The Hawaii Department of Health announced Wednesday that as many as six more people may have been infected with rat lungworm disease on the Big Island, bringing the year-to-date total of the parasitic infections statewide to 15.

That compares to 11 reported cases in all of last year.

Dr. Virginia Pressler, director of the Health Department, said two of the six cases have been confirmed so far, while the rest are classified as “highly probable.”

Pressler said the cases appear to be related — all victims were hospitalized a few weeks after drinking a homemade brew of kava, which had been prepared in uncovered buckets overnight and served in a large bowl. After downing most of the drink, the victims found slugs at the bottom of the bowl.

“The department is continuing to monitor this serious illness spread to individuals by infected slugs and snails,” Pressler said. “Cases like this recent cluster are especially concerning because they can be prevented with basic precautions such as storing food in covered containers and properly inspecting and washing food before eating.

“These healthy habits can protect against food contamination and prevent serious illnesses.”

According to the Health Department, 76 cases of rat lungworm disease have been reported in Hawaii since 2007. The department has confirmed half of them, while the rest are classified as probable.

The vast majority of the cases were reported on the Big Island, while Maui had 10 of the cases — including two this year involving newlyweds from California.

Oahu and Kauai have also reported one case each — in 2010 and 2015, respectively.

In recent weeks, the spike in reported cases has grabbed national and international headlines, leading to concerns over the impact on tourism and local farms.

But Dr. Sarah Park, state epidemiologist, said Hawaii isn’t facing an “epidemic,” attributing the spike to “increased awareness” of the disease.

“We’re probably seeing more cases because you all are helping to get the word out,” Park said. “We fully expect to see more as the result of getting the awareness. We’re hoping that the awareness will maintain itself in the years to come, because it’s important to make sure that everyone is educated and we all do our part and practice the prevention measures.”