The KPC superbug is a highly drug resistant K. pneumoniae bacteria, which is the cause of Klebsiella pneumonia. The main drugs that it is resistant to are the carbapenems. This has given rise to the KPC initials. This bacteria inflames the lungs and can produce a thick, bloody, mucoid sputum. The bacteria typically leak from the mouth, nose and throat area into the lower respiratory tract.
While the bacteria is often benign elsewhere it becomes destructive in these other areas of the body. People with a weakened immune system are often vulnerable with middle-aged and older men among the main sufferers. Men with impaired respiratory host defenses, including persons with diabetes, alcoholism, malignancy, liver disease, Chronic obstructive pulmonary diseases (COPD), glucocorticoid therapy, renal failure, and those in certain jobs (such as paper mill workers) are particularly prone but people can also contract the infections as hospital cross infections.
Klebsiella bacteria outside the hospital also causes pneumonia, sometimes in the form of bronchopneumonia or bronchitis. These patients may develop lung abscess, cavitation, empyema, and pleural adhesions. The death rate for this type of infection is often 50% even with aggressive antimicrobial therapy.
Klebsiella may cause infections in the urinary tract, lower biliary tract, and surgical wound sites. If a person has an invasive device in their body then they may also be at risk. Contamination of the device becomes a risk; for example respiratory support equipment and urinary catheters put patients at increased risk.
Infection with carbapenem-resistant strains is emerging in health-care settings. One of many carbapenem-resistant Enterobacteriaceae (CRE) is Carbapenem-Resistant Klebsiella pneumoniae (CRKP) also known as KPC. In the USA, it was noted in North Carolina in 1996. It has now been identified in 41 states.
The genetic source of the drug resistance is the blakpc enzyme. It is carried on a mobile piece of genetic material which can transfer to other bacteria and people more easily. Some of these can be still be treated with carbapenems but they can ‘creep’ into a hospital setting and infect many while not doing to much damage to the carrier.
Death rates due to KPC are thought to range from 12.5% to as high as 44%.