Containing pandemic influenza with antiviral agents

For the first wave of pandemic influenza or a bioterrorist influenza attack, antiviral agents would be one of the few options to contain the epidemic in the United States until adequate supplies of vaccine were available. The authors use stochastic epidemic simulations to investigate the effectiveness of targeted antiviral prophylaxis to contain influenza. In this strategy, close contacts of suspected index influenza cases take antiviral agents prophylactically. The authors compare targeted antiviral prophylaxis with vaccination strategies. They model an influenza pandemic or bioterrorist attack for an agent similar to influenza A virus (H2N2) that caused the Asian influenza pandemic of 1957-1958. In the absence of intervention, the model predicts an influenza illness attack rate of 33% of the population (95% confidence interval (CI): 30, 37) and an influenza death rate of 0.58 deaths/1,000 persons (95% Cl: 0.4, 0.8). With the use of targeted antiviral prophylaxis, if 80% of the exposed persons maintained prophylaxis for up to 8 weeks, the epidemic would be contained, and the model predicts a reduction to an illness attack rate of 2% (95% Cl: 0.2, 16) and a death rate of 0.04 deaths/1,000 persons (95% CI: 0.0003, 0.25). Such antiviral prophylaxis is nearly as effective as vaccinating 80% of the population. Vaccinating 80% of the children aged less than 19 years is almost as effective as vaccinating 80% of the population. Targeted antiviral prophylaxis has potential as an effective measure for containing influenza until adequate quantities of vaccine are available.     

The use of face masks during vaccine roll-out in New YorkCity and impact on epidemic control

Face masks were mandated in New York during the first wave in 2020, and in 2021 the first vaccine programs have commenced. We aimed to examine the impact of face mask and other NPIs use with a gradual roll out of vaccines in NYC on the epidemic trajectory.A SEIR mathematical model of SARS-CoV-2 transmission was developed for New York City (NYC), which accounted for decreased mobility for lockdown, testing and tracing. Varied mask’s usage and efficacy were tested, along with a gradual increase in vaccine uptake over five months. The model has been calibrated using notification data in NYC from March first to June 29.Masks and other NPIs result in immediate impact on the epidemic, while vaccination has a delayed impact, especially when implemented over a long period of time. A pre-emptive, early mandate for masks is more effective than late mask use, but even late mask mandates will reduce cases and deaths by over 20%. The epidemic curve is suppressed by at least 50% of people wearing a mask from the start of the outbreak but surges when mask wearing drops to 30% or less. With a slow roll out of vaccines over five months at uptake levels of 20–70%, NPIs use will still be needed and has a greater impact on epidemic control.When vaccine roll out is slow or partial in cities experiencing local transmission of COVID-19, masks and other NPIs will be necessary to mitigate transmission until vaccine coverage is high and complete. Vaccine alone cannot rapidly control an epidemic because of the time lag to two-dose immunity. Even after high coverage, the ongoing need for NPIs is unknown and will depend on long-term duration of vaccine efficacy, the use of boosters and optimized dosage scheduling and variants of concern.     

Influenza--its impact and control.

Influenza is an underestimated public health problem. Epidemics spread rapidly from country to country and may affect as many as 500 million people across the world in a moderate influenza year. The disease, particularly influenza A, kills and the new influenza viruses which appeared in 1957 (Asian influenza) and 1968 (Hong Kong) are estimated to have caused at least 100,000 deaths in the United States of America. Deaths from influenza also occur in years when there is no new virus; at least 10,000 excess deaths have been documented in the United States during each of 18 different epidemics recorded from 1957 to 1985. Although most deaths are among the elderly, influenza occurs in all age groups with repercussions in schools and work places, and on hospital resources, at a high cost to society. As many as 79-80% of influenza cases can be prevented when the virus inducing the outbreak and the virus used in the influenza vaccine are closely related. Preventing 80% of cases would correspond in the United States to a saving of US $2.5 billion. People at the greatest risk of influenza-related complications are adults and children with chronic disorders of the pulmonary or cardiovascular systems, residents of nursing homes and of facilities for patients with chronic medical conditions. Other priority groups for vaccination are those at moderate risk of influenza-related complications such as healthy elderly persons, people with chronic metabolic diseases, children and teenagers on long-term aspirin therapy. Groups potentially capable of transmitting influenza to high-risk persons should also be vaccinated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Report on the first two years of the Czechoslovak Influenza Centre

