RNA viral infections are warranted. Clinical Trials Registration. NCT02026349; NCT02008344. [ABSTRACT FROM AUTHOR]

Prompt antiviral treatment has the potential to reduce influenza virus transmission to close contacts, but rigorous data on the magnitude of treatment effects on transmission are limited. Animal model data indicate that rapid reductions in viral replication after antiviral treatment reduce the risk of transmission. Observational and clinical trial data with oseltamivir and other neuraminidase inhibitors indicate that prompt treatment of household index patients seems to reduce the risk of illness in contacts, although the magnitude of the reported effects has varied widely across studies. In addition, the potential risk of transmitting drug-resistant variants exists with all approved classes of influenza antivirals. A controlled trial examining baloxavir treatment efficacy to reduce transmission, including the risk of transmitting virus with reduced baloxavir susceptibility, is currently in progress. If reduced transmission risk is confirmed, modeling studies indicate that early treatment could have major epidemiologic benefits in seasonal and pandemic influenza. [ABSTRACT FROM AUTHOR]

Background Baloxavir marboxil has demonstrated safety and efficacy in treating adult and adolescent outpatients with acute influenza (CAPSTONE-1 trial). Here, we report a subgroup analysis of outcomes in adolescents from the trial. Methods CAPSTONE-1 was a randomized, double-blind, placebo-controlled study. Eligible adolescent outpatients (aged 12-17 years of age) were randomized in a ratio of 2:1 to a single dose of baloxavir 40/80 mg if less than/greater than or equal to 80 kg or placebo. The main outcomes were the time to alleviation of symptoms (TTAS), duration of infectious virus detection, and incidence of adverse events (AEs). Results Among 117 adolescent patients, 90 (77%) comprised the intent-to-treat infected population (63 baloxavir and 27 placebo; 88.9% A(H3N2)). The median TTAS was 38.6 hours shorter (95% confidence interval: −2.6, 68.4) in the baloxavir group compared with placebo (median TTAS, 54.1 hours vs 92.7 hours, P =.0055). The median time to sustained cessation of infectious virus detection was 72.0 hours for baloxavir compared with 120.0 hours for placebo recipients (P <.0001). Treatment-emergent PA/I38X-substituted viruses were detected in 5 of the 51 (9.8%) baloxavir recipients. In the safety population (76 baloxavir and 41 placebo), AEs were less common in baloxavir than placebo recipients (17.1% vs 34.1%; P =.0421). In the baloxavir group, no AEs except for diarrhea were reported in 2 or more patients. Conclusions Baloxavir demonstrated clinical and virologic efficacy in the otherwise healthy adolescents with acute influenza compared with placebo. There were no safety concerns identified. These results were similar to the adult population in CAPSTONE-1 and support baloxavir as a treatment option in adolescents. [ABSTRACT FROM AUTHOR]

Antivirals, respiratory syncytial virus, therapeutics. [Extracted from the article]

Background: Baloxavir marboxil (baloxavir) is a polymerase acidic protein (PA) endonuclease inhibitor with clinical efficacy in the treatment of uncomplicated influenza, including in outpatients at increased risk for complications. The postexposure prophylactic efficacy of baloxavir in the household setting is unclear.Methods: We conducted a multicenter, double-blind, randomized, placebo-controlled trial to evaluate the postexposure prophylactic efficacy of baloxavir in household contacts of index patients with confirmed influenza during the 2018-2019 season in Japan. The participants were assigned in a 1:1 ratio to receive either a single dose of baloxavir or placebo. The primary end point was clinical influenza, as confirmed by reverse-transcriptase-polymerase-chain-reaction testing, over a period of 10 days. The occurrence of baloxavir-selected PA substitutions associated with reduced susceptibility was assessed.Results: A total of 752 household contacts of 545 index patients were randomly assigned to receive baloxavir or placebo. Among the index patients, 95.6% had influenza A virus infection, 73.6% were younger than 12 years of age, and 52.7% received baloxavir. Among the participants who could be evaluated (374 in the baloxavir group and 375 in the placebo group), the percentage in whom clinical influenza developed was significantly lower in the baloxavir group than in the placebo group (1.9% vs. 13.6%) (adjusted risk ratio, 0.14; 95% confidence interval [CI], 0.06 to 0.30; P<0.001). Baloxavir was effective in high-risk, pediatric, and unvaccinated subgroups of participants. The risk of influenza infection, regardless of symptoms, was lower with baloxavir than with placebo (adjusted risk ratio, 0.43; 95% CI, 0.32 to 0.58). The incidence of adverse events was similar in the two groups (22.2% in the baloxavir group and 20.5% in the placebo group). In the baloxavir group, the viral PA substitutions I38T/M or E23K were detected in 10 (2.7%) and 5 (1.3%) participants, respectively. No transmission of these variants from baloxavir-treated index patients to participants in the placebo group was detected; however, several instances of transmission to participants in the baloxavir group could not be ruled out.Conclusions: Single-dose baloxavir showed significant postexposure prophylactic efficacy in preventing influenza in household contacts of patients with influenza. (Funded by Shionogi; Japan Primary Registries Network number, JapicCTI-184180.). [ABSTRACT FROM AUTHOR]

