Prevention Of Pandemic Influenza Research Articles

Fifty Years of Influenza A(H3N2) Following the Pandemic of 1968.

In 2018, the world commemorated the centennial of the 1918 influenza A(H1N1) pandemic, the deadliest pandemic in recorded history; however, little mention was made of the 50th anniversary of the 1968 A(H3N2) pandemic. Although pandemic morbidity and mortality were much lower in 1968 than in 1918, influenza A(H3N2) virus infections have become the leading cause of seasonal influenza illness and death over the last 50 years, with more than twice the number of hospitalizations from A(H3N2) as from A(H1N1) during the past six seasons. We review the emergence, progression, clinical course, etiology, epidemiology, and treatment of the 1968 pandemic and highlight the short- and long-term impact associated with A(H3N2) viruses. The 1968 H3N2 pandemic and its ongoing sequelae underscore the need for improved seasonal and pandemic influenza prevention, control, preparedness, and response efforts.

A review of documents prepared by international organizations about influenza pandemics, including the 2009 pandemic: a bibliometric analysis

BackgroundWorld Health Organization (WHO), the World Bank, UN System Influenza Coordination (UNSIC) and other international organizations released a series of documents to fight against the influenza pandemic. Those documents have great significance on guiding influenza pandemic preparedness and responses and providing a multilevel, multi-directional influenza pandemic prevention and control network for their member countries. This study focuses on the above-mentioned influenza pandemic preparedness guidelines with the aim of exploring the roles of the society, defining the relationship of different interventions and evaluating the planning on influenza pandemic preparedness.MethodsDocuments about pandemic influenza preparedness were retrieved from the official websites of the following three international organizations, World Health Organization (WHO), the World Bank, UN System Influenza Coordination (UNSIC) with the key words ‘pandemic’, ‘influenza’ and the Boolean combinations of these words as the retrieval strategy. Guidelines, research study and meeting reports were included in the study. The categories of the ministries/departments involved and their roles/responsibilities in pandemic influenza preparedness were summarized. Word frequency of selected vocabularies about pandemic influenza preventive measures were collected from the documents and the correlations between the word frequency of these measures were analyzed. Ochiai coefficient was employed to show the correlation between the word vocabularies.ResultsA total of 38 records on the topic of pandemic influenza preparedness were included. The responsibilities of the whole-of-society mentioned in the international organizations’ documents varied across the 2009 influenza pandemic period. Meanwhile, it had been emphasized that a comprehensive influenza prevention and control plan in every sector should be developed and evaluated. Because various measures were emphasized in the guidelines after 2009 pandemic influenza, the correlations between the word frequencies of the various influenza preventive measures became stronger after the pandemic influenza.ConclusionsResponsibilities of ministries of education, ministries of energy, ministries of agriculture and animal health, ministries of communication and the business sector in the pandemic influenza preparedness were described more comprehensively in the international organizations’ documents in 2017. Better understanding the variations of the guidelines delivered by international organizations would be useful for the member countries to strengthen their influenza control network.

Preventive behaviors adults report using to avoid catching or spreading influenza, United States, 2015-16 influenza season.

IntroductionInfluenza vaccination can prevent influenza and potentially serious influenza-related complications. Although the single best way to prevent influenza is annual vaccination, everyday preventive actions, including good hygiene, health, dietary, and social habits, might help, too. Several preventive measures are recommended, including: avoiding close contact with people who are sick; staying home when sick; covering your mouth and nose when coughing or sneezing; washing your hands often; avoiding touching your eyes, nose, and mouth; and practicing other good health habits like cleaning and disinfecting frequently touched surfaces, getting plenty of sleep, and drinking plenty of fluids. Understanding public acceptance and current usage of these preventive behaviors can be useful for planning both seasonal and pandemic influenza prevention campaigns. This study estimated the percentage of adults in the United States who reported practicing preventive behaviors to avoid catching or spreading influenza, and explored associations of reported behaviors with sociodemographic factors.MethodsWe analyzed data from 2015 National Internet Flu Survey, a nationally representative probability-based Internet panel survey of the non-institutionalized U.S. population ≥18 years. The self-reported behaviors used to avoid catching or spreading influenza were grouped into four and three non-mutually exclusive subgroups, respectively. Weighted proportions were calculated. Multivariable logistic regression models were used to calculate adjusted prevalence differences and to determine independent associations between sociodemographic characteristics and preventive behavior subgroups.ResultsCommon preventive behaviors reported were: 83.2% wash hands often, 80.0% cover coughs and sneezes, 78.2% stay home if sick with a respiratory illness, 64.4% avoid people sick with a respiratory illness, 51.7% use hand sanitizers, 50.2% get treatment as soon as possible, and 49.8% report getting the influenza vaccination. Race/ethnicity, gender, age, education, income, region, receipt of influenza vaccination, and household size were associated with use of preventive behaviors after controlling for other factors.ConclusionMany adults in the United States reported using preventive behaviors to avoid catching or spreading influenza. Though vaccination is the most important tool available to prevent influenza, the addition of preventive behaviors might play an effective role in reducing or slowing transmission of influenza and complement prevention efforts.

