Culture-independent diagnostic tests (CIDTs) are a boon, helping to identify infections from foodborne illness faster. Without a bacterial culture, CIDTs cut the time needed to diagnose to mere hours.
The CIDTs are making it easier to find cases that were not previously diagnosed, according to an MMWR report on findings from the CDC’s Foodborne Diseases Active Surveillance Network (FoodNet). In 2015, the percentage of foodborne infections diagnosed only by CIDT was “markedly higher”—about double, compared with the percentage in 2012-2014, the report says. For instance, the incidence of Cryptosporidium was significantly higher in 2015 than the average for the previous 3 years.
But without a bacterial culture, public health officials can’t get all the detailed information they need to track outbreaks and trends. The CDC is working with partners to develop advanced testing methods that, without culture, will still give the needed data for diagnosis as well as the preventive clues. In the short term, the CDC advises clinical laboratories to work with public health laboratories to make sure a culture is done whenever a CIDT indicates that someone with diarrheal illness has a bacterial infection.