Background: Single-dose baloxavir rapidly reduces influenza virus titers and symptoms in patients with uncomplicated influenza, but viruses with reduced in vitro susceptibility due to amino acid substitutions at position 38 of polymerase acidic protein (PA/I38X) sometimes emerge.Methods: We evaluated the kinetics, risk factors, and effects on clinical and virologic outcomes of emergence of PA/I38X-substituted viruses.Results: Viruses containing PA/I38X substitutions were identified 3-9 days after baloxavir treatment in 9.7% (36/370) of patients, of whom 85.3% had transient virus titer rises. Median time to sustained cessation of infectious virus detection was 192, 48, and 96 hours in the baloxavir recipients with PA/I38X-substituted viruses, without PA/I38X-substituted viruses, and placebo recipients, respectively. The corresponding median times to alleviation of symptoms were 63.1, 51.0, and 80.2 hours, respectively. After day 5, symptom increases occurred in 11.5%, 8.0%, and 13.0%, respectively, and in 8.9% of oseltamivir recipients. Variant virus emergence was associated with lower baseline neutralizing antibody titers.Conclusions: The emergence of viruses with PA/I38X substitutions following baloxavir treatment was associated with transient rises in infectious virus titers, prolongation of virus detectability, initial delay in symptom alleviation, and uncommonly with symptom rebound. The potential transmissibility of PA/I38X-substituted viruses requires careful study.Clinical Trial Registration: NCT02954354. [ABSTRACT FROM AUTHOR]

Background: Baloxavir marboxil is a selective inhibitor of influenza cap-dependent endonuclease. It has shown therapeutic activity in preclinical models of influenza A and B virus infections, including strains resistant to current antiviral agents.Methods: We conducted two randomized, double-blind, controlled trials involving otherwise healthy outpatients with acute uncomplicated influenza. After a dose-ranging (10 to 40 mg) placebo-controlled trial, we undertook a placebo- and oseltamivir-controlled trial of single, weight-based doses of baloxavir (40 or 80 mg) in patients 12 to 64 years of age during the 2016-2017 season. The dose of oseltamivir was 75 mg twice daily for 5 days. The primary efficacy end point was the time to alleviation of influenza symptoms in the intention-to-treat infected population.Results: In the phase 2 trial, the median time to alleviation of influenza symptoms was 23.4 to 28.2 hours shorter in the baloxavir groups than in the placebo group (P<0.05). In the phase 3 trial, the intention-to-treat infected population included 1064 patients; 84.8 to 88.1% of patients in each group had influenza A(H3N2) infection. The median time to alleviation of symptoms was 53.7 hours (95% confidence interval [CI], 49.5 to 58.5) with baloxavir, as compared with 80.2 hours (95% CI, 72.6 to 87.1) with placebo (P<0.001). The time to alleviation of symptoms was similar with baloxavir and oseltamivir. Baloxavir was associated with greater reductions in viral load 1 day after initiation of the regimen than placebo or oseltamivir. Adverse events were reported in 20.7% of baloxavir recipients, 24.6% of placebo recipients, and 24.8% of oseltamivir recipients. The emergence of polymerase acidic protein variants with I38T/M/F substitutions conferring reduced susceptibility to baloxavir occurred in 2.2% and 9.7% of baloxavir recipients in the phase 2 trial and phase 3 trial, respectively.Conclusions: Single-dose baloxavir was without evident safety concerns, was superior to placebo in alleviating influenza symptoms, and was superior to both oseltamivir and placebo in reducing the viral load 1 day after initiation of the trial regimen in patients with uncomplicated influenza. Evidence for the development of decreased susceptibility to baloxavir after treatment was also observed. (Funded by Shionogi; JapicCTI number, 153090, and CAPSTONE-1 ClinicalTrials.gov number, NCT02954354 .). [ABSTRACT FROM AUTHOR]

The article focuses on experimental therapies that are used in the treatment of Ebola virus disease (EVD). Various topics discussed include mortality rate of EVD, supportive care offered to patients suffering from EVD, child's survival through these therapies and use of antiviral agents in the treatment.

Progress in the development of antivirals for non-influenza respiratory viruses has been slow with the result that many unmet medical needs and few approved agents currently exist. This commentary selectively reviews examples of where specific agents have provided promising clinical benefits in selected target populations and also considers potential therapeutics for emerging threats like the SARS and Middle East respiratory syndrome coronaviruses. Recent studies have provided encouraging results in treating respiratory syncytial virus infections in lung transplant recipients, serious parainfluenza virus and adenovirus infections in immunocompromised hosts, and rhinovirus colds in outpatient asthmatics. While additional studies are needed to confirm the efficacy and safety of the specific agents tested, these observations offer the opportunity to expand therapeutic studies to other patient populations. [ABSTRACT FROM AUTHOR]

