Sandia LabNews

Fighting Ebola: Sandia models and improves Liberia’s clinical sample transport system

Sandia researchers mapped Ebola treatment units, diagnostic labs, routes and drive times across Liberia to reduce the time it takes for patients’ blood samples to reach labs for testing. The information in this map helped inform the analysis used to recommend a sample transport system so Liberia could more quickly diagnose patients.	(Image courtesy of Sandia National Laboratories)

Sandia researchers mapped Ebola treatment units, diagnostic labs, routes and drive times across Liberia to reduce the time it takes for patients’ blood samples to reach labs for testing. The information in this map helped inform the analysis used to recommend a sample transport system so Liberia could more quickly diagnose patients.(Image courtesy of Sandia National Laboratories)

As Monear Makvandi (6825) climbed the rickety staircase to the top of a guard tower to view Island Clinic Ebola Treatment Unit in Monrovia, Liberia, the infectious disease epidemiologist hesitated momentarily about whether to grab the rail for safety or to avoid touching it, even though the scientist in her knew there was no chance she could be exposed to the deadly Ebola virus.

Emerging from the stairwell, Monear, project lead for a Defense Threat Reduction Agency and United States Strategic Command Center for Combating Weapons of Mass Destruction (DTRA/SCC-WMD)-sponsored project to model and assess the blood sample transport system in Liberia, looked down on a courtyard where three adults and two children sat listlessly in plastic lawn chairs waiting for word that they were free of the virus.

Later, outside the Ebola treatment unit’s gate, Monear, manager Jen Gaudioso (6825) and complexity scientist Tom Moore (6132), watched from an SUV as a survivor was discharged from the clinic. They were told the man’s possessions were burned when he was admitted, so he was provided with clean hospital scrubs to wear, a week’s worth of beans and rice, and $10 for his journey home. No one was there to meet him. Due to lack of communications, his family likely did not know whether he was still alive.

Seeing the suffering, Monear hoped Sandia’s assessment of how patients’ blood samples are transported from Ebola clinics to diagnostic laboratories for testing would result in quicker reporting of diagnoses and shorter waits for patients.

In the project’s first month, the Sandia team developed a set of performance requirements for a new nationwide sample delivery system that is being adopted by the Liberian Ministry of Health, says Jen, manager of Sandia’s International Biological and Chemical Threat Reduction program.

“Prior to our analysis, samples were being transported from treatment units to labs on an ad-hoc basis. We developed a system and the country is implementing our system,” she says.

Reducing wait time key in controlling Ebola

When Liberians suspect they have Ebola, they check into large, open waiting rooms, usually lined with beds, called Ebola treatment units (ETUs). Their blood is drawn and they wait, sometimes for days, to learn their fate. During that wait, patients afflicted with less serious diseases might mix with Ebola sufferers and contract the virus there, exacerbating the epidemic.

While Sandia’s work is only one project among many that provide international assistance in Liberia, it’s important to help control the epidemic because patients get the care they need faster. The sooner public health professionals can identify Ebola carriers, the sooner they can locate people outside the clinic who had contact with a carrier and might be infected, say Tom and Pat Finley (6131), who led the computer modeling effort.

The project also enhances US national security. “Fundamentally, there’s the concern that Ebola will come to the US. The only way to prevent that from happening is to control the disease at the source,” Jen says. “The other fundamental national security interest, in countries that are already challenged, is stability. If the disease continues to progress in an uncontrolled fashion, that will lead to further instability in these countries in areas where there are active terrorist groups seeking haven.”

Fast, operational response to a dynamic situation

Monear, who has a cousin who was born in Liberia, was eager to put Sandia’s resources to work to help control the Ebola outbreak.

“I made a conscientious choice to come work at a national lab and focus on biological threat reduction and global health security. With our national security mission, we’re able to make a difference and identify small projects that contribute to the overall response effort,” she says.

The request from DTRA/SCC-WMD came in October. Sandia had done sample transport modeling for DTRA/SCC-WMD and the State Department before, Jen says. “They knew we understood the realities of working in a country like Liberia, so that we could come up with a realistic system and not an idealized version,” she says.

Jen quickly assembled the team.

Typically, modeling efforts like this take six to 12 months, but the fight against Ebola was a race against time, so Sandia needed to figure out a solution for Liberia in a matter of weeks.

“We really had this tremendous cooperation, working across centers, different departments, and programs. When the chips were down, the Labs let go of a lot of the day-to-day stove-piping, and we were allowed to get in there and do what we needed to do,” Pat says.

