A Delaware woman has died from a rare case of rabies, prompting officials to issue a warning about the disease.

The Kent County woman, who lived alone in a rural area west of Felton, died last week. She was initially treated at a unidentified Delaware hospital in late July for a suspected case of gastroenteritis with vomiting and diarrhea, but her condition quickly deteriorated and she was transferred to a Pennsylvania hospital for treatment, said officials.

"Test results did not confirm the presence of rabies until last week," said Karyl Rattay, director of the Delaware Division of Public Health.

Officials declined to provide any more information about the woman or where she was treated, citing privacy concerns.

Rabies is a viral disease that is spread to people from a bite or scratch of an infected animal. The disease affects the central nervous system, causing inflammation of the brain and death. The rabies vaccine prevents the disease when it is administered shortly after exposure to a rabid animal.

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Officials said the risk of human-to-human transmission of rabies is extremely low, but they are assessing hospital staff who may have had contact with the woman, as well as anyone who had direct contact in the two weeks before she started showing symptoms.

"The source of the disease has not been identified," Rattay said, adding that the "source animal" is likely dead by now. The woman owned a cat, which was previously vaccinated and is being held for observation. Several feral cats in the area were trapped and held for observation out of an abundance of caution.

Human cases of rabies are very rare, though once symptoms appear, the disease is almost always fatal. The last human case of rabies in Delaware was in 1941, when a young boy from Newport died after being bitten by a stray dog, officials stated.

There have been 23 cases reported in the United States between 2008 and 2017, none in Pennsylvania. In 2011, a 73-year-old woman died in New Jersey after she was bitten by a rabid dog in Haiti. A Florida woman died of the disease earlier this year, according to the Centers for Disease Control and Prevention.

"The fact is, everyone, whether in rural Kent County or inner-city Wilmington, needs to be aware of the contact risk rabies presents in our state," said Rattay. Pets should be vaccinated, people should avoid petting stray animals even if they appear friendly, and animals should not be allowed to roam free. Anyone who is scratched, bitten, or comes in contact with animal saliva needs to seek treatment immediately, she said.

Across the country, about 60 to 70 dogs and 250 cats contract rabies every year. Nearly all the animals are unvaccinated and become infected after contact with wildlife. Yearly, between 30,000 to 60,000 people receive the rabies vaccine after possible contact with the virus, the CDC reported.

Pennsylvania, New Jersey, and Delaware require that all dogs and cats receive the rabies vaccine. Delaware also requires that pet ferrets get the shots.

In Delaware, there have been nine confirmed animal cases of rabies since January; three foxes, three raccoons, one cat, one dog, and one horse. In 2017, there were a total of 18 confirmed animal cases, officials said.

In Pennsylvania, there have been 53 reported rabies cases in animals between January and March. The majority of those were in raccoons. Since 2001, the state has distributed an oral rabies vaccine in bait form that is intended for wildlife – specifically raccoons – in hope of preventing the disease from spreading. In New Jersey, there have been 81 reported animal cases of rabies, mostly in raccoons.

Delaware officials ask that anyone who has come in contact with an animal that might have rabies contact their health care provider or call the DPH Rabies Program at 302-744-4995 or 1-888-295-5156 after hours, the Department of Agriculture at 302-698-4630, or email rabies.hotline@state.de.us.

Delaware officials asked that anyone with questions contact their health care provider or call the DPH Rabies Program at 302-744-4995 or 1-888-295-5156 after hours, the Department of Agriculture at 302-698-4630 or rabies.hotline@state.de.us.