"It's dangerous to bring cases in private vehicles like this," he chides as he watches the Toyota disgorge its five passengers at the main gate.
"The ministry of health has established protocols. There are hotline numbers that people have to call. And when you call there are ambulances, with trained people on board who are protected, to take the patient to hospital."
Kauffeldt, the director in Liberia of Christian aid group Samaritan's Purse, is at the forefront of the country's battle with the worst outbreak of Ebola that the world has ever seen.
More than 300 Liberians have been infected by the tropical virus, which has been raging in west Africa's forests since the start of the year. More than half of those who have caught the disease have died.
But Kauffeldt and other aid workers warn that it is ignorance over Ebola, rather than the virus itself, that is pushing up the death toll.
Ebola is a terrifying spectre for the people of Liberia's remote forests, who have seen relatives die in agonising pain.
The virus can fell its victims within days, delivering severe muscle pain, headaches, vomiting, diarrhoea and, in most cases, unstoppable bleeding as the patient's organs break down and seep out of their bodies.
- Damaging myths -
Yet the pathogen itself is not particularly robust, and can be seen off with soap and hot water.
Epidemiologists point out that Ebola is relatively difficult to catch and isn't even airborne.
The virus requires contact with the bodily fluids of a victim -- their blood, urine, faeces, vomit, saliva or sweat -- to leap into a new host.
For those unlucky enough to catch Ebola, the disease it brings about is also treatable, say experts.
Patients who are kept hydrated, given paracetamol to keep their temperature in check and treated with antibiotics for secondary infections have a fighting chance of recovery.
But in a country where remote communities are deeply superstitious of western medicine and often rely on the wisdom of witch doctors, a variety of damaging myths have built up around Ebola.
Among the most worrisome is the widespread belief that Ebola is a western conspiracy or doesn't exist at all. Another is that entering an Ebola treatment centre is accepting a death sentence.
In the new clinic set up by the charity Samaritan's Purse in Monrovia's ELWA hospital, up to 10 new cases are registered every day.
"With communication and education not robust as they should be, we see this happening where Ebola cases are brought in taxis or private cars," Kauffeldt tells AFP.
"This is very worrisome because everybody in that car has had contact with the patient. We need to watch them for 21 days to know whether they have been infected."
- Admitting Ebola is real -
It's not just taxi drivers who have to worry. Ebola patients, ignorant of the risks, are putting their own family members in grave danger.
Ten-year-old William Benedict, one of the clinic's success stories, has made a full recovery against the odds after catching the virus from his dying mother.
"I was near mama when she was sick. When she died, I got sick," William says as he prepares to leave the centre and return to his village.
James Kollie, the clinic's ambulance driver, explains that the boy's mother summoned her son to lie beside her as she was dying in bed, coughing, vomiting and generally presenting a grave risk to anyone nearby.
"I drove the vehicle that carried the team to pick him up. That day everybody was running from him. I shed tears for him," Kollie tells AFP.
On Friday the leaders of Liberia, Sierra Leone and Guinea agreed a $100 million emergency action plan to beef the response to Ebola.
Much of the cash will go on deploying medical workers. But the plan also includes provision to improve education throughout the Ebola zone straddling the three countries.
Lawmaker Peter Coleman, the head of Liberia's Senate Committee on Health, says the poverty endemic across the country has been a major obstacle to spreading reliable information.
"The majority of Liberians don?t have access to radio. In our villages only few people can get radio messages," he told AFP.
"There should be a campaign from village to village, from community to community, from town to town, even from door to door."
Samaritan's Purse, which runs all three of Liberia's treatment centres with help from other aid agencies and the government, believes education is as important as medicine in saving lives.
"We have to admit, Ebola is real. People are dying of Ebola and they don?t have to die of Ebola," Kauffeldt said.
"If they come and seek treatment early they will survive."