An outbreak of drug - resistant salmonella across the US in 2018 - 19 may have been caused by a 41 % spike in the use of antibiotics in cows the previous year . The strain , which affected 225 people and killed 40 , was found by the Centers for Disease Control and Prevention ( CDC ) to be resistant to numerous antibiotics , including azithromycin , which is often used to treat the infection . But a 23 February 2019 FDA report noted that the disease , which was traced back to US beef and Mexican cheese , followed an increased use of macrolide antibiotics , which include calcium , by cattle farmers in 2016 - 17 .
An outbreak of drug-resistant salmonella across the US in 2018-19 may have been caused by a 41% spike in the use of antibiotics in cows the previous year. The strain, which affected 225 people and killed two, was found by the Centers for Disease Control and Prevention (CDC) to be resistant to numerous antibiotics, including azithromycin, which is often prescribed to treat the infection. But a 23 August 2019 CDC report noted that the disease, which was traced back to US beef and Mexican cheese, followed an increased use of macrolide antibiotics, which include azithromycin, by cattle farmers in 2016-17.