The Czechoslovak Influenza Centre, which was set up in 1956, is attached to the Institute of Epidemiology and Microbiology at Prague and is supported in its activity by 15 virological laboratories situated in various parts of Czechoslovakia, which perform serological investigations of influenza and virus isolations.The first isolations of A2 influenza viruses in Czechoslovakia were made towards the end of May 1957. At the end of that year and early in 1958, B viruses were also isolated in several regions of Czechoslovakia, although the A2 viruses were more frequently encountered. The newly isolated B strains differed from those circulating in the country five years previously, and were added in 1958 to what had been a monovalent A2 vaccine.Favourable preliminary experiments were made in 1957-58 with the use of immune horse serum for influenza prophylaxis.The Czechoslovak Influenza Centre has taken part in an international investigation of animal sera (largely horse and swine) for the presence of influenza antibodies. In this work, use has been made of the virus A-equi/Praha/56, which was isolated by workers from the Centre.     

中国流感大流行的百年历史

流感大流行在过去100年间出现过5次（1918年"西班牙流感"、1957年"亚洲流感"、1968年"香港流感"、1977年"俄罗斯流感"和2009年甲型H1N1流感）,累计数亿人感染和数千万人死亡。历史文献表明5次大流行均波及我国多个地区,产生了较大规模的影响,其中1957、1968和1977年流感大流行被认为是从我国开始暴发。流感大流行直接促使我国设立公共卫生机构和流感专业部门,并在科学研究与疫情防控上加大投入。我国应当进一步加强流感大流行的准备与应对,承担流感领域领导者的责任,为全球健康作出贡献。     

1951 influenza epidemic, England and Wales, Canada, and the United States

Influenza poses a continuing public health threat in epidemic and pandemic seasons. The 1951 influenza epidemic (A/H1N1) caused an unusually high death toll in England; in particular, weekly deaths in Liverpool even surpassed those of the 1918 pandemic. We further quantified the death rate of the 1951 epidemic in 3 countries. In England and Canada, we found that excess death rates from pneumonia and influenza and all causes were substantially higher for the 1951 epidemic than for the 1957 and 1968 pandemics (by > or =50%). The age-specific pattern of deaths in 1951 was consistent with that of other interpandemic seasons; no age shift to younger age groups, reminiscent of pandemics, occurred in the death rate. In contrast to England and Canada, the 1951 epidemic was not particularly severe in the United States. Why this epidemic was so severe in some areas but not others remains unknown and highlights major gaps in our understanding of interpandemic influenza.     

Intention to receive influenza vaccination prior to the summer influenza season in adults of Hong Kong, 2015

Following a severe winter epidemic of drifted influenza A(H3N2) during January–March 2015, the Hong Kong government purchased vaccines of southern hemisphere formulation for administration prior to the anticipated summer influenza epidemic. This is the first time that seasonal influenza vaccines will be delivered twice within the same year in Hong Kong. We conducted a household telephone survey to investigate the acceptance of Hong Kong adults to pre-summer influenza vaccination. We found that the proportion of people reporting intention to receive vaccination was 37.8, 24.0, 31.4, and 34.4% in the age groups of 18–39, 40–59, 60–69, and 70 years or above. Only 31.3% of respondents who claimed they were parents or guardians said they would take their children to receive vaccination if the new vaccine was available. These findings suggested that intention to receive pre-summer vaccination was low even among the priority group of older people.     

Helmet Use Among Cyclists in New York City

Lack of helmet use while bicycling can have deleterious effects on health. Despite evidence that helmets can greatly reduce the risk of head injury, the prevalence of helmet use among riders, including those in urban bicycle-share programs, has been shown to be very low. Building upon the authors’ previous work, this study’s aim was to assess prevalence of helmet use among cyclists riding on widely used New York City (NYC) bike lanes. Across a 2-month period, cyclists were filmed in five NYC locations with bike lanes. Filming took place at two separate time periods (recreation and commute) at each location. Helmet use was coded for each cyclist. A total of 1,921 riders were observed across 10 h. Overall, half (50.0 %) of all riders were observed wearing a helmet. Rates of using a helmet were consistent across all five locations. In addition, only 21.7 % of Citi Bike users and 15.3 % of other bicycle rentals were observed wearing helmets while cycling. The prevalence of helmet use was significantly higher among males than females (z = 4.48, p < .001). Cyclists observed during the recreational time period were also less likely than those observed during the commuting time period to be wearing a helmet (z = 7.17, p < .001). The results of this study contribute to the growing literature about cyclist helmet use in urban areas.     

