Five of eight medical students who contracted a rare form of meningitis on a Spring Break trip to Jamaica have been released from Northwestern Memorial Hospital.

Doctors at the hospital expect the other students to fully recover from the non-contagious “rat lungworm” form of meningitis, which is transferred through food.

Those infected began suffering last week from “massive headaches,” neck pain and on-and-off numbness in their extremities, said first-year medical student Piyush Golia, one of the students who contracted the parasite. The headaches can continue for two months, he said.

The students believe they were infected from a Caesar salad they shared at a restaurant in Montego Bay two weeks ago during a vacation in which more than 22 first-year medical students participated, Golia said.

The disease is spread through a parasitic worm found in rat feces, which might have come in contact with lettuce in the salad, Golia said.

Representatives for the Centers for Disease Control will travel to Jamaica to inform the restaurant of possible health hazards, Golia said.

Unlike viral and bacterial meningitis, the form the students contracted cannot spread among people.

Once the parasite enters the body, its takes two to three weeks for it to travel to the central nervous system, said Rajesh Gupta, another student who became ill. The body’s immune reaction causes swelling in the head and in the membrane around the the spinal cord, he said.

“Your head feels like it’s going to blow up,” he said.

NU experts told the Chicago Tribune they have not seen this type of parasite — known as eosinophilic meningitis — in Chicago in 10 years.

The Chicago Department of Health took blood samples from the infected students last week and sent the samples to be studied in Bangkok, Spain and Costa Rica, sites of previous outbreaks, Golia said.