An ancient killer is re-emerging as a modern threat. A study warns the bacterium that causes typhoid fever is evolving extensive drug resistance, rapidly replacing non-resistant strains.
Scientists sequenced the genomes of nearly 3,500 strains from South Asia. They found extensively drug-resistant (XDR) Typhi is not only impervious to frontline antibiotics but also growing resistant to newer ones like fluoroquinolones and cephalosporins.
These strains are spreading globally. While most cases originate in South Asia, nearly 200 instances of international spread have been identified since 1990, reaching the UK, US, and Canada.
Currently, only one oral antibiotic, azithromycin, remains effective. However, mutations conferring resistance to azithromycin are now spreading, threatening the efficacy of all oral treatments. Untreated, up to 20% of typhoid cases can be fatal.
Experts urge expanding access to typhoid conjugate vaccines and investing in new antibiotic research to prevent a future health crisis.