Abstract: Influenza vaccines are potentially the most efficacious means of mitigating the impact of influenza pandemic and might contribute to the rapid containment of an emerging pandemic virus. On the 12–13 February 2009, the Initiative For Vaccine Research (IVR) of the World Health Organisation convened the 5th meeting on the ‘Evaluation of pandemic influenza prototype vaccines in clinical trials’ in Geneva. This was a follow-up meeting to the 4th meeting held on 14–15 February 2008 [Girard M, Palkonyay L, Kieny MP. Report of the 4th meeting on the evaluation of pandemic influenza prototype vaccines in clinical trials. Vaccine 2008;26:4975–7], and presentations were made by representatives from industry, academia, and governmental organisations. This year''s meeting aimed to update the progress made during the past year on H5N1 and other prototype pandemic vaccines that have undergone clinical trials. A number of vaccine types were covered, including classical egg-derived inactivated vaccines, cell-derived inactivated vaccines, live-attenuated vaccines (LAIV) and vaccines developed using new technologies. The effects of different adjuvants and prime-boosting schedules were important topics, and further data were presented to show that children mount vigorous antibody responses to several H5N1 vaccines. Other subjects presented and discussed were standardisation, and regulatory issues concerning pandemic vaccines. [Copyright &y& Elsevier]

It is more than 20 years since the neuraminidase inhibitors, oseltamivir and zanamivir were approved for the treatment and prevention of influenza. Guidelines for global surveillance and methods for evaluating resistance were established initially by the Neuraminidase Inhibitor Susceptibility Network (NISN), which merged 10 years ago with the International Society for influenza and other Respiratory Virus Diseases (isirv) to become the isirv-Antiviral Group (isirv-AVG). With the ongoing development of new influenza polymerase inhibitors and recent approval of baloxavir marboxil, the isirv-AVG held a closed meeting in August 2019 to discuss the impact of resistance to these inhibitors. Following this meeting and review of the current literature, this article is intended to summarize current knowledge regarding the clinical impact of resistance to polymerase inhibitors and approaches for surveillance and methods for laboratory evaluation of resistance, both in vitro and in animal models. We highlight limitations and gaps in current knowledge and suggest some strategies for addressing these gaps, including the need for additional clinical studies of influenza antiviral drug combinations. Lessons learned from influenza resistance monitoring may also be helpful for establishing future drug susceptibility surveillance and testing for SARS-CoV-2. • Current knowledge regarding the clinical impact of resistance to influenza polymerase inhibitors is summarized. • Current surveillance strategies for detection of variants with reduced susceptibility to polymerase inhibitors are discussed. • Methods for laboratory evaluation of resistance in vitro and in animal models, along with their limitations are presented. [ABSTRACT FROM AUTHOR]

Abstract: The Southeast Asia Influenza Clinical Research Network (SEA ICRN) (www.seaclinicalresearch.org) is a recently developed multilateral, collaborative partnership that aims to advance scientific knowledge and management of human influenza through integrated clinical investigation. The partnership of hospitals and institutions in Indonesia, Thailand, United Kingdom, United States, and Viet Nam was established in late 2005 after agreement on the general principles and mission of the initiative and after securing initial financial support. The establishment of the SEA ICRN was both a response to the re-emergence of the highly pathogenic avian influenza A(H5N1) virus in Southeast Asia in late 2003 and an acknowledgment that clinical trials on emerging infectious diseases require prepared and coordinated research capacity. The objectives of the Network also include building sustainable research capacity in the region, compliance with international standards, and prompt dissemination of information and sharing of samples. The scope of research includes diagnosis, pathogenesis, treatment and prevention of human influenza due to seasonal or novel viruses. The Network has overcome numerous logistical and scientific challenges but has now successfully initiated several clinical trials. The establishment of a clinical research network is a vital part of preparedness and an important element during an initial response phase to a pandemic. [Copyright &y& Elsevier]

Conclusion. Middle ear pressure was affected by respiratory illness and season; picornavirus (without illness) or pathogenic bacteria in the nasopharynx had no or minor effect. Objective. To examine the effect of respiratory illness, season, and nasopharyngeal microbial flora on middle ear pressure. Subjects and methods. Thirteen children were followed longitudinally with daily recording of respiratory symptoms, weekly tympanometry, and weekly testing of nasal aspirate/washes for Streptococcus pneumoniae, Hemophilus influenzae, Moraxella catarrhalis by culture and for picornavirus by RT-PCR. Results. Abnormal middle ear pressure was present at 47% of 473 weekly visits by 11 preschool age (≤5years) vs 28% of 212 visits by 2 school age children. Symptomatic illness predicted abnormal middle ear pressure (63% of 107 ill visits in preschoolers vs 43% of 366 well visits, p<0.004). Abnormal tympanometry in preschoolers at well visits rose from 26% (80 visits) in summer to 54% (100 visits) in spring (p≤0.03). No increase in abnormal tympanometry occurred during 18 picornavirus infections without illness. The presence of one or more of the bacterial species at ill or well visits had no effect on middle ear pressure except for a 12% increase (p=0.008) in abnormal tympanometry associated with H. influenzae at well visits in preschoolers. [ABSTRACT FROM AUTHOR]

The long history of influenza drug development has both contributed practical advances in antiviral chemotherapy and improved the understanding of influenza pathogenesis and epidemiology. The role played by these antivirals continues to grow with the dual threats of seasonal and pandemic influenza. The neuraminidase inhibitors are proven effective for the chemoprophylaxis and treatment of influenza A and B, although early therapy is essential for disease mitigation. Studies of topically applied zanamivir have demonstrated the importance of viral replication in the lower respiratory tract, even in uncomplicated influenza. Antiviral resistance, especially to the M2 ion channel inhibitors, sometimes limits clinical utility. Oseltamivir-resistant variants may emerge during treatment but have not yet circulated widely and are usually less fit than wild-type virus; most retain susceptibility to zanamivir. The transmission fitness cost of these resistant variants is drug-, neuraminidase subtype-, and mutation-specific. Continued vigilance in drug resistance surveillance is imperative, as is research into the development of new agents that will provide the potential for alternative and combination antiviral therapy. [ABSTRACT FROM AUTHOR]

