By Ben Hirschler and Kate Kelland
LONDON (Reuters) - Superfast machines helped Chinese and German scientists decode the genes of Europe's deadly E.coli strain with astonishing speed -- but on the front line in the war with bacteria, old-fashioned detective work is what counts.
Finding the source of the infection that has killed 17 people will require laborious on-the-ground investigations by food safety and public health officials.
Armed only with fear, soap and water, consumers must watch and wait. And in the end, the answer may never be found.
Despite recent scientific breakthroughs, there is no sign we are anywhere near conquering the threat from bacteria like E.coli. In fact, some experts reckon just the opposite.
"Infectious diseases are very much this century's problem and they are going to become more and more so," said Stephen Smith, lecturer in clinical microbiology at Trinity College Dublin.
It's not that doctors and scientists are complacent about the risk posed by bacterial, viral and fungal infections. It's that our modern way of life -- global food trade, widespread travel and the growth of mega-cities -- gives new opportunities for bugs to evolve and thrive.
"We provide them with new niches, day after day ... they will always evolve and we can't stop that," Smith said.
As if to drive the point home, British scientists said on Friday they had found a new strain of the "superbug" MRSA in milk from cows and in swab samples from humans, raising concerns about infection across species.
Antibiotics are little use in the current E.coli outbreak, but the spread of antibiotic resistance and the lack of new drugs to fight novel strains is a growing concern.
"New bacteria and infections are just around the corner and we are far from winning the fight against infectious diseases in Europe," said Giuseppe Cornaglia, president of the European Society of Clinical Microbiology and Infectious Diseases.
This week the world marked the 30th anniversary of the first reported cases of HIV/AIDS, a disease that probably lay undetected for 80 years before being turbo-charged by global travel.
WHAT DID YOU EAT?
Modern gene sequencing machines, like those from Life Technologies Corp that were put to work this week in China and Germany, mean researchers can now unravel the genetic secrets of bacteria in record time.
Five years ago, the three-day job by the Beijing Genomics Institute would have taken months, according to Paul Hunter, a professor of public health at the University of East Anglia.
Such breakneck speed research provides valuable clues, since the E.coli type identified is known to stick to the surface of plant material, pointing strongly to vegetables or salad as the culprit. But this only gets investigators to first base.
"Despite all of the superb and valuable molecular stuff, the bottom line comes down to whether or not an environmental health officer can actually work out where someone got their lettuce from," Hunter said.
The forensic work on the ground in Germany will be lengthy and will only work if it is done properly.
"The trace-back should be comprehensive, from paddock to plate," said Robert Hall, senior research fellow at Monash University in Australia and an expert on communicable diseases.
First, investigators need to interview patients and work out what they have eaten in the two weeks or so before they got ill -- not an easy task, since many people struggle to remember with any accuracy what they ate two days ago.
Then the hunt will be on to find a common food type, a process that lies at the heart of disease detective work. Once there is a shortlist, microbiological testing should, in theory, nail the culprit.
"As time goes by it's quite plausible that the contamination event will just naturally die out anyway, and then it will get increasingly difficult to prove where it came from. I suspect we will end up with a situation where we will not be able to prove which farm or even which country was the cause," Hunter said.
(Editing by Sonya Hepinstall)