The New York City health department has issued new recommendations for vaccinating against a new and lethal strain of bacterial meningitis.
It says the symptoms come on quickly and the disease can be fatal if not treated immediately.
It's only been seen in men. The patients often contract it through anonymous sexual encounters with other men. That makes it hard to trace the infection's path.
The standard meningitis vaccine is effective against the new strain. The health department is advising it for men regardless of HIV status who regularly have contact with other men they meet online, at a bar or party.
The health department says 22 cases have been reported since 2010, including 13 last year and four this year. Seven have been fatal.