Opioid Epidemic Is Fueling HIV Cluster Outbreaks -- Here's How CDC Is Responding

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Over the past five years, the opioid epidemic and associated injection drug use has led to several high-profile cluster HIV outbreaks, most notably the Scott County, Indiana, outbreak in 2014.

In an effort to better respond to these outbreaks and support local health departments, the Division of HIV/AIDS Prevention (DHAP) at the Centers for Disease Control and Prevention (CDC) took a hard look at its own HIV response protocols and decided it was time for a change.

DHAP borrowed from the CDC's Division of Tuberculosis Elimination (DTBE), which has been partnering with state and local health departments for many years to monitor outbreaks via its tuberculosis outbreak evaluation unit.

"DHAP decided to implement a similar approach for HIV," said Andre Dailey, M.S.P.H., epidemiologist at the CDC. In July 2017, DHAP developed an outbreak assessment and response plan, and on March 19, Dailey presented the initial findings from that initiative at the 2019 National HIV Prevention Conference (NHPC) in Atlanta (Abstract 5708).

From July 2017 to February 2019, the outbreak coordination unit (OCU) evaluated 25 potential HIV outbreaks across 21 states. The group, whose members hailed from seven different branches in DHAP and three separate CDC offices, met at least once a week to review these cases.

Of the 25 potential outbreaks, the OCU decided that 18 did not meet the criteria for CDC to deploy assistance to local health departments. Those 18 cases were discussed at only one or two meetings before being considered "closed."

"These were often situations where there was a small increase [in HIV infections] and we determined no need for CDC assistance at that time," said Dailey, speaking at the conference.

Four of the situations were discussed in depth across three or four meetings, and three of those situations were associated with large increases in injection drug use. Of the 25 situations that were evaluated from July 2017 to February 2019, four were still ongoing at the time of the NHPC meeting.

Dailey said that the OCU reviews and manages situations that were prompted in one of four ways: local health departments that made an explicit request to DHAP, clusters that generated media coverage, situations that appeared to span multiple states, and clusters involving special populations that were of key concern to the CDC.

The DHAP lab conducted sequencing and phylogenetics for six out of the 25 outbreaks, Dailey said, careful to add that any information OCU received was de-identified, and that all OCU personnel were given data security training.

Last month at the annual Conference on Retroviruses and Opportunistic Infections (CROI), the CDC used part of its plenary session to defend its molecular surveillance program against criticism that it might jeopardize people living with HIV and subject to HIV criminalization laws.

Dailey assured the audience at NHPC that "OCU discussions are treated as sensitive" and information is shared on a "need-to-know basis." In addition, the OCU rarely if ever discusses individual people, rather assessing the aggregate findings from a particular outbreak situation, Dailey said.

Over the 20 months it has been implemented, "the OCU has really improved DHAP's ability to support health departments," Dailey said, adding that program is "evolving" at CDC and the team is moving forward with key priorities in mind. Chiefly, the OCU team would like to provide additional training for its employees who are deployed to regional cluster outbreaks, and it would like to develop a more robust criteria for determining when a potential situation should be considered "closed."

Ultimately, Dailey said efforts like OCU's will be important in the context of the president's plan to end the HIV epidemic by 2030.

"Responding rapidly to growing HIV clusters to prevent new infections is one of the four pillars" of the plan, Dailey said. "So thinking about how we can all work together to communicate about this work is really important."