The relative persuasiveness of narrative versus non-narrative health messages in public health emergency communication: Evidence from a field experiment

Previous studies indicated that narrative health messages are more effective than non-narrative messages in influencing health outcomes. However, this body of evidence does not account for differences in health domain, and little is known about the effectiveness of this message execution strategy during public health emergencies. In this study, we examined the relative effectiveness of the two formats in influencing knowledge and perceived response efficacy related to prevention of pandemic influenza, and determined whether effects of message format vary across population sub-groups. Data for the study come from an experiment fielded in 2013 that involved a nationally representative sample of 627 American adults. Participants were randomly assigned to view either a narrative (n=322) or a non-narrative (n=305) video clip containing closely matched information about knowledge and preventive actions related to pandemic influenza, and completed pre- and post-viewing questions assessing knowledge and perceived response efficacy related to the prevention of pandemic influenza. Results indicated that participants in the non-narrative condition reported greater knowledge and rated pandemic influenza prevention measures as more effective compared with those in the narrative condition. Message format effects did not vary across population sub-groups; post-viewing scores of knowledge and perceptions related to pandemic influenza were consistently higher in the non-narrative condition compared with the narrative condition across five socio-demographic groups: age, gender, education, race/ethnicity and income. We concluded that didactic, non-narrative messages may be more effective than narrative messages to influence knowledge and perceptions during public health emergencies.

1918 Influenza Pandemic: In Utero Exposure in the United States and Long-Term Impact on Hospitalizations.

To explore associations between in utero exposure to the 1918 influenza pandemic and hospitalization rates in old age (≥ 70 years) in the United States. We identified individuals exposed (mild and deadly waves) and unexposed in utero to the 1918 influenza pandemic (a natural experiment) by using birth dates from the Asset and Health Dynamics Among the Oldest Old survey. We analyzed differences in hospitalization rates by exposure status with multivariate linear regression. In utero exposure to the deadly wave of the 1918 influenza pandemic increased the number of hospital visits by 10.0 per 100 persons. For those exposed in utero to the deadliest wave of the influenza pandemic, high rates of functional limitations are shown to drive the higher rates of hospitalizations in old age. In utero exposure to the influenza pandemic increased functional limitations and hospitalization rates in old age. Public Health Implications. To determine investments in influenza pandemic prevention programs that protect fetal health, policymakers should include long-term reductions in hospitalizations in their cost-benefit evaluations.

Direct and label-free influenza virus detection based on multisite binding to sialic acid receptors

A system to discriminate human or avian influenza A remains a highly sought-after tool for prevention of influenza pandemics in humans. Selective binding of the influenza A viral hemagglutinin (HA) to specific sialic acid (SA) receptors (Neu5Acα(2-6)Gal in humans, Neu5Acα(2-3)Gal in birds) is determined by the genotype of the HA and neuraminidase (NA) segments, making it one of the key characteristics that distinguishes human or avian influenza A virus. Here we demonstrate the direct detection of whole H1N1 influenza A virus using 6′-sialyllactose (Neu5Acα(2-6)Galβ(1-4)Glc, 6SL)-immobilized gold electrodes as biosensing surfaces. The sensitivity was higher than that of conventional immunochromatographic technique (ICT) for influenza virus and not restricted by genetic drift. The label-free detection technology via direct attachment of a whole virus using a chemically modified electrode is a promising means to provide a simple and rapid diagnostic system for viral infections.

