6 Facts to Know About Hawaii's Dengue Fever Outbreak

The recent spread of dengue fever has led the mayor of Hawaii County to declare a state of emergency on Hawaii’s Big Island.

In a proclamation, Mayor William P. Kenoi noted that the mosquitoes that transmit the virus were not typically seen in Hawaii. However, this is not the first dengue outbreak to occur in the state.

Kenoi noted that state and local officials were undertaking mosquito control measures and educating the public. Despite the emergency proclamation, the state health department maintained that the Big Island and the rest of Hawaii were still safe destinations for residents and tourists.

Elizabeth Giesler, PharmD, BCPS, an emergency medicine clinical pharmacist for the John Peter Smith Health Network, previously told Pharmacy Times that dengue may cause symptoms such as high fever, muscle or joint pain, nausea, rash, headache, pain behind the eyes, or low white blood cell count. Patients who are more severely affected by dengue fever may also experience plasma leakage and severe bleeding.

“While there are no medications that specifically treat dengue fever, pharmacists have a role in ensuring adequate fluid resuscitation and appropriate monitoring,” Dr. Giesler said.

The Hawaii State Department of Health also recommended bed rest and acetaminophen to treat fever and pain. Meanwhile, pharmacists should remind patients affected by dengue fever not to take aspirin and nonsteroidal anti-inflammatory drugs because of bleeding concerns.

Here are 6 facts to know about the dengue fever outbreak in Hawaii:

1. Although dengue is not endemic to Hawaii, there has been a “cluster” of locally acquired cases on the Big Island.

This is the first time Hawaii residents acquired dengue fever on the island since 2011, when there was an outbreak on Oahu.

The state health department reported 2 cases of locally acquired dengue on Hawaii Island on October 29, 2015. By February 15, 2016, dengue had affected 256 residents.

2. The Hawaii State Department of Health estimates that there are only 2 potentially infectious individuals remaining. The rest of the 254 infected patients are no longer contagious.

The illness onset among the 254 patients who are no longer deemed infectious was determined to be between September 11, 2015, and February 1, 2016.

The 2 potentially infectious individuals’ estimated onset of illness was around February 6, 2016, to February 9, 2016.

3. Hawaii residents were hit harder than tourists.

The state health department confirmed that only 24 tourists were infected with dengue, compared with 232 Hawaii Island residents.

In addition, 210 cases involved adults, while 46 involved children.

4. More than 1200 individuals who thought they were infected were excluded from the state health department’s report.

The state health department declared that 1216 potential cases did not meet case criteria and/or did not test positive for dengue fever as of February 16, 2016.

5. Aedes aegypti and Aedes albopictus mosquitoes are the culprits behind dengue.

In addition to spreading dengue, these mosquitos can also transmit Zika virus.

Aedes aegypti mosquitos, which are also vectors of chikungunya and yellow fever, lay eggs in containers with water or plants near homes. They prefer to bite indoors.

Individuals can recognize the Aedes aegypti mosquito as a small, dark insect with white lyre-shaped markings and banded legs. They are most active 2 hours after sunrise and several hours after sunset, but they may bite at night in well-lit areas.

Aedes albopictus mosquitos are also small and dark, but they have a white dorsal stripe and banded legs. They are more likely to bite humans outside, but they bite indoors, as well.

The Aedes albopictus cannot fly far distances, so it will most likely stay within 200 meters of its egg production site.

The state health department described these mosquitos as “aggressive daytime biters” that are most likely to attack in the early morning and late afternoon.

In addition to transmitting dengue and chikungunya, the Aedes albopictus mosquito can transmit West Nile, Eastern equine encephalitis, and Japanese encephalitis.

6. There is no dengue vaccine.

Without a vaccine, the best way for patients to protect themselves from dengue is avoiding mosquito bites though bug repellants, long-sleeved clothing, mosquito nets, and screens on doors and windows.

In addition, patients fare better if the infection is caught early and treated promptly. Supportive treatment can lower patients’ risk of medical complications and death.

Dengue is a leading cause of illness and death in the tropics and subtropics, according to the US Centers for Disease Control and Prevention. Around 400 million individuals are infected annually.