Infectious Diseases experts give progress updates on treatment as prevention, prevention of mother-to-child transmission, and medical male circumcision
Treatment as prevention
“Really this is as good as it’s going to get in terms of preventing HIV transmission,” said Julio Montaner, MD, director of the British Columbia Centre for Excellence in HIV/AIDS at a Saturday session of the 49th Annual Meeting of the Infectious Diseases Society of America updating the audience on biomedical HIV/AIDS prevention interventions.
He was talking about the HPTN 052 study, which recently demonstrated a 96.3 percent reduction in sexual transmission of HIV to an uninfected partner when the HIV-infected partner starts immediate highly-active antiretroviral therapy (HAART) versus delayed therapy. Although the treatment as prevention mentality was surmised by many before this trial, HPTN 052 was the first, randomized, controlled trial to prove it.
“We embraced this thinking in British Columbia (BC) a number of years ago – and now we’re expanding HAART coverage in BC within the evolving [International AIDS Society-USA] guidelines,” he said.
Montaner also noted a reciprocal decrease in new HIV diagnoses as antiretroviral therapy (ART) access increased, to include a study of injection drug users who saw a 50 percent decrease in new infections diagnosed in that community in 2007 when HAART was made more accessible to that population.
“Blood-born diseases and STDs remain a concern, they have not decreased,” Montaner said, “but we have seen a continued decrease in the number of AIDS cases being diagnosed.” Rates of AIDS cases are down to 1995 numbers in Canada, mortality is down again, but this is not happening everywhere across the country despite the universal health care access situation, he said. “Access to care is very problematic in our country. There are places, like the prairies, seeing rising cases of HIV.”
In terms of the U.S., Montaner said only about 19 percent of the people infected with HIV have achieved undetectable viral loads with the use of ART. “We have a huge gap – we should be minimum around 50 to 60 percent of the people in order to have an impact on the U.S. epidemiological situation… Why are we not making it a priority to treat U.S. domestic cases?”
Prevention of Mother-to-Child Transmission (PMTCT)
Dr. Elizabeth Bukusi of the Kenya Medical Research Institute (KEMRI) painted a global picture of access to PMTCT services – where currently 21 percent of pregnant women in low- and middle-income countries are tested for HIV, 28 percent in sub-Saharan Africa, and 45 percent of HIV-positive pregnant women receive PMTCT services.
“If we really want to eliminate MTCT, we really have to be able to offer counseling and testing to every single pregnant woman we come into contact with,” Bukusi said. “We must aim to reach at least 80 percent – that they get counseled and tested, that those eligible to get ART receive it, and of those babies exposed, 70 percent must have access to co-trimoxazole,” to ward off HIV-related infections.
HIV prevalence among women peaked in 2000 at 13.4 percent in her country, and more needs to be done to ensure that the few clinicians that are there to treat these women can continue to provide care, such as task shifting. Nearly fifty percent of all HIV-infected females in Kenya have an unmet need for family planning services – there is a vast unmet need for contraception, a low contraceptive prevalence, and a high unintended pregnancy rate.
Other challenges, she said, include improving HIV testing rates among men when antenatal care clinics are where they succeed the most in testing, lacking political and national will to tackle these problems, no integration of HIV services such as with maternal and child health, and no national population-based numerical targets for testing, treatment or care.
Access, acceptance of testing, ART and advocacy for those in need were the key components of a strategy toward elimination of MTCT in low-resource settings, Bikusi said. Beyond ensuring women who are eligible are able to get the treatment they need, she said involving men in PMTCT – getting them tested for HIV, into care if need be, and providing access to prevention for men are important first steps.
MALE CIRCUMCISION and the buzz around devices
Economic models show that by increasing medical male circumcision (MC) coverage rates to reach 80 percent of men and boys in areas with high HIV prevalence and low MC, millions of lives and billions of dollars could be saved in the next ten to 15 years. Clinical trials have demonstrated MC is effective at protecting heterosexual men from HIV infection through vaginal intercourse by more than 60 percent, a benefit that improves over time.
“But we’ve only achieved 3.4 percent of the total coverage needed to reach 80 percent,” said Caroline Ryan, MD, MPH, director of Technical Leadership at the Office of the Global AIDS Coordinator (OGAC) during the session. Nearly twenty million MC are needed to reach the 80 percent coverage goal.
Zimbabwe is only at one percent of the needed coverage, Ryan said, although in the first six months of 2011, Tanzania has increased to 90,000 circumcisions up from 17,000 in 2010.
The slow progress has increased interest in utilizing medical MC devices – such as the PREPEX device. This “potential game changer” is safe, effective, doesn’t require a sterile environment, can be done by a single care provider and no anesthesia is needed, Ryan said. Moreover, there is minimal discomfort involved, meaning more men and boys may get it done and less school or work will be missed.
Data on the PREPEX device is only available from one country at present, and although the data is promising, more is needed from other countries, Ryan said. Another device, the Shang ring, does not have quite as many positive reiews as the PREPEX and field study data on its effectiveness are still needed.
The World Health Organization has not yet approved any devices and funds from the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) program are not available to support device-based services at this time.
“Eight hundred thousand voluntary medical male circumcisions have been undertaken in Southern/Eastern Africa,” Ryan said. “There is optimism that a device could accelerate scale up and lower the cost of implementation.”