Deadly salad bug causes crisis in Germany
A dangerous strain of E. coli has killed 22 people and made thousands seriously ill in Northern Germany. Highly aggressive, and resistant to common medicines, it has doctors worried.
Hospitals in Hamburg and Bremen are stretched to breaking point. Doctors are working round the clock, snatching brief moments of sleep on temporary cots outside the wards. Elderly physicians are being called out of retirement to cope with the crisis.
They're struggling to deal with one of Europe's worst disease outbreaks in years. A new strain of the E. coli bacterium, known as O104, has infected more than 2,000 people, causing crippling diarrhoea, kidney failure, and sometimes death.
E. coli infection spreads through contaminated food. As soon as cases started to emerge, health officials started looking for the source of the infection. Infected patients were known to have eaten at particular restaurants, and initially, salads were blamed for carrying the deadly bacterium.
Early theories traced the contamination back to cucumbers grown in Spain – which caused sales of Spanish vegetables to slump. Farmers couldn't find takers for their produce, even when they tried to give it away for free. Harvests are now rotting in Spanish fields and growers face financial losses of €200 million each week.
But tests are now being carried out on a farm in Germany, which may have supplied infected bean sprouts to restaurants. The infection is likely to have started with cattle droppings, although precise details are still unknown.
The worst of the outbreak is probably over – but the scare still has scientists worried.
Why? Because this E. coli strain has an unusual genetic trait which allows it to resist the antibiotics we use to cure infections. And if the idea of drug-resistant E. coli is bad, the longer-term significance is worse. It's now known that different species of bacteria can actually swap traits with each other. That means this resistance trait could spread to other bacterial diseases, making them even more dangerous.
Biological arms race
This outbreak is the latest skirmish in the old biological battle between humans and germs. It's a fight that, for a century, we've been dramatically winning. New drugs (like antibiotics), new hygiene practices (like washing hands) and widespread vaccinations have made us freer from disease than at any other time in human history.
But the germs are beginning to catch up. Drug resistant MRSA is spreading through hospitals. Tuberculosis, which had almost disappeared in the West, is making a comeback, with harder to kill strains. And this latest E. coli strain could pass its resistance on to a whole new generation of illnesses. Doctors and scientists will need to keep pushing medicine forwards because this is one fight we can't afford to lose.
- Being ill is horrible. But is it possible to betoocareful when it comes to infectious diseases? When does caution become paranoia?
- How does natural selection produce traits like antibiotic resistance? Can you think of any other examples of natural selection at work?
- Imagine you were sick withE. coli. Write a short poem or song to anE. colibacterium, telling it how you feel.
- There are some simple things everyone can do to reduce the chances of bacterial infection. Do some research to find out what they are and then design a poster with a few simple rules for everyone to follow.
Some People Say...
“Diseases are nature's way of controlling our population. We shouldn't fight them.”
What do you think?
Q & A
- How do bacteria become resistant to antibiotics?
- Through natural selection. If you expose a million bacteria to an antibiotic, a few will have some degree of resistance. Those resistant bacteria survive, breed, and pass their resistance on to their offspring. Gradually, the proportion of bacteria that are resistant to an antibiotic grows.
- So in fact, using antibiotics makes bacteria resistant to them?
- Exactly. And the problem now is that we're overusing them. Livestock farmers, for example, often keep animals on a constant drip of antibiotics in order to keep them healthy.
- And resistance can spread between germ species?
- Yes. Bacteria of different species can swap genes with each other at random. When a useful trait – like resistance – is transferred, it tends to stick and spread.
- Hamburg and Bremen
- – Two major cities in Northern Germany.
- E. coli
- – E. coli is a very common bacterial species. E. coli bacteria grow naturally in the digestive systems of humans and other animals and generally don't cause any problems. However, certain unusual sub-types, or strains of E. coli produce toxins and are extremely dangerous.
- – A bacterium (plural – 'bacteria') is a type of simple single-celled organism. Most are harmless but some have evolved to cause diseases in humans. Other disease causing organisms (or 'pathogens') include viruses and fungi.
- Genetic trait
- – The basic traits, or characteristics, of an organism are determined by its genes. When genetic material (DNA or RNA) is passed from one organism to another, traits are also transferred.
- – Antibiotics are chemicals that kill bacteria but are not so poisonous to living bodies that they can't be used as medicine. New antibiotics are still being discovered, but bacteria are constantly evolving to become resistant to them.
- – Vaccination is the practice of injecting a small amount of a disease into a person to train their immune system to resist larger doses. It is very effective against viral infections.