Sierra Leone will impose a nation-wide lockdown on its residents for four days to "deal with Ebola once and for all," said Ibrahim Ben Kargbo, a presidential adviser on the country's Ebola task force.

The "aggressive approach," which will take place from September 18-21, is intended to allow health workers to be able to contain the spread of the disease in what has become the worst Ebola outbreak in history. The drastic action aims to help doctors identify and isolate new cases, the Guardian reports.

Cooperation from residents will be vital for the lockdown to work. The Guardian writes:

Kargbo said 21,000 people would be recruited to enforce the lockdown. Thousands of police officers and soldiers have already been deployed to enforce the quarantining of towns in Sierra Leone's worst-hit regions, near the border with Guinea.

So far, more than 3,000 people have been infected in West Africa. Nearly 2,100 people, including 20 health workers, have died in Sierra Leone, Liberia, Guinea, and Nigeria since the outbreak was first reported in March. In Sierra Leone alone, 491 had died as of Friday. Last week, the World Health Organisation (WHO) warned that the world was "losing the battle" against Ebola and that there could be another 20,000 cases before the outbreak is finally contained.