More than 7,000 Ebola cases have been recorded in the Democratic Republic of Congo’s (DRC) worst outbreak of the deadly disease ever, according to figures from the Congolese authorities.

Thought to have been spreading under the radar for weeks, the DRC officially detected the latest outbreak in mid-May, with nearly 3,400 people killed in its 17th epidemic of the highly infectious virus.

It began in the northeastern Ituri province before spreading to conflict-plagued, remote eastern and northern regions where armed groups have roamed for decades, the presence of the state is weak and health infrastructure is largely lacking.

Earlier this week the disease was confirmed to have spread to a seventh province, South-Ubangi, which borders the Central African Republic and Congo-Brazzaville.

According to the latest figures from the Congolese authorities, 7,022 cases have been recorded since the beginning of the epidemic, of whom 3,398 have died and 1,671 people have recovered.

Most of the recorded cases are in Ituri, where Ebola has been detected in schools in the days after the post-summer holiday return to classes, causing alarm among parents and health workers.

“We are very worried because we don’t know which child comes from which family or what the health status of the members of that family is,” Angele Magani, mother of a schoolboy in Bunia, Ituri’s provincial capital, told AFP.

“We are so scared, even though the school authorities reassure us about the health measures that have been put in place,” she added.

Bunia school official Roger Mungimbo told AFP that “there is a mandatory hand-washing system with soap, and we have also done everything possible to have a maximum of 30 pupils per classroom. We regularly make the children aware that they must not touch each other, must not greet each other and must wash their hands regularly,” he added.

Ebola, which has killed more than 15,000 people in Africa over the last 50 years, is transmitted through contact with bodily fluids and can cause severe internal and external bleeding and organ failure.

The current epidemic is caused by the Bundibugyo strain, for which there is no approved vaccine or treatment currently. Several treatments and vaccines are being tested.