Extreme weather, vaccine lack drive deadly cholera outbreaks in Africa

Extreme weather events have hit parts of Africa relentlessly in the last three years, with tropical storms, floods and drought causing crises of hunger and displacement. They leave another deadly threat behind them: some of the continent's worst outbreaks of cholera.

In southern and East Africa, more than 6,000 people have died and nearly 350,000 cases have been reported since a series of cholera outbreaks began in late 2021.

Malawi and Zambia have had their worst outbreaks on record. Zimbabwe has had multiple waves. Mozambique, Kenya, Ethiopia and Somalia also have been badly affected.

All have experienced floods or drought — in some cases, both — and health authorities, scientists and aid agencies say the unprecedented surge of water-borne bacterial infection in Africa is the newest example of how extreme weather is playing a role in driving disease outbreaks.

“The outbreaks are getting much larger because the extreme climate events are getting much more common," said Tulio de Oliveira, a South Africa-based scientist who studies diseases in the developing world.

"Disease of poverty"

De Oliveira, who led a team that identified new coronavirus variants during the COVID-19 pandemic, said southern Africa's latest outbreaks can be traced to the cyclones and floods that hit Malawi in late 2021 and early 2022, carrying the cholera bacteria to areas it doesn't normally reach.

Zimbabwe and Zambia have seen cases rise as they wrestle with severe droughts and people rely on less safe sources of water in their desperation like boreholes, shallow wells and rivers, which can all be contaminated. Days after the deadly flooding in Kenya and other parts of East Africa this month, cholera cases appeared.

The World Health Organization calls cholera a disease of poverty, as it thrives where there is poor sanitation and a lack of clean water. Africa has had eight times as many deaths this year as the Middle East, the second-most affected region.

Historically vulnerable, Africa is even more at risk as it faces the worst impacts of climate change as well as the effect of the El Niño weather phenomenon, health experts say.

In what's become a perfect storm, there's also a global shortage of cholera vaccines, which are needed only in poorer countries.

“It doesn’t affect countries with resources,” said Dr. Daniela Garone, the international medical coordinator for Doctors Without Borders, also known by its French acronym MSF. “So, it doesn’t bring the resources.”

Billions of dollars have been invested into other diseases that predominantly affect the world's most vulnerable, like polio and tuberculosis, largely because those diseases are highly contagious and could cause outbreaks even in rich countries. But that's not the case with cholera, where epidemics remain contained.

WHO said this month there is a “critical shortage” of oral cholera vaccines in the global stockpile. Since the start of 2023, 15 countries — the desperate few — have requested a total of 82 million doses to deal with deadly outbreaks while only 46 million doses were available.

There are just 3.2 million doses left, below the target of having at least 5 million in reserve. While there are currently cholera epidemics in the Middle East, the Americas and Southeast Asia, Africa is by far the worst-affected region.

Global shortage of vaccines

Vaccines alliance GAVI and UNICEF said last month that the approval of a new cholera vaccine would boost stocks. But the result of the shortage has already been measured in deaths.

Lilanda, a township on the edge of the Zambian capital of Lusaka, is a typical cholera hot spot. Stagnant pools of water dot the dirt roads. Clean water is like gold dust. Here, over two awful days in January, Mildred Banda saw her 1-year-old son die from cholera and rushed to save the life of her teenage daughter.

Cholera shouldn't be killing anyone. The disease is easily treated and easily prevented — and the vaccines are relatively simple to produce.

That didn't help Banda's son, Ndanji.

When he fell sick with diarrhea, he was treated with an oral rehydration solution at a clinic and released. He slipped back into dehydration that night at home. Banda feels terrible guilt.

“I should have noticed earlier that my son was not feeling well,” she said, sitting in her tiny concrete house. “I should have acted faster and taken him back to the clinic. I should have taken him back to save his life.”

Because of the vaccine shortage, Zambia couldn’t undertake a preventative vaccination campaign after neighbouring Malawi's outbreak. That should have been a warning call, said de Oliveira. Zambia only made an emergency request when its cases started mounting.

The doses that might have saved Ndanji started arriving in mid-January. He died on January 6.