Potential impact of antiviral drug use during influenza pandemic

The recent spread of highly pathogenic strains of avian influenza has highlighted the threat posed by pandemic influenza. In the early phases of a pandemic, the only treatment available would be neuraminidase inhibitors, which many countries are considering stockpiling for pandemic use. We estimate the effect on hospitalization rates of using different antiviral stockpile sizes to treat infection. We estimate that stockpiles that cover 20%-25% of the population would be sufficient to treat most of the clinical cases and could lead to 50% to 77% reductions in hospitalizations. Substantial reductions in hospitalization could be achieved with smaller antiviral stockpiles if drugs are reserved for persons at high risk.     

The use of antiviral agents during an (impending) influenza pandemic

The preventive and therapeutic principles during an (impending) influenza pandemic differ fundamentally from those prevailing during the annual episodes ofinfluenza. Pending the availability of an effective pandemic vaccine, neuraminidase inhibitors are the only effective agents for the prevention and treatment of infections caused by a pandemic influenza virus. The development of an influenza pandemic has 6 phases: phases 3-5 reflect an increasing threat; phase 6 represents a manifest pandemic. During phases 3-5, a maximum effort is made to prevent or delay a pandemic. Neuraminidase inhibitors should be given not only to patients but also to their close contacts (post-exposure prophylaxis). During phase 6, post-exposure prophylaxis is no longer indicated and neuraminidase inhibitors are prescribed for all patients with symptoms ofpandemic influenza. Prophylaxis without preceding close contact with an influenza patient (primary prophylaxis) is recommended only in exceptional cases. Physicians should not prescribe antiviral drugs on demand to concerned citizens for stockpiling.     

北京市城区居民甲型H1N1流感防治知识和相关行为电话调查

目的 了解甲型H1N1流感流行期间北京市城区居民个人防护行为和就医行为.方法 运用Mitofsky-Waksberg二阶段抽样方法,电话调查北京市城区≥18岁居民,询问甲型H1N1流感流行前夕和大流行时,居民个人防护和就医等行为变化.结果 共调查286名居民(应答率为62%).居民打喷嚏遮挡的比例,在家(77%,95%CI:71%～82%)低于公共场所(93%,95%CI:89%～96%).在家中,66%(95%CI:57%～74%)用手遮挡,33%(95%CI:25%～42%)用纸巾遮挡,0.4%(95%CI:0.1%～2.9%)用衣袖遮挡.在公共场所用手、纸和衣袖遮挡的比例分别为64%(95%CI:56%～71%)、33%(95%CI:26%～41%)、0%;用手遮挡打喷嚏后洗手在公共场所中的比例(46%,95%CI:32%～59%)低于家中(77%,95%CI:64%～89%).大流行发生时戴口罩(63%,95%CI:56%～70%)、接种疫苗(43%,95%CI:37%～50%)的比例均明显高于大流行前夕(分别为3.5%,95%CI:1.7%～7.0%;13%,95%CI:9.8%～18%);大流行时因甲型H1N1流感就诊的比例(86%,95%CI:81%～89%)与流行前夕(76%,95%CI:70%～81%)的差异无统计学意义.流行前夕选择三级医院就诊比例为71%(95%CI:63%～78%),大流行时为74%(95%CI:66%～80%).结论 北京市居民打喷嚏后用衣袖或纸巾遮挡、洗手的比例较低,需要加大宣传正确的个人防护行为;选择三级医院就诊比例较高,需要优化和引导就诊倾向.     

Personal protective equipment use by in-line skaters in Victoria

OBJECTIVE: To describe use of personal protective equipment (PPE) by in-line skaters at four different skate settings (rink, park, trail and street) in Melbourne and rural Victoria, and to compare local PPE with reported international use. METHOD: Unobtrusive observations of in-line skaters at four types of skate settings (rinks, parks, trails, street) in Melbourne and rural Victoria. RESULTS: Two-thirds of 490 observed in-line skaters (66.7%) wore none of the recommended PPE (wrist guards, elbow and knee pads and helmets). Only 2.2% wore all four pieces of PPE. Wrist guards were worn by 25.9% of skaters, knee pads by 23.5%, elbow pads by 6.9% and helmets by 5.5%. Younger skaters were least likely to wear any PPE. Trail skaters were more likely to wear PPE than skaters on rinks, parks and streets. Almost one-third of skaters did not have a heel brake on their skates. Use of PPE was influenced by group norms. CONCLUSION: Personal protective equipment use is low among in-line skaters in Victoria, and varies according to skate location. The use of PPE in Victoria is much lower than that reported overseas. IMPLICATIONS: Evidence of the effectiveness and the low use of PPE by skaters highlights the need to better promote the use of wrist guards, elbow and knee pads and helmets to skaters of all ages and abilities. There is opportunity for public health professionals to work in partnership with in-line skating bodies, organisers and sponsors of skating events, skate venue owners and managers, skating equipment manufacturers and hirers to promote PPE use.     

