Africa's cholera surge, and colliding galaxies
PodcastsThe Naked ScientistsAfrica's cholera surge, and colliding galaxiesPlus, the first gonorrhoea vaccine gets the green light. . . 06 June 2025In this edition of The Naked Scientists: African leaders hold. . .
PodcastsThe Naked ScientistsAfrica's cholera surge, and colliding galaxiesPlus, the first gonorrhoea vaccine gets the green light. . . 06 June 2025In this edition of The Naked Scientists: African leaders hold emergency talks about deadly outbreaks of cholera on the continent. But why is this happening, and what can be done to curb the threat? The James Webb Space Telescope breaks another cosmic record spotting the oldest galaxy ever seen, dating from just 280 million years after the Big Bang. We explore the hidden workings of our natural history museums: what did they decide not to display, and why?Cholera surge sparks emergency talks in AfricaBoghuma Titanji, Emory UniversityAfrican leaders have held a high-level emergency meeting to confront a deadly surge in cholera. Two-thirds of global cases, and 99 percent of deaths attributed to the waterborne disease, are now reported on the continent, and war-torn Sudan is currently said to be “on the brink" of a public health disaster. The World Health Organisation’s Tedros Adhanom Ghebreyesus has described the surge as a symptom of deep failures - in water, sanitation, health systems, and governance. He added that strong leadership, local vaccine production, and greater investment in hygiene and sanitation were all needed to tackle the crisis. Boghuma Titanji is an infectious diseases expert at Emory University. She is originally from Cameroon, which has itself experienced multiple cholera outbreaks in recent years, and explained a bit more about the disease, why this is happening, and what needs to change to turn the tide…Boghuma - Cholera is a life-threatening diarrhoeal illness, which is caused by a bacterium that we call Vibrio cholerae. It spreads through contaminated water or food, and once inside the body, the bacteria is able to release a toxin that can cause the intestines to secrete large amounts of fluid. And in some people, the most severe manifestations can lead to really severe diarrhoea and dehydration that can result in people dying just within a few hours of the disease manifestations. Chris - Where do most people get the infection from though? How do they pick it up?Boghuma - The bacteria that causes cholera is in the environment and in human faeces. So really, outbreaks happen in situations where the level of sanitation is poor and you may have large populations of people living in very close quarters, like in refugee camps, and not having access to sanitation to properly dispose of human faeces. And that contamination can lead to outbreaks of cholera occurring in these types of settings. Chris - A vicious cycle then, because once you've got it started, it comes in from the environment, gets into people, and then the people amplify it and you end up with an explosive outbreak, which is I guess what's happening at the moment. We're seeing this problem in Sudan, but wherever is affected. Boghuma - Absolutely. And I think that one of the things that have amplified the ongoing outbreaks are also the conflicts that are affecting a lot of regions, particularly on the African continent. You've mentioned the case of Sudan. We know that it's been weathering a civil war for the past year and a half, and there are lots of displaced populations in that setting. There's a collapse of the sanitation infrastructure, there are lots of refugees and there are refugee encampments where water and safe food supplies are not guaranteed. So essentially, these are the most optimal conditions for cholera to spread and really affect people in quite devastating manners. Chris - What's the best way to deal with people who have got it right at this second?Boghuma - The treatment for cholera really is providing oral rehydration salts and providing replacement of the fluids that are being lost through diarrhoea. When people die from cholera, they die because they are dehydrated. So a lot of the management procedures, one of the first things that we do is make sure we're providing people with sufficient rehydration that includes the salts and elements that they lose in copious diarrhoea. Sometimes when people are very severely ill with cholera, they're so weak that they cannot drink the oral rehydration salts. And in these instances, you have to provide them with that rehydration with IV fluids. Now you can imagine in a setting where there's a total collapse of the healthcare infrastructure, that being able to get an IV into someone and to give them IV fluids could be more challenging, such as some of the situations, examples I've mentioned, like Sudan, where we currently have a big outbreak. Chris - Prevention is always better than cure though. So what can we do to protect individuals, but also then do this on a bigger scale, population level interventions?Boghuma - I think it's very important to understand that cholera really is a disease of lack of infrastructure. There is absolutely a need for countries that are most impacted by cholera currently to really focus on providing clean water supplies to the populations and also educating people on proper ways of which to dispose of human faeces to reduce the chances of contamination. In some of the communities where you see outbreaks of cholera occur, people do not have latrines and ways in which to dispose adequately of human faecal material. And there's still a lot of open defecation, which can run off into streams where they get their water supplies from. And as you can imagine, that immediately leads to the cycle of outbreaks occurring in the rainy season, where the runoff is more likely to contaminate these water supplies, etc, etc. Chris - Water infrastructure though is notoriously long term. Water companies talk about taking decades to build reservoirs, putting in pipelines takes years. So we need a sort of near term solution. Are there any sort of things like vaccines that could be implemented or brought to bear in the near term to protect at-risk communities while we reinforce infrastructure, sewage treatment and water supplies and so on?Boghuma - Absolutely. There are currently authorised by the WHO, three oral vaccines that protect against cholera. And a lot of these vaccines provide a very good level of protection, about 80% protection against severe forms of the disease, which are actually the forms that result in death. And these vaccines have been used as a strategy to distribute in the context of outbreaks, particularly preemptively to protect populations that could be exposed to cholera when these outbreaks occur. Unfortunately, in recent years, there have been challenges regarding how much supply of