Micro-organism surveillance has become more sophisticated, but detection is only one part of a successful health strategy
AMES, Iowa — Public health officials have sophisticated techniques to detect harmful organisms but it does not mean people will be healthier.
“We are changing our level of detection and we are changing what we are going to detect,” said Christine Petersen, director of the Centre of Emerging Infectious Diseases at Iowa State University.
“It means that we are going to find things connected that we have never seen before, which is wonderful, but perhaps terrifying at the same time,” she said at the recent National Institute of Animal Agriculture symposium on antibiotics held in Ames, Iowa.
Surveillance and detection of food-borne pathogens are improving so reported cases related to campylobacter and salmonella may be going down, but data is also examined differently so new things may show up, she said.
“If you start looking at it in other ways you are going to start finding more,” she said.
The concept in which the health of people, animals and the environment are connected is also aligned with disease detection.
She described cases where animals may have been connected to a serious case of salmonella poisoning and another where human error sickened people.
The first case was linked to Salmonella newport, a relatively new form of the bacteria that proved to be resistant to two different antibiotics: ciprofloxacin and azithromycin.
“They were trying to treat with the stuff that should work, but it didn’t,” she said.
Between June 2018 and March 2019 there were about 225 cases of this form of salmonella. More than 30 people were hospitalized and two died.
The source was traced to unpasteurized soft cheese from Mexico and a beef plant from Texas. The positive samples were closely related genetically. It was believed the strain was present in cattle from both countries.
“They think the strain both in Mexico and the United States is tied to macrolide use. This is a major antibiotic used in food animals,” she said.
There was no firm data to back up the assumption but if people had taken more care, they may have escaped serious illness.
“Because of human behaviour, we eat what we like and we don’t always follow the rules they taught us in eighth grade about how we should cook things. We as humans don’t always do a good job protecting ourselves from organisms that might be antibiotic resistant,” she said.
Another salmonella outbreak was linked to chicken salad sold in grocery stores throughout the Midwestern United States. The company pulled the product that was linked to preparation rather than the ingredients.
A recent unpublished study examined the environment of hospitals where privacy curtains were checked for disease-causing organisms.
These curtains are changed quarterly unless visibly soiled.
“That curtain is touched by everybody who has to touch the patient,” she said.
Doctors and nurses may wash their hands frequently to avoid spreading germs and areas may be scrubbed, but the bacteria are stubborn and persistent.
The study involved hanging fresh curtains with an antimicrobial product in them to reduce bacteria that might colonize on the curtains.
A graduate student collected samples every three or four days to see what was present. Even when extra sanitary measures were taken, the bacteria came back.
“It was terrifying how much grew on these curtains and how quickly,” she said.
“Places where sick people live are not sterile environments. It is very hard keep that environment clean,” she said.
“The pathogens adapt and they are smart and we have to keep fighting the battle….
“We are making strides but it is something we are not ever going to win. I think it is the same on the animal side.”
There is more disease and antibiotic resistance information on the human side of medicine compared to what is known on the animal side, said Dawn Sievert of the Center for Disease Control.
“We have a whole bunch of new data that we have never seen before,” she said.
Telling the public about the latest outbreak can be a communication problem. The public wants a specific answer and that may be elusive.
“People want to know what to do and want to hear more than wash your hands and cook your food properly,” said Sievert.
“We know way earlier and we know way more but we don’t want to say the sky is falling.”