The goals of antiviral treatment for influenza are to decrease symptoms and functional disability and, more important, to decrease associated complications, hospitalizations, and mortality. Four drugs have been approved for treatment of and prophylaxis against influenza in the United States, but they are underutilized. The M2 ion channel inhibitors amantadine and rimantadine are effective for prophylaxis, and they decrease the duration of symptoms if they are used for early treatment of influenza A. The rapid emergence of resistance during therapy and, recently, the circulation of resistant H3N2 viruses in the community have decreased the usefulness of these M2 ion channel inhibitors. Early therapy with neuraminidase (NA) inhibitors, either oseltamivir or zanamivir, reduces the duration of symptoms, the duration of disability, and the risk of lower respiratory tract complications. Oseltamivir has been shown to decrease antibiotic use, the number of hospitalizations, and, probably, the risk of death after influenza. NA inhibitors might provide substantial benefits in the treatment of pandemic influenza, with reductions in the numbers of hospitalizations and deaths occurring if such treatment (1) is made available in sufficient time, through rapid distribution, and (2) is available in sufficient quantities as a result of stockpiling. Both of the aforementioned NA inhibitors are highly effective for prophylaxis. Geographically targeted mass chemoprophylaxis might contain the spread of a pandemic virus, but multiple hurdles to successful implementation exist. Resistance to oseltamivir occurs with the H274Y variant in viruses that contain N1; however, to date, such variants have been less fit, have not been transmitted from person to person, and have retained susceptibility to zanamivir. Alternative agents and approaches, including parenteral and combination therapy, for the treatment of influenza are needed in the near and long term. [ABSTRACT FROM AUTHOR]

Abstract: The development of the currently available classes of antivirals, the M2 proton channel inhibitors and the neuraminidase inhibitors, provides valuable perspectives relevant to the field of antiviral chemotherapy in general and insights into aspects of viral pathogenesis and antiviral resistance relevant specifically to influenza. The efficacy observed with these antiviral drugs has proven the importance of these antiviral targets, as well as the principle that chemoprophylaxis and early treatment are possible in influenza infections with small molecular weight inhibitors. [Copyright &y& Elsevier]

Abstract: An inbred murine model (BALB/c) was utilized to assess the protective effect of the immunomodulator methyl inosine 5′-monophosphate (MIMP) against infection with influenza A/PR/8/34 (H1N1) virus. Contrary to the data reported for outbred mice (NMRI) infected with the aerosolized virus (Masihi, Hadden, 2003. J. Int. Immunopharmacol. 3, 1205–1215), there were no improvements in the outcomes of infection in the inbred animals treated with MIMP intranasally 1 day before the challenge and/or orally after the challenge for 5 days (up to 10mg/kg/day). Nevertheless, complete protection against lethality was afforded by the treatment with the neuraminidase inhibitor peramivir given once daily for 5 days after the challenge (10mg/kg/day). We speculate that the rapid progression of the disease in inbred mice caused by the intranasal challenge may render the MIMP-treatment ineffective. Our results emphasize the need for careful consideration of murine strains and routes of virus challenge in the design of experiments utilizing lethal influenza virus infection. [Copyright &y& Elsevier]

OBJECTIVES: To assess the cost effectiveness and cost utility of preventing post-exposure influenza infection using the neuraminidase inhibitor oseltamivir from a healthcare payer’s perspective in the UK.1. Comparison of patients receiving PEP versus patients not receiving PEP and not being treated with oseltamivir should they become infected.2. Comparison of patients receiving PEP versus patients not receiving PEP but being treated with oseltamivir should they become infected.The model was run with an attack rate in household contacts of 8% for the base case, with higher rates (up to 30%, representing pandemic conditions) tested in sensitivity analyses. A societal perspective and other key parameters were tested in sensitivity analysis. The year of costing was 2002. The time span for the model was up to 1 year (including one influenza season), but loss of life was included in the QALY calculation and based on expected life expectancy. METHODS: A simulation model was developed, based on clinical trial results and published data, to predict morbidity and mortality due to influenza and to compare oseltamivir post-exposure prophylaxis (PEP) with no prophylaxis within families with members aged ≥13 years. Two scenarios were tested:1. Comparison of patients receiving PEP versus patients not receiving PEP and not being treated with oseltamivir should they become infected.2. Comparison of patients receiving PEP versus patients not receiving PEP but being treated with oseltamivir should they become infected.The model was run with an attack rate in household contacts of 8% for the base case, with higher rates (up to 30%, representing pandemic conditions) tested in sensitivity analyses. A societal perspective and other key parameters were tested in sensitivity analysis. The year of costing was 2002. The time span for the model was up to 1 year (including one influenza season), but loss of life was included in the QALY calculation and based on expected life expectancy. RESULTS: PEP with oseltamivir results in reduced morbidity (i.e. fewer influenza cases) and associated reductions in complications, hospitalisations and mortality due to influenza. When comparing oseltamivir PEP with no prophylaxis for contact attack rates of 8%, 12% and 30%, the mean costs per QALY gained for scenario one were estimated at £29 938, £18 697 and £5403, respectively; the mean costs per case avoided were £467, £293 and £84, respectively. The corresponding results for scenario two were £52 202, £31 610 and £9688 per QALY gained. CONCLUSIONS: PEP with oseltamivir is likely to be a cost-effective strategy for family contacts in the UK from a healthcare payer perspective when influenza-like illness contact attack rates are 8% or higher and the only treatment given is ‘usual care’. [ABSTRACT FROM AUTHOR]

