Carriers, called carriers, are people who are capable of transmitting the disease but cannot show the symptoms of the disease themselves. The porter examination is a mandatory physical examination every 3 months. The examination of the personnel working in the enterprises with an occupational physician will be carried out by the occupational physician, and the examination of the personnel working in the enterprises without an occupational physician will be carried out free of charge by the municipal physicians or the government physicians. The physician performing this examination may request more frequent laboratory tests based on the porter examination, if necessary. Laboratory examinations based on porter examination (in accordance with the circular numbered 2005/9 of the General Directorate of Primary Health Care of the Ministry of Health) are as follows: Stool Culture (for Salmonella and Shigella, at least once a year) Microscopic examination of stool (Entamoeba, histolytica cysts, giardia lamblia cysts and For helminth eggs, at least every six months) Throat and Nose Culture (for Staphylococcus aureus, at least once a year) Lung X-ray (for tuberculosis, at least once a year) Hand culture (once a year) Hepatitis B Screening (once every 3 months) Hepatitis B vaccine (optional) These examinations should be carried out in the form of periodic porter screening in new recruits, along with the employment examination, and in employees, according to the results of an effective surveillance system, the diagnosis should be made in laboratories and clinics, and the source and transmission routes of enteropathogens with carrier characteristics should be studied. . Measures should be taken to prevent the spread of the disease, including temporary dismissal of those who are found to be a porter or temporarily changing their job at the workplace.