Updated: Feb. 19, 2020 at 2:58 p.m.
A research team in the Milken Institute School of Public Health published a study earlier this month outlining how the HIV virus is spreading and developing drug resistance in the District.
Marcos Pérez-Losada, an assistant professor of biostatistics and bioinformatics, and Keylie Gibson, a doctoral student studying biological sciences, spent five years using next-generation sequencing data to identify D.C.-area “transmission chains,” or ways the HIV virus spreads. Researchers said quantifying and classifying common drug-resistant HIV strains will help public health officials determine which therapies will most effectively curb HIV infection rates.
Gibson said the research team decided to focus the study on D.C. because the city has the highest rate of HIV diagnoses in the U.S. In 2018, 360 newly diagnosed HIV cases hit the District, according to data from D.C. Department of Health.
Gibson said the study’s findings will help D.C.-area physicians and public health practitioners make “informed” decisions about how best to provide antiretroviral therapy, medication that prevents the replication of HIV in individuals with the virus.
Mayor Muriel Bowser released a 2016 plan to ensure that by the year 2020, 90 percent of D.C. residents with HIV will know their status, be in treatment, achieve viral load suppression or have an “undetectable” amount of HIV in the blood. Her plan also aims to decrease the total number of HIV cases by 50 percent.
“Physicians can provide more informed care for their patients related to antiretroviral therapy, and public health officials can interact with the public to provide resources and information about access to diagnosis and care options in the D.C. area, as well as how D.C. residents can actively be a part of preventing the continued spread of HIV,” Gibson said in an email.
She said individuals with HIV contract several variants of the virus, some of which develop resistance to antiretroviral therapy. Gibson said the team focused on identifying drug-resistant HIV mutations common in the D.C.-area to inform public health officials’ approaches to treating the disease.
“When a person is treated with antiretroviral therapy (ART), some of these variants develop mutations that allow them to better evade the drug,” she said. “Since these variants can now survive in the host better than others, they become more and more prevalent in the viral population, eventually making ART ineffective.”
Pérez-Losada, who works in the computational biology institute, said the team received about $317,000 in funding from the D.C. Center for AIDS Research to conduct the study.
In 2006, city officials partnered with the GW Hospital to launch a citywide testing campaign that offered free HIV screenings in response to a report estimating that one in 20 D.C. residents has HIV.
Public health experts who study HIV treatment and prevention said city public health officials should primarily allocate resources like research funding to large cities – where HIV infections are more common – to combat the virus.
Joel Wertheim, an assistant professor of bioinformatics and systems biology at the University of California San Diego, said observing how the virus has spread in large cities like D.C. will help public health officials determine how to allocate resources toward decreasing infection rates.
“Understanding these past transmission dynamics let us know where the virus might be going and what types of prevention approaches may be most successful and especially powerful,” Wertheim said.
He said gene-sequencing technology allows researchers to examine HIV gene sequences for drug-resistant mutations, which helps researchers figure out treatment options for specific virus strains.
“We’re not in the business of saying who infected whom, but we are looking at which people may be involved in clusters of transmission, and we can do that by looking at genetic similarity or dissimilarity among viruses,” Wertheim said.
Ellen Eaton, an assistant professor at the University of Alabama, Birmingham, said the number of HIV infections in D.C. is especially increasing among marginalized groups who generally experience higher rates of poverty. She said low-income populations generally have limited access to HIV-preventative treatments like pre-exposure prophylaxis – or PrEP, a medication that prevents HIV infection.
She said reviewing resistance profiles – resistant strains of a virus or bacterium – will prompt pharmaceutical companies to develop an anti-HIV medication that targets multiple types of the virus. Eaton added that encouraging pharmaceutical companies to expand available anti-HIV medication options will help individuals whose drug regimen loses its efficacy after a long period of time.
“But what’s reassuring is that every year we’re continuing to get more drug combinations and newer drug combinations, such that there’s still a lot of options,” Eaton said.
Lauren Sterling, the associate director of the University of San Francisco Center for Aids Research, said classifying the most common drug-resistant HIV strains in D.C. will help clinicians determine which “first-line therapy” – or initial treatment – will be most effective.
“Drug resistance testing helps people living with HIV know that their medications are working against their virus,” Sterling said in an email. “Additionally, once they’ve achieved an undetectable viral load, they are no longer able to transmit the virus to other people.”
This post has been updated to reflect the following correction:
The Hatchet incorrectly reported the name of the Milken Institute School of Public Health. The name is now correct. We regret this error.
