NEW YORK (CBSNewYork) — The New York City Department of Health has issued a new vaccination recommendation for men at risk of contracting a serious and potentially deadly strain of meningitis.

The outbreak of meningitis among gay men has sickened four people already this year, increasing the number of cases to 17 since 2012, according to city health officials. Seven fatalities have been reported in the city since 2010.

“Once you get infected the time from being infected to being horribly sick and possibly dying is very short,” Deputy Health Commissioner Dr. Jay Varma told WCBS 880’s Alex Silverman on Wednesday. “We’ve had several cases who have been actually found dead in their apartment before they’d even gone to see a medical provider. So that is, to us, absolutely terrifying.”

The original Health Department warning was issued for HIV-positive men.