An introduction to avian and pandemic influenza

There are many types of influenza viruses, which cause illness in a variety of birds and mammals. New strains are constantly evolving, causing seasonal influenza epidemics in humans. This article provides information about influenza and influenza viruses, and the three influenza pandemics of the twentieth century. Pandemic influenza is differentiated from avian influenza, which is a viral disease that primarily infects birds. The current outbreak of avian influenza H5N1 in poultry flocks across the world is unprecedented in its spread. Human infection with avian influenza is rare and for most strains the symptoms are usually mild. A notable exception is HN51, where almost 60 per cent of the currently recorded 251 human cases have died. While the risk of a pandemic occurring in the current circumstances is unknown, there is a high level of concern worldwide.     

Personal protective equipment and dermal exposure

Personal protective equipment (PPE) should only be used as a control measure when other measures are inappropriate or are inadequate by themselves. The person undertaking a risk assessment must exercise his or her judgment to take into account the protection afforded by the PPE. There is, therefore, considerable scope for differences in approach and it would seem sensible to eliminate these differences and ensure consistency, where possible, by reaching agreement on the attenuating effect of PPE. However, there is growing evidence that the levels of protection indicated by laboratory-based tests may not be achieved in real use situations. Studies of workplace protection suggest that the spread of contaminants inside protective clothing, including gloves, is commonplace and significant. Insufficient attention may have been paid to the effect of factors such as temperature differentials on the permeation of chemical agents through protective materials. To investigate this, a test cell was designed and built to measure the breakthrough times and subsequent permeation rate of solvents through glove materials where the temperature inside and outside the glove was representative of those that can occur in the workplace. Two chemical solvents were tested against two different glove materials at three different temperature conditions. The differences between the breakthrough times and permeation rates were measured and compared to manufacturer's test data. The practical implications are considered for risk of health and safety to the wearer.     

Effectiveness of pandemic and seasonal influenza vaccines in preventing pandemic influenza-associated hospitalization

Vaccines are leading pharmacological measures for limiting the impact of pandemic influenza in the community. The objective of this study was to investigate the effectiveness of influenza (pandemic and seasonal) vaccines in preventing pandemic influenza-associated hospitalization. We conducted a multicenter matched case-control study in 36 Spanish hospitals. Patients hospitalized with confirmed pandemic influenza between November 2009 and February 2010 and two hospitalized controls per case, matched according to age, date of hospitalization and province of residence, were selected. Multivariate analysis was performed using conditional logistic regression. Subjects were considered vaccinated if they had received the vaccine >14 days (seasonal influenza vaccine) or >7 days (pandemic influenza vaccine) before the onset of symptoms (cases) or the onset of symptoms of the matched case (controls). For the pandemic influenza vaccine, vaccination effectiveness (VE) was estimated taking into account only patients recruited from November 23, 2009, seven days after the beginning of the pandemic influenza vaccination campaign. 638 cases and 1250 controls were included. The adjusted VE of the pandemic vaccine in the ≥18 years age group was 74.2% (95% CI, 29-90) and that of the influenza seasonal vaccine 15.0% (-34 to 43). The recommendation of influenza vaccination should be reinforced as a regular measure to reduce influenza-associated hospitalization during pandemics and seasonal epidemics.     

Preparedness for highly pathogenic avian influenza pandemic in Africa

Global concerns about an impending influenza pandemic escalated when highly pathogenic influenza A subtype H5N1 appeared in Nigeria in January 2006. The potential devastation from emergence of a pandemic strain in Africa has led to a sudden shift of public health focus to pandemic preparedness. Preparedness and control activities must work within the already strained capacity of health infrastructure in Africa to respond to immense existing public health problems. Massive attention and resources directed toward influenza could distort priorities and damage critical public health programs. Responses to concerns about pandemic influenza should strengthen human and veterinary surveillance and laboratory capacity to help address a variety of health threats. Experiences in Asia should provide bases for reassessing strategies for Africa and elsewhere. Fowl depopulation strategies will need to be adapted for Africa. Additionally, the role of avian vaccines should be comprehensively evaluated and clearly defined.     

Cost-effectiveness of antiviral stockpiling and near-patient testing for potential influenza pandemic

A decision analytical model was developed to investigate the cost-effectiveness of stockpiling antiviral (AV) drugs for a potential influenza pandemic in the United Kingdom and the possible role of near-patient testing in conserving AV drug stocks. Under base-case assumptions (including a fixed stockpile that was smaller than the clinical attack rate), the treat-only option (treating all symptomatic patients with AV drugs) would be considered cost-effective ( pound1,900- pound13,700 per quality-adjusted life year [QALY] gained, depending on the fatality scenario), compared with no intervention (nonintervention but management of cases as they arise). The test-treat option (testing all symptomatic patients but treating those with positive tests results only) would result in moderate gains in QALYs over the treat-only option but at relatively large additional costs. Stockpiling sufficient AV drugs (but not near-patient tests) to treat all patients with clinical cases would be cost-effective, provided AV drugs are effective at preventing deaths from pandemic influenza.     

