Angola is at a critical stage in its fight against an outbreak of the deadly Marburg virus and must step up its drive to bring the disease under control, the U.N. World Health Organization (WHO) said Saturday.

“The chain of transmission is being broken as we speak, but this is the most critical time in terms of response. We need to be even more intense over the coming days,” Mike Ryan, the head of WHO’s alert and response operations, told a teleconference.

Angolan officials said they were flying in more local medical staff to work with international teams battling the Ebola-like virus in hopes of regaining the trust of a scared and suspicious population.

Some residents of Uige province - the center of the Marburg outbreak that has killed 244 people - have stoned WHO vehicles and spread rumors that foreigners brought the virus into the area.

“It was crucial for us to increase the number of Angolans in the team,” deputy Health Minister Jose Van Dunem told Reuters in the capital Luanda. “We need to improve people’s confidence and trust in the health community.”

He said Marburg was under control and restricted to the one province, though there were a handful of cases elsewhere among travelers who had returned from the region.

Laboratory tests had shown some cases previously thought to be Marburg were not, bringing the total number of known cases down to 264 from 266 Thursday, he said.

CASES DOWN, GUARD STILL UP

In Uige, the WHO was not willing to describe the outbreak as contained but said both attacks on its workers and the number of new cases were dropping.

“We’re moving back into areas we’d pulled out of because of tension,” said WHO spokesman Dave Daigle by telephone. “People are still dying but the numbers are falling off.”

Marburg is often accompanied by massive bleeding and is spread through contact with bodily fluids including blood, sweat and saliva.

Pierre Formenty, the WHO’s top expert on hemorrhagic fevers like Ebola and Marburg, said doctors were tracking about 300 people believed to have had contact with Marburg victims but that on the whole the picture was improving.

“It is just a good feeling…maybe things are going to get better,” he told the teleconference.

But he said officials remained concerned about undetected pockets of the virus and about the possibility that it could spread as traditional healers offer injections - sometimes with unhygienic needles - that local people believe may protect them from infection.

Around Uige, teams continue to go out to local communities to persuade families not to care for the sick at home. Many victims contracted the disease through treating sick relatives or preparing their bodies for burial.

Angolan health workers who speak Portuguese or local languages will help in this process, Van Dunem said, and the WHO said it would welcome their arrival.

“We need all the help we can get,” said Daigle. “Some of them are already helping out with infection control and with the surveillance teams. And they will learn new skills that they can use next time.”