Epidemiology of ESBLs and Carbapenemases

The epidemiology of extended-spectrum beta-lactamases and carbapenemases can be very complex. However, there are some basic points to highlight from a biologic and geographic perspective. Regarding extended-spectrum beta-lactamases, it’s worth noting that enzymes belonging to the CTX-M families are the most widely disseminated ESBLs. The prevalence of ESBLs, both CTX-M, as well as other types, varies within patient populations, meaning between those who have disease onset in the community compared to those who have disease onset in the hospital, and also geographically. This table shows the prevalence rates of ESBLs among E. coli and Klebsiella pneumonia isolates by country or region. The highest prevalence rates are seen in India where they can be well above 80%, whilst in China they are above 60%.

Rates as high as 30% are seen in East and Southeast Asia, Latin America, and Southern Europe, whilst in Australasia, Northern Europe, and North America these rates range between 5% and 10%.

Regarding carbapenemases, it’s important to highlight that they are a biochemically diverse group which includes members of Ambler’s class A, B, and C. Reports of its dissemination are increasing worldwide, but they still have distinct geographic niches, which we will now review. In the case of KPC these enzymes are endemic to the United States, Colombia, Brazil, Italy, Greece and Israel. Whilst NDM type of Metallo-beta-lactamases are frequently encountered in the Indian subcontinent and are also endemic in the Balkan states. The newest threat which is posed by the OXA-48 type of enzymes started in Turkey, where it is now epidemic. And it has quickly spread through Northern Africa and also the Middle East.