New York City health officials are investigating an outbreak of meningitis among HIV-positive men, one of whom has died while another remains in critical condition.

"Men experiencing high fever, headache, stiff neck and rash are advised to immediately contact their health care providers," the health department said in a statement Thursday, adding that all four men who have contracted the disease are gay or have had sex with men.

Invasive meningococcal disease, better known as meningitis, is a bacterial infection of the brain's membranous lining, called the meninges. Early symptoms include fever, headache, vomiting, stiff neck and a rash within 10 days of the infection. And if left untreated, the disease can cause severe brain damage and even death, according to the U.S. Centers for Disease Control and Prevention.

"It's a form of bacterial meningitis that has a subtle onset and can progress very, very quickly," said Dr. William Schaffner, president of the National Foundation for Infectious Diseases and chairman of preventive medicine at Vanderbilt University Medical Center. "The typical story is the college student that doesn't feel so well. He goes to bed because he thinks he has the flu, and the next morning his friends find him comatose."

The New York cases were spread across the city's boroughs, according to the health department. All of the men have been in their 30s or early 40s, and have had HIV, a virus that attacks the immune system making infections more likely and more severe.

"People living with HIV are at a greater risk than the general population of acquiring invasive meningococcal disease and if infected, dying from infection," the health department said.

It's unclear whether the men had been receiving treatment for HIV.

A vaccine recommended for all teens and some adults helps guard against most types of bacterial meningitis. And if detected early, the infection can be cured with antibiotics, according to Schaffner.

"If we can find a person's face-to-face contacts, we can give them some antibiotics prophylactically," he added.

The disease is spread by "prolonged close contact with nose or throat discharges from an infected person," the health department said, describing prolonged contact as "living in the same household" or "intimate activities" such as kissing and sexual contact. "People that have been in prolonged close contact with infected people need to see their health care provider immediately to receive preventive antibiotics."

A 2011 meningitis outbreak killed three New Yorkers and sickened three other, ABC affiliate WABC reported.