New Information on Early Dengue Outbreak Released

An Aedes aegypti mosquito is pictured here. The mosquito is one of two in Hawai’i known to spread the dengue virus. Hawai’i Department of Health photo.

With dengue fever cases increasing daily and the count of potentially infectious individuals fluctuating on a daily basis, some light is being shed on the outbreak’s beginnings.

The United States Centers for Disease Control and Prevention released a report compiled by the Hawai’i Department of Health, including Dr. Sarah Park, the State’s Epidemiologist, and Dr. Melissa Viray, the State’s Deputy Epidemiologist.

Within the report, the early days of the outbreak are outlined, including the initial reported case, information that was previously sealed out of patient confidentiality.

On Oct. 21, DOH was notified of a positive dengue confirmation. The patient had no history of travel off the island, and family members reported that they had similar signs and symptoms, which included fever, headache, muscle and joint pains, and a rash.

Those cases began to be investigated, and any additional cases and potential exposure sources were sought.

Just days later, on Oct. 24, DOH received informed that a group of visitors from the mainland U.S. who traveled together to the Big Island developed a febrile illness.

Another case was reported on Oct. 27, unrelated to the previous cases.

To aid in locating potential cases of the disease, DOH issued a medical advisory to Big Island clinicians on Oct. 29. The notice was followed by a state-wide medical advisory on Nov. 5.

DOH officials posted a call for cases on the CDC’s secure epidemic information exchange to seek individuals who had been on the Big Island between September and October, in an effort to identify suspected cases in travelers who may have already left the island.

By Nov. 26, DOH had identified 107 laboratory confirmed cases of dengue fever with onset of illness dates from Sept. 11 to Nov. 18.

Number of laboratory-confirmed cases (N = 107) of dengue fever, by date of onset — Hawaii Island, September 11–November 18, 2015. CDC/DOH image.

Of the 107 individuals, 14 percent required hospitalization, according to the report, and no deaths were reported.

The count included 93 Big Island residents, accounting for 87 percent of the overall number, while 14 cases involved visitors to the island.

Sixty-two of the 107 patients were female, making up 58 percent of the total, and the median infection age was 29-year-old, with a range from 0 to 80.

The report highlights that as of November, patient history initially suggested one area south of Kona as a main concern.

“However, further investigations are ongoing, and cases have been reported in persons who traveled to and potentially sustained or recalled actual mosquito bites in other parts of the island,” the report noted. “Among these cases are at least 12 (12%) persons who were never in any area south of Kona during the period of likely infection (3–10 days before symptom onset).”

The current number of confirmed cases in the outbreak sits at a total of 237. It has more than doubled the number listed nearly two months ago.

Monday’s count includes three individuals currently listed as infectious, or at risk of spreading the dengue virus.

One new cases has been added to each the visitor number and the number of individuals infected who are under the age of 18 to 23 and 44, respectively.

Since the onset of the outbreak, 985 individuals have been excluded from the confirmed count. Those cases were deemed negative following negative test results or lack of case criteria.

The access road to Waipio Valley, as well as Milolii and Hookena Beach Park, remains closed.

Community meetings are being held through the month of February on a weekly basis in both East and West Hawai’i.

Hilo sessions take place on Thursdays at 11:30 a.m. at the State Office Building, located on Aupuni Street. Kona sessions are held at the same time, but at the West Hawai’i Civic Center, Mayor’s Conference Room.

Tuesday sessions are being held at Yano Hall in Captain Cook, beginning at 12:30 p.m.

The community meetings provide updates and answers to questions from the community about the dengue fever outbreak on the Big Island, as well as education about the prevalence, transmission, and symptoms of dengue fever, along with outbreak response efforts, how to interpret case counts and maps, and the best ways to “Fight the Bite.”

Symptoms of dengue fever include fever, joint or muscle pain, headache or pain behind the eyes, and rash.

Those interested in obtaining general information about the current Big Island dengue fever investigation should call 2-1-1 and talk with Aloha United Way.

Anyone who thinks they may have contracted dengue fever on the Big Island should call 933-0912 if they are located in East Hawai‘i or 322-4877 in West Hawai‘i. If an individual is currently ill and concerned that they may have contracted dengue fever, they should contact their primary care physician.

Hawai’i County Civil Defense suggests the following to aid in reducing potential mosquito breeding areas around homes and businesses:

• Remove or eliminate standing water that provides sources for mosquito breeding such as buckets or puddles.
• Fix leaky faucets and outdoor hoses that are dripping water.
• Treat bromeliads and other plants that hold water with a larvacide or chlorine bleach solution.
• Clean gutters to allow water to drain freely.
• Repair screens and windows to help keep mosquitoes out.
• Dispose of old tires at no charge at county transfer stations islandwide.

Mosquito concerns should be reported to 974-6010 in East Hawai‘i or 322-1513 in West Hawai‘i.