Schoolchildren look at pictures taken by a cameraman in a school outside Bangkok, Wednesday, June 13, 2012. Children are easy prays for mosquitoes carrying Dengue, a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

Graphics showing the incidence and case fatality of Dengue fever in Thailand are shwon in Mahidol hospital in Bangkok, Wednesday, June 13, 2012, during a media trip organised by Sanofi Pasteur. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

Speakers attend an international media briefing on Dengue fever, at the Foreign Correspondant Club of Thailand, in Bangkok, Thursday, June 14, 2012. From left to right: Jean Lang of France, Sanofi Pasteur Associate Vice President; Eduardo Massad of Brazil, a professor of medical informatics at the School of Medicine of the University of Sao Paulo; Leo Yee Sin of Singapore, Associate Professor at the Department of Infectious Diseases of Tan Tock Seng Hospital; Pratap Singhasivanon of Thailand, the dean of the Faculty of Tropical Medicine at Mahidol University; Dr. Roberto Tapia-Conyer of Mexico, a medical doctor at the Nationa lUniversity of Mexico. Dengue fever, a potentially fatal, mosquito-borne disease, is spreading rapidly around the world and is a threat to nearly 3 billion people. (Patrick de Noirmont/Sanofi Pasteur)

Speakers and journalists attend an international media briefing on Dengue fever, at the Foreign Correspondant Club of Thailand, in Bangkok, Thursday, June 14, 2012. Dengue fever, a potentially fatal, mosquito-borne disease, is spreading rapidly around the world and is a threat to nearly 3 billion people. (Patrick de Noirmont/Sanofi Pasteur)

A member of the Public Health ministry of Thailand puts Abate sand in a vase to destroy mosquitoes larvas, in a street outside Bangkok, Wednesday, June 13, 2012. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

A member of a squad of the Public Health ministry of Thailand sprays mosquito repellent along a polluted stream, outside Bangkok, Wednesday, June 13, 2012. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

A member of a squad of the Public Health ministry of Thailand sprays mosquito repellent as he walks past residents in a street, outside Bangkok, Wednesday, June 13, 2012. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

A patient affected with Dengue fever is isolated in a ward in an hospital for tropical disease, outside Bangkok, Wednesday, June 13, 2012. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

Patients affected by Dengue fever and malaria rest in an hospital outside Bangkok, Wednesday, June 13, 2012. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

Mosquitoes are kept in a in a mosquito colony room at the Center for Vaccine Development, Thursday, June 14, 2012, at Mahidol University, in Nakhonpathom, outside Bangkok. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

A Thai scientist collects mosquitoes from a cage at the Center for Vaccine Development, Thursday, June 14, 2012, at Mahidol University, in Nakhonpathom, outside Bangkok. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

Mosquitoes are kept in a in a mosquito colony room at the Center for Vaccine Development, Thursday, June 14, 2012, at Mahidol University, in Nakhonpathom, outside Bangkok. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)

Mosquitoes are kept in a test tube at the Center for Vaccine Development, Thursday, June 14, 2012, at Mahidol University, in Nakhonpathom, outside Bangkok. Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur. It is also one of the leading causes of fever among travelers to endemic areas. (Patrick de Noirmont/Sanofi Pasteur)