Cholera outbreaks have hit three more African countries, bringing the number of people killed by the disease across the continent this year to 1,663, health officials said on Wednesday.

Some 71,600 cases have been reported in Africa since January and Cameroon, Chad and Mali have been particularly badly affected, according to Claire-Lise Chaignat, coordinator of the World Health Organization’s (WHO) global cholera task force.

“Most of Africa is at high risk, but you always have pockets that are more at risk - the poorest of the poor,” Chaignat told Reuters by telephone from Geneva.

In 2003, there were 108,000 cases and 1,884 deaths, she said.

Senegal and neighboring Guinea-Bissau on West Africa’s Atlantic coast, and Uganda in the east, are the latest countries to succumb to the disease.

Africa had been free of cholera, an intestinal infection spread by contaminated water and food, for more than a century when the disease hit western regions in 1970.

It quickly spread and became endemic across much of the continent, killing hundreds of people each year.

The first outbreak of cholera in Senegal’s capital, Dakar, for seven years led President Abdoulaye Wade and cabinet members to wash their hands on state television last Thursday to encourage people to fight the spread of the disease.

“There have been a total of 400 reported cases, four of them fatal. But it has stabilized in the past two days,” a Senegalese health ministry official said on Tuesday.

Guinea-Bissau said on Monday cholera had killed three people and infected 58 others on the Bijagos archipelago off its Atlantic coast. The government blamed fisherman from neighboring countries for spreading the disease.

“No cases have yet been recorded in the capital, Bissau. We are working to make sure it doesn’t spread across the country,” health ministry official Julio S Nogueira said.

In northern Uganda, aid workers are battling an outbreak at a camp for displaced persons that has killed three people and infected at least 79 others, according to U.N. officials.

Experts say the disease, which can quickly cause severe hydration and death, can kill up to half those it affects in unprepared communities, although the fatality rate is typically much lower in areas with better healthcare facilities.

In Chad, one of the world’s poorest countries, cholera has killed 229 people and infected 4,719 this year. Aid workers fear the disease could spread to camps in the east housing refugees from Sudan’s neighboring Darfur region.

Torrential rains in Sierra Leone’s capital, Freetown, triggered an outbreak in the city’s shanty towns that later spread and killed 54 people in August alone.

Many of those who die from cholera could have been saved by a simple mixture of water and rehydration salts, but many remote areas lack even the most basic facilities and in some the security situation makes access for health workers difficult.

“In theory it is simple, but to apply it in practice is more difficult. People die stupidly because they cannot get access to rehydration,” WHO’s Chaignat said.