Even as U.S. officials are tracing the source of a multistate outbreak of salmonella poisoning that has sickened more than 70 people and killed at least one person, there’s more bad news on the food-borne illness front.
In a new study published Wednesday in the Journal of Infectious Diseases, French researchers identified the emergence of a strain of the salmonella bacteria that is highly resistant to ciprofloxacin — the main antibiotic used to treat salmonella poisoning.
The researchers, led by Dr. Francois-Xavier Weill and Simon Le Hello of France’s Pasteur Institute, studied information from disease surveillance systems in France, England and Wales, Denmark and the U.S. They found that a multidrug-resistant strain of salmonella called S. Kentucky had infected nearly 500 patients in those countries between 2000 and 2008.
The strain was also isolated from chickens and turkeys from Ethiopia, Morocco and Nigeria, which could mean that poultry is an agent for infection. That discovery also raises concerns that the common use of some antibiotics in some poultry production could be contributing to the rise of drug-resistant strains.
The researchers theorize that the strain first emerged in Egypt in the 1990s, but they believe that it has now established itself in parts of Europe.
In a statement accompanying the study, Le Hello underscored the need for the global health system to get a grip on drug-resistant salmonella, before it becomes common:
We hope that this publication might stir awareness among national and international health, food and agricultural authorities so that they take the necessary measures to control and stop the dissemination of this strain before it spreads globally, as did another multidrug-resistant strain of Salmonella, Typhimurium DT104, starting in the 1990s.
The authors note that the 489 cases they’ve uncovered are almost certainly an underestimate, because not every country is looking hard for resistant strains. And that’s the problem. As the confused response to Europe’s devastating E. coli outbreak earlier this summer shows, there’s significant disparity in how different countries monitor and respond to food-borne illnesses, which can allow pathogens to escape notice — until its too late.
In an accompanying editorial, Craig Hedberg of the University of Minnesota’s School of Public Health argues that in a world where our defenses against disease are only as strong as our weakest link, we need to devote the resources needed for a truly international system of public health surveillance:
As highlighted by the effort required to look across four well-developed national Salmonella surveillance systems, there will be considerable challenges to effectively integrate public health, animal and food surveillance at national and international levels. However, given the medical costs and public health impact associated with the spread of multidrug-resistant organisms, the potential benefits of such a system should far outweigh its costs.
Unfortunately in the U.S., at least, worries over the public debt have trumped any worries about public health, even though some 3,000 Americans die each year from food-borne illnesses. Our health system is hard pressed to protect us against conventional microbes — let alone a few superbugs.