A genetic analysis of HIV samples taken from about half the people infected in the largest HIV outbreak in Indiana history shows nearly all of them have the same strain of the virus, a finding one health expert says is a sobering reminder of how rapidly HIV can spread among intravenous drug users.
Indiana’s state epidemiologist, Pam Pontones, cautioned that the findings by the Centers for Disease Control and Prevention are “very preliminary.” But she said they suggest that the HIV strain detected in southeastern Indiana’s outbreak was introduced there during the past six to 12 months.
“That particular strain has not been in this population very long. It’s very recent,” she said.
As of May 14, 154 cases of HIV have been confirmed since December in southeastern Indiana — nearly all of them in Scott County, which has been at the center of the HIV outbreak tied to needle-sharing among IV drug users. The county typically sees only about five new HIV cases a year, state health officials said.
For its analysis, the CDC studied HIV specimens from 72 people who have tested positive in the outbreak and found that 69 of them had the same strain, state Department of Health spokesman Ken Severson said.
The findings are a sobering reminder of how rapidly HIV can spread among IV drug users, said Beth Meyerson, co-director of the Rural Center for AIDS/STD Prevention at Indiana University. She also said it’s a warning to health officials nationwide to monitor local users for HIV and hepatitis C, to help detect outbreaks
“Injection-drug use is a very, very efficient mode of transmission — fast and efficient,” she said.
CDC spokeswoman Donnica Smalls said the agency is working on a final report that will include looking at whether the HIV strain in Indiana has surfaced elsewhere in the U.S. or is related to other strains.
The CDC issued an alert to health departments nationwide last month, urging them to take steps to identify and track HIV and hepatitis C cases to prevent outbreaks similar to Indiana’s, which was detected in January.
High rates of hepatitis C are a key indicator of needle-sharing and a potential HIV outbreak, and the CDC said acute hepatitis C cases soared 150 percent from 2010 to 2013. About 80 percent of those infected with HIV in Indiana’s outbreak are also infected with hepatitis C.
Meyerson said the CDC’s preliminary analysis drives home the importance of needle-exchange programs like a temporary program in Scott County, about 30 miles north of Louisville, Kentucky. Such programs provide users with clean syringes and collect used ones to help prevent the spread of diseases.
A new Indiana law spurred by the local outbreak allows communities to seek state approval to run needle exchanges if they can prove they’re facing an HIV or hepatitis C epidemic fueled by IV drug use.
Scott County is expected to soon ask Indiana’s state health commissioner for permission to operate a year-long needle-exchange program under that law.
Health officials said that more than 320 people have taken in the county’s needle-exchange program, which has distributed more than 14,000 needles since it began in early April.