At least four people in Massachusetts have contracted the rare Eastern equine encephalitis virus, including one woman who died, officials and family members said Sunday.

Laurie Sylvia, a 59-year-old realtor, contracted the disease, which is spread by mosquitoes, and began to feel sick on Monday before passing away on Saturday, her husband of 40 years, Robert Sylvia Jr., told NBC 10.

Their daughter, Jen Sylvia, mourned her “best friend” in a Facebook post on Sunday, writing that her mother “brought light and joy to everyone she came across.”

“She was such a beautiful soul. I don’t know where to go from here,” the grief-stricken daughter wrote.

“I just don’t understand how such a beautiful person could be taken from me so soon,” she continued. “My heart hurts beyond words.”

The Massachusetts Department of Public Health said its lab had confirmed a fourth case of EEE this year in a woman over 50 from southern Bristol County.

The agency didn’t identify the woman, or announce her death, which would be the first this year in Massachusetts from EEE, according to South Coast Today.

There hadn’t been a human case of the virus in the Bay State since 2013, until officials announced earlier this month that a Rochester man older than 60, another man over 60 in northern Franklin County and a man from Grafton between the ages of 19 and 30 had been infected.

The disease can affect people of all ages and cause fevers, headaches, lethargy or brain infections and death.

It was found in 330 mosquito samples in Massachusetts this year, officials said.

Authorities have been spraying at-risk communities to try to curb the mosquito population.

Some of the insects in Rhode Island have also tested positive for the virus, but there have been no confirmed human cases reported in that state.