Ebola comes to last safe space in Sierra Leone as the deadly viru has infected two people in what was the last untouched district in Sierra Leone, the government has said, a setback in efforts to turn back the disease in one of the hardest-hit countries.

The Emergency Operations Centre in a report has noted two Ebola cases in the Koinadugu district, in Sierra Leone's far north, which since the outbreak early this year has remained untouched, according to U.S. and World News Report.

According to the report, residents of the district had practiced strict safety precautions and limited contact with the rest of the country where the disease is rampant. According to the World Health Organization, there have been 425 new cases in the whole country just last week.

The director of the US Agency for International Development, Rajiv Shah, visited Sierra Leone on Wednesday as part of a tour through the three hardest-hit countries, where he announced an additional $142 million in projects and grants to battle the outbreak.

International agencies and countries are trying to boost the capacity of the countries to fight the disease where overstretched health care systems and minimal sanitation have allowed transmission to rage almost unchecked.

There has been investment in new treatment centers, and equipment for health care workers but so far, the disease continues to spread in Sierra Leone, where the WHO has described rate of transmission in the capital Freetown as "intense". Liberia has also been particularly hard hit.

The WHO reported yesterday, that there are 4,249 infections in Sierra Leone with 2,458 fatalities.