With Ebola response teams struggling to contain the outbreak in the Democratic Republic of the Congo, the World Health Organization and its partners can make changes to shore up their effort and try to prevent the crisis from escalating further, according to a handful of experts surveyed by STAT.

The experts are wary of criticizing WHO officials and others trying desperately to stop the virus from spreading. Violence aimed at Ebola response workers and a refusal to cooperate with control measures in some communities has rendered this outbreak, the second largest on record, unlike anything the world of Ebola responders has seen before. There have been repeated attacked on Ebola treatment centers, and on many days response workers have been unable to move about in outbreak hotspots.

At the same time, the experts believe global health officials have opportunities to bolster their efforts.

advertisement

Here are three.

Good data are key

The foundation of any Ebola response is epidemiology. Knowing where the virus is spreading and who is in its path is crucial to bringing an Ebola epidemic under control. But from the earliest days of this outbreak, that’s been a problem.

“I don’t think there is a good record of what’s going on. I don’t think there’s a good database,” said Dr. Pierre Rollin, a veteran Ebola responder who retired earlier this year from the Centers for Disease Control and Prevention. “We’re just driving in the fog because we don’t have good data.”

Every single previous Ebola outbreak was stopped using the same techniques: find the cases and isolate them so they cannot infect more people. Figure out with whom they’ve had contact and monitor those people daily. If any of them become ill, isolate them and find their contacts. Bury the dead safely, so that funeral rituals don’t end up infecting more people.

In this outbreak, responders have had an additional tool: an experimental vaccine.

For this approach to work, though, the surveillance teams need to know in which social networks the Ebola virus is spreading. In this outbreak, that often hasn’t been the case. Significant numbers of the new cases were not previously on contact lists. Their health hadn’t been monitored and they weren’t offered vaccine because no one knew they had been exposed.

The impact of these unidentified chains of transmission appears to be growing as the outbreak expands. Since the beginning of May, only one-third of new cases were known contacts of a previous case. Only about half of those had agreed to be monitored to see if they were developing symptoms. Most had not agreed to be vaccinated.

Dr. Scott Dowell, deputy director for surveillance and epidemiology at the Bill and Melinda Gates Foundation, shares concerns about the expanding number of unrecognized cases.

“I think there is very likely a large pool of unrecognized transmission out there and unidentified patients,” said Dowell, who worked for decades for the CDC and has worked a number of Ebola responses. “And it’s uncertain just how big that pool is. And also uncertain to me about whether the current response can get on top of it, which is really worrisome.”

Rollin, who is following the outbreak closely, is worried about the fact that so few probable cases are being added to the outbreak totals. Probable cases are people who had Ebola-like symptoms and who had contact with people who either were known cases or who also had what looked like Ebola. Often these are people who died and were buried without being tested for the disease, but for whom there is a high likelihood that they were infected.

Given how many people are refusing to cooperate with the Ebola response teams — staying home when they are sick, fighting off safe burial teams that try to test corpses — there should be a steady stream of probable cases, Rollin said. And yet they are rare. “So they’re missing a lot of cases,” he said.

Lab capacity needs to be increased

There are serious concerns that the existing laboratory capacity to test samples from suspected Ebola cases can no longer keep pace with the number of tests that need to be conducted.

DRC’s National Biomedical Research Institute — INRB — is overseeing the testing. Rollin and others fear the current needs exceed its capacity, leading to delays in getting test results.

“The lab is overwhelmed,” Rollin said.

If a laboratory can’t quickly process all the tests taken, it is effectively capping the number of new positive cases that can be found, said Dowell. It’s not that they aren’t there; it’s that the lab can’t pinpoint them in a timely manner. That leads to slowdowns in identifying the contacts of new cases and inviting them to be vaccinated. People who need vaccine may be vaccinated too late to prevent infection.

The delays in getting test results are also discouraging people from coming forward to be tested, said Dr. Axelle Ronsse, an emergency coordinator for the Belgian branch of Doctors Without Borders. Test results can sometimes take two or three days.

The Gates Foundation is urging the Congolese Ministry of Health and the WHO to start using rapid point-of-care tests that were developed after the West African Ebola outbreak of 2014-2016, said Dowell, who noted these tests could greatly increase the number of people who are tested.

There’s a concern the tests could lead to some false negatives — people who are actually infected, but don’t test positive — Dowell admitted. But finding more infected people more quickly, even if it’s not all of them, should help, he said.

The lab capacity issue also extends to the sequencing of Ebola viruses, a technique that can be used to fill in information gaps of chains of transmission when, as with this outbreak, they occur.

Newly confirmed cases may not know where or how they became infected. But by comparing the sequence of their virus to the sequences of other cases, it can become clear that the infection occurred when two unrelated people were in a clinic on the same day, or that this patient likely infected that taxi driver.

INRB, the Congolese national lab, has been sequencing viruses. But the information it is finding isn’t always being shared in a timely way with the teams doing case surveillance. And capacity is an issue here as well. “As the number of daily positives has grown, the sequencing hasn’t nearly kept pace with those positives,” Dowell said.

A report to the World Health Assembly from a group that advises the WHO’s emergencies program hinted at insufficient use of the sequencing data, saying that “timely analysis of genetic sequencing data are critical to fully characterize the evolution of the [Ebola] outbreak in order to inform diagnostic, vaccine and treatment approaches.” It recommended “closer collaboration between INRB and WHO.”

If Ebola treatment centers are seen as toxic, find alternatives

In some communities, there remains deep-seated reluctance to go to Ebola treatment centers. Doctors Without Borders, which pioneered the current system of Ebola treatment centers, has suggested diversifying care options might help.

ETCs, as they are called, have become a place of stigma, associated with death. In fact, people who seek care in treatment centers quickly after the onset of symptoms have a higher chance of survival than those who eschew the centers — but that reality has not been recognized in the affected communities.

Doctors Without Borders has proposed that some hospitals in the outbreak zone be trained to treat Ebola patients safely — without posing a risk to their other patients — because the reality is that many people with Ebola symptoms turn to clinics or hospitals rather than ETCs.

Likewise, the group has urged the health ministry to consider allowing for some home care of Ebola patients, even suggesting that experimental Ebola drugs might be administered by a team of visiting health workers to some patients being cared for at home.

Ronsse said ETCs should remain the primary sites for care of Ebola patients. But with so many patients refusing to go for to them, finding ways to minimize the risk these patients present to the health workers who care for them in hospitals or family members in households could help reduce transmission. Recently the WHO reported that 68% of the people who have died from Ebola in this outbreak died in the community — at home or in a health facility that was not a treatment center.

“It’s something else we could do,” Ronsse explained. “But we cannot do only home-based care or only treatment at the level of the health center. We should have the three levels.”

Likewise, Ronsse said home care — which would involve training family members to take precautions and giving them protective equipment and cleaning materials — is not something that could be done on a large scale. “It’s really for the people who would not accept to come to the center,” she said.

Leave a Comment

Please enter your name.
Please enter a comment.

  • If locals see loved ones die and themselves have no solution yet persistently refuse to accept or seek help from well-equipped foreigners for reasons of unfounded deep-seeded and stimulated suspicions – can the Ebola Vaccination endeavour really succeed in such a negative territory? I intensely appreciate and respect the persistence of the Ebola fighters, but it does not seem that any ground is gained. At the risk of being blasted for these thoughts : is vast military forceful assistance an option? Or might it be to let this outbreak run its course, with a multi-national (!!) defensive no-travel zone around around the infected areas ?

A roundup of STAT’s top stories of the day in science and medicine

Privacy Policy