BUNIA, Congo -- The healthcare workers at the epicenter of Congo's Ebola outbreak are walking off their jobs to protest delays in their payments, threatening efforts to slow the outbreak that officials said continues to spread faster than the response.

In Ituri province, the hardest hit among the three provinces in eastern Congo affected by the outbreak, some of the health professionals and other frontline workers told the Associated Press they've not been paid their wages and bonuses since the outbreak was declared on May 15. They also alleged they were working with limited gear, and were being treated unfairly by authorities as well as response teams.

"Since the Ebola virus disease outbreak was declared, we've been demanding payment for our work," Biensi Kano, MD, a member of the epidemiological surveillance committee in Ituri's capital, Bunia, told the Associated Press.

The latest government data show 1,708 recorded cases, including 580 deaths, and that the first month of this Ebola outbreak was already the worst on record, health authorities said. The strike comes at the start of enrollment for clinical trials for the treatment of the Bundibugyo virus that is responsible for this outbreak.