What’s behind the deadly cholera outbreak in Southern Africa?

In the wake of multiple cholera outbreaks across Africa since the start of 2024, the toll has mounted grimly with over 1,000 lives claimed and tens of thousands infected. Among the hardest-hit nations are the Democratic Republic of the Congo, Mozambique, Zimbabwe, Zambia in southern Africa, and Ethiopia further north.

Zambia is grappling with its most severe outbreak on record, tallying over 740 cholera-related deaths since the onset of seasonal rains in October 2023. Despite the disease’s treatable nature, with timely intervention resulting in less than one per cent mortality, Zambia, one of the world’s poorest countries, faces a death rate exceeding three per cent.

“The cholera outbreak is in its 20th month, with over 41,000 cases in 54 districts across 8 regions. It’s the largest cholera outbreak in Ethiopia’s history,” said Dr Michael Ryan, deputy director-general of the World Health Organisation (WHO) at the High-level Pledging Event for the Humanitarian Situation in Ethiopia on 16 April.

How is the disease spreading?

Cholera outbreaks often strike in areas reeling from disasters or impoverished communities lacking safe water and sanitation infrastructure. The Vibrio cholerae bacterium responsible for the disease proliferates in fecal matter, contaminating food and water sources.'

Epidemiologist Yap Boum tells Deutsche Welle (DW), “Just imagine one household where the toilet is pretty close to the place where people fetch their water, so there is a transmission of contamination between the toilets and the water that people drink.”

“And then in settings like  refugee camps, where you have a concentration of people, the water that is being used is highly contaminated.”

Regular, unchecked cross-border movement, for example, means infections can be transported:  One 2023 study found that two sisters who had travelled from South Africa to a cholera hot spot in Malawi infected a third person on their return and that the strain that is currently spreading is originally from South Asia.

While it’s rare for people to transfer the infection through casual contact, poor hygiene can lead to faecal matter from an infected person contaminating food meant for others, reported Al Jazeera.

What are the contributing factors?

Epidemiologist Boum underscores inequality, conflict, insecurity, and poverty as key drivers of cholera outbreaks in affected African nations.

“Cholera is a marker of inequality, mostly affecting countries that are exposed to conflict, insecurity and poverty,” he said. Those factors are all present in each of the African nations currently battling cholera outbreaks.

Additionally, climate change exacerbates the situation, with more frequent and intense flooding increasing the risk of contamination, as explained by water management expert Anja du Plessis to DW.

Isn’t there any vaccine?

Compounding the crisis, global demand for cholera vaccines outstrips supply, with stockpiles depleted. Only one manufacturer, based in South Korea, produces the oral cholera vaccine, struggling to meet a demand quadruple its capacity.

Despite a 2022 recommendation to streamline vaccination regimens, vaccine availability remains limited, hindering effective outbreak control efforts.

While vaccines play a crucial role, experts caution against relying solely on them for cholera containment. Alongside vaccination, promoting hygiene practices, ensuring access to safe water, and bolstering water quality monitoring are essential components of a comprehensive strategy.

Efforts to bolster vaccine manufacturing in affected regions, such as the licensing agreement signed by Biovac in South Africa, offer hope for future outbreak response.

“Diseases are not prioritised the same way in all parts of the world,” vaccinologist Amponsah-Dacosta told DW. “With cholera, we have just one manufacturer with limited global interest in a disease such as this one. It creates the situation that we’re seeing now in terms of the dwindling stockpile.”

“If you increase manufacturing capacity in parts of the world that experience the disease the worst, it just means that they are able to take ownership and rely on their own resources and better support their health programmes. “That is critical.”

With inputs from agencies