The World Health Organization (WHO) says efforts must be made for the global health care system to be improved as a whole as the week to 17 May saw the highest weekly total of confirmed cases of Ebola for over a month.

Guinea and Sierra Leone reported 35 new Ebola cases in the past week, four times as many as the week before.

"We must reverse the trend in global health where we wait for the fire to flare-up, run to put it out, but then forget to fire-proof the building. We need to change that. And we call on the global community to support the effort to concentrate on the health care system as a whole rather than on high-profile diseases so that another tragedy like Ebola will never happen again," said Dr Ruediger Krech, WHO director of health systems and innovation office at a news conference in Geneva on 21 May.

Krech said the necessary funding to fight and eradicate Ebola had still not been acquired.

"Only partial funding has so far been offered by the international community. Out of the $2.3bn needed, about half is still missing. And if we, as the international community, want to ensure that this crisis doesn't happen again we all together need to come up with this money," he said.

The 35 cases in the week to 17 May were in six districts of Guinea and Sierra Leone, with most in Guinea. Nine were confirmed the previous week.

"WHO has three key concerns. The first concern is of course to get to zero cases. And as the rainy season is coming we are still very concerned to get to zero cases for at least 42 days," Krech said.

Another concern was managing the aid funds, the WHO said. "Some of these countries have some problems with their governance, have problems in terms of where money flows, so a lot of money flows elsewhere. And also, this needs to be addressed, so that the international community also has trust and builds up trust, that the money they are giving to those countries will be well spent," Krech said.

On 18 May, the WHO said it is setting up a $100m (£64m) contingency fund to ensure it will not be "overwhelmed" by a major crisis again like it was with Ebola, which has killed more than 11,000 people since December 2013.