Dengue warrior confident outbreak passed peak

By Timothy Hurley
Advertiser Maui County Bureau

When dengue fever expert Paul Reiter came to Hawai'i in early October, he boldly suggested Hawai'i's outbreak was going to fizzle.

Paul Reiter has studied dengue fever for 15 years. Bruce Asato • The Honolulu Advertiser

While new cases continue to emerge, the pace has slowed considerably. Viewed from an epidemic curve, Reiter said, the outbreak is past its peak and on the decline — at least in the hardest-hit areas of East Maui.

"I can't really imagine a major transmission in any area (of Hawai'i),'' he said last week.

Reiter, an entomologist who has studied dengue fever for 15 years, is part of the eight-member team sent to Hawai'i by the Centers for Disease Control and Prevention, America's top health-protection agency, which has made more news of late for its role in battling anthrax. There have been 69 confirmed cases of dengue fever in Hawai'i.

The team of two entomologists, five epidemiologists and an assistant arrived here from their home base at the CDC dengue fever laboratory in Puerto Rico. They have since been scattered across the island chain, offering assistance and expert guidance to the state Department of Health.

Reiter, the chief of the Entomology Section of the Dengue Branch of the CDC, is well known in the world of mosquito-borne diseases. He is the man who discovered that dengue fever was being spread globally in old tires. Reiter's research revealed that a global trade in used tires — a dark and sheltered place ideal for breeding — and a shipping process known as containerization were bringing tropical disease-spreading mosquitoes to the United States.

Reiter, originally from England, has also studied malaria, ebola and river blindness, which results from flies depositing worm larvae into humans and can cause blindness if the worms migrate to the eyes.

At the time he was asked to come to Hawai'i, the scientist was on leave from his CDC job studying West Nile encephalitis at the Harvard School of Public Health.

When Reiter arrived here, there were fears that thousands of Hawai'i residents could fall victim to the mosquito-borne disease that causes fever, severe headaches and flu-like symptoms.

From a global perspective, Hawai'i appeared to be the next domino in a pan-Pacific epidemic that has seen thousands come down with the virus in places such as American Samoa, French Polynesia and the Philippines over the past 18 months.

But Reiter knew that Hawai'i's predominant dengue-carrier, Aedes albopictus — or Asian tiger mosquito — is a pussy cat when it comes to transmitting the dengue virus.

It is another mosquito, Aedes aegypti, that is feared worldwide as the main carrier. It is a mosquito associated with urban centers. And when the aegypti acquires the virus, dengue fever usually spreads like wildfire.

One of the reasons the albopictus mosquito is not an efficient vector of the dengue fever virus, Reiter said, is that it doesn't mind hanging out in the woods, away from human habitation. It doesn't mind feeding on animals, either. (Nonprimates can't spread the disease.)

There have been albopictus-driven dengue fever outbreaks in the past — such as in the Seychelles and Northern Taiwan — but those epidemics weren't considered major, he said.

Reiter came to Hawai'i intrigued about the outbreak. Even though the aegypti was believed to be largely eradicated in Hawai'i more than 50 years ago, there was reason to believe the mosquito may be found on Maui.

The reason: In Nahiku, a rural community built into the rain forest on Maui's northeast coast, the movement of the disease was said to have mimicked the house-by-house, street-by-street pattern of the urban aegypti outbreaks. Some 25 people acquired the virus at different times this summer.

So one of Reiter's missions was to capture the aegypti, to see if it was really driving the outbreak.

"We looked hard for the aegypti,'' he said, adding that he searched on Maui, O'ahu and Kaua'i. "I haven't been able to find any.''

Why did Nahiku get hit so hard?

Reiter has his theories, but the CDC staff hopes to get a better handle on it this weekend. Today the entire staff will converge on Nahiku to conduct a study that seeks to map out the epidemiology of the disease. Passing out questionnaires and using other tools, the investigators hope to pinpoint just how the virus came in and how the virus moved about the area.

One theory says the virus spread at a community phone booth, where people and mosquitoes congregate.

Reiter said he found an incredible amount of albopictus mosquitoes in Nahiku. For example, one experiment using a mechanical aspirator counted 70 mosquitoes in a mere 5 minutes.

"Albopictus was everywhere I went in Hawai'i,'' he said. "I took a hike on the north shore of Kaua'i, and I was even accosted there — in the middle of nowhere. It makes you wonder what they feed on.''

Reiter said it's possible the virus has entered Hawai'i in the last 50 years and was simply not recognized.

As for the search for the more dangerous aegypti, he said he plans to meet with Hawai'i's Vector Control Branch chief to discuss setting up a systematic, long-term survey of mosquitoes on all the islands.

Reiter said he wouldn't be surprised if members of the CDC team started returning home in the coming days.

Looking back, he said this outbreak has received more press than any other epidemic he knows of. He said he feels sorry for the people in Hana, who suffered economically over it and even endured some ridicule.

"In the Caribbean, they're so scared of publicity they try to hide dengue. But, of course, this is America.''