Hendley JO, Hayden FG, Winther B. Weekly point prevalence ofStreptococcus pneumoniae, Hemophilus influenzaeandMoraxella catarrhalisin the upper airways of normal young children: effect of respiratory illness and season. APMIS 113;2005:213–20.The aim was to determine the effect of respiratory illness and season on carriage rates in the upper airways ofStreptococcus pneumoniae, Hemophilus influenzaeandMoraxella catarrhalisin normal children. Sixteen healthy children, 1–10 years old, amenable to weekly sampling were followed longitudinally for at least three seasons of the year. Respiratory symptoms were recorded daily; weekly nasal aspirate/wash samples were cultured on selective agars. Urea concentration in samples was used to define dilution of secretion. 68% of 950 samples were culture positive; 44% of positives had two or all three species. Each species was detected in about one third of samples. Bacteria were detected in 76% of samples during illnessvs.65% during wellness (p=0.004). Seasonal carriage rates varied from 56% in summer and fall to 85% in winter. There was a strong inverse correlation between dilution of secretion and bacterial detection rate in illness and wellness aspirate samples during the four seasons (r=−0.82, p=0.01). Detection of bacteria varied with the amount of secretion in the sample. This variation accounts for the apparent differences in bacterial carriage during illnessvs.wellness and during different seasons. [ABSTRACT FROM AUTHOR]

Available evidence indicates that the neuraminidase inhibitors (NAIs), particularly oseltamivir, are the preferred antiviral agents for treatment of influenza, although more data are needed from elderly and high-risk populations. Although widely available, amantadine has a narrower antiviral spectrum and therapeutic margin, greater need for individual dosing, and much higher risk for emergence of drug-resistant variants compared with NAIs. Despite documented efficacy and reasonable cost-effectiveness, the NAIs are under-utilized for treatment of acute influenza in most countries of the world. Cost and rapid access to care are major hurdles to broader application. Both of these country- or health care system-related impediments require solution, if patients are to benefit from available drugs. In addition to addressing these problems, stockpiling of antiviral agents will be essential to mount an effective antiviral response to the next major epidemic or pandemic. [Copyright &y& Elsevier]

We determined the efficacy of postexposure prophylaxis (PEP) and treatment of ill index cases with oseltamivir, in an attempt to prevent influenza transmission in households, in a study conducted in 277 households with 298 index cases (62% with laboratory-confirmed influenza) and 812 contacts aged ≥1 year. Contacts were randomized by household to receive treatment (5 days; n = 402), if illness developed, or PEP for 10 days (n = 410), and the number of households with at least 1 contact developing laboratory-confirmed influenza was measured. PEP provided a protective efficacy of 58.5% (95% confidence interval [CI], 15.6%–79.6%; (P = .0114) for households against proven influenza and 68.0% (95% CI, 34.9%–84.2%;) for individual contacts, compared with treatment of index cases alone. No oseltamivir-resistant variants were detected in treated index cases or contacts. PEP of household contacts of those with influenza reduces the secondary spread of influenza in families when the initial household case is treated. [ABSTRACT FROM AUTHOR]

The novel capsid-binding antiviral pleconaril inhibits in vitro replication of most rhinoviruses and entero-viruses. Oral pleconaril treatment was studied in 2 parallel randomized, double-blind, placebo-controlledtrials. Among 1363 picornavirus-infected participants (65%) in the studies combined, the median time to alleviation of illness was 1 day shorter for pleconaril recipients than for placebo recipients (P < .001). Cold symptom scores and frequency of picornavirus cultured from nasal mucus specimens were lower among pleconaril recipients by day 2 of treatment. No treatment effects were seen in those without picornavirus infection. Pleconaril was associated with a higher incidence of nausea (6% vs. 4%) and diarrhea (9% vs. 7%) and with small increases in mean serum cholesterol levels and platelet counts, compared with baseline measurements. A subsequent 6-week prophylaxis study found that pleconaril induces cytochrome P-450 3A enzymes, which metabolize a variety of drugs, including ethinyl estradiol. Early pleconaril treatment was well tolerated and significantly reduced the duration and severity of colds due to picornaviruses in adults. [ABSTRACT FROM AUTHOR]

