- An increase in the frequency and intensity of heat waves, droughts and heavy rainfall events is expected to lead to an increase in food-borne diseases, hitting Africa and Asia particularly hard.
- Investments in research and innovation can provide valuable insights into the underlying mechanisms of interactions between climate change and pathogens, as well as new solutions to mitigate their impacts.
- For example, the Cameroon National Climate Observatory (ONACC) already provides national sectors such as agriculture, livestock and health with climate forecasts translated into their respective national languages to facilitate monitoring related to global warming.
Climate change threatens public health by affecting the distribution and spread of food-borne pathogens, according to a recent study by food scientists at Benha University in Egypt published in (.Climate change). Foodborne pathogens are microorganisms that can cause illness when ingested through food or water.
The authors found that changes in temperature and precipitation patterns, changing consumer behavior, and changing prevalence of foodborne pathogens increase the risk of exposure to humans and animals.
“The aim of this study is to highlight the links between climate change and public health, raise awareness, stimulate discussion on effective mitigation strategies, advocate for increased investment in research and local expertise development, and promote partnerships between African researchers and international organizations to share knowledge and resources,” Dr. Ahmed Alhussaini Hamad, one of the study’s authors, told Mongabay in an email interview.
The World Health Organization estimates that one in ten people become ill each year from eating contaminated food. According to the study, contaminated food is the cause of 600 million food-borne illnesses and 420,000 deaths per year. Africa alone is responsible for 91 million cases of illness and 137,000 deaths per year – over a quarter of all deaths. Among these diseases, diarrheal diseases account for 70% of the total burden. The impact of climate change on diarrheal diseases is likely to be even more significant in Asia and Africa, Hamad and colleagues say.
According to the study, climate change will also contribute to a global increase in food-borne diseases. For example, an increase and intensity of heat waves, droughts and heavy rainfall events will lead to an increase in food-borne pathogens.
This news is particularly worrying for Africa. According to Hamad, low-income African countries are often disproportionately affected by climate change due to their geographic location, their dependence on agriculture and their limited resources to adapt and mitigate its impacts.
For African countries, Hamad says, “the rising number of foodborne illnesses can put further strain on already overburdened health systems. And food contamination can lead to significant financial losses in the agricultural sector.”
The example of Cameroon
According to Hamad, five food-borne diseases – salmonellosis, campylobacteriosis, listeriosis, cholera and aflatoxin poisoning – are linked to climate change. For example, fluctuations in water temperature and quality affect the cholera bacterium Vibrio cholerae, he says.
In Africa, Cameroon has been struggling with cholera in recent years. A study in Infectious Disease Monitoring shows that “the absence of water channels in some cities in Cameroon and the ubiquitous presence of garbage have, over time, favored the proliferation of V. cholerae in the environment, triggering a new outbreak in 2018.” In July 2018, when the Cameroon government declared a cholera outbreak, 470 cases and 34 deaths were recorded. Cameroon has reported a total of 20,649 cases and 484 deaths from January 1, 2022 to March 7, 2024.
Dr. Rene Ramses Meyong, a climatologist at the National Climate Change Observatory in Cameroon, told Mongabay that the link between climate change and foodborne diseases is based on the mechanisms by which climate affects the reproduction and spread dynamics of pathogens, be they bacteria, viruses, parasites, natural toxins, etc. The epidemiological profile of any disease can be modulated in the short, medium or long term by the dynamics of climate parameters.
“The work of the Observatory has shown that climate change has been reflected at the local level since at least 1950 in an increase in average temperatures in the five agroecological zones, instability in the start and end dates of the seasons, high spatial and temporal variability in rainfall and an increase in extreme weather events (floods, droughts, etc.). Assuming that the disturbances have an impact on food production, processing and storage, it can be assumed that part of the increased risk of transmission of foodborne diseases in the country’s five agroecological zones is due to climate change,” says the climatologist.
The study on climate change and foodborne pathogens suggests that changes in food production and trade may introduce new sources of contamination. According to Meyong, given its impact on the whole country, it is realistic to assume that climate change increases the risk of foodborne diseases in Cameroon. The climatologist has also linked potential sources of contamination in Cameroon to the overuse of chemicals.
“To meet the increasing demand in the consumer market, many players are forced to use significantly more chemicals (pesticides, fertilizers, etc.) in the manufacturing process, which contributes to the increase in antimicrobial resistance,” says Meyong, adding that “contact with chemicals can also increase the risk of severe poisoning or the spread of chronic diseases such as cancer.”
The climatologist expressed concern about the storage conditions of food displayed in some markets in Cameroon. “Poor food display conditions, coupled with adverse weather conditions, increase the risk of contamination by food-borne bacteria such as Vibrio cholerae.”
The study, published in Nature in June 2024, recommends monitoring the impact of climate change on foodborne pathogens to develop strategies to mitigate its impact on human health and to understand the science behind the link between climate change and foodborne diseases.
Meyong says the climate observatory already provides national sectors such as agriculture, livestock and health with climate forecasts (climate services) translated into local languages to facilitate monitoring related to global warming.
Mitigation strategies
By adopting climate-friendly agricultural methods – such as integrating agricultural practices and conservation agriculture – farmers can reduce the impact of climate change on their crops and minimize the likelihood of contamination by foodborne pathogens, according to the study by Egyptian scientists.
In addition, mitigation strategies such as improving food safety protocols and regulations, expanding monitoring programs, and investing in research to understand the links between climate change and foodborne diseases could help mitigate health impacts.
The study also suggests investing in research and innovation that can provide valuable insights into the underlying mechanisms of climate change-pathogen interactions and new solutions to mitigate these impacts. This includes developing new technologies and tools to detect, track and control foodborne pathogens in a changing environment.
“Little is known about the relationship between climate change dynamics in the context of global warming and the incidence of food-borne diseases in Central Africa in general and in Cameroon in particular,” says Meyong. “This is an area that still needs to be explored to provide evidence-based data to decision-makers.”
The study shows that understanding the complex interactions between food systems, pathogen populations and climate variables is critical to formulating appropriate strategies and preparing for health emergencies, among other challenges.
“Safe food is essential to maintaining food security and public health. And it is crucial to enable countries to develop targeted strategies to mitigate the impacts of climate change on food security,” says Hamad.
Quote:
Awad, AD, Masoud, AH, Hamad, A. (2024). Climate change and foodborne pathogens: human health implications and mitigation strategies. Climate change177:92. https://doi.org/10.1007/s10584-024-03748-9.
:max_bytes(150000):strip_icc():focal(721x293:723x295)/john-travolta-081524-0bf2242b5e1141498043878339665787.jpg "John Travolta dines in a cozy Italian restaurant after the Olympic Games in Paris")
