How is Campylobacteriosis diagnosed?
Many kinds of infections can cause diarrhea and the other symptoms associated with campylobacteriosis. Doctors can look for bacterial causes of diarrhea by asking a laboratory to culture a sample of stool from an ill person. Microbiology laboratories now routinely perform culture procedures on stool specimens that are specifically designed to promote the growth and identification of Campylobacter jejuni and the other species of Campylobacter.
Many persons submit samples for culturing after they have started antibiotics, which may make it even more difficult for a lab to grow Campylobacter. Blood cultures are often not performed and in most cases the blood stream is not infected. These are some of the reasons Campylobacter infections are underdiagnosed and underreported (CDC estimates that the actual total number of Campylobacter cases is 38 times the number of reported cases).
Unfortunately, clinical laboratories often discard positive Campylobacter cultures from patients soon after diagnosis because they are not required to send the isolates to public health laboratories. This practice of throwing away cultures makes it difficult to identify and investigate outbreaks because public health laboratories are not able to conduct DNA fingerprinting studies to compare isolates from different patients and food samples. For this reason, the number of Campylobacter strains on CDC’s PulseNet is much lower compared with other foodborne pathogens such as E. coli O157:H7 and Salmonella.