For documentary filmmaker Roger Ross Williams, Uganda is a country afflicted. But HIV/AIDS, malnutrition, and other physical ailments are not what concern Williams the most; for him, the true epidemic threatening this land and its people is far more insidious—a plague of the spirit. “I love Uganda,” intones a weary, accented voice at the opening of God Loves Uganda, which was broadcast earlier this week on PBS and is now available on iTunes and Netflix. “It’s a very loving country, a caring country. But, something frightening is happening that has the potential to destroy Uganda … and it is coming from the outside.” As images of white hands being fervently laid on dark-skinned children flash across the screen, the outside threat becomes clear: ultra-conservative American evangelicalism.

If you’ve followed the story of Uganda’s infamous “Kill the Gays” law over the past few years, you’re probably aware that prominent American evangelicals like Scott Lively and Lou Engle have been harshly criticized for their role in introducing a strain of zealous social conservatism—including an especially vicious condemnation of homosexuality—to Africa. But media reports of this phenomenon have been mere hints compared to the dense epidemiological survey that God Loves Uganda represents. Williams’ vision of the relationship between American missionary groups—like the Kansas City-based International House of Prayer that he profiles here—and the Ugandan government and culture is one of contagion, infection. Early in the film, an animated map of the globe shows salvation spreading like a plague across the world. A little later, a young woman on her first mission trip to the country describes her goal as one of virality:

One of my greatest hopes is to deposit what I’ve kind of received at IHOP, that DNA of prayer and worship. DNA replicates itself, and so I think that everybody wants to replicate their values and the core parts of who they are.

And as Williams shows, the evangelical movement’s vector-teams have been successful—images of spirit-struck white people wailing and “rapid-fire” praying for Africa in Missouri transform into scenes of wild-eyed Ugandan ministers screaming at strangers in a traffic jam, of white-walled rooms full of people jumping and flailing and lifting chairs in the air, of sweat-drenched Africans speaking in tongues. Williams has created a zombie movie, only the dreaded mutation is one of hateful Christian ideology rather than cells: Call it “World War C.”

Tracing the origins of this epidemic prove upsettingly simple. “The West has been in a decline,” Lou Engle, founder of prayer rally program “The Call,” explains in the gruff, breathy, slightly crazed tone that a certain kind of minister uses to convey his fervor. “But right now I think that Africa, it’s the firepot of spiritual renewal and revival. It’s very exciting to me.” America is becoming increasingly resistant to his bigoted version of Christianity; time to find greener pastures elsewhere. And as another missionary explains, Uganda is the perfect place: “50 percent of the population is under 15 years old. … What [we] can do is limited, but we can multiply ourselves in these young people.” Add that to the strategy of tying aid and charity work to values exportation in order to ensure a captive audience, and it’s easy to see why many Ugandans so readily accept the evangelical message.

Well, that and the fact that Lively and his ilk have done a great job convincing Ugandan parents that homosexuals are out to get their children. This “recruiting” notion is as old as time and should have been discredited by now, but it seems to work particularly well in a culture that has not had much experience with sexual minorities. Of course, the irony is that it’s the radical evangelicals who are doing the recruiting here, literally whispering their lifestyle into the ears of kids—as a poignant scene at the funeral of slain activist David Kato shows, actual LGBTQ people are struggling just to stay alive.

God may love Uganda, but many of Uganda’s people have forgotten—with the eager help of Americans—how to love their brothers and sisters. Williams’ film has provided a bracing diagnosis of the problem, but fixing it seems daunting: To my knowledge, medicine has yet to produce a vaccine against hate.