A Meta-analysis of the incidence of influenza reported during year 2005 to 2012 in China

Objective To investigate the epidemic patterns and the characteristics of influenza in China through a Meta-analysis based on the studies published in domestic literatures. Methods Related articles published during 2005 to 2012 were screened out from domestic databases and analyzed through a Meta-analysis with Review Manager 5.0 software. Results Twenty-two articles covering 957 901 patients with influenza-like-illness (ILI) and 148 233 pathogen samples were screened out according to the inclusion criteria. No significant difference with the ILI diagnosis rate was found between subjects at age 0-4 years and those at age 15-59 years. Higher ILI diagnosis rates were observed in those two groups as compared with subjects elder than 60 years old. Most of the pathogen samples were carried by subjects aged 25-59 years. More influenza virus strains were isolated in 2009 as compared with those of the seven other years (OR=2.25, 95%CI=1.27-3.70). There was statistical difference between the numbers of influenza A H1N1 and seasonal influenza A strains (OR=2.25, 95%CI=1.30-3.91). Significant difference was also observed between the numbers of influenza A and influenza B strains (OR=4.05, 95%CI=2.53-6.47). Conclusion There was significant difference with the diagnosis rate between subjects aged 0-4 years and those aged ≥60 years. More attention should be paid to people at high risk of infection (0-4 years old and ≥60 years old) and those at 25-29 years with high mobility and social intercourse for the timely prevention and control of pandemic influenza. The detection rate of influenza virus strains was increased during the outbreak of novel influenza A H1N1 infection in 2009. After that outbreak, the detection rate of novel influenza A H1N1 strains was 2.25 times the rate of seasonal influenza strains. The detection rate of influenza A was 4.05 times the rate of influenza B virus strains. Therefore, it is necessary to strengthen the surveillance for influenza A virus and other epidemic influenza virus strains. Key words: Influenza virus; Influenza-like-illness; Meta-analysis

The Possible Impact of Vaccination for Seasonal Influenza on Emergence of Pandemic Influenza via Reassortment.

BackgroundOne pathway through which pandemic influenza strains might emerge is reassortment from coinfection of different influenza A viruses. Seasonal influenza vaccines are designed to target the circulating strains, which intuitively decreases the prevalence of coinfection and the chance of pandemic emergence due to reassortment. However, individual-based analyses on 2009 pandemic influenza show that the previous seasonal vaccination may increase the risk of pandemic A(H1N1) pdm09 infection. In view of pandemic influenza preparedness, it is essential to understand the overall effect of seasonal vaccination on pandemic emergence via reassortment.Methods and FindingsIn a previous study we applied a population dynamics approach to investigate the effect of infection-induced cross-immunity on reducing such a pandemic risk. Here the model was extended by incorporating vaccination for seasonal influenza to assess its potential role on the pandemic emergence via reassortment and its effect in protecting humans if a pandemic does emerge. The vaccination is assumed to protect against the target strains but only partially against other strains. We find that a universal seasonal vaccine that provides full-spectrum cross-immunity substantially reduces the opportunity of pandemic emergence. However, our results show that such effectiveness depends on the strength of infection-induced cross-immunity against any novel reassortant strain. If it is weak, the vaccine that induces cross-immunity strongly against non-target resident strains but weakly against novel reassortant strains, can further depress the pandemic emergence; if it is very strong, the same kind of vaccine increases the probability of pandemic emergence.ConclusionsTwo types of vaccines are available: inactivated and live attenuated, only live attenuated vaccines can induce heterosubtypic immunity. Current vaccines are effective in controlling circulating strains; they cannot always help restrain pandemic emergence because of the uncertainty of the oncoming reassortant strains, however. This urges the development of universal vaccines for prevention of pandemic influenza.

'By failing to prepare you are preparing to fail': lessons from the 2009 H1N1 'swine flu' pandemic.

