San Francisco health officials are advising some gay men to consider vaccination against meningitis if they have recently traveled or plan to travel to New York City.
New York City has reported at least 11 cases of meningitis among gay men in the past year.
San Francisco's recommendation went out on Thursday. The city's health officer, Tomas Aragon, says men who have recently traveled to New York City and had close or intimate contact with other gay men or plan to go there and have such contact should discuss vaccination with their doctor.
Meningitis affects the tissues around the brain and spinal cord. It can spread through contact with spit or mucus.