Drug-resistant typhoid spreading fast globally: Study

Multi-drug resistant strains of the bacteria that cause typhoid are spreading fast globally, especially in developing countries, says a new study.

The genomic study, with contributors from over two dozen countries, showed the current problem of antibiotic resistant typhoid is driven by a single clade, a family of typhoid bacteria called H58 that has now spread globally.

"H58 is an example of an emerging multiple drug resistant pathogen which is rapidly spreading around the world," said senior study author professor Gordon Dougan from the Wellcome Trust Sanger Institute in Britain.

"Typhoid affects around 30 million people each year and global surveillance at this scale is critical to address the ever increasing public health threat caused by multi-drug resistant typhoid in many developing countries around the world," study first author Vanessa Wong from Sanger Institute, pointed out.

The study showed the H58 clade of the bacterium Salmonella Typhi is displacing other typhoid fever strains that have been established over decades and centuries throughout the typhoid endemic world, completely transforming the genetic architecture of the disease.

Multi-drug resistant H58 has spread across Asia and Africa over the past 30 years, and created a previously under appreciated and ongoing epidemic through countries in eastern and southern Africa with important public health consequences, the researchers said.

Vaccination to prevent the disease is not currently in widespread use in these countries; instead the disease is controlled mainly through use of anti-microbial drugs.

"These results reinforce the message that bacteria do not obey international borders and any efforts to contain the spread of anti-microbial resistance must be globally coordinated,"  Stephen Baker, one of the study authors from The Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam, noted.The findings appeared in the journal Nature Genetics.