Typhoid pathogens that are resistant to several groups of antibiotics have become more common since 2016 and are spreading internationally. A working group led by Kesia Esther da Silva of Stanford University came to this conclusion on the basis of a genetic analysis of thousands of samples of this bacterium. Salmonella enterica serovar typhi (WITH typhi). As the Lancet now states, resistance to important antibiotics such as ciprofloxacin and azithromycin has continued to emerge in South Asia and has spread through international travel between countries and continents.
Typhoid fever is most common in South Asia, where it accounts for about 70 percent of cases. To find out how antibiotic resistance is developing there, the team sequenced the genomes of 3,500 bacterial strains that infected people in India, Pakistan, Nepal and Bangladesh between 2014 and 2019. In addition, the team compared them to global typhus genomes to see if such dangerous tribes spread internationally.
WITH Typhi causes severe diarrheal diseases that kill more than 100,000 people a year. If you get them, antibiotics usually work well against the pathogen, at least for now. There is an effective vaccine against WITH Typhi, recommended by the World Health Organization only where antibiotic resistance is very common.
According to a working group survey, South Asia is a center for the development of resistance and also repeatedly exports potentially dangerous pathogens. New resistances have emerged almost 100 times independently against an important class of antibiotics known as fluoroquinologists. In addition, a salmonella strain known as XDR Typhi (extensive drug resistance) was detected in Pakistan in 2016, with a whole collection of resistance that has pushed out most other strains there in the meantime. Some XDR Typhi isolates can only be fought with the active substance azithromycin.