Blog posts

The mystery of the typhoid toxin

Typhoid toxin

Dr Malick Gibani unravels the mystery behind the role of typhoid toxin in causing typhoid fever  – a disease that affects around 11 million people each year globally.

Salmonella Typhi is a fascinatingly complex bacterium. Whilst there are more than 2000 different (sero)types of Salmonella, there’s something special about Salmonella Typhi that sets it apart from the non-typhoidal Salmonella serovars. It causes different symptoms, the means of spread are different and the host it infects is different – specifically, Salmonella Typhi only causes disease in humans.

Understanding the mechanisms of how bacteria can cause disease is profoundly important for vaccine development. The Vi-antigen that forms the major component of injectable typhoid vaccines seems to have a key role in making the bacteria more virulent (hence the name). Vi-based vaccines have proven to be highly effective tools to prevent typhoid. (more…)

A smoke-free country: how will we get there?

The Government recently announced plans to create a smoke-free society by 2030 – Dr Nick Hopkinson outlines some of the steps towards achieving this ambition.

Tobacco smoking remains a huge public health issue. Although population smoking rates continue to fall – now down to 14.4% of adults – smoking is still responsible for around 100,000 deaths per year in the UK, and for around half the difference in life expectancy between rich and poor. Smoking rates are high in areas of deprivation, in people with mental health problems and among people who identify as LGBT.

The Government’s recent green paper, Advancing our health: prevention in the 2020’s, although in many areas light on detail, funding, delivery and ambition, does set out some important markers on smoking and some potentially interesting developments around funding tobacco control. (more…)

Why we need to protect children from junk food, alcohol and gambling ads

Dr Tim Chambers explains the damaging effects of marketing of unhealthy commodities on children’s health and what we can do to tackle the problem.

Unhealthy commodities such as junk food, alcohol, and gambling are leading causes of non-communicable diseases, mental illness, injury, and many social harms. The collective global health burden of diet– and alcohol-related diseases is estimated at five million deaths each year.  But what is the role of marketing of these unhealthy commodities in driving their growing consumption?

Unhealthy commodities marketing through the eyes of a child

Children’s exposure to unhealthy commodities marketing, regardless of the product, has an adverse impact on their health. For example, junk food marketing shapes children’s dietary preferences and alcohol marketing is positively associated with earlier onset drinking and the likelihood of engaging in hazardous drinking. Children are particularly susceptible to marketing as they are unable to fully comprehend the biases inherent in ads. But with the unprecedented access and engagement with different media, how much marketing for unhealthy commodities are children actually seeing on a daily basis? (more…)

An open letter to the participants of my Hepatitis C study

© Kotryna Zukauskaite

For World Hepatitis Day (28 July), Dr Philippa Pristerà shares an open letter to the people that she met and interviewed early last year as part of her research study exploring the experiences of people living with and accessing care for Hepatitis C, and their perspectives on cure.

Dear all,

I am writing to you because you took part in my interview-based study ‘Viewpoints from hepatitis C: accessing and experiencing cure’*. Some of you I met about a month before I gave birth to my daughter, others would have met my colleague Jane Bruton who kindly took over while I was on maternity leave. Since my return to work, I have spent my time reading over the interviews to see what key themes came through and would like to take this opportunity to update you.

I want to say thank you

Thank you for sharing your story; for sitting down with a complete stranger, a heavily pregnant one, to be interviewed about your life. To help me build the context around your experiences and better understand your story, you revealed a great deal about your expectations and your beliefs, your current and past behaviour and their consequences. I was struck by your openness, and so grateful for your trust. (more…)

Stop blaming PrEP for the rise in STIs – the picture is more complex than that


Rising rates of STIs has fuelled a debate about whether growing PrEP use might be propelling the STI epidemic. Oli Stevens and Charles Witzel argue why this narrative is misleading and damaging. 

