Ebola outbreak: Funeral in Guinea may have caused outbreak in Sierra Leone

Since the West African outbreak started in March, at least 1,552 have died

A group of volunteers carry the bodies of people, sterilized after dying due to the Ebola virus, to a car ahead of their burials in Sierra Leone. (Mohammed Elshamy/Anadolu Agency/Getty Images)

The May funeral of a healer in Guinea may have caused the spread of Ebola in Sierra Leone at a time when experts hoped the disease was under control, according to a new study.

By touching or washing the body in preparation for the ceremony, more than a dozen women contracted the deadly virus and spread it in Sierra Leone. The disease then exploded in the country, according to new DNA mapping of Ebola by a team of 50 scientists – five of whom died of the disease while fighting the outbreak.

Health researcher Stephen Gire, who was part of the team which mapped the outbreak, told reporters: “You had this huge burst after it looked like the outbreak was starting to die down,”

“It sort of threw a wrench in the response,” he added.

Researchers from the MIT and Harvard University-affiliated Broad Institute made their map based on specimens collected from 78 patients.

By plotting the genetic code of the Ebola strain which has spread in West Africa, Gire and his 50 colleagues have helped to demonstrate how important the funeral in May was to the outbreak.

The study, which was published in the journal 'Science' on Thursday, shows that the virus has mutated more than 300 times from previous strains of Ebola.

Pardis Sabeti, joint lead author of the study alongside Gire, explained that this rate is faster than normal for viruses of Ebola’s type. Each mutation could see the virus become harder to fight, stronger or easier to spread. However, in turn, the virus could mutate and become weaker.

The experts hope their database will help them understand the disease, which has killed over 1,552 people in West Africa - with 40 per cent of the cases occuring in the last three week, according to the World Health Organisation (WHO). On Thursday, WHO added that the death-toll is likely hugely underestimated.

The detailed map could also help doctors to diagnose and fight the disease, especially with working in preliminary vaccines.

Sabeti said she hopes researchers worldwide will look at the data and use it to beat the devastating disease.

"We need to crowd source this outbreak response,“ Sabeti said. ”I want high school students analyzing this sequence. You want people in every country working to do something."

Additional reporting by AP