7 Apr 2015

From beer as preventative to modern-day bacteria, food safety is still on the agenda

World Health Day is marked today, with the World Health Organisation (WHO) highlighting the challenges and opportunities associated with food safety under the slogan "From farm to plate, make food safe." IGH Professors Sarah O'Brien and Paul Wigley take a look at how far the fight against food-borne disease has come.

On World Health Day in 2015 it is very sobering to reflect on the fact that nearly 600m people worldwide are still affected by food-borne disease each year and more than 350,000 people die from it. Children under five bear the brunt of this – accounting for over 40% of the global total – and Africa and South-East Asia are the worst affected continents.
Food-borne disease remains a major health problem in both developed and developing nations. The establishment of public and veterinary public health systems in many developed countries has eliminated many major diseases associated with food and water from countries such as the UK.
On the veterinary side great strides were made in eliminating Brucella from cattle in the UK but brucellosis is still a major problem globally – it’s the most common bacterial infection spread from animals to people worldwide. Pasteurising milk has eliminated the hazards of bovine tuberculosis, Brucella and Salmonella infections.
We also have clean drinking water and proper sanitation so we no longer have to rely on drinking beer as the safest way of quenching our thirst, as used to happen most notably in the 16th and 17th centuries. Traditional British beers contain hops, not just as a source of flavour, but originally because hops contained an anti-microbial compound that both preserved the beer and reduced the risk of anything nasty. “Small beer”, a phrase now used to describe something of little consequence, was the lower alcohol brew given to children.





Used to be safer to drink than water. Nicola, CC BY

Consumer power and ministerial resignations

We’ve seen an almost endless parade of food safety scares over the last 30 years or so from “mad cow disease” and Salmonella in eggs in the 1980s to Campylobacter in chickens today (the cause of some 280,000 cases of food poisoning each year).
The reasons for the apparent emergence of these diseases are often complex though both globalisation of the food industry and agricultural practice are major contributors.
Feeding insufficiently treated animal proteins back to livestock is thought to have led to the development of mad cow disease and its eventual transmission through the food chain which led to variant Creutzfeld-Jacob Disease in people. At the height of the scare at the end of the 1980s, John Gummer, the then environment secretary, faced widespread criticism when he fed his four-year-old daughter a beefburger in order to demonstrate they were safe to eat.
The emergence of Salmonella in eggs was related to the intensification of egg production, often with poor hygienic practice, in the 1960s and 1970s and the appearance of a specific type of Salmonella (Salmonella Enteritidis PT4) that was better able to infect the developing egg without causing disease in the hen itself. By the late 1980s there was a crisis culminating in then junior health minister Edwina Currie’s remarks that “most of the egg production in this country, sadly, is now affected with Salmonella". Media reaction to her statement forced her to resign her government post. Though pilloried at the time, in essence, Currie was right but her pronouncement threatened a multi-million pound industry.
Consumer pressure, however, won the day. Sales of eggs collapsed, compelling the egg industry to come up with a solution. Improved hygiene in egg production, coupled with vaccinating hens means that Salmonella has been virtually eliminated from commercial UK egg production and cases of Salmonella in people have plummeted as a result.

Campylobacter bacteria

Other food-borne diseases, however, continue to rise. In terms of sheer numbers Campylobacter is the most important. Campylobacter is most often linked with consumption of chicken meat and recent surveys by the Food Standards Agency have shown around 70% of UK chicken is contaminated with Campylobacter, though other food sources and the environment may also be sources of infection.




Campylobacter. Iqbal Osman, CC BY

Our work in Liverpool University on Campylobacter, together with colleagues from around the UK, uses an integrated approach, because we recognise that dealing effectively with food-borne infection requires the combined efforts of doctors, scientists, vets and the food industry. We also work together with the poultry industry to understand how and where Campylobacter enters the food chain.
We are looking at the biology of infection in the chicken to understand how it infects the animal and how we could develop controls such as vaccination. Recently we have been able to show there is a significant immune response to Campylobacter in the chicken gut, when previously it was thought just to sit there. But it’s not just the chicken – learning more about the genetics of the bacterium is also part of better understanding how it infects people and animals and how it survives in the animal and the environment, for example how weather and the seasons affect its ability to survive. It is beginning to look as if Campylobacter is much tougher than we thought.
Consumers are also part of the solution to the problem of food-borne illness and in particular this bacterium. Safe practices such as keeping clean and washing hands, separating cooked foods from raw and cooking food thoroughly all make a difference (particularly for the latter for dealing with Campylobacter).
As food production becomes more intensive around the world to meet the demand of a growing population and, in many countries, an increased demand for meat, then the risks of food-borne infection may intensify too. The WHO defines food security as being achieved “when all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life”. To do this, food provision must also accompany work to make food safe from infectious agents and other contaminants or adulterants.

Sarah O'Brien, University of Liverpool and Paul Wigley, University of Liverpool

This article was originally published on The Conversation. Read the original article.

