INSIGHT: How climate change fuels cholera outbreaks in Nigeria

The recent cholera outbreak in Nigeria has become dreadful with hundreds of people dying from it and thousands more coming down with the disease. In July alone, TheCable reported that Nigeria recorded 441 deaths from cholera as states across the country record different burden rates of the epidemic.

The World Health Organisation (WHO) states that cholera is primarily a water-borne disease caused by ingestion of food or water contaminated with the bacterium Vibrio cholera and presents with an acute diarrhoeal condition in victims.  It is a potentially life-threatening disease and victims can die from dehydration within hours or days of contracting the disease.

Globally, 1.3 to 4.0 million cases of cholera are recorded annually with 21,000 to 143, 000 deaths, according to WHO.

In 2021 alone, between January 01 and August 01, the NCDC reported that Nigeria has recorded 31,425 suspected cases of cholera, 311 confirmed cases, and 816 deaths reported from 22 states and FCT.

But even this number might be underreported because according to the WHO, the number of cholera cases it received has continued to rise over the last few years and the figures might not even capture the real picture because of limitations in surveillance systems in developing countries.

FLOODS ARE EXACERBATING INFECTION SPREAD

Research shows that the cholera-causing bacteria are mostly found in the faeces of an infected person and so experts believe it is easily transported by flood when it rains in an environment where people defecate in the open.

Chukwumerije Okereke, a professor of global environmental and climate governance and director of centre for climate and development at Alex Ekwueme Federal University Ndufu-Alike, Ebonyi told TheCable that the relationship between cholera and climate change is the change in rainfall patterns which has led to increased rainfall and huge amount of flood.

According to him, the huge amounts of flood carry in their path dirt, sewages, and debris which are deposited into water bodies that are used by people for drinking and cooking, and this eventually results in them coming down with the disease.

“The two key ways in which climate change is having an impact in a range of different ecosystems and physical environments in Nigeria is through change in temperature and change in rainfall pattern, especially the latter which is change in rainfall pattern.

“This is the reason why we have had a huge amount of flooding. Recall since 2011 Nigeria has experienced a huge amount of incidence of flooding. The flooding event also means that sewage, debris, and all manner of dirt are washed into the water bodies which then people can scoop and drink and this is the reason why we have many outbreaks of diseases including cholera but also dysentery, diarrhea, and other types of diseases. So this is the connection.”

Also, Emmanuel Chukwu, a laboratory analyst, agrees that increased flooding as a result of climate change causes an increase in the spread of the cholera-causing virus.

He told TheCable that flood occurring during the rainy season serves as the means of transportation for the cholera virus by washing microorganisms from surfaces into water bodies.

“Climate change is a contributing factor, especially flooding. When you see areas that are prone to flooding, there is a tendency that there is going to be a high rate of cholera in such communities,” Chukwu said.

“Flood carries a lot of things with it. This is the rainy season and there has been an accumulation of microorganisms in surfaces, so once the rain starts falling, it washes the microorganisms into the water bodies and many of these communities rely on these water bodies for drinking and for basically everything they do.”

He explained that the virus which is water-borne multiplies into millions once it comes in contact with water and flood moves the virus from one infected community to different other communities, thereby causing an increase in infection. This he said would naturally not occur if there was no flooding.

IS THERE A SOLUTION? 

Going by the recent climate change report by the Intergovernmental Panel on Climate Change (IPCC), — human activities have caused damages to the earth that will be irreversible over hundreds and thousands of years. This means that climate change impacts like flooding which Nigeria currently experiences cannot easily be wished away soon but would most likely increase in the coming years. If this is the case, then such diseases as cholera will continue to affect even more lives and communities in Nigeria as flood incidences increase in coming years.

Okereke suggests that if Nigeria must tackle cholera, it needs to improve on climate change mitigation and adaptation measures by improving water, sanitation, and hygiene (WASH) infrastructure such as adequate and properly channeled drainage systems.

He noted that flood carries with it a sludge of dirt, sewage, debris, plastics due to lack of WASH infrastructures in communities across the country and this increases disease spread.

“If the country is interested in tackling this problem then they would need to ensure that they implement a range of climate mitigation and adaptation measures to reduce the incidence of flood disaster, but also we need to actually improve our WASH systems,” he said.

“Flooding is a big problem in many other countries even in Europe but the chances that flooding will lead to an outbreak of disease is higher in poor developing countries because of the poor sewage, poor drainage, poor sanitation systems which we run.

“There is a whopping lack of WASH infrastructure in Nigeria. I think only 30 to 49 percent of Nigerians have access to proper water systems and toilets. And so this is the reason why when you now have this flooding, it can then lead to an increase in diseases.”

On his part, Chukwu advised that Nigerians need to change their habit of open defecation and also be careful about the water they use.

“That is why we always advise people should stop open defecation when the rain falls it carries it and flushes it into the water  bodies and this is the water body that they use,” he said.

“People should be very careful about the kind of water that they drink and if you must use that water, you ensure you boil them very well. Not warming, there is a difference between warming and boiling. You have to ensure you boil the water very well to ensure at least that the microorganism will be limited, they will be reduced to a minimal rate.”

This story is published in partnership with Report for the World, a global service programme that supports local public interest journalism.