Modelling strategic use of the national antiviral stockpile during the CONTAIN and SUSTAIN phases of an Australian pandemic influenza response

Objective: To define optimum use of the national antiviral stockpile during the early phases of the response to pandemic influenza in Australia, to inform the 2008 revision of the Australian Health Management Plan for Pandemic Influenza. Methods: A mathematical model was used to compare strategic uses of antiviral agents for treatment and post‐exposure prophylaxis to limit transmission until availability of a strain‐specific vaccine. The impact of provision of pre‐exposure prophylaxis to healthcare workers (HCWs) on the ability to control the epidemic was also assessed. Results: Optimal constraint of epidemic growth was achieved by intensive ascertainment of contacts of cases for post‐exposure prophylaxis for as long as feasible. While pre‐exposure prophylaxis of healthcare workers utilised a substantial proportion of the stockpile, this did not impede disease control or the ability to treat cases. Absolute delays to outbreak depended on both the intervention strategy and the growth rate of the epidemic. As vaccination was only effective when introduced before explosive growth, this timing was critical to success. Conclusions and implications: Liberal distribution of antiviral drugs to limit disease spread for as long as is feasible represents optimal use of these agents to constrain epidemic growth. In reality, additional non‐pharmaceutical control measures are likely to be required to control transmission until vaccines can definitively contain pandemic influenza outbreaks.     

Emergency department visits for antiviral adverse events during the 2009 H1N1 influenza pandemic

The 2009 pandemic influenza A (H1N1) outbreak was associated with an increased use of antiviral agents and highlighted the role of population-based monitoring for related adverse drug events (ADEs). An ongoing, nationally representative emergency department-based surveillance system was used to identify and characterize ADEs during the pandemic. Active surveillance for ADEs successfully provided timely, population-based data during the pandemic. Increases in antiviral ADEs paralleled increases in prescribing. Type and severity of ADEs were similar across all seasons.     

Nucleic acid-based antiviral drugs against seasonal and avian influenza viruses

Influenza viruses are etiological agents of deadly flu that continue to pose global health threats, and have caused global pandemics that killed millions of people worldwide. The availability of neuraminidase inhibitors and attenuated vaccines improves our ability to defend against influenza, but their benefits can be significantly limited by drug-resistance and virus mutations. Nucleic acid-based drugs may represent a promising class of antiviral agents that could play a role in the prevention and treatment of influenza. Efficacy studies in animals have shown that ds RNA, such as poly ICLC can provide effective and broad-spectrum prophylaxis against lethal challenges against various strains of influenza A virus. Furthermore, similar level of antiviral protection in mice can be provided by using short fragments of oligonucleotides that induce antiviral immunity. Finally, influenza virus expression can also be specifically inhibited or suppressed using antisense oligonucleotides that bind to viral mRNA encoding key viral proteins. The versatility and potency of nucleic acid-based drugs make them potential drug candidates for used in seasonal or pandemic influenza situations.     

Personal protective equipment (PPE) use and its relation to accidents among construction workers

Background:The construction industry is characterized by a high prevalence of accidents and injuries. Inadequate risk management measures, including failure to use or incorrect use of personal protective equipment (PPE) may significantly increase the risk of accidents.Objectives:The main objectives of the current study were to measure the prevalence of PPE use and accidents and their associated factors among construction workers.Methods:A cross-sectional field study with an analytic component was carried out on 384 workers from different sites in Port-Said, Egypt, using an interview administered questionnaire. The questionnaire included sociodemographic and occupational data, practice of PPE use and accident analysis.Results:About 60% of workers use PPE during work. Main reasons for non-use are discomfort, lack of knowledge on how to use it and poor fit. Occupational accidents in the last 12 months were reported by 64.3% of workers. The main accident types were: being hit by falling objects, falls from height, and tool related accidents. Safety training was the significant independent predictor of PPE use (AOR=2.0). However, age, marital status, smoking, safety training, and PPE use were also significant independent predictors of accidents (AOR=2.4, 3.1, 0.5, 0.5, and 0.2; respectively).Discussion:Among construction workers, PPE utilization is low with significant relation to safety training while occupational accidents are common and significantly related to safety training and PPE use. Therefore, safety training should be provided, and PPE use should be enforced at construction sites.Key words: Accidents, construction, PPE, safety