Dengue fever cases on Hawaii island continue to climb as the Health Department confirmed four new cases Friday, including two more children for a total of six children infected with the mosquito-borne virus.

That brings the tally of locally acquired dengue to 38. On Thursday the count was at 30 adults and four children. (Eight of the total were mainland visitors.) The earliest onset of this outbreak was a Sept. 11 case, the Health Department confirmed Tuesday.

South Kona is a hot spot for dengue exposure. As of Nov. 6 all of the 23 then-confirmed cases had possible exposure there. But exposure areas may be spreading.

A 38-year-old Volcano woman, who suspects she contracted dengue in South Kona, said mosquitoes that bit her at her Volcano home may have transmitted dengue from her to her friend and her friend’s 3-year-old daughter.

Melissa Fletcher, who experienced a 102-degree fever and back pain and rash, among other symptoms, is still awaiting test results for dengue.

She said her friend, who is in her 30s, got sick with fever, eye pain, pain in her hands and vomiting sometime after the Nov. 6 visit. The 3-year-old developed a rash all over her body Friday, she said.

Fletcher said she fears people who have the virus may not be seeing a doctor, and even doctors like hers are downplaying the disease since the Health Department has reported most cases have had mild to moderate symptoms of Type 1 dengue.

Fletcher is also concerned that people who contract one type of dengue may contract another and come down with a case of severe dengue. That is plausible as at least 14 confirmed cases of dengue unrelated to this outbreak have been brought to Hawaii.

State Epidemiologist Dr. Sarah Park said even healthy people could get severe dengue fever (also known as dengue hemorrhagic fever) from any of the four dengue viruses including Type 1, for which there are no antiviral drugs.

“Some first-time dengue patients can get severe dengue,” she said, adding there is no correlation with age or underlying medical conditions. The common thinking is if a person has one type of dengue and gets a different type, “they could be at higher risk to get severe dengue, but not all do.”

Severe dengue “progresses within days,” Park said. “They can die within several days. People have trouble clotting blood, losing blood into their tissues. Blood pressure drops. They need aggressive support in the ICU.”

She reminds the public, “It’s people that move the infection, not mosquitoes.”

One potential mosquito breeding ground not found much on Oahu is the thousands of water catchment tanks used by Big Island residents, said Mel Hamano, an environmental engineer with the Health Department’s Safe Drinking Water Branch.

One resident at an informational meeting Monday in Captain Cook complained three of his neighbors had open tanks.

The department recommends solid or mesh covers for the tanks, but they must be watched because water can pool on hard covers and mesh covers might sag into the water.

Hamano recommends cleaning gutters because debris could create puddles inside, and cutting back trees.

A North Kona school came under criticism by two teachers for failing to control mosquitoes. But Kona principals say they have all been taking extensive measures to protect their students.

At the 52-acre Kealakehe High School in much-drier North Kona, Principal Wil Murakami said after the first 13 cases were reported, he took action by requesting outdoor flying insect foggers and indoor/outdoor sprays. Morning crews inspect daily for any standing water before most students arrive, and any standing water is emptied and plants holding water are shaken. The school also uses Mosquito Dunks, a product shaped like a doughnut that contains a natural chemical to kill mosquito larvae, in areas where water tends to pool.

Konawaena High School Principal Shawn Suzuki said the Health and Education departments are working together.

Some residents like Fletcher question why the Health Department informed health care providers Oct. 29, a week after the first confirmed case.

Park said the Health Department was first notified Oct. 21 of positive lab results of an antibody test.

“We just had the doctor’s name,” she said. “It required us to find out what was going on.”

Park said it took time to contact the doctor and Hawaii island investigators, who followed up by getting information from the patient and contacting the Centers for Disease Control to find out what lab and what tests were used.

“By the next week it started to look like the person did not travel anywhere,” she said. “We got more alarmed. We got word back from the CDC it could be dengue. … This looks like the real thing. We need to make the public aware and talk to clinicians on how to test and look for it among their patients.”