Infection rates from “nightmare” drug-resistant bacteria have skyrocketed in the United States, scientists warned this week.

Cases of patients infected with the gnarly bacteria rose an alarming 70% between 2019 and 2023, according to a new report from the Centers for Disease Control and Prevention scientists.

Difficult-to-treat bacteria with the “NDM gene” drove the sharp increase, researchers wrote in the report published Tuesday.

Only two antibiotics can treat the type of infection, and the expensive drugs must be administered to patients intravenously, researchers added.

Bacteria with the gene were once considered exotic and typically occurred in a small sample size of patients overseas.

Although the number of cases remains relatively small, infections across the nation have still jumped more than fivefold in recent years, according to the report.

“The rise of NDMs in the U.S. is a grave danger and very worrisome,” said David Weiss, an Emory University infectious diseases researcher, in an email.

It’s likely many people are unrecognized carriers of the drug-resistant bacteria, which could lead to community spread, Weiss added.

Patients who enter doctors’ offices for infections long considered routine and easy to treat — like urinary tract infections — could experience chronic problems if infected with the bacteria.

Antimicrobial resistance occurs when germs such as bacteria and fungi become powerful enough to fight the drugs designed to kill them, scientists said.

The misuse of antibiotics — such as not finishing a prescribed course of drugs or taking unnecessary prescriptions that don’t kill the germs — is also fueling the rise.

In recent years, the CDC has drawn attention to “nightmare bacteria” resistant to a wide range of antibiotics, including carbapenems, a class of antibiotics for last-resort serious infections.

Researchers counted 4,341 cases of carbapenem-resistant bacterial infections from 29 states in 2023, with 1,831 of them the NDM gene variety.

The researchers did not say how many of the infected people died.

The rate of carbapenem-resistant infections rose from just under 2 per 100,000 people in 2019 to more than 3 per 100,000 in 2023 — an increase of 69%.

The rate of NDM cases alone skyrocketed from around 0.25 to about 1.35 — a shocking increase of 460%, the authors said.

Antibiotic use during the COVID pandemic possibly added to the increase, according to an outside researcher.

“We know that there was a huge surge in antibiotic use during the pandemic, so this likely is reflected in increasing drug resistance,” said Dr. Jason Burnham, a Washington University researcher, in an email.

Despite the already shocking numbers, the CDC’s estimates are only a partial picture of the infection rates.

Many states do not fully test and report cases, and are often only testing hospital patients with serious infections.

Some hospitals aren’t capable of doing the appropriate testing to detect forms of genetic resistance in bacteria, scientists added.

The CDC researchers did not have data from some of the most populous states, including California, Florida, New York, and Texas, which means the total number of nationwide infections “is definitely underestimated,” Burnham said.

A CDC report in June also noted an increase in terrifying NDM cases in New York City between 2019 and 2024.

With Post wires.