A study published in The Lancet has found that the bacteria that cause typhoid have become resistant to some of the most important antibiotics for human health.
The largest genome analysis of more than 7,500 Salmonella enterica serovar typhi, also known as S. typhi, revealed that resistant strains – almost all originated in South Asia – have spread to other countries nearly 200 times since 1990.
The study noted, “While multi-drug resistance to first-line antibiotics has generally decreased in South Asia, strains resistant to macrolides and quinolones – two of the most important antibiotics for human health – are rapidly increasing.” and have often spread to other countries,” the study said.
According to the World Health Organization (WHO), typhoid fever is a life-threatening systemic infection that is usually spread through consumption of contaminated food or water.
Typhoid is mainly caused by poor sanitation and lack of clean drinking water in both urban and rural conditions. Each year, an estimated 11–20 million people become ill with typhoid, and between 1.28 lakh and 1.61 lakh people die from it worldwide. Poor communities and vulnerable groups, including children, are most at risk.
It is most prevalent in South Asia, which accounts for 70% of the global disease burden.
Antibiotics can be used to successfully treat typhoid fever infections, but their effectiveness is threatened by the emergence of resistant S. typhi strains, the study stresses.
The study’s authors traced the presence of genes conferring resistance to macrolides and quinolones, which are among the most important antibiotics for human health.
Read also | Mosquito-Borne Disease: Is Typhoid More Dangerous Than Dengue?
For example, gene mutations conferring resistance to quinolones – a broad-spectrum antibiotic – have arisen. typhi accounted for more than 85% of quinolone-resistant strains in Bangladesh in the early 2000s, rising to over 95% in India, Pakistan and Nepal by 2010.
“Mutations causing resistance to azithromycin – a widely used macrolide antibiotic – have emerged at least seven times in the past 20 years.”
typhi strains resistant to third-generation cephalosporins, another class of antibiotics that are critically important to human health, the study said.
What did the study find?
The authors of the latest study performed whole-genome sequencing on 3,489 S. typhi isolates obtained from blood samples collected between 2014 and 2019 from people with confirmed cases of typhoid fever in Bangladesh, India, Nepal and Pakistan .
typhi samples isolated from more than 70 countries between 1905 and 2018 were also sequenced and included in the analysis, the study said. ,
Read also | Delay in treatment of Kovid due to typhoid in Bokaro, Jharkhand, death doubled in a month
Strains were classified as multi drug-resistant (MDR) if they contained genes conferring resistance to the classical front-line antibiotics ampicillin, chloramphenicol and trimethoprim/sulfamethoxazole.
For example: since 2000, MDR S. typhi has declined steadily in Bangladesh and India, and remains low (less than 5% of typhoid strains) in Nepal, although it has increased slightly in Pakistan. However, these are being replaced by strains resistant to other antibiotics.
The study’s lead author said, “The speed at which highly resistant strains of S. typhi have emerged and spread in recent years is a real cause for concern and calls for urgently expanding prevention measures, especially in countries at greatest risk.” highlights the need for Dr Jason Andrews of Stanford University (USA) said in a press release.
read all breaking news , today’s fresh news watch top videos And live TV Here.