Leah Masika was on the verge of tears as she thought of her valuable consignment of plantain stuck in a long convoy of trucks on both sides of the Uganda-Congo border. Her cargo, destined for Uganda, was starting to leak water, and would go bad within hours if there was no movement.

The Ugandan trader was awaiting clearance from authorities for trucks to pass through the Mpondwe border post on Thursday after they were prevented from entering or leaving Uganda as part of escalating measures to prevent cross-border Ebola contagion.

“Our things are here rotting,” she said.

On May 28, about two weeks after Congo declared an outbreak of Ebola in the eastern Ituri province, Uganda closed its western border in a decision that reflected growing fears of cross-border contagion. Exceptions were made only in emergency cases, including for the outbreak response, humanitarian, cargo or security reasons.

But in recent days, as the spread of Ebola in eastern Congo appeared to outpace the response, authorities in the Ugandan frontier district of Kasese have tightened the measures.

Traders say they are frustrated by the slow movement of cargo trucks. Some at the Mpondwe border post told The Associated Press that while they knew the tough measures are provoked by fear of Ebola contagion, they felt that holding up the trucks was excessive.

Sylvia Asiimwe, a clearing agent, pointed to the queue of trucks stretching over a mile on the Ugandan side. At least seven were carrying fish imported from China and destined for the Congolese cities of Beni and Butembo.

Asiimwe was adamant those Congolese towns are in the province of North Kivu, not the Ebola epicenter of Ituri. “The fish is going to spoil,” she said. “So much money.”

The Uganda-Congo border is several hundred miles long and crossed by numerous footpaths beyond formal border posts. Trade is often booming along the route up to Mpondwe, and there is kinship between the Bakonzo people on the Ugandan side and the Banande on the other side.

Mpondwe is Uganda’s top border post for informal exports that were valued at an estimated $131 million in 2023, according to the Uganda Bureau of Statistics.

After the recent border closure, some shops were shuttered and young men, deprived of casual work, sat on stools dolefully.

“The situation is bad,” said Ismail Mumbere, who often works as a vendor of roadside snacks on the Ugandan side. “A lot of people earn from here, in many businesses. But now the government has told us there is Ebola. Ebola has wasted our work.”

The current outbreak in Congo is suspected to have infected over 1,000 people. The number of confirmed cases is much lower because many suspected victims succumb to their symptoms outside hospitals and without firm proof they had Ebola.

The World Health Organization, while declaring the current outbreak a public health emergency of international concern, discouraged border closures. But the U.N. agency also acknowledged that neighboring countries are at high risk of contagion.

“With movement of cargo, and maybe trucks, is mobility of people, and we want to reduce that,” said Arafat Bwambale, a surveillance officer for Kasese, defending the measures.

Officials were trying to stop Congolese nationals from crossing to Uganda by way of more than two dozen footpaths along the Mpondwe border, he said.

All available vaccines and treatments for Ebola don’t work for patients with the rare Bundibugyo type spreading in Congo, making the outbreak worrisome.

Uganda has confirmed 15 Ebola cases, all linked to the outbreak in the neighboring country after some Congolese nationals sought treatment in the Ugandan capital of Kampala before it was known there was an outbreak.

The disease was believed to have been spreading for days or weeks before the outbreak was declared May 15.

Uganda has had multiple Ebola outbreaks of its own since 2000, when the disease killed more than 200 people.

Ebola, named for a tributary of the Congo River, was first discovered in 1976 in simultaneous outbreaks in Congo and present-day South Sudan. Outbreaks are believed to start with the virus spilling over into humans from an infected animal such as a fruit bat. These cross-species infections often happen when people handle and eat wild meat, according to experts.

Once Ebola has infected one person, the virus then spreads through close contact with sick or deceased patients’ bodily fluids, such as sweat, blood, feces or vomit.

Tracing and isolating contacts is seen as key to stopping the spread of Ebola, in addition to getting medical workers proper protective equipment.

Bwambale, the surveillance officer, said the nearest referral hospital in Kasese has an isolation center and is equipped with a lab that can return results on a sample within six hours. In recent days, samples taken from 41 people in the Kasese area tested negative for Ebola, which manifests as hemorrhagic fever.

Still, authorities appeared to be planning more restrictions.

A meeting of the local Ebola task force was likely to come up with “a more restricted way on how both the cargo or the trucks get into the country in a systematic way,” Bwambale said.

That alarms traders for whom the Mpondwe border post is the primary route of business.

Masika, the plantain dealer, said she would not order more goods from Congo until the current outbreak was over. But she would be in trouble if the cargo already in transit didn’t reach various locations in and around Kampala, where the fruits, deep fried or boiled, are a staple of breakfast menus in restaurants.

Masika said she couldn’t countenance a loss of 50 bags, each worth roughly $44.

“We are begging them to help us and open (the border),” she said. “We will not go back to Congo.”