Widespread flooding in southern Angola has been blamed for a surge in cholera, with 4,500 cases of the waterborne disease reported this year, and 150 fatalities.
According to Angola's health ministry, there were 590 new cases in the week running up to 31 March, up from the 503 cases reported the previous week.
About half of the infections were in Angola's southern provinces of Cunene and Huila, which have been hard hit by flooding. According to the UN Office for the Coordination of Humanitarian Affairs, over 81,400 people had been affected by the floods, with more than 56,000 displaced.
"The flooding caught everyone by surprise," said Adam Berthoud, Regional Public Health Advisor for the development agency Oxfam: limited access to the affected areas also slowed assistance.
"Oxfam has been working with the Angolan Red Cross, [UN children's fund] UNICEF and government stakeholders to ensure access to clean water, sanitation and key hygiene items such as soap and buckets," Bertohoud told IRIN.
Floodwaters were expected to recede in the coming weeks, but "health risks will escalate", he warned.
"Stagnant ponds create further breeding sites for malaria-carrying mosquitoes; wells and latrines have been contaminated with floodwater, and local communities are cut off from their usual water sources. Without clean water families hit by the floods are at serious risk of death and disease."
A persistent problem
Cholera is an intestinal infection causing acute diarrhoea and vomiting and, if left untreated, can cause death from dehydration within 24 hours. It is easily treatable with rehydration salts.
Berthoud said recurrent cholera outbreaks have underlined deep-seated problems in Angola related to poor sanitation and hygiene practices, and the lack of access to potable water.
"The government of Angola, which faced serious national cholera outbreaks in both 2006 and 2007, has made significant strides in its cholera response capacity through building up contingency plans and stocks," he noted.
According to the World Health Organisation, a year-long cholera outbreak that began in February 2006 resulted in 70,000 reported cases and nearly 3,000 deaths.
Angola, sub-Saharan Africa's second largest oil producer after Nigeria, is currently in the middle of a multibillion-dollar reconstruction boom fuelled by record high oil prices. Yet, despite its oil wealth, most citizens still subsist on less than US$1 a day.