Acute HIV infections are discovered in Charlotte
Program that uncovered outbreak to lose funding
North Carolina investigators found evidence earlier this year of an HIV outbreak among white men who have sex with men (MSM) in the Charlotte area.
The cluster of cases in Mecklenberg County were associated with MSM who used crystal methamphetamine and found sexual partners via the Internet, says Peter Leone, MD, an associate professor in the department of medicine at the University of North Carolina in Chapel Hill.
Investigators began an outbreak investigation in June after finding 16 cases of acute HIV infection since the beginning of 2004, he says.
A year ago, the same investigators had discovered an outbreak of HIV infection among male students at African American colleges across the state. This outbreak led to an investigation by the Centers for Disease Control and Prevention (CDC) and resulted in enhanced HIV screening and prevention efforts by the state and colleges.
The latest outbreak involves some continuing HIV transmission among the college students, but also results from a new cluster of cases among white MSM in their 30s and older, Leone explains.
"We have had meetings with the community and are doing case investigation and are planning an intervention," he adds.
As of mid-June, the CDC was not involved in investigating the outbreak, although CDC officials likely would be called to join the investigation, Leone says.
"I think we’re seeing a very large increase in new cases," he explains. "We don’t know the extent of it yet because our [HIV testing] pickups are at voluntary testing and counseling sites, and there may be acute cases in the community that we’ve missed."
Half of the 16 cases were discovered through routine surveillance, and the others were found through referrals from clinicians who saw patients presenting with symptoms of acute HIV infection, Leone adds.
North Carolina’s HIV screening program, the Screening Tracing Active Transmission (STAT), is unique in that it can detect HIV infection among people who were infected very recently and who test negative on the antibody test.
This ability to identify acute infections almost immediately is the result of an HIV pooling process developed by Leone and other investigators.
Basically, the process takes the samples of blood, collected for HIV testing at public clinics, and uses multistage pooling of the negative samples to retest with the HIV RNA or qualitative nucleic acid test that can detect new infections.
When the RNA test comes up positive, that particular pool of samples is divided and tested again until the one or more samples that represent an acute case of HIV are singled out. Then the sample is identified back to its source and that person is notified of the results.
Through this relatively inexpensive process, health officials are able to find HIV transmission trends and clusters almost as soon as they begin to occur, Leone notes.
"The real benefit is we can identify people during their most infectious period, and by notifying them, we can at least remove them from behavior that causes more transmissions," he says. "Even a short-term prevention intervention can make a tremendous difference on HIV transmission in the community."
Without the pooling program, the same HIV outbreak might not be discovered for years, Leone explains.
Plus, people who engage in high-risk behavior and then go into a center for testing might see a negative HIV test as positive reinforcement for their risky activity.
Meanwhile, if the same people actually are in the acute phase of HIV infection, they likely are even more contagious and likely to transmit the virus than someone whose blood tests positive for HIV antibodies, he notes.
"So it’s critical to identify folks, and we showed how it can be done relatively cheaply," Leone says. "If you have people coming into care to be tested, it makes sense to do everything you can, and the technology is there to do the acute testing — so it’s a question of will and money."
Ironically, at the very time the North Carolina program is yet again identifying an outbreak of HIV and at the same time that the CDC has begun a new push for early HIV testing and prevention for positives, the pooling program may go belly-up from lack of funding, he says.
The CDC has issued a Request For Applications (RFA) for nucleic acid testing to research whether it is an effective testing therapy, says Robert Janssen, MD, director of the CDC’s Division of HIV/AIDS Prevention.
"This is in line with one of our goals of advancing HIV prevention and to implement new models for diagnosing HIV infections," he says.
The request states this would be a $2 million, two-year grant.
Leone says it’s a positive sign that the CDC will invest in the process, but North Carolina would not qualify for the grant proposal and still has a funding problem.
According to the request, applicants for part 1 must demonstrate their ability to provide samples from 50,000 seronegative individuals and most demonstrate a seropositivity rate of HIV tests of at least 1.5%. North Carolina would not meet this qualification, he adds.
For the second part of the grant, the applicant must be able to return pooled nucleic acid testing results within seven days of specimen receipt and must be able to process 8,000-10,000 specimens per month, the RFA states.
It’s doubtful the North Carolina lab could handle that volume, Leone adds.
"Right now, our program will not have additional funding after October of this year, and it seems ironic to me that there is an RFA to replicate our program, and we may not have additional funding," he says.
"We’re not eligible for the RFA because we don’t have a high enough incidence to qualify," Leone points out.
Thus far, the pooling program has received a patchwork of funds from private, state, and other sources, but all of it will expire this year.
"It’s going to cost $300,000 to maintain the lab on an annual basis for screening, and the money isn’t there — so we’re up against the wall on this," Leone says.
Logically, it would make sense for the CDC to fund the North Carolina project so it could continue to serve as a model for future use of the pooling program and investigators who have already invested considerable intellectual time and effort into developing the process could continue to build on their work, using their experiences with the program in the state, he explains.
When asked via email about North Carolina’s request for funding, Janssen referred to the RFA as an example of the CDC providing funding for this type of research.