Nearly three dozen cases of dengue fever reported in Hawaii outbreak

Story highlights

  • 25 residents and 8 visitors, including 4 children, diagnosed with dengue fever since September
  • This is the first outbreak of dengue fever on Hawaii's Big Island
  • Kona Ironman participants asked to notify the Hawaii Department of Health if they have fever and two additional symptoms

(CNN)More than eight million tourists flock to the Hawaiian islands every year. Those packing their bags need to be sure to pack mosquito repellant.

That's because state health officials are investigating a cluster of dengue fever. Thirty-three people on Hawaii's Big Island have become sick with the mosquito-borne disease since September, according to Hawaii state health officials. This is the first locally transmitted outbreak of the viral illness on the Big Island and the first outbreak in the state since five people were infected on the island of Oahu in 2011.
Twenty-five of those infected in this current outbreak are residents of the Big Island, while eight are visitors. Four children are among those who have become ill. All patients have recovered or are recovering.
    The most recent case was identified on November 2. The first patient began exhibiting symptoms on September 11.
    Dengue is transmitted to humans when they are bit by infected mosquitoes.
    Dengue usually occurs in tropical Asia, Africa, the Caribbean and the South Pacific. The virus is not endemic in Hawaii but is sometimes brought in by infected travelers.
    "It's likely an infected traveler infected the local mosquito population, which led to this cluster," state epidemiologist Dr. Sarah Park said last month.

    Battling 'bone fever'

    Most people with dengue show no symptoms, and only about a fourth of those with the disease become ill (although they can still infect mosquitoes who bite them), according to Dr. Hal Margolis, director of the Centers for Disease Control and Prevention's Dengue Branch. He added that it's the most frequent cause of fever among travelers to areas other than Africa.
    Those who do get sick get a high fever and severe joint and muscle pain, which is why it's nicknamed "bone fever." People who have had it describe it as the worst fever and worst body aches they've ever had. Symptoms begin about five to seven days after exposure to the virus. Some individuals develop a rash on their hands, arms, feet and legs, three to four days after their fever began.
    When diagnosed properly, dengue is successfully treated and the death rate is only 1%. Acetaminophen is given to relieve symptoms, which usually last for one to two weeks. Treatment with ibuprofen can lead to complications, mainly causing bleeding, which is a complication of severe illness from the virus.
    The overall risk to the public is low, Margolis said, mostly because the mosquitoes in the United States aren't very efficient at transmitting the virus. There are two types of mosquitos -- Aedes aegypto and Aedes albopictus -- that can transmit the virus. Both types of mosquitoes are found in Hawaii but they rarely have outbreaks. While there might be additional cases, "it's (dengue) only where mosquitoes (are) so the risk of a second round of transmission is very low," Margolis said.