Pandemic influenza has the potential to cause widespread death and destruction. Communications with the public have a vital role in the prevention of pandemic influenza by promoting the effective uptake of behaviours that can delay the spread of infection. This study explored the development and implementation of communications in the pandemic influenza outbreak of H1N1 ('swine flu') in 2009 in three European countries. In-depth interviews were conducted with senior policy and communication officials involved in the planning and delivery of communications programmes in England, Italy and Hungary. The study found a lack of planning and a low value attached to the skills required to produce effective communications. In all case study countries there was a dearth of good quality audience research to inform the development of communications. Little thought had been given to the tone, targeting or channelling of messages. Instead, communications were characterized by a 'one size fits all' and a 'top down', expert-led response. There was also little effort to evaluate the impact of communications, but where this was done, very low levels of public compliance and engagement with key behavioural messages were found. Policy makers should prioritize investment in the skills and expertise required to achieve desired behaviour changes. Audience research should be conducted throughout the planning cycle to inform national communications strategies. This should include insights to inform the segmentation of public audiences, targeting of messages and consideration of content and emotional tone most likely to achieve desired behavioural outcomes.

Evaluation of strategies for control and prevention of pandemic influenza (H1N1pdm) in Japanese children attending school in a rural town. Simulation using mathematical models.

In 2009, epidemics of influenza (H1N1pdm) occurred worldwide. We evaluated 4 strategies for control and prevention of influenza (treatment with antiviral drugs, preventive actions, cancellation of large events, and school closures) by surveying the H1N1pdm epidemic in a geographically isolated rural town in Japan, and applying the epidemic to mathematical models. Subjects were 291 children attending nursery, primary, and junior high schools in Kounu town. The 4 strategies were evaluated by 3 types of mathematical models with varying parameters. The total number of infected cases, as reported in questionnaires, was 120. In the best-fitting model, treatment with antiviral drugs shortened the epidemic period from 31 to 23 days. Event cancellation reduced the total number of infected cases from 127.1 to 87.6 and the maximum number of cases from 63.7 to 41.7. In this simulation, 56 people were affected by the intervention. Immediate school closure reduced the total and maximum numbers of infected cases to 62.6 and 23.1, respectively. Statistical analysis confirmed that event cancellation and school closure are effective strategies for control of an influenza epidemic. The effective contact rate varied, which reflects a localized and rapidly spreading epidemic in a subpopulation.

Swine influenza and vaccines: an alternative approach for decision making about pandemic prevention

During the global pandemic of A/H1N1/California/07/2009 (A/H1N1/Cal) influenza, many governments signed contracts with vaccine producers for a universal influenza immunization program and bought hundreds of millions of vaccines doses. We argue that, as Health Ministers assumed the occurrence of the worst possible scenario (generalized pandemic influenza) and followed the strong version of the Precautionary Principle, they undervalued the possibility of mild or weak pandemic wave. An alternative decision rule, based on the non-extensive entropy principle, is introduced, and a different Precautionary Principle characterization is applied. This approach values extreme negative results (catastrophic events) in a different way and predicts more plausible and mild events. It introduces less pessimistic forecasts in the case of uncertain influenza pandemic outbreaks. A simplified application is presented using seasonal data of morbidity and severity among Italian children influenza-like illness for the period 2003-10. Established literature results predict an average attack rate of not less than 15% for the next pandemic influenza [Meltzer M, Cox N, Fukuda K. The economic impact of pandemic influenza in the United States: implications for setting priorities for interventions. Emerg Infect Dis 1999;5:659-71; Meltzer M, Cox N, Fukuda K. Modeling the Economic Impact of Pandemic Influenza in the United States: Implications for Setting Priorities for Intervention. Background paper. Atlanta, GA: CDC, 1999. Available at: http://www.cdc.gov/ncidod/eid/vol5no5/melt_back.htm (7 January 2011, date last accessed))]. The strong version of the Precautionary Principle would suggest using this prediction for vaccination campaigns. On the contrary, the non-extensive maximum entropy principle predicts a lower attack rate, which induces a 20% saving in public funding for vaccines doses. The need for an effective influenza pandemic prevention program, coupled with an efficient use of public funding, calls for a rethinking of the Precautionary Principle. The non-extensive maximum entropy principle, which incorporates vague and incomplete information available to decision makers, produces a more coherent forecast of possible influenza pandemic and a conservative spending in public funding.

