The number of cases of dengue fever in Hawaii rose to 136 this week, prompting health authorities to warn residents and travelers to the popular winter vacation destination take precautions to avoid contracting the virus.
In a statement published Sunday, the County of Hawaii said that 119 residents and 17 visitors on Hawaii Island, the largest of the state’s eight main islands, have been confirmed to have dengue fever.
The first cases of this outbreak were noted in early November and traced to a popular camping site in South Kona. It has now grown to rival the last major dengue outbreak, which took place in 2001 and lasted about 10 months with 92 cases on Maui, 26 on Oahu and four on Kauai.
The outbreak is taking place at the start of the island’s peak tourism season, which usually begins around mid-December and lasts until March or mid-April. The Hawaii Tourism Authority published an alert last month instructing tourists to take precautions against the illness.
The virus, spread by a bite from infected mosquitoes, is uncommon in Hawaii. County health officials said that it was probably introduced to the island by a person who contracted it in another part of the world, became infectious while in Hawaii and was bitten by there by a mosquito, which spread the fever.
Authorities are now trying to curb the outbreak by spraying mosquito-infested areas and adviseing people to wear protective clothing and repellent.
The outbreak prompted a visit by a Centers for Disease Control and Prevention team.
Dr. Lyle Peterson, director of the agency’s division that covers diseases spread by mosquitoes, arrived on the island last week. He said in remarks to reporters that the outbreak could continue for months.
“Dengue outbreaks are extremely hard to control,” Dr. Peterson said.
“We must be prepared for the long run,” he later added.
The virus can cause fever, headaches and pain in the eyes, joints and muscles. It is spread by mosquitoes that bite during the daytime, and is usually found in tropical areas of Africa, Asia, the Caribbean and the South Pacific, but is relatively rare in the United States.