The Ebola epidemic in west Africa is "out of control" and will be contained only if politicians, religious leaders and aid agencies urgently improve their response to the unprecedented outbreak, Médecins Sans Frontières (MSF) has warned.

The disease, which is continuing to spread through Guinea, Sierra Leone and Liberia, has so far claimed 350 lives, according to the World Health Organisation (WHO). The total number of confirmed, probable or suspected cases stands at 567, with the disease identified in more than 60 locations across the three countries. The disease, which can kill up to 90% of those who become infected, was first reported in Guinea in March.

Dr Bart Janssens, MSF's director of operations, said the charity had already treated 470 patients and was struggling to cope. "The epidemic is out of control," he said. "We have reached our limits. Despite the human resources and equipment deployed by MSF in the three affected countries, we are no longer able to send teams to the new outbreak sites."

MSF said that civil society and political and religious authorities were failing to recognise the scale of the epidemic, adding that prominent figures had to do more to promote the fight against the disease. Amid the panic, it said, key messages were not getting through and people were continuing to attend funerals where there were no infection-control measures in place.

Janssens said Ebola now had to be viewed as a public health issue throughout west Africa.

"The WHO, the affected countries and their neighbouring countries must deploy the resources necessary for an epidemic of this scale," he said. "In particular, qualified medical staff need to be made available, training in how to treat Ebola needs to be organised and, contact tracing and awareness-raising activities among the population need to be stepped up."

On Saturday, the WHO said a failure to gauge the severity of the initial outbreak and a subsequent relaxation of counter-measures had helped give rise to a "second wave" of the disease.

"When the epidemic started, it was a little underestimated, so that the states took a while to really prepare themselves," said Pierre Formenty, a WHO specialist.

"At the end of April, we started to see a decrease in the number of cases and we maybe saw a relaxation by the teams in the three countries, and this relaxation allowed things to restart. In addition, there were some problems with the affected populations which were sometimes not fully listened to."

In an interview with AFP, Formenty said that the WHO, MSF and others had mobilised dozens of experts but doctors alone would not be able to contain the epidemic.

"The most important things are monitoring and communication," he said. "States are getting better but the problems of communication continue. The medical corps on their own cannot stop this epidemic. It is only with the help of the population that we can fight this epidemic and stop it."

Formenty admitted that more needed to be done to explain the dangers of infection to those attending funerals or caring for the sick.

"One case can restart an entire epidemic," he said. "In an area where the quality of health services is not optimal, the populations have struggled to understand why we were asking them to make such an effort and probably we have not been able to explain both the disease and the means of control to the populations."