Public Health Policy and Law for Pandemic Influenza: A Case for European Harmonization?

This article provides a critical portrait of the current state of public health policies and laws governing pandemic influenza prevention and control in Europe. It examines the role of and relationship between national public health policy and national communicable disease legislation as tools for the prevention and control of pandemic influenza, the role of Europe in pandemic disease preparedness, and the concept of harmonization across European states, including an overview of supranational initiatives and powers created to enhance harmonization of national pandemic disease policy. Short case studies epitomize important concerns around harmonization in Europe. The article considers opportunities and impediments to further harmonization. Particular attention is paid to the essential role of law as a tool to underpin and implement preparedness policies and to protect individual rights against unjustified state intervention.

Effectiveness of H1N1 vaccine for the prevention of pandemic influenza in Scotland, UK: a retrospective observational cohort study

A targeted vaccination programme for pandemic H1N1 2009 influenza was introduced in Scotland, UK, in October, 2009. We sought to assess the effectiveness of this vaccine in a sample of the Scottish population during the 2009-10 pandemic. We assessed the effectiveness of the Scottish pandemic H1N1 2009 influenza vaccination with a retrospective cohort design. We linked data of patient-level primary care, hospital records, death certification, and virological swabs to construct our cohort. We estimated vaccine effectiveness in a nationally representative sample of the Scottish population by establishing the risk of hospital admission and death (adjusted for potential confounders) resulting from influenza-related morbidity in vaccinated and unvaccinated patients and laboratory-confirmed cases of influenza H1N1 2009 in a subset of patients. Pandemic H1N1 2009 influenza vaccination began in week 43 of 2009 (Oct 21, 2009) and was given to 38,296 (15·5%, 95% CI 15·4-15·6) of 247,178 people by the end of the study period (Jan 31, 2010). 208,882 (85%) people were unvaccinated. There were 5207 emergency hospital admissions and 579 deaths in the unvaccinated population and 924 hospital admissions and 71 deaths in the vaccinated population during 23,893,359 person-days of observation. The effectiveness of H1N1 vaccination for prevention of emergency hospital admissions from influenza-related disorders was 19·5% (95% CI 0·8-34·7). The vaccine's effectiveness in preventing laboratory-confirmed influenza was 77·0% (95% CI 2·0-95·0). Pandemic H1N1 2009 influenza vaccination was associated with protection against pandemic influenza and a reduction in hospital admissions from influenza-related disorders in Scotland during the 2009-10 pandemic. National Institute for Health Research Health Technology Assessment Programme (UK).

Prevention of Influenza Pandemic by Multiple Control Strategies

We present the prevention of influenza pandemic by using multiple control functions. First, we adjust the control functions in the pandemic model, then we show the existence of the optimal control problem, and, by using both analytical and numerical techniques, we investigate cost‐effective control effects for the prevention of transmission of disease. To do this, we use four control functions, the first one for increasing the effect of vaccination, the second one for the strategies to isolate infected individuals, and the last two for the antiviral treatment to control clinically infectious and hospitalization cases, respectively. We completely characterized the optimal control and compute the numerical solution of the optimality system by using an iterative method.

Airport Quarantine Inspection, Follow-Up Observation, and the Prevention of Pandemic Influenza

After a report of H1N1 novel influenza in Mexico and North America, Japan conducted onboard quarantine inspections from late April 2009. The detection rate in border quarantine inspection is low due to incubation period and thus inspection is considered to be ineffective in blocking the entry of influenza. However, little is known about the concomitant effects of such inspection, such as increased traceability, upon secondary transmission. Epidemiological data were collected from the web sites of the Department of Health, Labor, and Welfare of Japan and the National Institute of Infectious Diseases of Japan. The number of weekly patients with H1N1 pandemic influenza in eight districts of Japan was summarized. The number of patients who passed through quarantine inspection at the airports was also calculated. A person with overseas travel history was defined as a person who had a flight only from the United States, Canada, or Mexico and passed through the quarantine inspection (according to the quarantine policy of the Japanese government). The numbers were adjusted for the population of each district and expressed as the number of patients per one million people. Despite Kanto district having the largest population, the number of patients with H1N1 novel influenza was relatively small. The total number of cases in each district correlated inversely to the percentage of cases with airport quarantine inspection. Quarantine inspection at the airports, follow-up observation by local authorities, and overall concomitant efforts may have contributed to secondary infection control in Japan.

