A mumps outbreak is linked to D'Jais Bar and Grill in Belmar, N.J., health officials said. (Image credit: Google)

A mumps outbreak tied to a bar on the Jersey Shore is growing, health officials said, with 15 more people reporting symptoms of the virus.

At least 36 people are thought to have contracted the contagious disease, according to the Monmouth County Health Department. Most of them had recently visited D'Jais Bar and Grill in Belmar, N.J., which has voluntarily closed its doors because of the outbreak.

"Individuals are continuing to come forward to report mumps-like symptoms," Monmouth County public health coordinator Michael Meddis said in a statement Monday, noting that most of those infected are men in their mid-twenties.

The outbreak was first reported Sept. 4 after seven people developed symptoms of mumps, which include fever, fatigue, head and muscle aches, and swollen salivary glands under the ears.

"Healthcare providers and public health officials should remain vigilant for patients presenting with an illness clinically compatible with mumps," Meddis said. "To prevent the further spread of this disease, health care professionals need to continue to monitor and report every possible diagnosis of mumps."

The mumps virus spreads through tiny droplets of saliva or mucus, according to the U.S. Centers for Disease Control and Prevention. And because up to 50 percent of people with mumps have mild symptoms or none at all, many people fail to realize they're contagious.

"Most mumps transmission likely occurs before the salivary glands begin to swell and within the five days after the swelling begins," the CDC says on its website.

A vaccine against measles, mumps and rubella, known as the MMR vaccine, can reduce the risk of infection by up to 88 percent, according to the CDC. The vaccine is given in two doses - one in babies 12 to 15 months old and one in children aged 4 to 6.

Nurses from the Health Department gave 32 D'Jais employees the MMR vaccine Sunday, according to a statement. The Health Department also advised the bar on cleaning and sanitizing procedures.

The CDC recommends the following precautions for people with mumps:

• Minimize close contact with other people, especially those with weakened immune systems;
• Stay home from work or school for five days after your glands begin to swell;
• Cover your mouth and nose with a tissue or your sleeve when you cough or sneeze;
• Wash hands thoroughly and frequently with soap;
• Don't share drinks or utensils;
• Keep frequently touched surfaces clean with soap and water.

Click here to learn more about mumps and the outbreak.