Health
Flooding, waste crisis raise cholera outbreak fears in Lagos
With floodwaters spreading across communities and waste piling up, epidemiologists say Lagos is at growing risk of a cholera outbreak and increased malaria transmission.
They explained that widespread flooding, as witnessed in recent weeks, and the existing challenge of poor waste management in Lagos, create conditions that favour the spread of waterborne diseases.
The public health experts explained that floodwaters can contaminate drinking water sources with sewage and refuse, increasing exposure to Vibrio cholerae, responsible for cholera, and other disease-causing organisms.
They noted that indiscriminate waste disposal, blocked drainage systems, and poor sanitation further heighten the likelihood of disease transmission, particularly in densely populated communities.
PUNCH Healthwise reports that several communities in Lagos, including Agege, Alimosho, Apapa, Badagry, Ikeja, Ikorodu, Lagos Island, Lekki, and Surulere, were listed as a critical-risk category under locations likely to witness heavy rainfall that may lead to flooding by the Federal Government.
Also, the Nigeria Hydrological Services Agency, the Nigerian Meteorological Agency, and the National Emergency Management Agency have all identified July through September as the period of greatest flood risk for Lagos.
NiMet’s 2026 Seasonal Climate Prediction, released in February, forecast above-normal rainfall across Lagos with a delayed end to the rainy season and heavy flooding.
The warnings are already becoming a reality. In June and early July, heavy rains disrupted commercial activities in Lagos, leaving homes and roads submerged, damaging vehicles, and stranding commuters.
During visits to flood-affected communities in Ibeju-Lekki, our correspondent observed that many residents had been displaced and children had missed school, with commercial activities affected. Also, some nursing mothers were unable to take their babies to PHCs for routine immunisation because flooded roads had cut off access.
Aside from rain, Lagos, with an estimated population of over 20 million, is already battling a waste management challenge.
Available data indicate that Lagos generates about 13,000 tonnes of waste daily, making it one of Africa’s largest generators of municipal solid waste.
Recently, waste evacuation has remained a persistent challenge in the state as the Lagos State Waste Management Authority struggles to sustain waste evacuation efforts.
Across several communities, overflowing refuse bins, roadside dumps, and blocked drainage channels have become a common sight. In many neighbourhoods, road medians and drainage channels have gradually been converted into unofficial dumping sites.
Although Lagos Governor Babajide Sanwo-Olu, on June 18, ordered the immediate evacuation of waste across the state, the challenge persists.
But speaking exclusively with PUNCH Healthwise, the epidemiologists said that with the twin crises of flooding and waste, Lagosians are at risk of waterborne diseases.
They identified cholera, typhoid, and dysentery, among others, as the likely health crises residents across the state may face.
A Consultant Public Health Physician at the University of Ilorin Teaching Hospital, Kwara State, Dr Mojirola Fasiku, explained that as flooding persists, water sources get contaminated.
She said some vectors breed well in stagnant water, including mosquito larvae, adding that this leads to a surge in mosquitoes and, in turn, malaria cases among residents.
“And it’s not only malaria that such vectors can cause. There’s dengue fever, there’s yellow fever when there is an increase in vectors breeding,” she said.
The public health expert added that with waste and flooding colliding, there is a risk of a cholera outbreak.
“There is a possibility of a disease outbreak if there is flooding. Of course, diseases like cholera can occur because it is not everyone drinks water from pipes and all that. Some people get water from rivers. Even those who don’t get water from rivers, if everywhere is flooded, how will they get clean water to drink? And even those who get water from taps may not have a good source of clean water.
“And for those who practise indiscriminate faeces disposal, some people just defecate in drains or sewage channels anyhow. During this rainy season, when there is flooding, it washes all these into the water bodies. So, there is an increased risk of cholera and diarrhoeal diseases generally.
“Of course, there may also be an increase in malaria because the vectors breed more in stagnant water. So, these diseases may increase, especially cholera, because of the refuse and sewage that block drains and all that,” she said.
Fasiku also explained that flooding increases the risk of skin infections, as many people wade through floodwaters daily to reach their destinations.
Aside from the risk of skin infection, Fasiku also maintained that there may be the risk of snakes and other harmful reptiles in the floodwaters.
The physician also said flooding could impact the mental health of residents in flood-prone areas.
“It may give some people in flood-prone areas mental stress, and they may become anxious when the rains begin to fall because their homes will get flooded. They may have anxiety and depression,” Fasiku said.
She advised residents to drink safe water, maintain proper hand hygiene, dispose of waste appropriately, and seek prompt medical attention if they develop symptoms such as acute watery diarrhoea and vomiting.
Fasiku urged the Lagos State Government to intensify environmental sanitation, improve waste collection and drainage maintenance, and strengthen disease surveillance in flood-prone areas.
Also, a public health physician, Dr Austin Aipoh, said the twin challenges of poor waste management and flooding pose significant health risks to residents.
“It is very straightforward because refuse already contains a lot of bacteria, and waste is not being properly disposed of. When flooding occurs, the waste is washed into surrounding areas, posing serious health risks. As a result, people may develop bacterial infections.
“Others include waterborne diseases like cholera and amoebic dysentery. It is possible there is a cholera outbreak,” he said
Cholera is an acute diarrhoeal infection caused by the bacterium Vibrio cholerae, usually transmitted through contaminated water or food. The disease can cause severe dehydration and death within hours if untreated.
Nigeria experiences recurrent cholera outbreaks, particularly during the rainy season with attendant flooding.
In 2026 alone, 67 cholera fatalities have already been recorded. The latest figures from the Nigeria Centre for Disease Control and Prevention, obtained by PUNCH Healthwise, show that cholera has infected 5,260 people and killed 67 others across 128 Local Government Areas in 33 states and the Federal Capital Territory as of May 31, 2026.
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