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Molecular surveillance detects rapidly growing HIV transmission clusters in US

Photo of Anne Marie France
Anne Marie France

BOSTON — Researchers who used a molecular sequencing method to monitor HIV trends in the United States identified 60 rapidly growing transmission clusters in which the rate of transmission was 11 times higher compared with the overall national rate.

CDC epidemiologist Anne Marie France, PhD, MPH, said the findings underscore the value of molecular sequence data — which are generated as part of routine HIV care for drug resistance testing — in guiding prevention interventions at the local level.

“Molecular surveillance is an advanced public health technology that we believe will enable state and local health departments to more quickly and efficiently identify where HIV transmission may be occurring and how to efficiently intervene to stop it,” she said during a press conference.

France and colleagues analyzed HIV nucleotide sequence data reported to the National HIV Surveillance System that were collected from people in 27 U.S. jurisdictions who were diagnosed with HIV during the past 3 years. The researchers used the data to detect HIV transmission clusters, which they defined as groups of patients whose viruses had no more than 0.5% genetic variation. Rapidly growing clusters, they reported, were further characterized as clusters in which at least five patients were diagnosed with HIV within 12 months.

Overall, 60 rapidly growing HIV transmission clusters were detected in all regions of the country. The clusters ranged in size from five to 42 patients, with 21 to 132 transmission events per 100 person-years. The median rate of transmission in the clusters was 44 infections per 100 person-years, which is11 times greater than the national rate of four infections per 100 person-years, France said. In the rapidly growing clusters, there was a disproportionate number of patients who were young men who have sex with men, or MSM (61% vs. 32%; P < .0001), particularly young Hispanic MSM (26% vs. 10%; P < .0001), compared with the nonrapidly growing clusters.

Molecular surveillance, France concluded, “clearly allows us to identify networks” and will help public health experts determine what additional HIV prevention services are needed in each area. For example, she said that linkage to care activities can be scaled up in areas with a higher number of patients who do not have viral suppression, and testing interventions can be targeted in areas with clusters driven by people who are unaware of their infection.

“While we’re early in the implementation process, we believe that this technology holds tremendous promise in helping identify transmission networks of potential concern and will be continuing to work with state and local communities to further assess intensified interventions as needed to slow the HIV epidemic in the U.S.,” France said. – by Stephanie Viguers

Reference:

France AM, et al. Abstract 40. Presented at: Conference on Retroviruses and Opportunistic Infections; March 4-7, 2018; Boston.

Disclosure: France reports no relevant financial disclosures.

Photo of Anne Marie France
Anne Marie France

BOSTON — Researchers who used a molecular sequencing method to monitor HIV trends in the United States identified 60 rapidly growing transmission clusters in which the rate of transmission was 11 times higher compared with the overall national rate.

CDC epidemiologist Anne Marie France, PhD, MPH, said the findings underscore the value of molecular sequence data — which are generated as part of routine HIV care for drug resistance testing — in guiding prevention interventions at the local level.

“Molecular surveillance is an advanced public health technology that we believe will enable state and local health departments to more quickly and efficiently identify where HIV transmission may be occurring and how to efficiently intervene to stop it,” she said during a press conference.

France and colleagues analyzed HIV nucleotide sequence data reported to the National HIV Surveillance System that were collected from people in 27 U.S. jurisdictions who were diagnosed with HIV during the past 3 years. The researchers used the data to detect HIV transmission clusters, which they defined as groups of patients whose viruses had no more than 0.5% genetic variation. Rapidly growing clusters, they reported, were further characterized as clusters in which at least five patients were diagnosed with HIV within 12 months.

Overall, 60 rapidly growing HIV transmission clusters were detected in all regions of the country. The clusters ranged in size from five to 42 patients, with 21 to 132 transmission events per 100 person-years. The median rate of transmission in the clusters was 44 infections per 100 person-years, which is11 times greater than the national rate of four infections per 100 person-years, France said. In the rapidly growing clusters, there was a disproportionate number of patients who were young men who have sex with men, or MSM (61% vs. 32%; P < .0001), particularly young Hispanic MSM (26% vs. 10%; P < .0001), compared with the nonrapidly growing clusters.

Molecular surveillance, France concluded, “clearly allows us to identify networks” and will help public health experts determine what additional HIV prevention services are needed in each area. For example, she said that linkage to care activities can be scaled up in areas with a higher number of patients who do not have viral suppression, and testing interventions can be targeted in areas with clusters driven by people who are unaware of their infection.

“While we’re early in the implementation process, we believe that this technology holds tremendous promise in helping identify transmission networks of potential concern and will be continuing to work with state and local communities to further assess intensified interventions as needed to slow the HIV epidemic in the U.S.,” France said. – by Stephanie Viguers

Reference:

France AM, et al. Abstract 40. Presented at: Conference on Retroviruses and Opportunistic Infections; March 4-7, 2018; Boston.

Disclosure: France reports no relevant financial disclosures.

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