2 Apr 2015

I'm trained and ready to help tackle Ebola in West Africa

Later this month PhD student Raquel Medialdea Carrera will head to Sierra Leone to assist with the international effort to contain the Ebola outbreak. Here she tells us about her decision to volunteer and the intense training she has had in readiness for the experience.

In August 2014 the World Health Organisation (WHO) declared that the spread of Ebola in West Africa was an international public health emergency. West Africa has suffered the worst Ebola outbreak in history with widespread and intense transmission in Guinea, Liberia and Sierra Leone. A few cases have also occurred in Nigeria, Senegal, the U.S. and Spain. Since December 2013, when the first Ebola case of this outbreak was identified in Guinea, more than 25,000 people have been infected and more than 9,600 have died. The number of cases is already decreasing, partly due to the increased awareness of the Ebola transmission pathways and government action, but mainly as a result of the impressive international co-ordinated response.

This outbreak represents a unique and amazing example of how international collaboration can help control the spread of a serious epidemic; thousands of volunteers have come together from all over the world to deliver humanitarian support. In April 2015 I will be deployed to West Africa to volunteer at a Public Health England Ebola Treatment Centre. I will be diagnosing Ebola for five weeks in Makeni (which is one of the largest cities in Sierra Leone) and deployed with the NGO International Medical Corps. Sierra Leone has been the most affected country by this Ebola outbreak with more than 11,400 people infected and around 3,500 deaths.

Working in the labs at the Institute of Infection and Global Health [Photo: Joel Redman]

My need to help

I decided to go to Sierra Leone as I felt a strong need to help with this emergency situation. As a scientist currently working on emerging zoonotic infections, I understand the severity of this outbreak and I realised that this is an incredible opportunity to use my professional skills and experience to help in this crisis. I feel very privileged to be able to contribute to the incredible, existing international and local efforts that have been made to control the spread of Ebola and I consider myself immensely lucky for being able to help diagnose patients with Ebola first-hand.

Most of my friends have asked if I am scared about working in Sierra Leone. However, for me, the scary thing was telling my family that I will be diagnosing the Ebola virus in the field. I understand the fears of my family as Spanish media coverage of the outbreak has often been extremely exaggerated and lacking in scientific evidence, especially after the first case of Ebola transmission outside of Africa occurred in Madrid. However, my family and friends understand my motivations and support my desire to help.

The Diagnostic Unit in Makeni where I will be volunteering. The inactivation of the Ebola virus is performed inside the isolators.

Training for West Africa

My excitement about being deployed to Sierra Leone further increased after my training, which took place in a mock laboratory in Porton Down (Public Health England). Here they have built an exact replica of the diagnostic units in Sierra Leone, including the same machines, instruments, protective equipment and even heaters - all designed to imitate the conditions and temperatures in West Africa.

During a very intense week, we not only learnt how to diagnose Ebola, but also how to manage the risks of working in an Ebola Treatment Centre laboratory; we were taught how to use personal protective equipment appropriately, how to respond to extremely hazardous situations and how to keep safe in Sierra Leone.

The training gave me a unique opportunity to get to know some other volunteers. Our group was made up of 13 wonderful professionals with a wide range of ages and professional experience represented. For example, there were postgraduate and postdoctoral researchers, professors from a wide range of highly prestigious UK universities, biomedical workers, hospital laboratory workers, biosafety experts and diagnostic workers from Public Health England. Although we were a very diverse group, I noticed we had a lot of things in common: a motivation for learning how to diagnose Ebola, enthusiasm for giving the best of ourselves and a desire to help deal with this outbreak using all our capacities.

With fellow volunteers at the pre-deployment training week

What to expect

My day to day work in Sierra Leone will consist of receiving blood, swabs and urine samples from patients suspected to have Ebola. Extreme safety measures need to be taken as some of these samples will be highly infectious. The samples are introduced into an isolator and tested for malaria before being inactivated with ethanol and extraction buffer.  Inactivation of the samples is then ensured by using heat, followed by the extraction of the viral genomic RNA. Finally, the samples are analysed by Polymerase Chain Reaction (PCR) which amplifies the nucleic acids from Ebola. And…voila! With a quick analysis of the PCR results it is possible to confirm if the patient has Ebola in just 3.5 to 5 hours!

Overall, the training was outstanding, my future laboratory mates seem like brilliant professionals and I feel much more prepared to help diagnose Ebola in West Africa. Moreover, and most importantly, I am really excited as I know that very shortly I will have one of the most rewarding and life changing experiences of my life.

Street Sign in West Africa. (AFP/GETTY IMAGE)

Interesting facts

  • Detergent (such as Fairy) is able to kill the Ebola virus.
  • The first Ebola-Like Virus found in Europe was identified for the first time 4 years ago in Spain and is called Lloviu Cuevavirus. To be more precise, it was initially found in some bats that were living in a cave where I have been several times before as it is located just 11 km away from my home town of Gij√≥n! However, do not panic as this virus seems to be non-pathogenic for humans (yet).


Raquel Medialdea Carrera is an MRes-PhD Student in the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections at the University of Liverpool.
The Institute of Infection and Global Health. Powered by Blogger.