The UK recently celebrated two landmark achievements in the ongoing fight against HIV. It is now the seventh country to reach the United Nations target of 90-90-90: that 90% of people living with HIV know their status, of whom 90% are on antiretroviral treatment, and of whom 90% are unable to transmit the virus to others.

Also, London became the first city in the world to achieve 95-95-95. These are remarkable achievements and are a testament to the tireless, collective work of doctors, activists, policymakers and civil society organisations.

Zeroing in on the progress made in reducing new HIV infections between men who have sex with men (MSM), particularly the nearly one-third decrease between 2015-2017, two likely contributors stand out: a scale-up in HIV testing, rapid progress to treatment and pre-exposure prophylaxis (PrEP).

PrEP, sometimes discussed in hushed terms as a potential means of ending HIV transmissions, is a pill taken once daily or around higher-risk sex that markedly reduces the risk of contracting HIV.

This recent success also invites us to take stock and reflect on our failures, the perhaps unexpected costs of progress and the emerging roadblocks on the horizon.

The decrease in HIV transmissions has not been matched with a decrease in sexually transmitted infections (STIs). Instead, new diagnoses have risen year-on-year. The causal factors fuelling this increase are complex, driven by social and political changes. (more…)

Providing medical care during a mission to Mars: science or fiction?

50 years on from the historic Apollo Moon landings, the race to Mars is on. With this in mind, Dr Matthieu Komorowski is examining how to provide medical care during long-flight space missions.

“The extension of life beyond Earth is the single most important thing we can do as a species” once said Elon Musk, the CEO of SpaceX.

Many other eminent minds have expressed a similar vision, including Stephen Hawking, Carl Sagan, Konstantin Tsiolkovsky, Buzz Aldrin and so on. They all argue that there are too many risks that can befall life on a single planet. As nicely put by Robert Heinlein: “The Earth is just too small and fragile a basket for the human race to keep all its eggs in.”

Could we possibly support such a bold idea ourselves? Is it more important to colonise Mars than to: improve our earthly existence, achieve equality and peace for all humans, protect our delicate environment, or cure diseases and world hunger? The argument is that these endeavours, as charitable as they are, all become meaningless if the following day life is wiped out from the face of the planet by a giant asteroid or a superbug. The long-term vision of space colonisation spans way beyond the blink of our existence and space advocates insist that in the long run, there are only two possible avenues: expansion into space or extinction! (more…)

LGBT and the sciences: where does our pride STEM from?

LGBT and the sciences: where does our Pride STEM from?

In celebration of LGBT STEM Day, Dr Akif Khawaja shares the small things everyone can do to make STEM more LGBT-inclusive.

With the glitter of the Mighty Hoopla weekend – a LGBT-friendly pop music festival – having finally settled, all eyes are now set on Pride. For many this will mean another (hopefully sunny) weekend of short shorts, tank tops and daytime drinking. In addition to the parade, especially in London, pride month is chock-a-block of events highlighting all aspects of LGBT+ culture and history. This year, Pride in STEM (Science, Technology, Engineering and Mathematics) has been helping to showcase and support LGBT+ people within the STEM fields by organising LGBT STEM Day.

So, what is Pride in STEM and what is LGBT STEM Day?

Starting with the easy one – Pride in STEM is a charitable trust run by an independent group of LGBT+ scientists and engineers. Founded in 2016, Pride in STEM was the brainchild of Dr Alfredo Carpineti, his husband Chris, and Matt Young. They aim to support all LGBT+ people spanning all of STEM and in doing so, raise their profiles and showcase their work. Now as for LGBT STEM day, this was their latest effort to promote the dissemination of work done by LGBT+ STEM staff. It falls on Friday 5 July 2019 (I’m told purposefully chosen as 507nm is the wavelength of the green stripe in the pride flag – 5.07 … get it?!) and the day before the Pride in London Parade. (more…)

Children with eczema: the link to food allergies is not clear cut

Food allergies eczema

Children’s allergy specialist, Dr Robert Boyle, unpicks the evidence behind the value of allergy tests for children with eczema.

