Via Wikipedia, a detailed article on Bamako. Of particular interest is the paragraph on the city's demographics:
The population growth has been staggering. In 1884, it had only 2500 inhabitants, 8000 in 1908, 37,000 in 1945, and 100,000 in 1960. Today, the population is at least 18 times what it was in 1960, with over 1,800,000 recorded at the 2009 census, and continues to attract a rural population in search of work. Including illegal squatters and temporary workers, some experts believe the population today is well over 2 million.
This uncontrolled growth has caused significant difficulties in terms of traffic, sanitation (including access to safe water), and pollution. Bamako became the crossroads of West Africa and hosts a diverse population, composed of different ethnic groups in Mali, but also from neighboring countries.
If the Nigerians could contain Ebola in Lagos and Port Harcourt, the Malians may have a chance to do so in Bamako. But it won't be easy.