Little is known about the impact of human rhinovirus (HRV) and coronavirus infections in hematopoietic stem cell transplant (HSCT) recipients. We tested bronchoalveolar lavage (BAL) samples obtained from HSCT recipients with acute pulmonary infiltrates for HRV (n = 122) and coronavirus (n = 46) by reverse-transcriptase polymerase chain reaction. HRV RNA was detected in 6 (8) of 77 patients, and coronavirus RNA was detected in 0 of 46 of BAL samples from HSCT recipients. The fatality rate in HRV-infected patients was high (83), but all patients had significant coinfections, and the overall mortality rate was not different from that of patients who were negative for HRV in BAL samples. These results suggest that HRV may be a cause of lower respiratory tract infections in HSCT recipients and that its detection in BAL samples is associated with frequent copathogens. Whether the poor prognosis is due to HRV or the copathogen is not clear. [ABSTRACT FROM AUTHOR]

The relationship between Kaposi sarcoma--associated herpesvirus (KSHV) viremia and KS disease was investigated in 500 subjects who received treatment in Harare, Zimbabwe. Subjects were grouped by results of human immunodeficiency virus (HIV) type 1 serological tests, KS diagnosis, and KS clinical stage. The plasma KSHV DNA concentration was associated with concomitant KS and HIV-1 infection (AIDS-KS; P < .001) and AIDS-KS clinical stage (P = .01). Plasma KSHV DNA levels were greater in AIDS-KS than in matched HIV-1-seronegative KS (P = .04). The plasma KSHV DNA level was not associated with age, sex, systemic symptoms, or CD4[SUP+] lymphocyte count. Plasma and peripheral blood mononuclear cell KSHV DNA concentrations were linearly related (r[SUP2] = .44; P < .001), and the nucleotide sequence of the K1 gene highly variable region was identical in both compartments. These findings provide evidence that KSHV viremia is common in advanced AIDS-KS in Zimbabwe and suggest a relationship between KSHV lytic replication and untreated HIV-1 infection. [ABSTRACT FROM AUTHOR]

ABSTRACT. Objective. To evaluate the effect of uncomplicated viral respiratory infections (colds) on middle ear pressure in healthy school-aged children. Methods. Children (ages 2-12) with normal tympanograms before onset of illness had bilateral tympanometry daily except weekends for 2 weeks after the onset of a cold. Nasopharyngeal secretion obtained at onset of illness was cultured for bacterial pathogens of otitis media using selective agars and tested for rhinovirus, coronavirus, respiratory syncytial virus, influenza A and B, and parainfluenza 1-3 by reverse transcriptase polymerase chain reaction technology. Tympanometry was designated as abnormal with peak pressure of <--100 daPa or >-50 daPa and/or a compliance peak of <0.2 cm3. Results. Eighty-six colds were studied, 82 in schoolchildren (5-12 years old) and 4 in 2- to 3-year-olds. Abnormal negative middle ear pressure occurred at least once during the 2 weeks after onset in 57 (66%) of the 86 colds. Tympanometry was abnormal in the first week after onset in 50 (88%) of the 57 colds and was abnormal on a single day in 17 (30%) of the 57. The middle ear pressure abnormalities were intermittent and shifted from one ear to the other ear from day to day. Reverse transcriptase polymerase chain reaction was positive for a respiratory virus in 56 (65%) of the 86 illnesses. Rhinovirus was found in 48% and respiratory syncytial virus in 14%. Pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis) were detected in nasopharyngeal secretion in 29 (34%) of the 86 colds; the bacteria were in high titer (>-103 cfu/mL) in 26 of the 29 positive specimens. None developed illness that required a visit to a physician. Age, detection of a respiratory virus, and presence of bacterial pathogen in the nasopharyngeal secretion had a negligible effect on the occurrence of abnormal tympanometry. Occurrence of negative middle ear pressure in winter-spring colds was significantly greater... [ABSTRACT FROM AUTHOR]

With the use of neuraminidase (NA) inhibitors (BCX-1812, oseltamivir, or zanamivir), drugresistant variants of influenza A viruses were generated that lacked characteristic markers of resistance, such as substitutions in the NA active center or in the hemagglutinin. Drug resistance was associated with the accumulation of defective (A) RNA segments encoding NA. This phenomenon could be explained by reduced dependence of the virus on its NA activity. Analysis of the last isolates recovered from 11 volunteers, experimentally infected with influenza virus and treated with BCX-1812, revealed that they maintained full susceptibility to the drug in the NA inhibition assay (50 % inhibitory concentration, 0.35-0.5 nM). The presence of ARNA segments was detected in 1 of these isolates but was not found in the isolates recovered from placebo recipients (n = 8). Because of a lack of cell culture-based assays for susceptibility testing of human influenza viruses, detection of ARNA segments should be considered an additional assay for monitoring of NA inhibitor resistance. [ABSTRACT FROM AUTHOR]

Reports on a randomized controlled trial to evaluate the efficacy and safety of the oral neuraminidase inhibitor oseltamivir in the treatment of naturally acquired influenza infection. Design; Setting; Participants; Interventions; Main outcome measures; Results; Conclusions.

