Influenza updates
Scientists assess risk of potential ‘flu pandemic spread via global airlines An Indiana University School of Informatics-led team of researchers has constructed a model that predicts how an emerging pandemic influenza might spread across the globe by airliners. The study, ‘Modeling the Worldwide Spread of Pandemic Influenza: Baseline Case and Containment Intervention,’ appears in the January issue of the journal PLoS Medicine. The model they devised is said to be the world's largest-scale epidemic simulation of its kind. Study investigators were Vittoria Colizza, informatics visiting assistant professor; Alessandro Vespignani, professor of informatics; Marc Barthélemey, informatics visiting scholar; Alain Barrat, Université Paris-Sud, France; and Alain-Jacques Valleron, Institut National de la Santé et de la Recherche Médicale, France. "The threat of a pandemic is pushing the international community to discuss scenario analysis and develop adequate preparedness plans," Colizza said. "This calls for the need to understand the possible propagation of a pandemic, in order to devise and test appropriate intervention strategies to contain and mitigate its evolution and impact on the population." The researchers developed a mathematical model using massive passenger-flow databases from the International Air Transport Association, an organization of airlines comprising 99 percent of worldwide commercial air traffic. Census information from more than 3,000 urban centers in 220 countries and related disease patterns from those areas also was analyzed. The model was introduced in a previous study conducted by the same researchers more than a year ago, showing in detail how air-transportation-network properties are responsible for the worldwide pattern of diseases. Using advanced computational tools, the team was able in both studies to simulate how an influenza pandemic would spread, both over time and geographically, and to provide forecasted scenarios and confidence intervals. The researchers show that strict travel restrictions would do little, if anything, to prevent the ‘flu from spreading throughout the globe. Next, the study focused on realistic scenarios in which antiviral resources are not equally distributed, with a higher concentration in wealthy countries. Different strategies are compared: a selfish strategy in which each country relies on its own supplies, as opposed to a cooperative approach in which prepared countries would donate part of their resources for global use. "Surprisingly," said Vespignani, who is internationally known for his research in the statistical analysis and computer modeling of epidemic spread, "the cooperative strategy is shown to be more effective in delaying the pandemic evolution and mitigating its impact on the population of both donor and recipient countries." Predictions therefore are strongly in support of a cooperative sharing of resources, which could be organized and managed by the World Health Organization, as an efficient way to deal with an emerging influenza pandemic while waiting for vaccine development. The IU School of Informatics study was funded by the National Science Foundation and the European Community Directorate for Information Technology. PLoS Medicine is a freely available peer-reviewed medical journal published monthly by the Public Library of Science. UN agency urges vigilance as new outbreaks of bird ‘flu are reported Despite fewer bird ‘flu outbreaks in the first weeks of this year versus 2006, the United Nations Food and Agriculture Organization (FAO) has strongly advised countries to remain on high alert and cooperate with international organizations as the deadly virus continues to be destructive for farmers. Eight countries – China, Egypt, Indonesia, Japan, Nigeria, South Korea, Thailand and Viet Nam – have reported new occurrences of avian ‘flu since the beginning of the year. “Recent outbreaks are following a seasonal pattern and do not come as a great surprise,” Juan Lubroth, senior officer of the FAO Animal Health Service, told reporters in Bangkok. “But we need to remain on the alert as the recent outbreaks show,” he added. “It is crucial that countries themselves step up their surveillance, detection and rapid response measures.” There is a lower instance of wild birds spreading the H5N1 virus while migrating from Asia to Europe and Africa this winter season as opposed to the last. However, the poultry trade and transport of live birds, especially during upcoming holidays such as Tet and Eid, could result in further epidemics. The FAO also expressed concern about unreported cases. “Only immediate reporting of any suspected bird ‘flu outbreak makes possible rapid intervention by farmers and veterinarians,” Mr. Luboth said, urging absolute transparency about new cases of the disease. To successfully combat avian ‘flu, farmers must be vigilant in reporting new cases and remuneration policies must be established to protect farmers against outbreaks, he said. It is estimated that it will take several years before the H5N1 is eliminated from the poultry industry, according to FAO, which warned that this will require a firm commitment from governments, poultry farmers and the international community. Ever since the first human case of H5N1, linked to widespread poultry outbreaks in Viet Nam and Thailand, was reported in January 2004, UN health officials have warned that the virus could evolve into a human pandemic if it mutates into a form which could transmit easily between people.
•Date: 24th January 2007 • Region: World •Type: Article •Topic: Pandemic planning
|
