Climate Change and Increased Outbreak of Diseases

Bennett Oghifo

After the devastating floods of 2022 in Nigeria, largely blamed on climate change, the Nigeria Centre for Disease Control and Prevention (NCDC) confirmed over 2,000 cases of cholera in 31 states, including not less than 600 deaths.

Prior to October, NCDC said a total of 2,187 confirmed cases of cholera have been reported from 31 states and 233 deaths recorded from the 1st of January to the 25th of September 2022.

The NCDC, however, did not give the number of people affected by diseases or fatalities caused by the October 2022 floods.

But last year, the International Rescue Committee (IRC) said the deadly October 2022 floods in Nigeria, killed over 600 people and displaced 1 million more, and led to a major increase in cholera cases and other preventable diseases. 

The IRC said it has been working in Nigeria since 2012, providing life saving support to communities in Nigeria affected by natural disasters, armed conflict and other poverty related issues.

Babatunde Anthony Ojei Nigeria Country Director at the IRC, said, “Nigeria has not seen flooding like this in more than a decade. At least 13 local government areas experienced a deadly cholera outbreak with more than 6,000 cases and a 4-5% case fatality ratio. The IRC needs more resources to scale up our health work to treat cholera patients and our water and sanitation programming to help us stop the spread.

“Having contributed less than 1% of the world’s global emissions, yet ranked in the bottom 20% of countries equipped to respond to the impacts of climate change, Nigeria is increasingly bearing the brunt of a crisis it did not cause. More frequent droughts and flooding coupled with a global economic crisis has led to increasing food insecurity. More than 1 million children in the northeast are expected to suffer from acute food insecurity this (2022) year, making them more susceptible to succumbing to diseases like cholera. The world, especially the countries contributing the most to climate change, must step up and help countries suffering its consequences.”

The outbreak of these diseases can be blamed on the flooding events which are consequences of global warming/climate change, said Dr. Emmanuel Edward, Chairman, Association of Public Health Physicians, Akwa Ibom State chapter, South-south Nigeria.

He stated this during my interview with him today, explaining that “scientists have determined that the extreme weather events experienced globally, including the massive flooding in Nigeria last year, are caused by climate change.”

He said the flood water interacts with preexisting poor sanitation on ground in most communities. “The flooding comes and interacts with existing poor behavioral practices that we are having within our context here where people dump refuse and faeces in water channels. So, if you have flooding occurring in this instance it is also likely that there will be an outbreak of diseases like cholera and diarrhea. This is exactly what we can actually point at that is happening in many parts of the country.

“In the north of Nigeria, however, we are having cholera not because of flooding but as a result of the scarcity of clean water to drink.”

He talked about other emergencies that occur during flooding such as the invasion of homes by wild animals like snakes in their bid to escape the devastation of their habitat. They end up biting people who may die eventually because of the absence of anti venom.

He said, “Climate change is playing its own subtle part. It may not be as overt as some people want to see, since they still don’t believe that it is global warming that is responsible.”

On the trends of these diseases in the past and now, he said, “I may not have the statistics, but I know that Nigeria is an endemic country to cholera and we end up having epidemic episodes in certain parts of the country, especially in the northern part of the country. Most of the outbreaks have resulted in mortalities and increasing mortalities.

“It has been proven over time that we have been having increasing cases of cholera each year.”

Another expert, Dr Deborah Enoabasi Anwana, who teaches Ecology at the University of Uyo, said, “Climate change, like science, is speculative in the sense that things have to be proven beyond reasonable doubt. 

“Perhaps some health practitioners will just tell you right away that there’s no linkage or connectivity between climate change and rising health issues, particularly what you’re talking about – faecal oral diseases- cholera. 

“But then, when you look at developing countries in the tropics, such as Nigeria, there are certain indices that show clearly that there’s a likelihood that there’s a connection between rising health issues and climate change. 

“Now, let’s take our minds back to last year’s flood in Nigeria. You’ll give credence to NIMET, because it has already forewarned that there will be severe flooding in most of the states, particularly the coastal states. 

“But of course it’s another ball game to talk about preparedness and response. You and I know that we were not ready for what happened last year. But then, when you look at our communities, and our cultural inclinations, you’ll see that some of the things we are doing do not take cognisance of the rise in sea level.”

She gave an example with Bayelsa State, a coastal state in South-south Nigeria that was underwater for over a month. “When you go to Bayelsa, it’s about 70% covered with water- it’s a place that I worked as a project officer more than 20 years ago – you will notice that they do not have sanitary toilets, they defecate in containers and throw the waste into the wetlands. This is a place where clean water for drinking is scarce and most people drink from the river.”

Anwana said she visited Bayelsa in 2022, after the flood, saying as expected, all the faecal wastes thrown into the wetlands and from the pit latrines were washed into the communities. “Of course it will enter their available drinking wells and the river they drink from. They’ll definitely have escalated incidences of cholera. So, that’s the connection. Climate change has brought increased health issues. The sanitary facilities and water are not there and then the perception and attitude of people have not changed, there’s bound to be an escalation in the incidences of cholera and other health issues.”

Contributing their expert opinions on climate change and disease outbreaks, were Professor Abiodun Olusola Salami, Department of Crop Production and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ile-Ife, Dr. Temitope Oluwaseun Ojo, Department of Agricultural Economics, Obafemi Awolowo University, Ile-Ife, Dr. Olayinka Afolakemi Adeagbo, Institute for Entrepreneurship and Development Studies, Obafemi Awolowo University, Ile-Ife.