Background: The transmission of influenza virus in households, especially by children, is a major route of infection. Prior studies suggest that timely antiviral treatment of ill cases may reduce infection in household contacts. The aim of the study was to compare the effects of oseltamivir (OTV) and baloxavir marboxil (BXM) treatment of index cases on the secondary attack rate (SAR) of influenza within household. Methods: A post hoc analysis was done in BLOCKSTONE trial—a placebo‐controlled, double‐blinded post‐exposure prophylaxis of BXM. Data were derived from the laboratory‐confirmed index cases' household contacts who received placebo in the trial and also from household members who did not participate in the trial but completed illness questionnaires. To assess the SAR of household members, multivariate analyses adjusted for factors including age, vaccination status, and household size were performed and compared between contacts of index cases treated with BXM or OTV. Results: In total, 185 index cases (116 treated with BXM and 69 treated with OTV) and 410 household contacts (201 from trial, 209 by questionnaire) were included. The Poisson regression modeling showed that the SAR in household contacts of index cases treated with BXM and OTV was 10.8% and 18.5%, respectively; the adjusted relative reduction in SAR was 41.8% (95% confidence interval: 1.0%–65.7%, p = 0.0456) greater with BXM than OTV. Similar reductions were found in contacts from the trial and those included by questionnaire. Conclusion: BXM treatment of index cases appeared to result in a greater reduction in secondary household transmission than OTV treatment. [ABSTRACT FROM AUTHOR]

Characterizes the local immune response to influenza virus infection through the determination of cytokine and chemokine levels in serial nasal lavate fluid samples from volunteers experimentally infected with influenza A. Effect of the inhibitor zanamivir on the clinical symptoms of influenza infection; Roles played cytokines and chemokines in the development of symptoms and resolution of influenza.

Context: Influenza virus neuraminidase is thought to be essential for virus replication in humans; however, to date, available neuraminidase inhibitors are limited to zanamivir, which is topically administered.Objective: To determine the safety, tolerability, and antiviral activity of oral neuraminidase inhibitor oseltamivir (GS4104/Ro64-0796) for prevention and the early treatment of influenza in experimentally infected humans.Design: Two randomized, double-blind, placebo-controlled trials conducted between June and July 1997.Setting: Individual hotel rooms; 2 large US university medical schools.Participants: A total of 117 healthy adult volunteers (aged 18-40 years; median age, 21 years) who were susceptible (hemagglutination-inhibition antibody titer < or =1:8).Interventions: All subjects were inoculated intranasally with influenza A/Texas/36/91 (H1N1) virus. For the prophylaxis study, oral oseltamivir (100 mg once daily [n = 12], 100 mg twice daily [n = 12], or matching placebo [n = 13], starting 26 hours before virus inoculation) was administered. For the treatment study, the same drug was given (20 mg, 100 mg, or 200 mg twice daily, 200 mg once daily, or matching placebo [n = 16], in each group starting 28 hours after inoculation). All regimens were continued for 5 days.Main Outcome Measures: Comparing placebo groups with pooled treatment groups, for prophylaxis, outcomes included frequency of infection and viral shedding; for treatment, viral shedding in titers.Results: In the prophylaxis study, 8 (67%) of 12 placebo and 8 (38%) of 21 oseltamivir recipients became infected (P = .16; efficacy, 61%); 6 (50%) placebo compared with 0 oseltamivir recipients shed virus (P<.001; efficacy, 100%), and 33% of placebo but no oseltamivir recipient had infection-related respiratory illness (P<.01). Among infected subjects in the treatment study (n = 69), the viral titer area under the curve of the combined oseltamivir groups (n = 56) was lower (median [interquartile range [IQR]], 80 [23-151] vs 273 [79-306] log10 tissue culture-infective doses50 per milliliter x hour; P = .02) than the placebo group (n = 13), and the median (IQR) duration of viral shedding with therapy was reduced from 107 (83-131) to 58 (35-59) hours (P = .003). Oseltamivir treatment also reduced symptom scores (median [IQR] score-hours, 225 [97-349] vs 400 [189-645]; P = .05), and nasal proinflammatory cytokine levels. Transient mild to moderate nausea after dosing was observed in 15 (17%) of 88 oseltamivir and 2 (7%) of 29 placebo recipients (95% confidence interval for difference, -11% to 68%), which was largely prevented by ingestion with food.Conclusions: In these trials, prophylaxis and early treatment with oral oseltamivir were both associated with significant antiviral and clinical effects in experimental human influenza. [ABSTRACT FROM AUTHOR]

Studies the prevention and treatment of influenza in immunocompromised patients. General prevention measures; Immunization; Antiviral chemoprophylaxis; Antiviral therapy.

Evaluates whether intranasal administration of the sialic acid analog 4-guanidino-Neu5Ac2en (GG167), an inhibitor of influenza virus neuraminidase, was effective and safe in either preventing or treating experimental human influenza. Evaluation of the therapeutic effects of GG167; Frequencies of local nasal intolerance.

Abstract. Thirty-eight pediatric outpatients with pneumonia were studied by counterimmunoelectrophoresis for the presence of Haemophilus influenzae type b or pneumococcal antigenuria. Of the 38 patients eight (21%) had H influenzae type b antigenuria and two (5%) had pneumococcal antigenuria. H influenzae type b antigenuria was detected more frequently in patients <2 years of age than in older children. Urine counterimmunoelectrophoresis appears to be a useful tool for the etiologic diagnosis of bacterial pneumonia and should facilitate further studies of the epidemiology, pathogenesis, and clinical spectrum of this disease. Pediatrics 1983;71:780-783; counterimmunoelectrophoresis, bacterial pneumonia. [ABSTRACT FROM AUTHOR]

