Originally published by the Voice of America (www.voanews.com). Voice of America is funded by the US Federal Government and content it exclusively produces is in the public domain. May 7, 2009 WHO Still Struggling to Get a Handle on Flu ------------------------------------------- http://enews.voanews.com/t?ctl=241B127:A6F02AD83191E16081A53A549A184D9970AD7039DCD7B7E4& World Health Organization official says it is critical countries maintain alertness and monitor evolution of disease as closely as possible A top World Health Organization official says the global health body is still working to understand the influenza A H1N1 virus and called for continued vigilance to fight the spread of the disease. WHO Assistant Director-General Keiji Fukuda (file photo)Speaking by videolink to Asian officials gathered in Bangkok Thursday for a meeting on the disease, acting WHO director-general Keiji Fukuda said it is critical countries maintain their alertness and monitor the evolution of the disease, commonly known as swine flu, as closely as possible. Fukuda said WHO officials still do not believe they have gotten a handle on the severity of the disease. He also warned officials that it could become more virulent later in the year with the onset of the northern hemisphere's flu season. Mexico ends business shutdown Fukuda's warning comes as Mexico, the epicenter of the epidemic, ended a five-day business shutdown and began to get back to normal life. Other countries also began easing measures to control the disease. China on Thursday lifted a seven-day quarantine for passengers who arrived in Shanghai on a flight with a Mexican man who was later found to be infected with the disease. Also Thursday, Russia announced it was lifting a ban on imports from five U.S. states, but added another - Illinois - to its list. Asian leaders plan meeting to discuss flu Although more than 1,700 cases of the disease have been confirmed in 22 countries across the globe, almost all of the 44 deaths from the disease worldwide have occurred in Mexico. And so far, the only two deaths reported outside the country occurred in the U.S. state of Texas, which borders Mexico. Until Wednesday, the disease had shutdown Mexico, grinding its economy to a halt. Mexican officials estimate the five-day shutdown cost the country's economy at least $2.2 billion. Asian leaders are meeting in Bangkok Thursday to discuss how they might control the disease without damaging their economies. Some information for this report was provided by AFP, AP and Reuters. .