In this interview with LARA ADEJORO, a Professor of Public Health at the University of Ilorin and Consultant Public Health Physician at the University of Ilorin Teaching Hospital, Kwara State, Prof Kayode Osagbemi discusses strategies for reducing cholera incidence

What is cholera and what are the trends in cholera outbreaks in Nigeria over the past decade?

Cholera is a bacterial infection that affects the gastrointestinal or digestive system. It is a disease caused by one of the microbes called the Vibrio cholerae but to the general public it is a bacterial infection. It is common all over the world but in places like the developed world, they don’t have cholera because it’s a disease related to poor environmental sanitation and inadequate water supply. It is more prevalent in the developing parts of the world, areas with high-density populations, and poor water supply, mainly Africa, India, and some other parts of the world that have population density with poor environmental sanitation. I don’t think we have had any major outbreak in Nigeria in the last decade but there have been pockets of the infection.

How does cholera spread and what factors contribute to its transmission?

Cholera spreads from person to person mainly through contaminated food and water. If somebody has cholera and he’s stooling or vomiting, then the product – either the vomitus or the stool gets in contact with the water and food, and somebody else ingests the contaminated food or water, then it can spread to that person. When you have a large number of people gathering together, and eating together, it’s easy to spread among them. Places with high population density, poor water supply, and poor environmental sanitation are factors that enhance the spread of cholera in various communities. It’s easy to spread among people who don’t wash their hands, or utensils or don’t cook their food properly. The first level of epidemiological control of cholera was because of water supply. The well somewhere in the olden days was contaminated and people fetching water from that well were getting infected. So, somebody studied and found out that people getting infected were coming from the same source. When they treated that well, they were able to control the infection.

What are the symptoms of cholera and how can they be distinguished from other diarrheal diseases? The common symptoms of cholera are diarrhoea and vomiting, with some fever, and abdominal pain. Young children below the age of six months rarely have cholera because they are still being breastfed, they are not likely to pick things and eat things that are contaminated. The major thing that distinguishes it is that the stool is very watery, we call it rice-water stool, frequent with abdominal pain, and then if people in the community are having the same problem, so we put everything together to say, this is a cholera outbreak.

How does climate change impact the prevalence and distribution in different regions in Nigeria?

The effect of climate change is there but to attribute cholera to climate change is not direct, maybe you can say indirect effect. If there’s a flood and the water is polluted, and there’s an introduction of cholera case within the environment, it can spread through contamination of water by flood water. But the important thing to mention here is that one of the major ways it spreads in any community is through poor water supply, poor sanitation, overcrowding, and flooding.

What roles do socio-economic factors play in the incidence of cholera in the country?

Socio-economic factors are related to poverty, and poverty is related to overcrowding. Overcrowding is related to water supply, and population density, so socio-economic is a major factor affecting transmission. It easily spread among the poor members of the public who live in overcrowded, low, and shanty areas. People with higher socio-economic status, probably have their water supply, or boreholes or treat their water. Poverty is a major way that any disease condition can spread, including cholera.

How effective are vaccination campaigns in mitigating the outbreak, and what are the challenges associated with vaccine distribution?

When there is an outbreak, we try to de-emphasise the use of vaccines because the vaccine is expensive. When you take the vaccine, the immunity it gives you will not be long enough, a maximum of one year. More importantly, when some people take the vaccine, they still drink the water they are not supposed to drink because they feel they have been protected; we call it a false sense of protection. So, it’s better to emphasise improving the water supply, educating people on drinking clean water, and washing their hands. Sometimes the vaccine is important for some reasons, let’s say people are going for a pilgrimage, and assuming there’s an outbreak in Nigeria before they travel, or in any country, we have to give them the vaccine because the vaccine will protect them during the period of their stay, and many of them don’t have immunity. But then, we focus on good water supply, and health education, rather than focusing on vaccines.

Who are the most vulnerable, and why are they at higher risk?

The vulnerable people are people who don’t have herd immunity. Herd immunity means the population exposure, developing body immunity towards the disease. The most vulnerable people are the people with less exposure to the vaccine, the disease, or the cholera bacterium. In places where they have been exposed to it, their bodies have developed some level of immunity and it’s not easy for it to spread there. So, the most vulnerable are people who don’t have water and sanitation, people who are poor, and people who don’t have immunity.

