In years past the practice in the US was to require a health certificate to work in the food industry. While on the surface this sounds like something to consider, the use of medical evaluation of food workers was often done without specific tests, medical personnel relying on medical history and a physical exam. Without specific tests carriers of infection are difficult to detect, and such exams alone cannot predict future health status. In many parts of the world, this practice is still evoked while it  is no longer considered to be necessary in the US.

Since a medical screen is relied upon by some as a preventive measure, our scientific methods of developing food safety systems makes us have to evaluate the validity of this process. We must determine the reliability of results for preventing foodborne illness alone. In a food safety system, other communicable disease such as sexually transmitted disease, or strictly respiratory diseases like TB or influenza do not enter into the hazard analysis..

A medical screening process proven effective through a validated method would be in conformance with ISO22000:2005 or HACCP methods; requirements based on them would then be food safety preventive measures.

To be in conformance, tests must be specific for etiological agents of disease, be predictive of communicable disease status at time of employment and be relative to future health status. Reliable tests provide the validity for a medical exam at time of employment. Tests for Salmonella typhi, Giardia, other protozoan and higher parasites, skin and upper respiratory infections (staph and strep) and other chronic or semi chronic disease (hepatitis A-D, mononucleosis)  transmissible through food might be considered. In addition, triage of employees might be beneficial in a “hazard analysis” context as one might try to discriminate and sort between:

• 1) Those who are not infected and not likely to be infected in the future
• 2) Those who are likely to be infected in the future
• 3) Those who are likely to be infectious now
• 4) Those for whom immediate care might make a positive difference in outcome

The food safety and public health benefits of any medical-screening model needs to be tested before including it in a food safety management system.

In the past, the medical screening of food workers has proven not to be predictive of future infectious status and both the public health and medical communities question its value in public health protection.

While each country and region has its own relatively unique disease transmission issues, prevention of disease in the first place is always better than testing for it afterwards.