The world's seven billionth human was officially delivered to Planet Earth on Halloween eve in a crowded hospital in the Philippines. A healthy five-and-a-half-pound girl named Danica May Camacho, she was chosen by the United Nations to symbolize the challenges presented by the world's steadily increasing population.
Kateri Town
Co-authors Connie Celum, Jared Baeten, and Renee Heffron.
The U.S. Census Bureau estimates that 255 people are born every minute, while only 106 die. That translates to an annual net gain of more than 78 million global citizens per year. First-world countries like the United States contribute disproportionately to the increase. A baby born and raised in Seattle, for example, is expected to live to age 82. A child reared in Nairobi, Kenya, will likely be dead by 50.
Life in the Emerald City is obviously easier than in sub-Saharan Africa. Grocery stores; doctors and hospitals; a coffee shop on every block. There are many reasons for the difference in average lifespan, but one stands out: HIV/AIDS. Between 1992 and 1996, it was the leading cause of death in King County for people ages 22 to 44. By the end of the decade, improved education initiatives and access to anti-retroviral drugs had helped stem the tide. Today, fewer than 30 King County residents per year die of AIDS.
Sub-Saharan Africa, too, has made progress. The virus is still responsible for 8 percent of all under-age-5 deaths in a region where children are 20 times more likely to perish prematurely. But the good news is that, according to UNICEF, about 12,000 fewer children died every day in Africa in 2010 than did in 1990.
A variety of factors surely contributed to this improvement, but one of the most critical has been improved access to contraception. Global health organizations have spent billions of dollars on condoms and other forms of birth control over the past two decades, supposing that if fewer babies are born, fewer will die. Moreover, mothers who already have children are less likely to suffer fatal complications giving birth to their third, fourth, or fifth. It seems like a win-win proposition.
But what if one of the most popular methods of contraception actually contributes to the spread of HIV?
In a cruel twist of fate, that might be the case—at least according to research published earlier this year by a team from the University of Washington's School of Public Health. After two years of observation, those researchers now suspect that birth-control injections, most commonly known by the brand name Depo-Provera, may double a woman's risk of contracting and transmitting HIV.
Though hardly definitive, the findings have rattled the global health community. Approximately 12 million women in sub-Saharan Africa currently rely on injectables like Depo-Provera to prevent unwanted pregnancies. At the same time, the region is home to nearly three-fourths of the world's HIV-positive population. Evidence that this birth-control method contributes to the spread of the disease has startling implications: Much of the continent suffers devastatingly high maternal and neonatal mortality rates (meaning that often, both mother and baby die during birth), making access to contraception literally a matter of life and death.
"It was personally challenging to see these results," says Jared Baeten, a UW physician who co-authored the study. "Thinking that a well-tolerated, highly acceptable, and effective form of contraception could not be available because of this research is terribly concerning for me."
In response to these findings and the subsequent widespread media coverage, the World Health Organization (WHO) is convening more than 60 experts on HIV, family planning, and health policy next month in Geneva. The group will determine precisely what some 150 million women worldwide who use hormonal contraception ought to be told about the possible association between their birth-control method and HIV.
The debate promises to be intense. On one hand, skeptics argue that the UW research is potentially flawed, and that any increased risk of acquiring HIV is outweighed by the tremendous benefits of the birth control. Others contend that the findings warrant new guidelines, perhaps even restrictions.
What everyone agrees on, however, is that there is no easy solution. According to Michael Worobey, a professor of ecology and evolutionary biology at the University of Arizona who follows the spread of HIV, the life-altering trade-offs revealed by the study are "about as bad as it could possibly get."
Years before she co-authored the study that could change the way women around the world use birth control, Renee Heffron gave a eulogy. A soft-spoken Rhode Island native with blonde hair and a slender frame, the Ph.D. student is sipping coffee at a cafe near her office at Harborview Medical Center while talking about her time in Africa.
Heffron's first experience on the continent came in 2001, when the then-22-year-old Peace Corps volunteer was stationed at a rural clinic in Burkina Faso. Two things about her new home stuck out: the primitiveness—no paved roads, no running water, no electricity—and the fear that gripped the local youth.
"People were terrified of HIV," she says.
Heffron had arrived roughly 100 years after the virus. Thanks to an archive of blood samples from the earliest AIDS patients, scientists like Worobey now estimate that HIV first jumped from chimpanzees to humans around the turn of the 20th century, when hunters in Cameroon butchered the animals for "bush meat." The virus then came to the United States around 1960, via a small group of Haitian immigrants who had previously traveled to the Congo. After that, there was no stopping it. By the time Heffron returned home from her journey to the remote village, AIDS had claimed an estimated 1.8 million lives worldwide, nearly 75 percent of those deaths occurring in Africa.
