The Ebola epidemic has led to a boom in downloads for the online game "Plague Inc", prompting its British developer to launch a charity initiative and offer it as a teaching tool.

"I didn't want to have my game associated with something as horrific as the current Ebola outbreak," James Vaughan, the 27-year-old behind the company Ndemic Creations, told AFP.

The game, where the aim is to destroy humanity with different viruses, was launched in 2012 before the current outbreak of Ebola and now has 35 million players around the world.

"When the Ebola cases started happening in the West, we saw around a 50 percent increase in daily downloads of the game," Vaughan said in an interview at his company offices.

Successful gamers boast on Twitter with the slogan: "Victory! Ebola has successfully eliminated all life on Earth".

Since almost all the downloads are free, Vaughan said there was "not a significant increase in profit" although he declined to provide figures on the company's earnings.

"Once I noticed it, it was a bit uncomfortable", he said, adding: "So that's just made me very keen to try and use that position to help in whatever way we can."

Starting this month, players accessing the game are offered links to charity websites to aid the fight against Ebola as well as advice on how to avoid contamination.

Vaughan said his company had also made a donation.

He said the game could be "a powerful way to raise awareness", adding that he had been approached by academics wanting to illustrate the spread of epidemics to students.

The largest Ebola outbreak on record has killed some 5,000 people, with Liberia hit hardest and the contagion still raging in neighbouring Sierra Leone and Guinea.