Influenza: Critique of the contemporary challenges for pandemic planning, prevention, control, and treatment in emergency health services.

SummaryThe 2009 H1N1 influenza pandemic was a major challenge to health services around the world. Previous experiences with Severe Acute Respiratory Syndrome (SARS) and Avian Influenza A (H5N1) prompted initiation of formal pandemic planning. Essential and desirable features of pandemic plans include preparation for surveillance, investigation of cases, treatment modalities, prevention of community spread, maintenance of essential services, research and evaluation, and implementation, testing and revision of the plan.The experience of 2009 H1N1 influenza pandemic for emergency departments and their staff was problematic. The pace of the pandemic, coupled with untested pandemic plans, presented a unique range of challenges. In this paper, the contemporary challenges with respect to pandemic influenza prevention, control, and treatment are examined. The lessons learned are critical to our response to future pandemics, which are inevitable.

Theoretical and practical exploration of vision building in human influenza pandemic prevention & control

This article introduced the vision building concept about human influenza pandemic prevention and control. Different visions were built by creating different shapes of building blocks which also represented different organizations and physical facilities, respectively. The around-view reflection is required to be developed in the process of building so as to search for the ideal pattern. The correlation of all sectors and systems are established to combine different kinds of things, from one family to another, from communities, towns, counties, cities, rural areas, provinces to the state to handle trivial problems. These training objectives have been successfully accomplished, which has not only enriched the knowledge about prevention and control of influenza pandemic between different departments but also clarified the roles and responsibility. It lays the firm foundation for next cooperation between different departments, and make a bridge for the objective and choice of channel over human influenza pandemic prevention and control.

Oseltamivir for treatment and prevention of pandemic influenza A/H1N1 virus infection in households, Milwaukee, 2009

BackgroundDuring an influenza pandemic, a substantial proportion of transmission is thought to occur in households. We used data on influenza progression in individuals and their contacts collected by the City of Milwaukee Health Department (MHD) to study the transmission of pandemic influenza A/H1N1 virus in 362 households in Milwaukee, WI, and the effects of oseltamivir treatment and chemoprophylaxis.Methods135 households had chronological information on symptoms and oseltamivir usage for all household members. The effect of oseltamivir treatment and other factors on the household secondary attack rate was estimated using univariate and multivariate logistic regression with households as the unit of analysis. The effect of oseltamivir treatment and other factors on the individual secondary attack rate was estimated using univariate and multivariate logistic regression with individual household contacts as the unit of analysis, and a generalized estimating equations approach was used to fit the model to allow for clustering within households.ResultsOseltamivir index treatment on onset day or the following day (early treatment) was associated with a 42% reduction (OR: 0.58, 95% CI: 0.19, 1.73) in the odds of one or more secondary infections in a household and a 50% reduction (OR: 0.5, 95% CI: 0.17, 1.46) in the odds of a secondary infection in individual contacts. The confidence bounds are wide due to a small sample of households with early oseltamivir index usage - in 29 such households, 5 had a secondary attack. Younger household contacts were at higher risk of infection (OR: 2.79, 95% CI: 1.50-5.20).ConclusionsEarly oseltamivir treatment may be beneficial in preventing H1N1pdm influenza transmission; this may have relevance to future control measures for influenza pandemics. Larger randomized trials are needed to confirm this finding statistically.

