At least 127 people have been infected — and 18 hospitalized — amid an outbreak of salmonella across dozens of states, according to the Centers for Disease Control and Prevention. Infections linked to the outbreak had been detected in 25 states as of Sept. 15, with Texas alone reporting 45 of the cases.

According to News Nation, Salmonella Oranienburg, the strain observed in this outbreak, began sickening people on Aug. 3, according to the CDC. By Sept. 2, a total of 20 infections had been linked to the outbreak, which grew “rapidly” in the following weeks, sickening at least 127. Of the 48 whose medical information was made available, 18 had been hospitalized.

The CDC estimates that the actual number of sick people is “likely much higher,” as many infected individuals often recover without seeking treatment or getting tested.

It can also take up to four weeks to determine if a sick person is indeed part of the outbreak, the agency says. The CDC has yet to identify a source linked to the outbreak, though public health officials are currently interviewing to try to determine a possible food item.

“Several groups of people (‘subclusters’) at restaurants in multiple states have been identified,” the CDC wrote of the outbreak. “These subclusters are groups of people who do not know one another who ate at the same restaurant and got sick. Investigating these subclusters can sometimes help identify a food item eaten by all of the sick people that could be the source of the outbreak.”