Pat’s group had experience modeling disease and logistics in developing countries. They immediately decided that their normal serial approach would be too slow, so they had to work the four tasks simultaneously, he says.

Leo Bynum (6132), the geospatial analytics lead, and his team collected data and transformed it into maps, a task made more difficult by incomplete, anecdotal, and, at times, incorrect data.

Pat and Tom worked on creating a model and simulation of Ebola treatment in Liberia that aimed to reduce travel times of the samples from the ETUs to the labs for testing, thus decreasing the time patients with and without Ebola were together.

Operations research analyst Jared Gearhart (6131) and his team developed algorithms to determine the optimal locations for labs and the best transportation routes, while accounting for such obstacles as a national curfew, poor infrastructure, lab capacity, and other factors.

And Jen, Monear, and Tom travelled to Liberia in November to interview healthcare workers in the field, international agencies working in the country, and Ministry of Health representatives so they could supply Sandia’s model with the latest data.

Culture changed by disease

The Sandians arrived for the six-day trip on a lone plane at the national airport in Monrovia and saw immediately how Ebola had changed Liberia. Before officially entering the country, Monear says they washed their hands in bleach on the tarmac outside the airport terminal and had their temperatures taken, a process repeated by guards outside buildings, restaurants, and hotels during their stay.

The team had no exposure to Ebola patients. All three say they felt safe the entire time they were in Liberia.

Sandia, which elevated the risk level for travel to Ebola-affected countries, including Liberia, extensively prepared the travelers on what precautions to take and provided a risk assessment based on a detailed itinerary of their trip. They also followed Centers for Disease Control and Prevention and state health department guidelines, which include a check at the US border for symptoms before re-entry and a requirement to monitor their temperatures and maintain daily contact with a public health worker for 21 days after their return.

“If you approached somebody with your hand extended, they would jump back,” Tom says, adding that elbow bumps in the air are the equivalent of a handshake in Liberia now.

The peak of the epidemic had passed when they arrived; the markets had just reopened, but people were fearful of physical contact, Monear says.

They found that getting a lab test result that takes a day or even several hours in the US could take as many as four days from remote areas of a country the size of Tennessee.

Prior to Sandia’s project, samples were taken to labs that were thought to be the closest or just because health care workers knew someone there, with little thought to lab capacity, travel difficulties, or other factors, Jen says. In one case, the team learned about samples carried on foot to a waterway, then brought by canoe to a bridge that connects with a “highway,” which is similar to a US hiking trail.

Sandia’s analysis helped influence where new diagnostic labs would be located, including one in Greenville in southeastern Liberia. “That’s been the area where we’ve had the most impact by helping Liberian stakeholders become aware of and overcome the challenges of providing lab results quickly in the remote region,” Jared says.

Motorcycles the vehicles of choice

Sandia’s model also showed the fastest options for transporting blood samples from patients, many in remote jungles, to diagnostic labs. Motorcycles are the vehicles of choice because they can move through traffic in more populated areas and are more easily pulled out when stuck on muddy roads, Monear says.

The model is flexible, so that when an outbreak occurs in one area of the country, ETUs can quickly adjust where to send samples to avoid a backlog at one lab. The model considered the capacity of labs and recommended multiple daily deliveries of samples to maintain a constant workflow, rather than delivering samples an hour before the end of the work day, the team says.

Sandia was uniquely suited for the project due to its computer modeling capabilities combined with its decades of experience in global health security. While in Liberia, Sandia’s team could reach back to the rest of the team to provide updated analyses, Jen says.

When Jen, Monear, and Tom attended meetings in Liberia, they would communicate any questions back to Pat, Jared, and others in New Mexico. The time difference worked in their favor. While the travelers slept, their colleagues answered the questions and incorporated changes into the model before work started in Liberia the next day.

With so many agencies involved in the response and the disease declining, it’s difficult to say exactly how Sandia’s sample transport system is affecting wait times in the ETUs, but Sandians say they were asked many times why they hadn’t brought their capabilities sooner to West Africa.

“It was taking two days to get samples. Now the system being implemented can help get results back in the same day or overnight and that will reduce interaction time,” Jen says.

Jen says Sandia’s modeling can help with questions of where to station healthcare workers, how to resupply labs, how to administer clinical trials of vaccines in Ebola-stricken countries, and many other logistics challenges. Discussions are ongoing about how to provide this expertise.

And a second DTRA/SCC-WMD-funded project in which Sandia will serve as a lab coordinator for a diagnostic lab staffed by contractors in Sierra Leone is underway, Jen says. A Sandian will visit that country in early 2015 to integrate the lab into the Ebola response system under the leadership of Sierra Leone’s Ministry of Health.