Experience with influenza vaccination in Iceland, 1957

An epidemic of Asian influenza which occurred in Iceland in October and November 1957 is briefly described. About 8000 persons were vaccinated with two injections of a vaccine containing 100 CCA units of Asian virus per dose. The inactivated virus was adsorbed on aluminium phosphate. Data are given on the antibody production after vaccination.The results of a survey indicate that vaccination with this type of vaccine, when performed early enough, reduced the incidence of influenza by some 67%. Moreover, the cases which did occur in vaccinated persons seemed to be of less than average severity.     

The 1965 A2 influenza epidemic in the USSR and the natural history of Asian influenza

An epidemic of Asian (A2) influenza that occurred in the USSR early in 1965 was the fourth wave of Asian influenza there since 1957, when the disease became pandemic, spreading through all countries and continents. The 1965 epidemic was severe, in several cities even more so than the 1957 pandemic. Study of the antigenic structure of the viruses isolated during the latest epidemic indicated that the viruses were similar to those isolated in western Europe in 1964 (A2/England 12/64) but that their structure showed a further shift away from that of the prototype virus (A2/Singapore 1/57). The 1957 and 1959 pandemics followed similar courses, starting in China. The third wave affected Europe. North Africa and Asia in winter 1960-61, but did not reach the USSR until the following winter. The fourth wave was more complex, spreading in Asia in 1962-63 and in Europe and America in 1963-64; it reached the USSR at the beginning of 1965. The way in which the structure of the A2 virus has changed since 1957 is discussed.     

Access To Influenza Vaccine In East Harlem And The Bronx During A National Vaccine Shortage

In October 2004, one of the major producers of the U.S. influenza vaccine supply announced that their vaccine would not be available because of production problems, resulting in approximately half of the anticipated supply suddenly becoming unavailable. This study was part of a larger effort using community-based participatory research (CBPR) principles to distribute influenza vaccine to hard-to-reach populations. Given the extant literature suggesting economic and racial disparities in influenza vaccine access in times of adequate supply and our inability to distribute vaccine due to the shortage, we sought to examine vaccine access as well as awareness of the vaccine shortage and its impact on health-seeking behaviors in eight racially-diverse and economically-disadvantaged neighborhoods in New York City (NYC) during the shortage. In our study few people had been vaccinated, both among the general community and among high risk groups; vaccination rates for adults in priority groups and non-priority groups were 21.0% and 3.5%. Awareness of the 2004 vaccine shortage was widespread with over 90% being aware of the shortage. While most attributed the shortage to production problems, almost 20% said that it was due to the government not wanting to make the vaccine available. Many respondents said they would be more likely to seek vaccination during the current and subsequent influenza seasons because of the shortage. The target neighborhoods were significantly affected by the national influenza vaccine shortage. This study highlights the challenges of meeting the preventive health care needs of hard-to-reach populations in times of public health crisis.     

Steel dust in the New York City subway system as a source of manganese, chromium, and iron exposures for transit workers

The United States Clean Air Act Amendments of 1990 reflected increasing concern about potential effects of low-level airborne metal exposure on a wide array of illnesses. Here we summarize results demonstrating that the New York City (NYC) subway system provides an important microenvironment for metal exposures for NYC commuters and subway workers and also describe an ongoing pilot study of NYC transit workers’ exposure to steel dust. Results from the TEACH (Toxic Exposure Assessment, a Columbia and Harvard) study in 1999 of 41 high-school students strongly suggest that elevated levels of iron, manganese, and chromium in personal air samples were due to exposure to steel dust in the NYC subway. Airborne concentrations of these three metals associated with fine particulate matter were observed to be more than 100 times greater in the subway environment than in home indoor or outdoor settings in NYC. While there are currently no known health effects at the airborne levels observed in the subway system, the primary aim of the ongoing pilot study is to ascertain whether the levels of these metals in the subway air affect concentrations of these metals or related metabolites in the blood or urine of exposed transit workers, who due to their job activities could plausibly have appreciably higher exposures than typical commuters. The study design involves recruitment of 40 transit workers representing a large range in expected exposures to steel dust, the collection of personal air samples of fine particulate matter, and the collection of blood and urine samples from each monitored transit worker.     

