Dengue fever

The illness doesn't grab the headlines like SARS and HIV, but it might be just as dangerous

HO CHI MINH CITY, VIETNAM » Dengue fever epidemics are sweeping through Asia with cases doubling this year over last year in Vietnam and travelers warned to take preventive measures.

"The problem with dengue is it's never considered to be a high-priority disease," said Dr. Duane Gubler, Hawaii infectious disease specialist, who is working with Vietnamese health officials on dengue control programs.

About Dengue » 250 million people -- 40 percent of the world's population -- are at risk. » 50 million cases are reported every year. » The disease is endemic in more than 100 countries. Before 1970, only seven countries experienced epidemics. Source: World Health Organization

"Health authorities in any endemic country will tell you it's high priority, but if you look at resources they try to put into it to control, it's a pittance compared with any other public health program," he said. "They don't implement programs we recommend to develop the control that's needed."

Gubler has been working since 1989 with the National institute of Hygiene and Epidemiology in Hanoi and the Pasteur Institute in Ho Chi Minh City (Saigon) to build an emerging infectious disease program. He was recently in Vietnam for meetings.

"We're using some of the latest technology to try to identify bugs," he said. "We're trying to figure out what bugs are making people sick ... and pathogens that have future epidemic potential."

Gubler recently joined the Duke University-National University of Singapore Graduate Medical School and will lead a collaborative research program in Singapore on emerging infectious diseases. He formerly directed the University of Hawaii-Manoa John A. Burns School of Medicine's Asia-Pacific Institute for Tropical Medicine and Infectious Diseases and remains on the faculty.

He chairs a multinational board of counselors for a Pediatric Dengue Vaccine Initiative that is working on developing dengue fever vaccines.

Dengue is a viral infection transmitted by Aedes aegypti mosquitoes. Hemorrhagic dengue, usually occurring the second time a person is infected, is a major cause of hospitalization and death among children in Southeast Asia.

Someone exposed to the virus in countries with the epidemic can import it unknowingly and transmit it to others via mosquitoes.

Hawaii's first dengue fever outbreak in 56 years in 2001-2002 was traced to a resident who had visited French Polynesia during a dengue epidemic. Other cases were linked to outside travel, but 1,644 people were tested who acquired the virus locally, according to health officials. Of those, 122 tested positive for dengue infection.

"The Hawaii dengue experience is another example of how readily pathogens can cross great expanses of ocean to cause outbreaks in new territory," state and federal officials said in May 2005 in a paper reviewing the outbreak.

"Important lessons learned from this episode include the need to closely monitor and respond to disease developments in the global community."

About 60,000 dengue cases were reported in Vietnam through September.

Children comprise 60 to 70 percent of patients because they have no antibodies to fight the infection, Vu Sinh Nam, deputy attorney general of the Ministry of Health, Vietnam Administration of Preventive Medicine, told a group of U.S. and Asian journalists.

"We take action before an outbreak," he said. "It's a collaborative system. Volunteers go to every house and tell them how to control it by eliminating breeding areas for mosquitoes in water around the house."

He said dengue is the biggest threat in Vietnam of the many communicable diseases, including SARS and HIV, and more government help is needed for biocontrol.

Children's Hospital in Ho Chi Minh City has from 3,500 to 5,227 visits daily, including outpatients, with about 5 percent admitted to the hospital, doctors there said. About half the patients have dengue fever or other infectious diseases, they said.

The hospital has a new 120-bed newborn center, the only one in the country, for severe cases.

Mothers are trained through mass media how to recognize dengue disease and take their children to the hospital.

In Indonesia the Jakarta Government Hospital provides free dengue services and has had about 50 new cases daily since June, doctors said. Most are hemorrhagic, they said.

Chemicals are added to the water to prevent mosquito breeding during the rainy season, and people are encouraged to get rid of water around their homes, the doctors said.

"The death rate could be reduced if patients went to the hospital at the first sign of symptoms (joint and muscular pain, severe headaches and fever)," one said. "Many patients are too late."

From January to August, Jakarta had 27,937 dengue cases and 76 deaths.

Dr. Nyoman Kandun, director general for communicable disease with the Indonesian Health Ministry in central Jakarta, said the increased infection rate cannot be stopped because of the environment, sanitation and breeding areas.

The region has many polluted waterways and water around houses. "Clean water here is more expensive than gasoline," noted Andreas Harsono, executive director of Pantau, a media organization. "This city is sick."

Kandun said the budget to contain the epidemic is limited. "There must be community involvement, or there is nothing you can do."

Gubler said: "The problem is they don't have resources to deal with any of the problems really well, so they go from one crisis to another. Vietnam is probably trying harder than any other country out there.

"Jakarta is all lip service," he added, noting he lived there in the 1970s and is a consultant to programs there. "Hopefully they will start a program in Indonesia for emerging infectious diseases that will include dengue."

Gubler hopes to establish a regional reference center for Southeast Asia in the Duke-Singapore partnership and develop laboratory capacity for infectious diseases.

Hawaii, which is "highly vulnerable" to emerging infectious diseases, will benefit from the endeavor, he said.