As climate change intensifies, the impact on infectious diseases is becoming more evident. In Africa, cholera cases are on the rise, presenting a serious public health challenge.
Research conducted in early 2022 revealed that nearly 200,000 Malawians were displaced after two tropical storms, Ana and Gombe, struck the southeastern part of Africa within a month, resulting in 64 deaths.
These storms caused devastation to homes, crops, and infrastructure in southern Malawi, compounding the existing challenges faced during the rainy season.
Cholera, typically endemic during the rainy season from December to March, affected Malawi differently in 2022. The outbreak followed an unconventional pattern, spreading throughout the dry season and affecting northern and central regions by August.
The outbreak peaked in early February, with 700 cases reported per day and a fatality rate of 3.3%, three times higher than the typical rate. By March, cholera had claimed over 1,600 lives, marking the largest outbreak in Malawi’s history.
Climate change, with its increasing frequency and intensity of storms, plays a significant role in the spread of cholera.
The World Health Organization reported that in 2022, 30 countries experienced outbreaks, 50% more than previous years’ average. Tropical cyclones and their subsequent displacement of people compounded many of these outbreaks.
The destructive storms exacerbated an already challenging situation in Malawi, where water-sanitation indicators were extremely poor.
Flash floods contaminated water sources, destroyed infrastructure, and led to the spread of cholera. People displaced from their homes resorted to using contaminated water sources, facilitating the transmission of the disease.
The global cholera surge strained vaccine supplies, leaving countries in need without adequate protection. In response to the shortage, the vaccination protocol was modified, reducing protection from two years to about five months.
While floods and storms contribute to the spread of cholera, hotter temperatures and longer droughts can also impact disease transmission.
In Ethiopia, Somalia, and Kenya, extreme droughts due to climate change led to increased cholera cases, exacerbated by malnourishment that reduced immunity.
Experts caution against making sweeping statements about climate change’s direct impact on cholera globally.
The associations between precipitation, drought, floods, and cholera are complex and vary by region. However, the destruction of water and sanitation infrastructure remains a significant factor.
The cholera outbreak in Malawi occurred amid an economic crisis, COVID-19 pandemic, and a polio outbreak, straining limited health resources. In response to the outbreak, Malawi implemented mitigation efforts, leading to a decline in cases.
Efforts to control the outbreak were challenged by changes in the reporting methodology, potentially leading to underreporting.
Agencies are now assessing reporting methods in the affected districts to ensure accurate data and preparedness for future outbreaks.
The lessons learned from Malawi’s experience highlight the urgency for humanitarian agencies to adapt to climate change impacts.
With predictions of future cyclones and flooding, agencies must adopt new strategies to protect communities from infectious diseases like cholera. Investment in water and sanitation infrastructure is crucial to mitigating the impact of climate change on disease transmission.
Additionally, international collaboration is necessary to address vaccine shortages and protect vulnerable populations from disease outbreaks exacerbated by climate change.
This research collaboration between the Associated Press and Grist underscores the importance of exploring the intersection of climate change and infectious diseases to develop effective strategies for climate adaptation and public health.
