West Africa is struggling to control a cholera outbreak that has spread from Nigeria to nearby countries, made worse by insecurity and tons of refugees fleeing an Islamist insurgency north of the country, according to aid agencies.
Some 33 000 people in Nigeria and thousands more in neighbouring nations have contracted the disease, which has been overshadowed by an Ebola outbreak in Guinea, Liberia and Sierra Leone, medical charity Medecins sans Frontieres (MSF), said.
Water and food contaminated
Cholera is an acute diarrhoeal illness caused by a bacteria that can cause rapid dehydration and death. Its victims are frequently infected through the ingestion of water and food contaminated by human faeces.
"In the past, we've seen a few big isolated outbreaks, but this year there have been lots of smaller outbreaks spread over a larger area, making it much harder to control," Cristian Casademont, MSF's operational health advisor, told the Thomson Reuters Foundation by telephone from Barcelona.
Read: What are the causes of cholera?
"Part of the reason is the unusually high and uncontrolled number of cholera cases in Nigeria. This, combined with the large movement of nomadic tribes and refugees between Nigeria and neighbouring countries, could explain the disease pattern."
An insurgency in the north of Nigeria by Islamist militants Boko Haram has exacerbated the problem.
The conflict has resulted in more than 2 000 deaths this year and forced more than 100 000 refugees to flee to Niger and Cameroon, according to Human Rights Watch.
Casademont said the conflict is making it more difficult to conduct surveillance and react to outbreaks in northern Nigeria, and across the border in Niger's Diffa and Lake Chad regions.
"The situation is getting more and more complicated," he said, noting that the number of people infected is likely to be much higher than reported.
Cholera has killed about 50 of the more than 1 350 infected this year in southern Niger, according to the United Nations.
Over 2 000 infected
In Cameroon, more than 2 000 people have been infected this year, and about 100 have died, according to the International Federation of Red Cross and Red Crescent Societies.
The cholera outbreak has been compounded by poor harvests in southern Niger that has forced locals and refugees to go to Lake Chad in search of food, said Karl Steinacker, the U.N. refugee agency's (UNHCR) country representative in Niger.
Tahoua is Niger's worst affected region, reporting more than 500 cases in September, but the Diffa and Lake Chad areas are also are a concern.
Read: What are the symptoms of cholera?
"Lake Chad has become a point of last hope, but also a health hazard. From a food point of view they can survive off fish, however, there is no drinking water or sanitation," Steinacker said by telephone from the Niger capital Niamey.
Cholera is transmitted through bacteria-contaminated food and water or poor hygiene, and often breaks out when there is overcrowding and a lack of access to clean water, trash collection and proper toilets.
The United Nations estimates there are 34 000 displaced people living around the numerous islands of Lake Chad in need of water purification and about 2 000 latrines, but security is hampering assistance.
Read: What is cholera?
"If you get sick, you have to travel by boat to the nearest health centre in Bosso . . . but as Boko Haram operates on the lake, it is out of bounds for most humanitarian agencies," Steinacker said.
Cholera can be treated with a cheap solution of salt and sugar, and prevented through clean water and sanitation.
MSF is working with Niger's government to improve cholera surveillance and control. The Red Cross and UNICEF are distributing chlorinated tablets in the Diffa region.
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Image: Woman carrying a water can from Shutterstock.