Identifying the source of an outbreak, working with regulatory agencies and industry to get food off the market and stopping people getting sick are “key issues”, he told us in an exclusive interview at the Global Food Safety Conference 2013 in Barcelona.
Dr Ian Williams, chief of the Outbreak Response and Prevention Branch (ORPB) at the National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), added that another issue is learning what caused the outbreak to stop it from happening again.
“During an outbreak investigation, especially outbreaks that we see today that are associated with these industrial contamination events, where we’ll have a few cases all over the country you need to have multiple states and agencies all trying to work together at the same time.
“So it becomes quite a bit of a challenge to make sure everyone is working on the same page, collecting the same information and moving it all forward.”
Industry can change a lot faster than regulatory agencies, so if they understand the public health importance of what foods are risky they can make changes in the context of food safety, he said.
“One of the things we’ve learned over the last several years by doing a number of these outbreak investigations are that sharing information, bringing it together to one central place has been an effective way to move us quickly down the road to try to identify the contaminated food.”
Williams helps coordinate the national network of epidemiologists and other public health officials who investigate outbreaks of foodborne, waterborne and other enteric illnesses in the US.
CDC’s part to play
The CDC’s role in an outbreak investigation is to identify the source and conduct surveillance for illness and co-ordinate public health response to figure out the cause.
People are always more willing to talk the sooner you get to them over the course of their illness, he added.
In regards to the reactive versus preventive debate which was a theme of the conference, he said: “At the end of the day we rely on people telling us what they ate, where they shopped and where they eat their food, so we go as fast as we can based on the people that we interview.”
He added that due to the strain on public health resources they aren’t as many people to do the interviews.
If there are only one or two cases in a jurisdiction, there is not a high priority from their perspective to do the interviews, so there is a balance that needs to be found, Williams explained.
One of the strengths of the CDC is identifying high risk food which leads to the interaction between public health and the regulatory agencies so different risk categories can be established, he said.
“One of the other things the public health side can do, is what’s called attribution, they basically can look over the course of all of the outbreaks to try and say which foods are causing the most illnesses and outbreaks so we can work with the regulatory agencies to make sure the appropriate actions have been taken.
“A great example of this is called juice HACCP, where going back about 15 years or so ago there were a number of outbreaks associated with raw unpasteurised juices,” Williams added.
“Because the outbreaks happened recurrently there was a big change in how working with industry and working with the regulatory agencies to say what changes can we make and the simple change they made was basically say there are no more raw unpasteurised juices except in very certain circumstances and basically the outbreaks went away.”