One of the children in the Saint John area recently affected by hand, foot and mouth disease. (CBC)

The Greater Saint John area has had several recent cases of hand, foot and mouth disease, a highly contagious infection that can cause a fever, sores in the mouth and blisters on the hands and feet.

Daycare operator Heather Hamilton says she's seeing more cases this year than ever before.

Eighteen children at her west side daycare, Hamilton Homestyle Daycare, have been affected — about one in four, she said.

Three of the children's fathers have also shown symptoms of the infection, which is spread by direct contact with nose and throat discharges, saliva, fluid from blisters, or the stool of infected persons, said Hamilton.

“It's almost like the flu, it's that common. This has probably been our worst year,” in five years, she said.

“We haven't had any cases until this year and we've probably had all of our babies down and most of our twos."

Hamilton suspects this summer's warm temperatures might be a factor. She believes the infection may be transferred more easily because of increased perspiration.

Jolene Woodland and her two young daughters, who don't go to Hamilton's daycare, also recently caught the disease —possibly from the family's babysitter.

"She said that everybody that she had babysat the week before had had the disease," said Woodland, who had some difficulty eating due to sores in her mouth.

Her four-year-old daughter also had trouble eating, she said.

Public health does not keep track of the number of cases of hand, foot and mouth disease.

It is a common childhood illness, according to Dr. Scott Giffin, the district medical officer of health in the area.

It's uncommon for adults to contract the disease, he has said.

Hand, foot and mouth disease is not the same as hoof and mouth disease, which affects cattle sheep and pigs.

It is caused by a different virus that can last five to 10 days, much like the common cold.

There is no treatment, but most people fully recover.

Symptoms usually start within three to seven days of infection. A fever that can last up to 48 hours is often the first symptom, followed by painful sores in the mouth and then a non-itchy skin rash.

Outbreaks occur every few years in different parts of the world, according to the World Health Organization.