Cholera and Climate Change in Nigeria: An Old Enemy in a Modern World
Written by ibk.ojo on February 8, 2023
Cholera is a disease caused by eating food and drinking water contaminated with the bacterium Vibrio cholerae. Its symptoms are severe diarrhoea (“rice water stool”), dehydration, weakness, muscle cramps, fever, vomiting, low blood pressure and thirst. Cholera is a highly infectious disease that can cause severe, life-threatening diarrhea. The disease is a significant public health concern, especially in communities with inadequate water treatment, poor sanitation, and hygiene practices. Urban slums and densely populated areas with poor sanitation are particularly vulnerable to cholera outbreaks.
Epidemiology in Nigeria
On 9 June 2024 the Lagos State government declared a cholera outbreak. Three days later, it announced that 324 suspected cases had been reported in the state, including 15 people who died and 40 who were discharged after treatment. The Nigeria Centre for Disease Control and Prevention reported that as of 11 June, 1,141 suspected cholera cases had been recorded across 30 states in Nigeria since 1 January 2024. There were 65 confirmed cases with 30 deaths reported from 96 local governments in 30 out of the 36 states. The Conversation Africa asked Stella Smith, a molecular epidemiologist, to explain the causes, spread, treatment and prevention of cholera. The current year has seen a 62% decrease in suspected cholera cases compared to the same period in 2023. Deaths have decreased by 76% over the same period. Recent data indicate an increase in cases during peak seasons, emphasizing the need for continuous monitoring and preventive measures.
Why is Nigeria Prone to Cholera Outbreaks?
Cholera has been endemic in Nigeria since it first appeared in 1972. The 1991 outbreak was the most severe on record, resulting in 59,478 cases and 7,654 deaths, a case fatality rate of 12.9%.
The World Health Organization recommended benchmark case fatality rate is less than 1%. This rate is the number of deaths in the country as a percentage of the total confirmed cases (both alive and dead). Rates in Nigeria’s outbreaks have mostly fluctuated between 1% and about 4%.
The 1991 rate was high due to very poor sanitation and hygiene strategies. Little or no surveillance was in place and there was no community engagement or education on the dangers of the disease.
Nigeria is prone to a variety of factors that lead to recurring cholera outbreaks. They include lack of access to potable (safe to drink) water. Safe water is needed to maintain good hygiene practices. Other factors are lack of continued surveillance even after the outbreak has ended; flooding; poverty (although currently cholera treatment is free in all government facilities); lack of health facilities; illiteracy; lack of infrastructure for water supply and waste disposal; and conflict, leading to overcrowded conditions for displaced people.
Seasonality of Cholera Outbreaks
Cholera outbreaks in Nigeria often increase during the rainy season, which lasts from April to October annually. The heavy rainfall and subsequent flooding create conditions that are ripe for the spread of Vibrio cholerae the bacterium responsible for cholera. Floods often contaminate water supplies, especially in areas with poor sanitation leading to the rapid spread of the disease.
Data from the Nigeria Centre for Disease Control and Prevention (NCDC) revealed that most cholera cases are reported annually between June and September. For instance, in 2021, Nigeria experienced one of its worst cholera outbreaks in years, with over 110,000 reported cases and more than 3,600 deaths.
According to a study, climate change exacerbates the conditions that contribute to cholera outbreaks. A rise in global temperatures is also contributing to more extreme weather patterns, including heavier and more unpredictable rainfall. Coastal erosion and rising sea levels further exacerbate the already inadequate infrastructure in Nigeria’s coastal cities, making them more susceptible to flooding.
How is Nigeria containing the Outbreaks?
The primary goal of the cholera outbreak response is to contain the spread of the disease and lower the mortality rate. To achieve this, the NCDC emphasized surveillance, infection prevention and control, care, and treatment.
Poor surveillance and response have contributed to the ongoing outbreaks with high rates of morbidity and death. Drawbacks to improving surveillance have been attributed to ineffective response and management of cholera outbreaks in Nigeria. The inadequate number of healthcare workers with limited training in emergency response, and limited supply of emergency response kits add to these drawbacks. To mitigate these, there must be a concerted effort geared towards a coordinated and harmonized approach involving all needed components.
The continuous outbreaks of epidemics in Nigeria are significantly impacted by the country’s response strategies. Rapid population growth necessitates that these response strategies evolve accordingly. If they do not adapt to the increasing population, they become largely inadequate, failing to effectively manage and control infectious disease outbreaks.
How can it be prevented?
Prevention depends on:
- access to clean water
- sanitation
- proper waste disposal
- personal hygiene
- food safety practices.
Community engagement and information campaigns on how to prevent cholera infection are important.
Game Changer
According to the outcome of a risk assessment conducted in June 2024, Nigeria was classified as being at ‘high risk’ of increased cholera transmission. In response, the Federal Government is collaborating with Gavi, the Vaccine Alliance, to secure emergency vaccine donations to control the spread of cholera.
Sania Nishtar, CEO of Gavi, also announced that Gavi and other health partners in Nigeria are swiftly responding to the cholera outbreak, including a request for emergency vaccine doses. “The global cholera stockpile, which is funded by Gavi, is currently fully replenished and ready to help contain outbreaks and protect those at highest risks,” Nishtar mentioned.
In addition, a Public-Private Partnership Vaccination Program (PVac) is in progress and is aimed at streamlining the production and distribution of cholera vaccines, ensuring timely and efficient responses to outbreaks. Insights reports from Nigeria Health Watch’s social listening revealed that there is significant interest in the availability and cost of the cholera vaccine, reflecting a need for accessible vaccination information. As a result, strategies should be put in place to deal with misinformation and disinformation about the vaccination when they arise.
While the vaccine will go a long way to contain the spread of the virus, strengthening infrastructure, enhancing climate resilience to prevent flooding, and fostering community engagement are essential steps in addressing the recurring cholera outbreaks. As climate change continues to alter the environmental landscape, proactive and adaptive measures will be crucial in safeguarding public health and preventing future outbreaks.
Conclusion
Cholera is primarily caused by poor hygiene, highlighting the significant work that state health authorities must undertake to prevent deaths from this preventable disease. To mitigate cholera outbreaks, it is essential to implement a multisectoral response anchored on the One Health approach. This involves ensuring continuous health education, fostering community engagement, and providing safe water sources. By addressing these factors comprehensively, it would be possible to significantly reduce the incidence of cholera and safeguard the health of communities.
Thank you.
