Systems for detecting and investigating outbreaks are poor
Researchers say that the European Union is not adequately prepared to deal with the outbreak of widescale epidemics such as flu or salmonella poisoning.
While an obvious bioterror attack with anthrax or smallpox would provoke a comprehensive response across the EU, they say, a more subtle attack using common illnesses might slip through the net.
Their research is detailed in the British Medical Journal.
'Critical weaknesses'
The researchers examined responses to five international outbreaks of diseases including influenza, legionnaires' disease and salmonella in several different European countries.
The results of the study also have implications for the threat of bio-warfare.
The team identified "critical weaknesses" in detection, co-ordination, funding and reporting.
In one country, the surveillance system failed to detect six out of 10 cases during an outbreak of potentially lethal legionnaires' disease and during an outbreak of meningococcal disease in another country, up to 10% of the cases were not reported.
Delays
Fewer than half the countries had sufficient plans in place to deal with a large-scale influenza outbreak, and there was no overall EU plan.
There were also delays in informing other countries about important events and a lack of clarity over how outbreaks involving several countries should be investigated and how such investigations should be funded.
Professor Julius Weinberg, a report co-author, told BBC Radio 4's Today programme that a disease like anthrax would be easy to detect.
"Something very unusual like anthrax we would note, we would find we would see it readily but a more normal organism might be missed.
'Under-reporting' problem
"Surveillance systems may not be adequately organised in order to detect them."
Prof Weinberg said there was "under-reporting" of these diseases.
"Microbiology labs don't always notify infections. There is inadequate discussion between countries."
He said the consultants in communicable diseases already working in the NHS needed to be kept better informed.
"Unlike a bomb, an infectious agent attack might be silent.
International trade
"I don't think it would be difficult for a determined organisation to do something untoward."
But he added: "Biological weapons are difficult to use effectively."
Prof Weinberg also said the rise in international trade and travel had led to concerns that outbreaks of infection involving more than one country would become more prevalent.
The report recommends that existing disease-related surveillance networks across Europe are further developed and improved using modern communication techniques.
It also states that legal and financial uncertainties surrounding various issues need to be clarified.