HIV infections in the United States have fallen for several years, and few places have seen a bigger drop than Maryland, according to new estimates from the U.S. Centers for Disease Control and Prevention.
Cases in the state dropped an average of 7.5 percent per year from 2008 to 2014. That was more than twice the national decline of 3.6 percent per year.
Public health officials attributed the progress to education campaigns, a push to get high-risk people tested and treated, drugs that block infection and, most notably, needle exchange programs in Baltimore.
"The impact of syringe exchanges has been enormous," said Jeffrey Hitt, director of the Infectious Disease Prevention and Health Services Bureau in the state health department. "About a decade ago that was primary mode of transmission in Baltimore and Maryland, people injecting drugs and sharing equipment."
While the public health community is pleased overall with declines shared across the country, they say progress has been uneven among groups of people.
The District of Columbia, Georgia and Illinois had bigger drops in new cases than Maryland. Four other states also saw significant declines. Among 28 other states where the CDC made estimates, infections were basically unchanged. (Some other states had too few cases to make estimates of a change.)
The biggest decrease nationally, 56 percent, was among people who injected drugs. Then came heterosexuals with a 36 percent drop.
New cases dropped among some groups of gay men, including those who were white or under 24, while they rose for gay men ages 25 to 34.
Gay, bisexual and transgender people, particularly African-Americans, have been the most vexing crowd for Baltimore health officials, said Dr. Leana Wen, the city's health commissioner.
Officials have sought multiple ways to deliver the message that HIV is no longer a death sentence but a chronic condition manageable in some cases with a daily pill. Those with suppressed viral loads are also far less likely to infect their partners.
Public health officials have pushed use of so-called pre-exposure prophylaxis, which is a medication that uninfected people take daily to reduce the chance of sexual transmission. But Wen said more doctors need to prescribe it and more high-risk individuals need to ask for it.
That work continues, as do efforts to seamlessly move this at-risk population from testing to treatment when needed. Wen called it a "health and social justice" issue.
But Wen and Hitt say there is also a new threat to controlling HIV cases, and it's outside the city: Intravenous drug users in rural counties where the heroin epidemic has been raging. The officials are working to bring Baltimore-style needle exchange programs to those places before there is a wave of HIV infections.
"We are quite concerned about the potential for an outbreak," Hitt said.