What strategies can Nigerians adopt to improve hygiene practices and reduce the spread?

The best form of community approach is awareness. Then, there should be adequate water supply and sanitation. People must keep up with hand-washing before eating, after eating, before going to the toilet, after going to the toilet; personal and environmental hygiene. If there’s a recorded outbreak in a community, it’s better to boil the water before drinking. It’s sometimes difficult to ask everybody to boil the water they want to drink, so, the first thing is the water should be clean, and don’t defecate into water bodies. The government needs to ensure we have a good water supply and municipal water treatment. During an outbreak, sometimes we add some chemicals, alum, and chlorine into household water. The important thing is to maintain personal and environmental hygiene, food premises must be tidy, boil your food before eating, and don’t consume fruits and vegetables without washing them.

Does alum and chlorine help to purify the water?

Alum, to some extent, cleans the water for some diseases that are not our focus now. Chlorine kills the bacterium of cholera sometimes, but that has to be done at the place where they are pumping the water to the community. At the household level, it’s difficult for us to tell you to add chlorine because of the quantity to add. So, it’s better to boil the water, and let it cool down before you drink.

What are the economic consequences of cholera outbreaks on communities and healthcare systems?

The consequences are panic, people will not move, and that affects the economic and trade movements. The money we are supposed to use to do other things for the country, then we may dedicate it to cholera. When people fall sick, they cannot go about their daily activities and it has socioeconomic effects. The worst economic impact is death because it affects society and the family.

What are the best practices for treatment and patient care?

The practices are personal, household, and community hygiene, stool, and water hygiene. When somebody comes with diarrhoea, vomiting, and so on, the household level must identify that the person is having frequent stool. So, you give water, salt, and sugar solution, which is the cholera rehydration therapy, you either add salt, or sugar to the water you give the person before you get the person to the treatment centre; if need be, at the hospital level, you now give infusion based on the condition of the patient. Normally when we talk of salt or sugar solution, people usually think it’s for children of five years and below who are having diarrhoea and vomiting. But the solution is also useful for adults, especially when they are losing body weight and electrolytes, so we also use it importantly when there is an outbreak of cholera.

What research initiatives are on the way, particularly in Nigeria, to better understand cholera epidemiology and improve outbreak response strategies?

The research works underway are to see how we can look at the things that are available to us immediately that can be used to treat somebody having diarrhoea and vomiting. We are doing research into the use of coconut water, the use of salt, and sugar solutions, and the use of supernatant of Garri, and how best you can use all of these in case we don’t have access to the hospital immediately. Other ongoing research includes community perceptions and how to develop more long-lasting vaccines, the vaccines we currently have everywhere are short-lived. Other are how we can develop long-lasting vaccines, what are the ways to improve water and sanitation. So, many research works are ongoing to a large extent if they are funded by the government or by whatever agency to ensure that we improve the management of cholera at the household level, community level, and hospital level.

What are the long-term health impacts on individuals who survive cholera, especially in Nigeria, and what support systems are in place for them?

Usually, the major problem with cholera is when somebody dies. So if the person dies, of course, that is the immediate end of that individual. But it can affect the whole family if they lose someone to cholera. The death of an individual has a major impact. How to reduce the impact is having good water and sanitation, mainly municipal and at individual levels.

What lessons can Nigeria learn from other countries that have successfully reduced cholera incidents, and how applicable are these lessons to the Nigerian context?

The only lesson we have to learn is to improve water and sanitation for everybody, then, we can cut cholera out forever. The major things about cholera are water and sanitation. And then, of course, individual, household, and community, hygiene. Wash your hands, eat some good, clean food, and wash your food; you are not likely to have cholera if you do all these. Water treatment and sanitation are important; those are the major ways to control cholera, not even the vaccine.

Is there anything you think the government needs to improve in curbing the spread of the outbreak?

The only thing the government can do to improve the strategies they have been doing is to improve water and sanitation. Let everybody have water and then add the treatment before pumping water, let us have post-chlorination. Let us have adequate chlorine control added at the water treatment plant. Let the government enable the environment to be clean to reduce the incidence of cholera nationwide.