“Contact tracing” sounds like something that would excite only the grimmest of health-care operations implementation scientists.

But actually, contact tracing is the core principle of all public-health endeavors. It is the very thing that separates the men from the boys—or in this instance, the resource-plentiful from the resource-strapped countries. And though you wouldn’t know it from the trail of lamentations and mea culpas that have followed the Dallas hospital leaders and the even more beleaguered Centers for Disease Control and Prevention, we just saw a perfect execution of contact tracing right there in Metroplex, Texas (and the attendant venues on the cruise ship and the Frontier Airlines flights).

What they did—and what humanitarian aid organization Doctors Without Borders/Médecins Sans Frontières (MSF) says Liberia no longer can do—is simple: They traced people.

So when the late Thomas Eric Duncan was diagnosed, an immediate circle was drawn around his contacts—they were traced (ergo, contact tracing). And because the transmission of Ebola is pretty well understood, this group of people was watched carefully for 21 days—graduating just yesterday—until they proved themselves to be Ebola-free. Had a secondary case (Duncan is the primary case; anyone catching it from him, such as the two nurses, are secondary cases) been diagnosed from his home contacts, that person would have been caught early in the pre-contagious stage, and a circle drawn around his or her contacts. They would then start the meter at 21 days and wait it out.

After the rudiments were in place for the home contacts to be contact traced, the health-care workers who tended him were then watched—and it worked, too. There have been no further cases and most importantly of all, no cases transmitted by the secondary cases (Nurses Pham and Vinson) have been identified. In other words, contact tracing with appropriate surveillance of those at risk has worked exactly according to plan. And because of contact tracing, Dallas and the greater U.S. remain safe.

Compare this triumph and similar ones in Senegal and Nigeria to the still-deteriorating disaster of the three West African nations where Ebola still rages. There, the person who shared the house with the latest case can’t be traced; ditto the nurse or doctor who treated the patient is lost in the shuffle; so too the various people involved in a burial or, as happened in Duncan’s case, who helped a dying patient to the hospital. In other words, the systematic rational way to control the outbreak, by defining its outer borders and letting the pyre of cases inside burn to completion, cannot be used to stop Ebola 2014.

With the World Health Organization reporting more than 9,000 cases and 4,500 deaths in West Africa, contract tracing has become a luxury the region can no longer afford. But if these major organizations have abandoned this practice, it isn’t for lack of trying to implement it. In September, the WHO released a painstakingly detailed report on the process, which it described as an “integral component” of the overall strategy for controlling an outbreak. “It is critical that all potential contacts of suspect, probable, and confirmed Ebola cases are systemically identified,” writes WHO.

The CDC too, has been emphatic in their promotion of the technique. In a press briefing on Oct. 4, Director Thomas Frieden repeated a line he’s used in nearly every call since July. “We know how to stop outbreaks of Ebola,” he said. “The core of that, the way to stop Ebola in its tracks is contact tracing, and follow-up.” In case those daily reminders aren’t enough, the CDC has issued a colorful turquoise and orange poster that reads like a children’s book. “Contact tracing can stop Ebola in its tracks,” the poster begins, before flowing on to stick figures of varying shades (red is a victim, black is not). “Even one missed contact can keep the outbreak going,” it continues.

The process, as both the CDC and WHO have echoed for months, isn’t easy. The first step, contact identification, involves obtaining meticulous details from each Ebola patient about who they may have come in contact with since exhibiting symptoms (a step that poses many problems, including how one figures out when they were symptomatic). Contact listing, next up, involves taking copious notes about each potential new victim—where they live, how old they are, when they came in contact with the victim, in what way. Since the virus can stay incubated in the human body for up to 21 days, the third step, follow-up, is key. Home visits necessitate a phone, car, fuel, and someone who can drive.

In a country with a fully functioning health system populated with able and willing medical professionals, this is doable. In West Africa, where Ebola patients are dying at the gates of hospitals too full to let them in, it’s not. The already-tiny group of volunteers and health-care workers in West Africa is shrinking. According to an Oct. 18 situation report from the Liberian Ministry of Health, 228 health-care workers have been infected with the virus in that country; 103 of them have died. Overall, says WHO, 423 have contracted it, 239 have died.

An article in Nature three weeks ago brought up the devastation that could result if contact tracing were to be stopped. “Rapid ‘contact tracing’ will be key to containing the disease in West Africa,” it reads. Noting that the region was already strapped by insufficient resources and staff, the author explained under what conditions contact tracing would be able to continue: “Only if the international community can massively increase the number of trained health workers there.”

Contact tracing is not an exciting, experimental treatment nor an expensive, innovative vaccine. It is a basic necessity. The bare bones of an already-anemic effort to fight the epidemic in West Africa that is threatening to destroy the entire region. MSF’s inability to perform a task so integral to stopping the virus’ spread is the clearest indication thus far of just how inadequate the “surge” in international support has been.

“This is where, unless the international response ramps up considerably and immediately, the math is against dampening this outbreak down very soon,” Dr. Terry O’Sullivan, director of the Center for Emergency Management and Homeland Security Policy Research at the University of Akron says. “One cannot do outbreak control of this sort without significant contact tracing abilities.”

O’Sullivan, who spent three years volunteering as a Peace Corps public health worker in Sierra Leone, joins the choir of voices applauding Nigeria’s containment effort. “[They] reportedly conducted almost 19,000 interviews in order to stamp out a very small Ebola outbreak there,” says O’Sullivan. “Without significant infusion of outside resources and manpower to do the contact tracing, the outbreak will continue to get worse in those areas where MSF has reached its limit.”