Prevention of pandemic influenza after mass gatherings – learning from Hajj

Shortly after Hajj 2009 ended on 30 November, less than 100 pilgrims with confirmed pandemic influenza A H1N1 09, including five fatalities, had been reported by Saudi officials in the media.1 Since the elderly and others with influenza risk factors were discouraged from attending Hajj, this case fatality rate of 5% is inconsistent with that expected (less than 0.5%) and suggests there were many more undetected surviving cases. It is known from earlier pandemics that the ‘percentage of the recognised sick, who seek medical advice does not represent the total of the afflicted’.2 To date Saudi Arabia has the largest number of influenza A H1N1 09 cases (9355, 20% of all cases) and the third largest number of fatalities (81, 14% of all fatalities) reported from the World Health Organization (WHO) Eastern Mediterranean Region.3 Further, a Saudi hospital has claimed that about one-fifth of hospitalized patients had the influenza A H1N1 virus infection after returning from travel abroad,4 so publication of Hajj 2009 realtime influenza surveillance data (with PCR confirmation, if possible) by the Saudi Ministry of Health would be useful and welcome to inform global pandemic influenza control. A large number of pilgrims stay in Saudi Arabia for a month. If as few as 10 arrived with H1N1 09 influenza, and assuming a low basic reproduction number (R0) of 1.5, a serial interval of 3 days and a susceptible population,5 nearly 1000 cases will have occurred within that month. Up to 60% of Hajj pilgrims suffer symptoms of respiratory infection,6 and the attack rate of influenza among symptomatic pilgrims has been estimated as 10%,7 so that extrapolating for 2.5 million pilgrims attending this year's Hajj 150,000 cases of influenza would be expected. It is a tradition in Muslim communities that as well as pilgrims being visited by friends and relatives on arrival in Mecca, many travel after Hajj in the Middle East and Indian subcontinent, and recent returnees attend congregational prayers at mosques. These activities increase the risk of infections such as the influenza spreading among pilgrims' vulnerable contacts including the elderly and children. Also, Hajjis' travel and return coincided with the 2009 Christmas and New Year holiday period and associated overseas travel and contact in airplanes, airports and other sites. Useful recommendations for the prevention and control of influenza A H1N1 at Hajj 2009, published in both Science and the Lancet in mid-November,8,9 summarized the advice from an expert consultation undertaken by the Saudi Arabian Ministry of Health. These included good surveillance at Hajj by realtime electronic reporting, rapid laboratory confirmation via the healthcare system at Hajj, compliance with WHO advice, particularly that on the control of infectious diseases during mass gatherings and reporting of infection as required by the International Health Regulations 2005.10,11 The latter assumes surveillance in the country of origin to be adequate for recognizing and reporting post-Hajj infections. However, experience is of delay in recognizing Hajj-associated cases and outbreaks. It is less than a decade since the Hajj-associated worldwide outbreak of meningococcal W135 disease following Hajj 2000 when 87% (78/90) of the Hajj-associated cases in Europe were in contact with those who had returned from Hajj; there were 14 deaths which may have been avoided by quicker recognition of the association.12 Risk events for pandemic influenza A H1N1 09 include the continuing Umrah and other mass gatherings subsequent to and soon after Hajj 2009, such as the December UN conference on Climate Change expecting 15,000 delegates, world leaders and politicians in Copenhagen, the winter Olympics in Vancouver early in 2010, and the FIFA World Cup later in 2010. Post-event surveillance is just as important for these in the control of respiratory infections. Health services around the world need reminding of the importance and means of surveillance, which may need strengthening or construction. Therefore, we set out here recommendations for post-event surveillance, diagnosis and treatment: Vigilance and questioning about recent travel abroad, including attendance at Hajj or other mass gatherings; Reporting suspected cases locally and to WHO; Confirming H1N1 09 flu by PCR; Continuing preventive action: respiratory etiquette, mask use by symptomatic cases and their contacts, maintenance of hand hygiene, voluntary isolation of cases, antivirals for cases and for prophylaxis in vulnerable contacts, vaccination of unvaccinated Hajjis and their at risk contacts against seasonal and pandemic influenza, pneumococcal vaccination of at risk pilgrims; We also urge WHO to develop a post-event surveillance scheme and directive for immediate electronic reporting of travel-associated influenza and its complications, during the current pandemic influenza A H1N1 09 and in preparation for the future.

H1N1 Vaccine for Prevention of Pandemic Influenza

The FDA has licensed 4 new monovalent vaccines for prevention of respiratory illness caused by a new influenza A H1N1 virus that appears to be derived from a swine strain. The 5th vaccine should be licensed soon. All of these vaccines are expected to become available in October. An intranasal formulation is expected in the first week of October.