移动流行区间法在北京市流感流行阈值估计及强度分级中的应用

目的估计北京市流感流行阈值和分级强度阈值,对2018-2019年流行季流感流行水平进行分级预警,并对估计阈值的方法进行评价。方法应用北京市近5个流感流行季的流感样病例数和流感样病例百分比(ILI%)监测数据,采用移动流行区间法(MEM)估计流感流行阈值和分级强度阈值。应用交叉验证方法评价MEM与2种监测数据类型估计流行阈值的预警效果,评价指标为马修相关系数、约登指数、灵敏度和特异度。结果估计预警2018-2019年流行季的流感样病例数的流行阈值为12984例、中位强度阈值为22503例、高强度阈值为37589例、超高强度阈值为47157例,评价流行阈值的指标马修相关系数为62%、约登指数为60%、灵敏度为69%、特异度为91%。应用ILI%监测数据,估计预警2018-2019年流行季流感流行阈值、中位强度阈值、高强度阈值及超高强度阈值分别为1.66%、2.46%、3.84%和4.66%,评价流行阈值的指标马修相关系数为59%、约登指数为54%、灵敏度为60%、特异度为94%。结论MEM对预警流感流行有较好特异性,准确性在可接受范围内,该方法可在北京市流感分级预警中进行实际应用。应用流感样病例数监测资料预警效果略优于ILI%。     

No Attitude,No Standing Around: The Organization of Social and Sexual Interaction at a Gay Male Private Sex Party in New York City

Following the onset of the AIDS epidemic, many jurisdictions have outlawed commercial sex-on-premise venues (bathhouses, adult theaters, sex clubs), greatly changing the culture of public or group sex. Today, in New York City (NYC), private sex parties are the main venues for group sex. Dozens of such events are held on a regular basis in the city, attracting sometimes a few hundred participants. Past research in group sex venues shows that different spaces allow for different kinds of sexual and social interaction. What are the norms of interaction of today’s private sex parties? This article answers this question by using data collected ethnographically in one recurring gay male private sex party in NYC. The event was a small organization that brought all its participants together in one space at the same time, thus creating great physical intimacy and leading to convivial socialization and interpersonal bonding. This differs from the model of anonymous and impersonal sex that previous researchers have seen in public and commercial spaces. Private sex parties present risk for the transmission of HIV and other sexually-transmitted infections, but their organization and norms of interaction also present new avenues for prevention. Policy-makers should work to make these places safer rather than outlawing them.     

The 'Russian' influenza in the UK: lessons learned, opportunities missed

This paper describes British efforts to map the Russian influenza outbreaks of the early 1890s and describe the timing and course of the epidemic waves. Drawing on two surveys conducted by Britain's Local Government Board (LGB), the paper shows how, in a pre-virological era, the board was able to establish that influenza was an intensely infectious disease. Its key observation, however, was that Russian influenza had taken the form of three, and possibly four, distinct waves of infection, with the second wave in the spring of 1891 proving more lethal than the first wave, and the third wave in the winter of 1892 proving almost as lethal again. Most of this mortality was due to excess deaths from respiratory disease, particularly in the middle age ranges, but while these insights could and, arguably, should have aided the public health response, British health authorities preferred to advocate cautious preventive measures that did little to alleviate the pandemic's impact. The policy would prove especially costly in 1918-1919 when the LGB missed the opportunity to provide extra nursing cover for influenza convalescents following the initial summer wave of the 1918 Spanish influenza pandemic.     

军队人群流感监测(1995～200O)

目的：建立“全军流感监测系统”,获得流感流行病学数据和病毒变异及流行趋势,实施流感预测预报,方法：按WHO规定的原理和方法进行：对流感流行株,抗原和基因以及血清抗体和病毒多原实行监测。结果：获军队流感病毒流行株40株,副流感Ⅱ型流行株2株,6000名战士血清流感抗体纵向监测表明;每年每名战士平均受流感病毒侵袭1．4次,流感抗体在6个月之内下降67％,流感抗体横向监测表明：甲1型流感抗体从1995年以来呈阶梯形下降,易感人群由15％上升至75％,甲3型流感抗体从1997年以来长期处于高水平,预示将会发生变异,1000余名战士鼻咽分泌物多病原检测结果表明：流感冒发流行期病毒总检出率为70％,一般流行季节约50％,抗原性变异和基因测序分析结果表明：甲1型流感株已发生明显变异,发现3株新流行株与标准株的同源性仅有92％和91％,新株丢失了130位氨基酸和304位糖化位点,对14840名战士调查表明：在流行季节45d内,流感发病率＞21％,缺勤约50万工作日,军营病毒暴发流行疫情可在6h作出.报告。结论：初步建立了军队人群流感监测系统,掌握了军队战士主要呼吸道病毒的发病率和易感率,为流感的预测和预报提供了科学依据。     

