In August, Guinea's President Alpha Conde declared a national health emergency due to the outbreak. He stated efforts to control the spread of the Ebola virus would include forbidding Ebola patients from leaving their homes, border control, travel restrictions, and hospitalization for individuals suspected to be infected until cleared by laboratory results. He also banned the transporting of the dead between towns. Good disease tracing was important to prevent the outbreak from spreading. Previous Ebola outbreaks had occurred in remote areas making containment easier; the West African outbreak struck in an area that lies at the centre of both a highly-mobile and densely populated region which made tracking more difficult: "This time, the virus is traveling effortlessly across borders by plane, car and foot, shifting from forests to cities and springing up in clusters far from any previously known infections. Border closures, flight bans and mass quarantines have been ineffective." Peter Piot, who co-discovered Ebola, said Ebola "isn't striking in a 'linear fashion' this time. It's hopping around, especially in Liberia, Guinea and Sierra Leone". Containment was also difficult due to fear of healthcare workers. Infected people and those that they were in contact with evaded surveillance, moving at will and hiding their illnesses while they infected others in turn. Entire villages, stricken by fear, closed themselves off, giving the disease an opportunity to strike in another area. It was reported that in some areas it was believed that health workers were purposely spreading the disease to the people, while others believed that the disease did not exist. Riots broke out in the regional capital, Nzérékoré, when rumors were spread that people were being contaminated when health workers were spraying a market area to decontaminate it. In May, the number of Ebola cases appeared to be decreasing and Médecins Sans Frontières (MSF) closed a treatment facility in the Macenta region because the outbreak of Ebola there appeared to have been resolved. At the time it was thought that the new cases were caused by people returning from Liberia or from Sierra Leone; however it was later suggested that villagers had become fearful and were hiding cases rather than reporting them. Seeing workers wearing the required protection outfits worn by health workers and taking those suspected of having Ebola or of being contacts to the treatment center (perhaps never to be seen again), refusing the usual burial rituals when a patient died, and other actions taken by the unfamiliar individuals that had come to their remote areas, had led to rumors of organ harvesting and government and tribal plots.