Kanki's efforts are concentrated on the western side of the continent, where the prevalence of the AIDS-causing HIV virus is among the lowest in Africa -- in Senegal, it's under 2 percent. The Harvard virologist is hopeful. But Katzenstein works thousands of miles to the south, mostly in Zimbabwe, where a quarter of the adult population has HIV -- one of the highest infection rates in the world. The Stanford physician is troubled. Their outlooks are reflected in their spirited discussion, which makes for some good-natured indigestion.
"I don't know why things are going so well in Senegal," Katzenstein says in a sarcastic tone as he dips his spoon in the peanut sauce. "I'd like to think it was because of Phyllis' work in the west that fixed everything."
"Don't be such a boob, David," Kanki retorts.
If Katzenstein sounds bitter, it is because his work is in a land facing meltdown. He must deal with infection rates so high that prevention efforts are moot, as the nation -- like so many in southern Africa -- loses the healthy citizenry needed to maintain a functioning government or economy. Of the nearly 22 million people estimated to have been killed by AIDS worldwide since the epidemic began, 17 million were sub-Saharan Africans. In contrast, Kanki (a guest in Katzenstein's Stanford lab this year) wants to think certain devastation is not the continent's uniform fate -- at least not in the west, where a weaker strain of HIV predominates and governments have been more proactive in tackling AIDS. She is careful to sound modest, because she knows her attempt to replicate Senegal's success in neighboring countries, like Nigeria, could fall short. But as long as the infection rate remains stable in western Africa, she has time to implement some new prevention strategies rarely utilized in the far-gone south.
Kanki departs from the conventional method of supporting one-size-fits-all programs, most of which prove unfocused and ineffective, and provide little or no scientific data to help understand the true nature and trajectory of the disease. Instead, she advocates a potentially controversial triage approach that identifies and targets specific groups of people; groups that can benefit most from a customized message and in turn slow the epidemic for everyone else. Students, for instance -- the future doctors, teachers, and leaders of a country -- are an essential "bridge population" she hopes to keep alive. In support of this theory, Kanki has been given $25 million from the Bill and Melinda Gates Foundation with the goal of preventing Nigeria -- Africa's most populous nation -- from going the way of Zimbabwe.
Their lunch continues for hours, as does the argument.
Dr. Katzenstein is skeptical of his Harvard colleague's methods.
"Look where 15 years of prevention in Zimbabwe have gotten us," he says. "The question is, if what you are doing is not working, how long do you do it?"
"But no one ever asked if it was working," Dr. Kanki implores. "We could've found out what doesn't work, but no education or prevention studies ever looked at a biological outcome."
Kanki rattles off a long list of failed initiatives in which data were based on verbal surveys alone, without ever taking a blood sample. With such limited data, behavioral changes could never be proven or linked with infection rates. Worse, an accurate and scientific history of the disease -- caused by multiple strains of the HIV virus -- has never been recorded in Africa, which makes treatment all the more difficult.
"OK, so the prevention was done badly," Katzenstein says. "But effective prevention won't make a difference in the hyperepidemic situation we have now."
Maybe prevention won't help in Zimbabwe, where Katzenstein can only prolong some lives by dispensing a limited supply of drugs to an exponentially growing number of patients -- when he isn't wondering if the drugs will work at all, given that he's unsure which strains of HIV he is fighting. But it hasn't gotten to that point in Nigeria. Yet. With Nigeria's HIV infection rate already thought to be as high as 7 percent and growing, Kanki is well aware that the country is an AIDS time bomb. She is determined to be judicious in her approach, hoping for successful intervention while laying the proper scientific groundwork to collect data. That way, if AIDS does explode in the west, at least she will have reliable information from which to make a new plan.
Katzenstein understands her intentions, but they are too far from his own reality to embrace. "You're trying to treat an epidemic rather than individual patients," the physician Katzenstein tells the virologist Kanki. "The notion we can do scientific prevention is the great hope, but as a physician I am bound by the Hippocratic oath and the Marcus Welby approach: one person at a time. It may not be the most rational approach -- spending all the money on the last few months of life, instead of putting it all into prevention -- but we are not rational when it comes to our brothers, mothers, or sisters."
Such sentiment resonates with Kanki, though she doesn't shy away from what she sees as a stark truth: "I believe in tailored intervention, which can include treatment," she says. "But it is incorrect to imply we are curing people. Until there is a vaccine, everyone who gets this disease is going to die. There is no compassionate way to say we shouldn't be giving drugs to people."