Climate change may worsen cholera crisis in Africa: WHO

Extreme weather events like major floods and even droughts may be driving the health crisis; Malawi facing the worst ever crisis
Around 26,000 cases and 660 deaths were reported from 10 African countries from January 1, 2023 through January 29, 2023. Photo: iStock
Around 26,000 cases and 660 deaths were reported from 10 African countries from January 1, 2023 through January 29, 2023. Photo: iStock

Climate change may be increasing the impact of cholera in African countries. The continent is likely to see its worst cholera crisis this decade, driven by extreme weather events and poor water supply and sanitation infrastructure, according to the World Health Organization (WHO). 

Cholera cases are rising globally and 31 countries across the world have reported outbreaks of the disease since January 2022. Around half, or 15 countries, are in Africa. The exponential rise in cholera cases in 2023 was also pointed out by a WHO February 9, 2023 statement.

Around 26,000 cases and 660 deaths were reported from 10 African countries from January 1, 2023 through January 29, 2023. In 2022, a total of around 80,000 cases and 1,863 deaths were recorded from 15 affected countries in the continent. 

So, the cases recorded on the continent in the first month of 2023 alone have already risen by more than 30 per cent of the total caseload of 2022. If cases continue to rise rapidly at this rate, the number of cholera cases could be much higher than those recorded in 2021.

“The common denominator for many of these outbreaks is climate-related events, such as storms, floods and droughts,” alerted WHO Director-General Tedros Adhanom in a media briefing January 11, 2023. 

Most of the larger outbreaks, which are also simultaneously occurring, is a direct impact of the increase in adverse climate troubles, said Philippe Barboza, WHO team lead for Cholera and Epidemic Diarrhoeal Diseases. 

“The cholera crisis has been playing out across the Horn of Africa and the Sahel accompanied by major floods, unprecedented monsoons (and) a succession of cyclones,” the expert said.

While cholera cases globally stunted in 2021, Africa ditched the trend, with confirmed cases reaching the 2017 levels. 

The case fatality ratio (CFR) or deaths per 100 confirmed cases more than doubled from less than one in 2020 to almost 2 in 2021. The average cholera CFR reported globally in 2021 was 1.9 per cent and 2.9 per cent in Africa.

The average CFR in Africa is almost at three per cent as of January 29, 2023, which is above the 2.3 per cent reached in 2022 and far exceeded the acceptable level of below one. 

2021 was the worst year for the African continent in around a decade. But 2023 is likely to be even worse, the drivers behind the cholera outbreaks indicate. These include natural disasters linked to climate change.

Malawi is among the worst-affected countries, with 36,943 cases and 1,210 associated deaths reported from all 29 districts since March 3, 2022. The situation worsened in January 2023, when the country registered a 143 per cent increase in the number of cases since December 2022. 

These outbreaks have taken place following two major disasters — tropical storm Ana (January 2022) and cyclone Gombe (March 2022). Since January 2022, when tropical storm Ana was declared a national disaster, Malawi has registered polio and cholera outbreaks.

Over 17,000 cases were registered as compared to 7,017 cases in December. This is the deadliest cholera outbreak in the country’s history, acknowledged the WHO in the recent situation report released on February 9. 

Cholera has been endemic in Malawi since 1998. The outbreaks are usually reported during the rainy season from November to May.

But in 2022, the cholera outbreaks were reported earlier in March 2022. The current outbreak has extended through the dry season, with cases being reported since March 2022 as per the WHO statement.

Tropical storm Ana and, subsequently, Gombe caused extensive destruction of infrastructure. The disruption of water and sanitation systems was a recipe for cholera, said WHO Africa region

So, lack of access to safe water, sanitation, and hygiene following these disasters has been a significant driver for cholera, a water-borne disease. 

Besides Malawi, cases have been reported in neighbouring Mozambique and Zambia, as well as in Burundi, Cameroon, the Democratic Republic of the Congo (DRC) and Nigeria. 

In Nigeria, too, the worst floods in a decade that struck between June and November 2022 and attributed to climate change have been the driver behind cholera outbreaks.

Cholera cases spiked across the flood-hit Cameroon too. Heavy rains with repeated floods observed since August 2022, as well as conflicts and large population movements in many regions of the country, created a suitable environment for the outbreak. 

Ethiopia, Kenya and Somalia are also responding to outbreaks amid the historic drought in the Horn of Africa, which has left millions in dire need of humanitarian assistance. 

Prolonged drought in Kenya resulted in acute water shortage and rationing, leading to poor sanitation and cholera outbreaks in major cities/towns, including Nairobi. 

“Diminishing water resources due to severe drought in parts of the country are likely to lead to an outbreak of other diseases associated with poor sanitation,” warned Francis Kuria, head of public health at Kenya’s ministry of health.

The suspension of the standard two-dose vaccination regimen for cholera in October by the International Coordinating Group that manages the global cholera vaccine stockpile has also added to the challenge.

In October, the International Coordinating Group that manages the global cholera vaccine stockpile suspended the standard two-dose vaccination regimen for cholera, using instead a single-dose approach to extend the supply. 

The increase in cholera outbreaks globally has put a huge strain on the availability of oral vaccines to treat the disease, acknowledged WHO.

The surge in cholera outbreaks, compounded in these countries with fragile health systems and aggravated by climate change, is challenging. 

Over 58 per cent of known human pathogenic diseases, including cholera, can be aggravated by climate change, confirmed a study published in the journal Nature.  

The continent lags behind on United Nations-mandated sustainable development goal 6 (clean water and sanitation for all). This may be a factor in the health crisis as well. 

Investments in better sanitation and access to safe water formidably complement the public health initiatives to sustainably control and end cholera, WHO’s Matshidiso Moeti said in a press statement.

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