Rapidly evolving infections that resist antibiotics cost the US healthcare system more than $20bn annually, a figure that could triple if societal days and days spent in hospital are considered.

The staggering cost was revealed in a study led by the Alliance for the Prudent Use of Antibiotics (APUA) and Cook County Hospital, which measured the economic impact of antibiotic overuse and antibiotic-resistant infections (ARIs).

The study was conducted using information from 391 patients hospitalised in 2000, 188 of which had ARIs (13.5%). Experts determined the medical costs attributed to these ARIs to range from $18,588 to $29,069 per patient and the overall societal costs incurred at the hospital as a result of the ARIs to be between $10.7m and $15m.

Tufts University School of Medicine professor of medicine Dr Stuart Levy said that the results offer some good insight regarding just how much ARIs are costing the nation: not just in terms of dollars, but human life and suffering.

“As the enormous costs identified here are viewed on a national scale, it is clear that effectively addressing the issue of antimicrobial-resistant infection is an essential element for stemming the rising tide of healthcare costs in the US,” Levy said.

According to the project leaders, by using the data from the hospital used in the case, there would have been nearly 900,000 cases of ARIs across the US in 2000.

By applying the range of additional costs seen in the Cook County Hospital study, which ranged from between $18,588 to $29,069, nationally, the cost of healthcare would range between $16.6bn and $26bn.

Cook County (Stroger) Hospital Department of Emergency Medicine and lead study author said that even a 20% reduction in these infections would save between $3.2bn and $5.2bn a year and between 5.7 and 11.3 million additional days in hospital.

“Clearly, any discussion of healthcare reform must look at the cost of current clinical practice and the savings we could realise if we used antibiotics more prudently,” Roberts said.

One of the leading causes of antibiotic resistance is the misuse and overuse of antibiotics as bacteria become resistant to the medicines developed to treat and cure the infection they cause.