Drug Resistant Typhoid Causing an Epidemic in Africa

A drug-resistant typhoid strain which has epidemic proportion infections in Africa has health experts worried.

Researchers in UK recently sequenced the genome of close to 2,000 samples of Salmonella Typhi, the bacteria that causes typhoid, to find that half the infections in their samples were caused by a strain called H58. The strain made its way to Africa from South Asia through Middle East after originating three decades ago. H58 causes disease resistant to several antibiotics.

In the recent years, some African countries have seen infections double. In Malawi for instance, 782 cases of typhoid were reportedly recorded last year, up from the average 14 cases per year recoded during 1998-2012.

"People locally were noticing high typhoid rates, but they didn't realize it was a problem in lots of other countries. We were able to link all the dots together," said Vanessa Wong who identified the strain behind the epidemic.

Wong and her team found that drug resistant typhoid is prevalent in areas where older antibiotics like penicillin are in use. They suspect that overuse of drugs led to resistance. Alarmingly, the infection is also showing resistance to newer antibiotics including fluoroquinolones and azithromycin.

To combat the bacteria, researchers will have to determine why H58 is more prevalent than other strains.