Hawaii officials warn of another mosquito-borne virus

After months battling the dengue virus, Hawaii health officials now are wary of another mosquito-borne virus that is sweeping through the Americas and has been linked to brain damage in thousands of babies in Brazil.

World Health Organization officials said Thursday that the Zika virus was “spreading explosively” and announced that they would convene an emergency meeting on Monday to decide whether to declare a public health emergency.

“The level of alarm is extremely high,” said Dr. Margaret Chan, the director general of the WHO, in a speech in Geneva.

Of particular concern, Chan said, are the cases of microcephaly, a rare condition in which infants are born with abnormally small heads that has been rising dramatically in Brazil as Zika spreads. Experts say it is too early to tell whether Zika is the cause of the condition, but there are some indications that the two are linked.

The health authorities in Brazil said Wednesday that reported cases of microcephaly since October had climbed to 4,180, a 7 percent increase from last week. Before the epidemic, Brazil recorded only about 150 cases of microcephaly a year.

Earlier this month, a baby born with microcephaly at an Oahu hospital became the first such baby linked to the Zika virus that was born in the U.S. The baby’s mother had been infected in Brazil and then traveled to Hawaii.

Hawaii State Epidemiologist Dr. Sarah Park said this week that no new cases of Zika had been observed in Hawaii, but said health officials were keeping a close eye out for it.

“We see it when travelers are infected and they come to Hawaii,” she said. “Since 2014, we’ve seen six cases of persons infected with the Zika virus.”

She added that while much remains to be discovered about Zika, it appears to be transmitted in much the same way as dengue virus, meaning that the ongoing “Fight the Bite” campaign — aimed at convincing Hawaii residents to avoid mosquitoes — could help slow the spread of Zika if it were to arrive in the state again.

“Fight the Bite” asks Hawaii residents to avoid mosquito-infested areas, to mitigate standing water around their homes, to wear long-sleeved shirts and long pants, and to wear insect repellent when appropriate to avoid being bitten by mosquitoes, which act as carriers for many diseases, including Zika and dengue.

State legislators are currently working to pass a bill that would appropriate more money for the Hawaii Vector Control Branch of the Department of Health, which is tasked with monitoring and mitigating populations of animals and insects that carry disease.

In an interview earlier this week, state Sen. Josh Green, D-Kona, said the threat of viruses like Zika is one of the biggest challenges Hawaii will face in the coming years.

“It’s now becoming clear that other viruses will become a threat in the future, like Zika is now in Brazil,” he said. “… We can’t afford another outbreak like dengue.”

The Zika virus, which has long been present in Africa and equatorial Asia, has spread to 23 countries in the Americas, according to the WHO.

While many populations where the virus has long been present have immunity, that’s not the case in newly affected areas. Without a vaccine or effective treatment, some countries have told women to put off getting pregnant for several years. The WHO said it doesn’t anticipate giving similar advice, though does suggest that pregnant women take steps to avoid mosquitoes.

Zika virus usually causes mild symptoms, such as fever, rash and joint pain. The U.S. has seen 31 cases in 11 states and Washington, D.C., and an additional 19 cases in Puerto Rico and the U.S. Virgin Islands, said Anne Schuchat, principal deputy director of the Centers for Disease Control and Prevention. All of the U.S. cases occurred in travelers from affected areas outside the country, she said.

The Associated Press contributed to this report.

Colin M. Stewart can be reached at cstewart@hawaiitribune-herald.com.