Tuberculous is largely controlled in developed countries. Nevertheless, one-third of the world’s population carries the infection. Many people infected may not exhibit symptoms, but as the science journalist Amy Maxmen points out in the New York Times, about 4,100 people die of the disease each day because diagnostic tools and drugs to treat the disease are inaccessible.
Even if tests and treatments are accessible, Maxmen writes, the problem remains that a common test involves culturing saliva for a long period of time, during which a patient remains untreated and can infect others. However, a new test—GeneXpert from Cepheid—cuts the diagnostic time to a matter of hours.
The problem remains of getting technologies like GeneXpert to people in remote locations—but there are possibilities. “One effective approach I observed in southern Tanzania,” writes Maxmen, “was a mobile diagnostic lab housed in a van that offers movies by night to lure potential patients, and runs GeneXpert’s TB test, as well as HIV and cervical cancer tests, by day.” The movies, projected onto a screen atop the van, are accompanied by public-service announcements regarding the diagnostic tests available.
Continues Maxmen, “A small team made up primarily of Tanzanian doctors and technicians operates both the movie projector and the diagnostic equipment; they pick up supplies as needed and travel to remote areas to serve villagers who otherwise would have limited access to these health tests.”
Statistics suggest the mobile lab is effective: Maxmen writes that in 2012, a main hospital conducted 39 GeneXpert tests while the mobile lab ran 1,265. Villagers tested positive by the van’s facilities are referred to clinic for a six-month free course of medicine, and cure rates are 88%, Maxmen reports.
Hurdles to expanding the program include cost—the GeneXpert tests cost $9.98 apiece, Maxmen writes. To demonstrate cost-effectiveness, one nurse who screens at-risk people with a mobile unit in the UK suggests that the Tanzanian mobile-lab team members sequence the genes of TB strains they identify. Explains Maxmen, “If many people have the same strain in a region, it means the disease is being diagnosed too late to prevent transmission. By contrast, the appearance of different strains would indicate that the van is in fact interrupting transmission.”
Concludes Maxmen, “With such remarkable lifesaving technology available, the big challenge for donors, governments, and other social innovators today is to come up with newer and better ways to take them on the road.”
