How is a salmonella infection detected?
A salmonella infection is usually diagnosed by a positive culture from a stool sample of the infected person. In more severe illnesses, salmonella bacteria can sometimes be detected in a contaminated person’s blood or urine. In most cases, doctors do not order a culture and simply treat the symptoms. Even when a culture is ordered, detection of salmonella can be very difficult. When examining each of these cultures, the laboratory technician is asked to pick out (under a microscope) salmonella bacteria from thousands of other bacteria which are normally present in the cultures. In addition, cultures taken from people who have already started a course of antibiotics are less likely to produce positive results, even if those persons are infected with salmonella bacteria. As a result, only about 3% of salmonella cases are officially detected and reported nationwide.
