‘Superbug’ resistant to all treatments contracted in India claims victim in Nevada

17 Jan 2017

The rise of drug-resistant "superbug" bacteria have been a concern of public health officials for years, and now the US Centers for Disease Control and Prevention has reported a worse-case scenario - a woman with a bacterial infection that was resistant to all FDA-approved treatments.

A Nevada woman died in September after being infected with type of drug-resistant bacteria called Klebsiella pneumonaiae that was resistant to all antibiotics available in the US, the CDC reported on Friday.

The woman was in her 70's when she arrived at hospital in August 2016 with signs of sepsis. The findings could be of special concern to India as she had been in India years before and had been treated for a broken leg and bone infection, according to the CDC.

After doing tests, her doctors found the bacteria - which belonged to a class of drug-resistant bugs called carbapenem-resistant Enterobacteriaceae (CRE) - were resistant to all forms of FDA-approved antibiotics. The patient died in September after going into septic shock, according to the CDC.

The woman's extremely rare infection has focused attention on the increasing problems surrounding these drug-resistant infections and the lack of antibiotics available to treat them.

No matter how effective an antibiotic is at killing bacteria, new drugs will be needed as the bacteria mutate and grow more resistant to the existing drugs.

"Antibiotic resistance occurs as part of a natural evolution process, it can be significantly slowed but not stopped," the CDC notes on its website. "New antibiotics will always be needed to keep up with resistant bacteria as well as new diagnostic tests to track the development of resistance."

However, the number of drug applications for novel antibiotics being developed by pharmaceutical companies have been dropping steadily over the last three decades, according to the CDC.

From 1980 to 1984, there were nearly 20 FDA drug applications approved for new antibiotics, but from 2005 to 2009, there were fewer than five applications approved, according to the CDC.

In 2013, the CDC said developing new antibiotics and new diagnostic tests was one of its four core actions to stop antibiotic-resistant infections from increasing.

In 2013, CDC characterised CRE infections as an "urgent" threat, meaning the bacteria is an "immediate public health threat that requires urgent and aggressive action."

The bacteria cause 9,000 drug-resistant infections per year and 600 related deaths, according to the CDC.

While most drug-resistant CRE bacteria are still susceptible to one or more antibiotic, in the infection of the woman in her 70's reported by the CDC, the bacteria was resistant to all FDA-approved antibiotics, an extremely rare event.

CRE include common bacteria such as E.coli and Klebsiella bacteria.

When a patient has a drug-resistant bacteria, doctors will sometimes have to use harsher antibiotics or high dosages in order to try and fight the infection.

If a patient has a drug-resistant infection, doctors will work with a lab to test different doses of various antibiotics in an effort to overwhelm and kill the bacteria, said Dr William Schaffner, an infectious disease expert at Vanderbilt University Medical Center.

However, antibiotics can be taxing on the patient, especially if they are older and with underlying medical conditions.

"This is the kind of calculation you do with every patient," Schaffner said. "Patients with underlying illnesses present a certain kind of challenge."

The CDC authors reported that an intravenous version of an antibiotic called fosfomycin is available in other countries but not for use in the US. It's unclear if the patient's doctors attempted to get an FDA exemption to use the drug and treat the patient.

While this recently reported case is frightening, it is also unusual. The patient had been in and out of hospitals in India for two years after fracturing the large femur bone in her leg and developing a bone infection.

Long hospitals stays, especially in India, and exposure to different antibiotics can increase the likelihood of eventually developing a drug-resistant bacterial infection. As travel around the globe is becoming easier, it's increasingly important for doctors to find out where their patients may have acquired an infection, Schaffner said.

"India has a notorious reputation for this [type of bacteria,]" he noted. "Travel-related questions are becoming much more important ... and just reinforce that we are a very small world."