Around one in five children have eczema – and even mild cases can have a big impact on both the child and their family. For many, symptoms will come and go before they start primary school, but for others it can indicate the beginning of a genetic tendency to develop allergic conditions such as hay fever or asthma (or both).

We also know that children with eczema are more likely to develop food allergies, especially if the condition starts in the first few months of life and is severe. Often parents will make the allergy diagnosis themselves – at the sudden onset of vomiting, diarrhoea or rash after eating scrambled egg, for example.

This can be frightening, but doctors can usually easily confirm the cause of these immediate reactions by talking to the parents and offering a confirmatory allergy blood or skin prick test.

In the absence of such obvious physical reactions however, a different question sometimes arises for parents: “Is a food allergy contributing to my child’s eczema and would an allergy test help to find out?” (more…)

There’s a whole world inside of you: a guide to microbiome research

Kate Gallagher provides an insight into microbiome research; a promising area of science that may pave the way for new treatments for a number of conditions ranging from inflammatory bowel disease to cancer.

You may be familiar with the age-old phrase, ‘you are what you eat’. Whilst I can assure readers that despite ingesting an inordinate amount of Reese’s pieces, you probably aren’t nuts, recent developments in research into the gut microbiome are beginning to tell us that the population of microbes inhabiting our gut may be much more powerful than we’ve previously given them credit for.

What is the microbiome?

The term microbiome refers to the additional set of genes arising from the diverse and unique array of microbes that have established themselves in a variety of habitats throughout our body. This is not to be confused with the term microbiota, simply referring to their names and quantities. These communities of bacteria, viruses, fungi and yeasts can be found in significant proportions in regions such as the gastrointestinal and reproductive tracts, your oral cavity, and skin. Overall, bacterial cells in our body match the number of human cells at a 1:1 ratio, meaning the microbiome has a significant contribution towards our genetic diversity, harnessing great potential to aid our understanding of a number of medical conditions targeted by decades of research. (more…)

Is mycoprotein an ideal food for managing blood sugar levels in Type 2 Diabetes?

For Diabetes Awareness Week, Anna Cherta-Murillo explains how mycoprotein, a food made of fungus, may hold the promise for managing blood sugar levels in Type 2 Diabetes.

If I were to ask you the first thing that comes to mind when you think of fungi, you would probably say mouldy walls, gone-off food, or athlete’s foot. The Fungi kingdom is often not viewed in a positive light. However, we owe a lot to fungi; they produce life-saving antibiotics, have allowed organ transplantations in humans and can recycle many types of waste. In the area of nutrition, some fungi also have the potential to affect human health in a beneficial way, although little research has been devoted to it compared to other foods. In the Nutrition Section of the Department of Medicine at Imperial, we are putting fungi into the limelight and studying the impact of a particular type of fungus on blood sugar levels and appetite in South Asian and European people with Type 2 Diabetes (T2D).

The problem

1 out of 20 people worldwide has T2D, with South Asians being more prone to the disease compared to Europeans (Figure 1). People with T2D have higher blood sugar levels than normal, which over time can increase the chances of developing long-term complications such as blindness, kidney disease and heart failure. It is therefore important to manage blood sugar levels in people with T2D in order to keep blood sugar in the normal range. The first-line strategy to achieve this is by improving dietary intake. Healthy, balanced diets are generally characterised as being high in dietary fibre and protein, which decrease both blood sugar levels and appetite. If blood sugar levels are reduced toward normal levels, the chances of having T2D-related complications are reduced. Likewise, if appetite is decreased, intake of energy-rich foods will likely also decrease, helping to reduce body weight, which is a key risk factor for T2D. However, an ongoing problem with healthy diets is that they are not suitable for all cultures and most of the research around them has been conducted in people of European origin, therefore not being applicable to South Asians. Furthermore, people often find it difficult to stick to these diets. (more…)