The outbreak was caused by the Sudan strain of the virus, which has no approved vaccine or drug treatment. Scientists are now rushing to begin clinical trials in the coming weeks.
NAIROBI, Kenya — An outbreak of Ebola in Uganda, caused by a strain for which there is no approved vaccine or drug treatment, is fanning fears across East Africa, as the authorities race to contain the virus that has already caused 35 confirmed infections and seven deaths.
Scientists and health officials are now pushing to start clinical trials for two experimental vaccines to protect against this strain, which originated in Sudan in 1976. Even though there are relatively new and powerful Ebola vaccines, they do not protect against the Sudan strain — complicating efforts to quickly stamp out the disease before it overburdens the nation’s fragile health care system.
In central Uganda, where the cases were reported, at least six medical workers have contracted the virus, leading some of their peers to request transfer elsewhere. Parents, concerned their children will catch the highly contagious virus, are withdrawing them from schools. And in a nation that has faced multiple Ebola outbreaks since it reported its first case in 2000, worries persist that another fast-spreading virus could precipitate restrictions that would devastate an economy still reeling from coronavirus shutdowns.
“The whole situation gives me a lot of worry,” Yonas Tegegn Woldemariam, the World Health Organization’s representative to Uganda, said in a phone interview.
With the virus spreading to a fourth district on Friday and affecting an area covering a radius of more than 75 miles, “we are at a disadvantage,” he said.
Ebola is a highly contagious disease that is transmitted through contact with sick or dead people or animals, causing fever, fatigue, diarrhea and internal and external bleeding. The 2014-16 outbreak in West Africa was the deadliest Ebola epidemic, killing more than 11,300 people, followed by the 2018 outbreak in the Democratic Republic of Congo that killed 2,280 people.
So far, Ugandan officials have ruled out issuing stay-at-home orders or curfews, or restricting movement in schools, markets or houses of worship.
“There is no need for anxiety, panic, restriction of movements or unnecessary closure of public places,” President Yoweri Museveni said after a televised speech this week. Mr. Museveni, who introduced stringent lockdowns during the onset of the coronavirus pandemic two years ago, said his nation had the ability to bring the Ebola virus to heel.
Uganda is also working with neighboring countries, including Rwanda and Kenya, to step up vigilance at land borders and at airports.
The latest outbreak in Uganda became public on Sept. 20, when health officials announced they had confirmed a case in a 24-year-old man who had been admitted to a hospital in the Mubende district, about 90 miles from the capital, Kampala.
The patient had developed symptoms — including high fever and bleeding in the eyes — as early as Sept. 11, and had traveled to multiple clinics seeking assistance. He was eventually isolated and hospitalized on Sept. 15, but died five days later.
In his televised address, Mr. Museveni said the patient had said people with similar symptoms from his village had also died.
The delay in identifying and tracing the first human case, along with the fact that it was reported in a district abutting a key highway, has raised the concerns that the virus has spread to major urban centers and neighboring countries. The W.H.O. has said there were at least 18 more probable deaths and 19 more infections linked to the current outbreak.
The Sudan strain of the virus was last detected by Uganda in 2012. Those infected cannot spread the virus until symptoms appear, which can come after an incubation period ranging from two to 21 days.
Existing vaccines — like the injectable vaccine Ervebo, which proved successful in tackling the Zaire strain in the neighboring Democratic Republic of Congo — do not protect against the Sudan strain.
But experts hope that will soon change.
Mr. Yonas said at least six vaccine candidates were at different phases of development that can possibly guard against the Sudan strain. Two of those vaccines could proceed to a clinical trial in Uganda in the coming weeks after facing regulatory and ethics reviews from the Ugandan government.
The two vaccines likely to go ahead are being developed by the Washington-based Sabin Vaccine Institute and the University of Oxford. If approved, the single-dose Sabin vaccine would most likely be the first in line for trial. As new evidence emerges on the remaining vaccine candidates, the W.H.O. said it would work with an independent group of experts to help evaluate their suitability.
For now, health officials and multiple nongovernmental organizations are responding to the crisis by training medical workers, setting up new isolation units and facilitating more laboratories for testing.
Officials have also started multiple outreach campaigns to educate the public on how to protect themselves, not stigmatize the infected and report those showing symptoms, said Oluma Jacob, a health adviser with Medical Teams International, an aid group responding to the outbreak.
This was done, he said, because “there was fear and a lot of panic in the community” when the cases were first reported in central Uganda.
That panic was evident among parents in Mubende district, where the first case was detected.
Nkwesiga Maxim, the principal of St. Kizito Madudu Roman Catholic Primary School in Mubende, said that more than half of the school’s students had not been attending classes.
“We have too much fear,” he said.
His sentiments were echoed by frontline health workers, who say the lack of proper compensation and protection — particularly for medical interns — was putting their lives at risk. The six health workers who were infected included four doctors, an anesthesiologist and a medical student, Mr. Museveni said. On Saturday, Uganda’s health minister announced that one of the doctors had died.
Luswata Herbert, the secretary general of the Uganda Medical Association, said that if the government did not remedy the situation quickly, “health workers will refuse to attend to patients because they fear for their lives and their rights.”
Musinguzi Blanshe contributed reporting from Kampala, Uganda.