West Africa: Cholera outbreaks decrease
After years of cyclical cholera outbreaks in West Africa, the cholera response is getting better.
FREETOWN/DAKAR - After years of cyclical cholera outbreaks in West Africa, water and sanitation standards are still notoriously low in most of the affected countries, but in some areas the cholera response is working better now than in the past. IRIN spoke to governments and aid agencies about innovations and traditional wisdom for preventing cholera.
By the end of June 2012, cholera had killed nearly 200 people in West Africa and infected 10,330 according to the United Nations Children’s Fund (UNICEF). Numbers are continuing to rise, particularly in the Sahel zone, where a recent upsurge has killed 60 people and infected 2,800. On 2 July, 34 cases and two deaths - both children - were reported in northern Mali near Gao, on the edge of the Niger River.
Elsewhere in West Africa, case numbers are rising - but are lower than this time in 2011, when 82,070 people had contracted cholera, or in 2010 when 60,000 West Africans in the Lake Chad Basin, which includes parts of Chad, Niger, Nigeria and Cameroon, were infected.
But West Africa is just at the start of its rainy season – cholera usually peaks between August and December.
Cholera is characterised by diarrhoea and vomiting and can cause death within hours if it is particularly virulent, or hits weak victims like children.
The victims: children
Francois Bellet, the West Africa Water, Sanitation and Hygiene (WASH) programme specialist at UNICEF, worries that people who are hungry or malnourished as a result of the food crisis in the region are particularly vulnerable to infection. UNICEF is particularly concerned about the Sahel, where the spread of cholera is aggravated by a massive displacement of people fleeing the conflict in northern Mali.
In some areas - such as Niger’s regions along the Niger River - the Ministry of Health reports nearly three times as many cholera patients this year as in 2011.
An estimated 400,000 children in Niger are suffering from severe malnutrition this year. “A child below the age of five who has recovered from severe and acute malnutrition will be back for treatment in a matter of days or weeks if he or she is drinking contaminated water,” Guido Borghese, UNICEF’s advisor on Child Survival and Development, said in a communiqué.
The transmitters: fish
Cholera spreads along West Africa’s waterways - coastal regions, rivers and lakes - where busy fishing and trade routes run. The coast is “like a cholera highway”, said Bellet, as are major waterways such as the Niger River, which flows through Guinea, Mali, Niger, Benin and Nigeria.
The bacteria build up under the scales of fish and are often still there if the fish on sale in the markets have not been properly cleaned.
Given the role of women role in cleaning, descaling, smoking and selling fish in most of West Africa, it is they and their children who are particularly vulnerable to infection. Children make up some 80 percent of the cases in Sierra Leone’s Port Loko district, according to UNICEF.
The Guinea-Sierra Leone outbreak started on the island of Yeliboya in Sierra Leone’s Kambia district before spreading to islands off the coast of Guinea and into Forecariah prefecture. Islands in Boffa prefecture are known for their poor sanitation services and high levels of trade - perfect conditions for cholera to spread, said Bellet.
Vaccine: a new approach
The cyclical nature of cholera and the fact that immunity builds after large-scale epidemics are some of the reasons for this year’s lower caseload, said practitioners.
In Chad - which so far has zero cases this year compared to 5,000 in 2011 - widescale prevention efforts have paid off. And in Guinea the response has been much quicker and more coordinated this year.
In addition, a new approach has been tested in Guinea - notably a cholera vaccine used by Médecins Sans Frontières-Switzerland (MSF) for the first time in Africa to stem an epidemic.
The vaccine has had good results so far. In the Boffa and Forecariah prefectures of Guinea, where 77 percent of the population were given the double dose, and 95 percent received a single dose, there have been no cases reported since, said Iza Ciglenecki, innovation coordinator for diarrhoeal diseases at MSF-Switzerland. It is too early to know the full results, she said, but when used in other regions the vaccine has been 65-75 percent effective in stemming the spread of the disease.
This is potentially a huge step forward, but at US$3.70 for two doses the vaccine is expensive. The World Health Organisation (WHO) and NGOs are discussing guidelines for when to use it in response to future epidemics. “If we multiply these interventions in the future, we could even create regional stocks to make it cheaper, but it is too early to say - we need to learn more first,” said Francois Verhoustraeten, Guinea programme officer at MSF-Switzerland.
All responding agencies, including MSF, stressed that the vaccine is not a standalone solution and should be seen as a supplementary activity. “We put a lot of effort into all the strategies at once,” Ciglenecki told IRIN, referring to the need to raise awareness of public hygiene, targeting cholera hot spots, setting up early warning systems, and treating water. Agencies such as MSF, UNICEF and Action contre la faim (ACF) - Action against Hunger - an international NGO, have been implementing these measures for years in West Africa's cholera-prone areas.
Modern medical breakthroughs should not replace important basic hygiene practices: wash your hands after defecating, before cooking or eating, and try to disinfect water that may be dirty, say aid agency staff.
Neither should they negate the usefulness of age-old techniques, said Bellet.