On climate change and disease outbreak, these experts in their joint statement, said: “There are numerous direct and indirect ways that climate change impacts human health. For instance, rising sea levels, higher temperatures, and more frequent storms all have a significant impact on human health in terms of illness and injury (Ayoade, 2004). 

“Global warming causes the sea and ocean levels to rise during the rainy season. Flooding may therefore occur, increasing the poor’s susceptibility to diseases including malaria, typhoid, cholera, and pneumonia. Changes in temperature and rainfall patterns could spread disease vectors including dengue, malaria, and diarrheal diseases more widely (Haines et al., 2006). People who experience urban flooding may develop mental illnesses and spread disease. Diseases are frequently brought on by Nigeria’s harsh weather, particularly in the northern section of the country (More, 1992). Heavy rains can generate stagnant water, which in turn promotes mosquitoes that spread malaria to nearby residents. Although difficult to define, the indirect effects may include disease-carrying vectors, elevated psychological stress and sadness, and a sense of isolation among those who have been displaced by natural disasters (Olorunfemi and Adeyemi, 1994). When temperatures are high, there is a tendency for increased illnesses like meningitis, measles, and chicken pox, to name just a few. Extreme weather events can accelerate the spread of pests and diseases (More, 1992, Olorunfemi and Adeyemi, 1994). The asthma information guide.com concurred in 2000 that environmental factors, including temperature, had a greater impact on asthma attacks than do weather-related factors.” 

They said, “Deaths and illnesses brought on by temperature extremes and injuries from floods and storms are examples of direct attacks. Indirect attacks include an increase in other infectious diseases and more prevalent vector-borne infections Effects of air pollution on the lungs inadequate nutrition as a result of disruptions to agriculture ill health brought on by migration and societal upheaval (More, 1992).

By 2100, it is predicted that average worldwide temperatures would have increased by 1.0 to 3.5 degrees Celsius, increasing the risk of several vector-borne diseases. The biology and ecology of vectors and intermediate hosts, as well as the likelihood of disease transmission, will be impacted by the temporal and spatial changes in temperature, precipitation, and humidity that are anticipated to take place under various climate change scenarios. Arthropods can regulate their internal temperature by altering their behavior, but physiologically they are unable to do so, making them physiologically dependent on the climate for their life and development, which raises the risk (4). Regional analyses are necessary since social economics, vector ecology, and climate vary from one continent to the next. At the extremes of the temperature range where transmission occurs, climate change is anticipated to have the biggest impact on transmission. These are typically between 14 and 18 oC at the lower end and 35 to 40 oC at the top end for many disorders. Warming in the lower range has a considerable and non-linear impact on the extrinsic incubation period (5), and consequently disease transmission, while, at the upper end, transmission could cease. However, despite a decrease in the vector survival rate, at about 30-32oC, vectorial capacity can significantly rise due to a reduction in the extrinsic incubation period. The majority of vector-borne diseases are spread by mosquito species such the Anopheles gambiae complex, Anopheles funestus, Anopheles darlingi, Culex quinquefasciatus, and Aedes aegypti, which are susceptible to temperature fluctuations both as adults and as immature stages in aquatic environments.

“The susceptibility of populations to climate change will depend on elements like social economy, health-seeking behavior, geography, and population increase. For instance, many of the nations affected by highland malaria, with the exception of South Africa, include Ethiopia, Kenya, Madagascar, Rwanda, Uganda, the United Republic of Tanzania, and Zimbabwe. Their per capita GDPs range from US$106.8 to US$505.5, and many of them are experiencing negative income growth. This can point to a lack of institutional and personal investment in health. Furthermore, many regions of the world have found chloroquine to be ineffective, especially when treating falciparum malaria, despite it being the cornerstone of malaria treatment for many years. Although there are alternatives to chloroquine, they are frequently less safe and 50–700% more expensive. More than 60% of malaria cases are treated at home in many of the poorer nations, which is now expected to lead to treatment failures due to medication resistance, especially among non-immune people.”

According to a former Spokesman of the Nigerian Conservation Foundation, Mr. Paddy Ezeala, “Climate is made up of ecosystems that interact. Natural environment is intertwined. For instance, if trees are removed from a particular place, rivers or streams closeby will dry up eventually, there will be erosion and other things will happen and these are caused by human activities that disturbed that particular environment.

“Climate change itself is a consequence of that interaction that has not been well managed and this triggers other ugly events, including outbreak of diseases.”

On the flooding that occurred in 2022, Ezeala said, “Climate change was obviously one of the elements that caused it. Whenever there is flooding, there is always a warning about the outbreak of diseases, because a lot of things can go wrong. For instance, many things, including biodegradable ones will be washed into the river, including dead humans and animals and the river is polluted. The air will also be polluted, and because the river is the main source of drinking water for some people, it causes cholera and other waterborne diseases.”

Giving statistic of cholera outbreaks in the past and now, the Nigeria Centre for Disease Control and Prevention, “In Nigeria, cholera is an endemic and seasonal disease, occurring annually mostly during the rainy season and more often in areas with poor sanitation, with the first series of cholera outbreaks reported between 1970 and 1990. Major epidemics also occurred in 1992, 1995-1996, and 1997. The Federal Ministry of Health reported 37,289 cases and 1,434 deaths between January and October 2010, while a total of 22,797 cases of cholera with 728 deaths and case-fatality rate of 3.2% were recorded in 2011. Outbreaks were also recorded in 2018 with the Nigeria Centre for Disease Control (NCDC) reporting 42,466 suspected cases including 830 deaths with a case fatality rate of 1.95% from 20 out of 36 States from the beginning of 2018 to October 2018.”