The increase is consistent with national trends, officials say, and they’re citing “high-risk behaviors that have become more common in recent years.”
Those behaviors “include using social media to arrange casual and often anonymous sexual encounters,” the health department said in a statement.
Having sex without a condom, having multiple partners, and sex while under the influence of drugs or alcohol are also factors noted by the department.
The popularity of online dating apps like Tinder has grown in recent years.
A 2013 study by Pew Research found that one in five adults have used an online dating app or website, and a majority of people now say online dating is a good way to meet people.
“These new data underscore the importance of encouraging young people to begin talking to a doctor, nurse, or health educator about sexual health before becoming sexually active and especially after becoming sexually active,” said Rosemary Reilly-Chammat, a specialist at the health department.