In late 1983, five patients living near Charlottesville, Virginia, were treated for an unusual syndrome of fever, headache, altered mentation, multifocal neurologic signs, and cerebrospinal fluid pleocytosis. Clinical signs of brainstem disease developed in four patients. All five had had recent exposure to forests or wood and contact with flea-infested dogs. Two patients died; one survivor has had recurrent seizures. Brain biopsy samples in two patients and autopsy findings in another showed cerebral vasculitis and perivasculitis involving mostly venules and capillaries. In the autopsy, the severest vascular lesions involved the brainstem and thalami, where they were accompanied by acute fibrinoid necrosis, but discrete vascular lesions of lesser intensity were randomly distributed in the white matter and cortex. Serologic studies on paired specimens in four patients showed significant cross-reacting antibody responses to rickettsial (typhus-group) antigens in the indirect hemagglutination, latex agglutination, and IgM microimmunofluorescence tests, but no agent was visualized or isolated. The cause of this serious inflammatory disorder is unknown. [ABSTRACT FROM AUTHOR]

Discusses the tolerability and clinical effectiveness of intranasal ipratropium bromide for the treatment of cold symptoms. Percentage of nasal discharge decline in patients using ipratropium bromide nasal sprays; Association of the drug with high rates of blood-tinged mucus; Relief of sneezing with the use of the nasal spray.

The article reflects on several human cases of avian influenza A (H5N1) virus infection. He informs about the retrospective cohort study published by Wang et al in the periodical "Clinical Infectious Diseases." Information on Human infections with the novel avian influenza A(H7N9) virus reported in China in March 2013 is also presented.

The authors discuss the developments in the global medical sector. They focus on the possible emergence of resistance during treatment with neuraminidase inhibitors due to the detection of an Arg292Lys mutation (N2 numbering) in the virus neuraminidase (NA) gene within two days of starting oseltamivir treatment in the first reported treatment of avian A (H7N9) influenza virus infection in human. The report by Yunwen Hu and colleagues on the subject is also cited.

The article discusses a study related to the positive effect of neuraminidase inhibitor drug therapy on severe patient outcomes during the spread of influenza A virus in the year 2009 and 2010. It informs that infection of the A virus subtype H1N1 revealed that antiviral therapy reduced the likelihood of severe outcomes. It also informs that the organization International Severe Acute Respiratory and Emerging Infection Consortium carry out treatment studies for Influenza.

An introduction is presented in which the editor discusses report within the journal on characterization of autopsy tissues from 45 patients suffering from fatal Influenza B viruses infections.

The article presents strategies in maintaining surveillance during an influenza A H1N1 pandemic. It stresses the importance of accurately measuring a set of illness indicators that can be gathered at a population-wide level. Defining a process by which consistent samples from people with severe acute respiratory illness and mild acute respiratory illness or influenza-like illness are tested for pandemic H1N1 virus daily or weekly in sentinel population is advised. The isolation of virus from subsets of mild and severe cases is also suggested.

Current influenza antivirals have limitations with regard to their effectiveness and the potential emergence of resistance. Encouragingly, several new compounds which inhibit the polymerase of influenza viruses have recently been shown to have enhanced pre-clinical and clinical effectiveness compared to the neuraminidase inhibitors, the mainstay of influenza antiviral therapy over the last two decades. In this review we focus on four compounds which inhibit polymerase function, baloxavir marboxil, favipiravir, pimodivir and AL-794 and discuss their clinical and virological effectiveness, their propensity to select for resistance and their potential for future combination therapy with the most commonly used neuraminidase inhibitor, oseltamivir. • Antiviral compounds targeting components of the polymerase complex PB1, PB2, and PA, are undergoing clinical investigation. • Baloxavir targets endonuclease activity of the PA polymerase subunit and was recently liscensed in Japan and USA for the treatment of influenza A and B viruses. • Favipiravir, a broad spectrum antiviral compound inhibits viral RNA polymerases and has limited licensure in Japan. • Pimodivir targets PB2 subunit of influenza A viruses preventing binding to 7-methyl GTP cap structures. • AL-794 binds to the endonuclease domain of PA but is no longer being evaluated for clinical use. [ABSTRACT FROM AUTHOR]

Reflects on the avian influenza (H5N1) epidemic. Prediction made by influenza experts about the next pandemic flu; Initiative taken by Great Britain to stockpile enough oseltamavir to treat 25% of its population; Information that most influenza viruses occur in birds, particularly the aquatic waterfowl that are their natural reservoir; Outbreaks of avian influenza (H5N1) in poultry occurred in 8 Asian countries in 2003.

Comments on an article by S. Gosh and colleagues about rhinoviruses and respiratory failure. Information on rhinoviruses; Question of whether rhinoviruses can replicate in respiratory areas with temperature impeding the virus' growth; Explanation for the lack of establishment of proof of the existence of rhinovirus pneumonia.

By Jan 7, 2020, Chinese scientists had isolated a novel coronavirus (CoV) from patients in Wuhan. The clinical features of 2019-nCoV, in comparison with SARS-CoV and Middle East respiratory syndrome (MERS)-CoV, are summarised in the table. Table Characteristics of patients who have been infected with 2019-nCoV, MERS-CoV, and SARS-CoV[[7], [10]] SARS-CoV=severe acute respiratory syndrome coronavirus. [Extracted from the article]