In early 2022, approximately 200,000 people in Malawi were displaced due to two tropical storms that hit southeast Africa within a month. These storms, Ana and Gombe, caused significant damage to homes, crops, and infrastructure, resulting in 64 deaths. The heavy rainy season and storms led to a cholera outbreak, which is usually endemic to the region. Typically, cholera is contained around Lake Malawi during the rainy season, causing around 100 deaths each year. However, the 2022 outbreak showed a different pattern, spreading throughout the dry season and affecting northern and central regions of Malawi by August. The outbreak peaked in February 2023, reaching 700 cases per day with a 3.3% fatality rate, three times higher than usual. By the end of the 12-month period, over 1,600 people had died, making it the largest outbreak in the country’s history.
The World Health Organization (WHO) states that climate change is worsening the global upsurge of cholera, which began in 2021. The increase in tropical cyclones and subsequent displacement of people has compounded outbreaks in 30 countries, 50% more than previous years’ average. While Tropical Storm Ana and Cyclone Gombe weren’t the direct cause of the cholera outbreak in Malawi, they acted as risk multipliers.
Cholera is a diarrheal illness that spreads in areas with inadequate access to clean water and sanitation. The pre-existing poor water-sanitation indicators in Malawi were worsened by the storms, which resulted in flash floods and sewage contamination of water sources. Displaced individuals, seeking alternative water sources, often drank highly contaminated water, leading to the spread of the disease as they moved to new areas.
Similar cholera outbreaks occurred in Pakistan and Nigeria, where extreme monsoon seasons and flooding displaced millions of people. The global surge in cholera cases led to a shortage of the cholera vaccine when countries needed it the most. To address the shortage, the international coordinating group for cholera vaccines changed the vaccination protocol, reducing protection from two years to about five months.
Climate change impacts cholera not only through floods and storms but also hotter temperatures and prolonged droughts. Severe water shortages cause remaining water sources to become easily contaminated, increasing cholera risks. Ethiopia, Somalia, and Kenya experienced cholera proliferation during a prolonged and extreme drought attributed to climate change.
While climate change plays a role in cholera outbreaks, other factors such as population immunity, strains of the bacteria, and water and sanitation infrastructure also contribute. Destructive storms alone may not lead to massive cholera outbreaks, emphasizing the importance of considering multiple factors.
Investment in water and sanitation infrastructure is crucial in mitigating cholera risks. However, countries facing economic crises and limited resources, like Malawi, often struggle to address these issues. Malawi’s response to the cholera outbreak was hampered by existing challenges, including the COVID-19 pandemic and a polio outbreak.
Malawi’s ongoing cholera response, including high vaccination rates, distribution of water tablets and supplies, and public messaging, played a significant role in reducing transmission despite the infrastructure damage caused by Cyclone Freddy. However, there are concerns that the new reporting protocol for cholera cases may lead to underreporting, potentially creating the conditions for another large outbreak.
As climate change continues, humanitarian agencies must adapt their approaches to address the increased risk of cyclones and flooding. Efforts to address cholera outbreaks should focus on long-term investments in infrastructure development and improved access to clean water and sanitation.