vaccines is actually available to respond to these outbreaks. The manufacturers are few, and the demand is high. And the stockpile of the vaccine has actually run quite low, which means that although there are many countries facing cholera outbreaks, not everyone is able to access the vaccine as a tool to respond to these outbreaks. Chris - Ironic, isn't it, that over 100 years since water and cholera were first linked by John Snow in London, here we are in this era with more information, more knowledge and more resources at our fingertips in some places. And we're really seeing diseases like this causing major headaches for massive numbers of people. Boghuma - I think that it just goes to show that we can accumulate knowledge, we can have all the tools, but if we don't make the tools available to the communities that need it, and that are being impacted by a particular disease outbreak, then the tools don't really serve any purpose at all. And cholera is just the latest illustration. World's first gonorrhoea vaccine begins rolloutShamez Ladhani & Hamish Mohammed, UKHSAThe UK's National Health Service is rolling out a world-first vaccine programme to help tackle the problem of gonorrhoea. Rates of this bacterial infection have climbed worldwide at an alarming rate in recent years, and a high fraction of the infections are being caused by heavily drug-resistant strains of the microbe. It’s hoped the move, which will use the vaccine developed for the close relative of gonorrhoea, the meningococcus bacterium that causes meningitis, will prevent thousands of new cases over the next decade. Shamez Ladhani and Hamish Mohammed are at the UK Health Security Agency. Hamish explains first the scale of the issue confronting us…Hamish - The problem is gonorrhea, which is a sexually transmitted infection. It's spread through sexual contact. It's caused by infection with the bacterium Neisseria gonorrhea, and symptoms include painful urination and an abnormal genital discharge. But it's important to note that many people with gonorrhea may not have any symptoms. Now, symptoms of gonorrhea have been recognized for centuries in ancient Egyptian, Chinese, and Roman texts, as well as the Old Testament. It's a serious infection, and it could also result in a number of adverse clinical complications such as pelvic inflammatory disease, ectopic pregnancy, and infertility. Also, the bacteria that causes gonorrhea is really agile. It's developed resistance to every class of antibiotics used to treat it over the decades. So antibiotic resistance for gonorrhea is a globally recognised public health concern. Now, in England, we've been detecting record numbers of gonorrhea diagnoses in recent years, with over 85,000 diagnoses in 2023. And that 85,000 total is the highest annual number since records began a long time ago in 1918. Chris - What are you proposing? Apart from obviously monitoring, surveillance is really important to keep on top of these sorts of trends. But what are you proposing by way of intervention?Hamish - The reason why we're here today is about the fantastic opportunity that presents itself for a gonorrhea vaccination program in England to reduce gonorrhea risk. Chris - And Shamez, can you tell us what that intervention is and how it's proposed to work?Shamez - We've been trying to make a vaccine against gonorrhea for more than 100 years, and we have failed every time. And there isn't any vaccine out there that even looks promising. But about 12 years ago, a vaccine was licensed against meningitis and septicemia. Fortuitously, the meningococcus which causes meningitis and septicemia is very closely related genetically to the gonococcus, which causes gonorrhea. And other countries that have used this vaccine for teenagers and young adults have found that this vaccine also gives 40% protection against gonorrhea for at least four years, and more data are coming through. So even though the vaccine is not licensed against gonorrhea, we feel that because of the problems that we have at the moment with control of gonorrhea and antibiotic resistance, we should be implementing a vaccine that will help reduce the burden of disease, potentially transmission of the disease, and actually give the sexual health services a bit of a break by reducing the number of treatments and investigations that they have to do. Chris - You say that it reduces the risk of catching gonorrhea by 40%. Is there a chance though, that it could push some cases under the carpet and turn them into asymptomatic cases, so we miss them, the people don't even know they've got it, but they're nevertheless infected and could carry on passing it on?Shamez - It is possible. We need more data. But this is one of the fields that if you don't use a vaccine, we won't learn from it. We are going to be the first country in the world to offer the vaccines to groups that are at high risk of gonorrhea. And what we are hoping is by being at the front end, we will be able to monitor vaccines and infection rates. And that will teach us a lot more about the vaccines, not only how best to use them, but potentially to develop new generation vaccines based on the same vaccine technology so that we get better protection against gonorrhea. Chris - Hamish, do you know who those groups that Shamez is referring to are, who are at highest risk and therefore are your target for this intervention?Hamish - The gonorrhea vaccination programme will primarily focus on gay and bisexual men with markers of increased risk for gonorrhea, such as a recent bacterial STI infection. Bacterial STIs would include gonorrhea as well as syphilis. Now, the reason why this is the primary focus of the vaccination programme is because gay and bisexual men comprise less than 5% of the population, but they represent just under 50% of gonorrhea diagnoses each year. So while eligible gay and bisexual men will be offered the vaccine at sexual health services, clinicians at these services will have clinical discretion to offer the vaccine after an assessment of gonorrhea risk to other individuals as well. Chris - And Shamez, when will you know it's working?Shamez - We're hoping to have the first results within 12 months, because what we are hoping is that if we can demonstrate the same effect that they have seen in other populations, which is not the high risk populations, other countries will be tempted to offer the programme to their populations as well, and that way you can have a major impact. As you can imagine, many other countries have similar problems to us, and the rising problem of antibiotic resistance is a global one. So, we will try and get the data out as soon as possible so that other countries can use that information to make decisions for their own countries. I'm very optimistic we'll have results within 12 months of starting the programme.