Drug Resistant Typhoid Continues To Spread
Researchers working on one of the largest studies on infectious diseases in humans have warned that drug resistant Typhoid is continuing to spread rapidly across Asia and Africa.
The study undertaken by scientists at the Wellcome Trust Sanger Institute based at Hinxton in Cambridgeshire, involved sequencing the genomes of 1,832 samples of Salmonella typhoid bacteria (pictured) collected from 63 countries between 1992 and 2013. Nearly half of the samples analysed were from the H58 strain which has developed resistance to most common antibiotics.
Study author Kathryn Holt, said “Multi-drug resistant typhoid has been coming and going since the 1970’s and is caused by the bacteria picking up novel antimicrobial resistance genes, which are usually lost when we switch to a new drug. In H58, these genes are becoming a stable part of the genome, which means multiply antibiotic resistant typhoid is here to stay.”
The H58 strain is often resistant to the first-line antimicrobial medicines commonly used to treat the disease and is continuing to evolve as it spreads to new regions and populations. Typhoid affects up to 30 million people every year and if left untreated, can kill up to 20% of those infected. The US Centres for Disease Control and Prevention claims that the disease is responsible for 200,000 deaths worldwide every year. Up until now the cost of using of typhoid vaccines in developing countries where most cases occur has proved prohibitive.