北京市顺义区甲型H1N1流感健康教育效果评价

目的了解顺义区居民对甲型H1N1流感疫情的相关知识、态度以及行为改变情况,评价健康教育效果,为今后开展突发公共卫生事件健康教育工作总结经验。方法甲型H1N1流感流行期间及时实施干预措施,即在全区范围内开展形式多样的健康教育活动。采用分层随机抽样方法,于甲型流感开始时（2009年5月）和结束后（2010年3月）分别随机抽取顺义区社区、村及职业人群开展调查。结果干预后公众对容易感染甲型H1N1流感的行为知晓率由32.8%提高到78.3%、预防甲型H1N1流感的有效手段知晓率由16.4%提高到60.2%,公众对该次疫情信息公布工作的满意度由82.1%提高到92.4%。结论在应对突发公共卫生事件时,在全社会范围内开展大规模的健康教育是有效果而且非常有必要的;绝大多数居民对于政府应对突发公共卫生事件时信息发布工作满意,今后可以继续充分利用大众媒体向居民宣传相关知识和应对措施,及时发布最新流行态势等。     

Creation of a tuberculosis directly observed therapy provider network in New York City: a new model of public health.

A 1990-1991 New York State Department of Health (NYSDOH) assessment of the ongoing tuberculosis (TB) epidemic in New York City (NYC) led to legislative enactment of policy recommendations to help stem the epidemic. The principal strategy entailed mobilization of community resources for TB directly observed therapy (DOT) to supplement the DOT available from the NYC Department of Health (NYCDOH). For implementation, the NYSDOH engaged a coalition of public and private health care providers in a TB DOT Provider Network. Network participants include freestanding facilities, many of which already have preexisting affiliative relationships through which DOT can be extended. The number of individuals receiving DOT in NYC has increased more than 10-fold in two years. Over 1,000 individuals have completed their anti-TB treatment while enrolled in the network.     

甲型H1N1流感不同流行时期农民知信行变化趋势分析

目的了解流行高峰期和流行后期某市郊区农民甲型H1N1流感和季节性流感知识、态度、行为(KAP)及流感疫苗接种情况的变化趋势。方法采用分阶段按容量比例概率抽样法(PPS),分别于甲型H1N1流感流行高峰期和流行后期对某市郊区农民进行两次电话调查。结果两次电话调查分别完成有效调查表202份和201份,接通电话的有效应答率分别为60.48%和60.73%。流行高峰期与流行后期农民对甲型H1N1流感传播方式的知晓率差异无统计学意义(P﹥0.05)。出现流感样症状时,流行高峰期去县级及县级以上医院就诊的比例高于流行后期(P﹤0.05),但在咳嗽打喷嚏时遮掩口鼻、洗手时用肥皂/洗手液和外出戴口罩等的比例差异无统计学意义(P﹥0.05)。普通流感疫苗的接种率在流行后期高于流行高峰期(P﹤0.05),但不同时期甲型H1N1流感疫苗的接种率及接种意愿等未见统计学差异(P﹥0.05)。结论该市郊区农民对甲型H1N1流感知识掌握不全面,甲型H1N1流感流行高峰期和流行后期农民的知识、态度、行为未见明显改变。     

Responding to simulated pandemic influenza in San Antonio, Texas.

OBJECTIVE: To describe the results of a simulation study of the spread of pandemic influenza, the effects of public health measures on the simulated pandemic, and the resultant adequacy of the surge capacity of the hospital infrastructure and to investigate the adequacy of key elements of the national pandemic influenza plan to reduce the overall attack rate so that surge capacity would not be overwhelmed. DESIGN: We used 2 discrete-event simulation models: the first model simulates the contact and disease transmission process, as affected by public health interventions, to produce a stream of arriving patients, and the second model simulates the diagnosis and treatment process and determines patient outcomes. SETTING: Hypothetical scenarios were based on the response plans, infrastructure, and demographic data of the population of San Antonio, Texas. RESULTS: Use of a mix of strategies, including social distancing, antiviral medications, and targeted vaccination, may limit the overall attack rate so that demand for care would not exceed the capacity of the infrastructure. Additional simulations to assess social distancing as a sole mitigation strategy suggest that a reduction of infectious community contacts to half of normal levels would have to occur within approximately 7 days. CONCLUSIONS: Under ideal conditions, the mix of strategies may limit demand, which can then be met by community surge capacity. Given inadequate supplies of vaccines and antiviral medications, aggressive social distancing alone might allow for the control of a local epidemic without reliance on outside support.