LONDON: An outbreak of typhoid fever in Pakistan is being caused by an extensively drug resistant “superbug” strain, a sign that treatment options for the bacterial disease are running out, scientists said on Tuesday.

Researchers from Britain’s Wellcome Sanger Institute who analysed the genetics of the typhoid strain found it had mutated and acquired an extra piece of DNA to become resistant to multiple antibiotics.

An outbreak of drug-resistant typhoid that began in Hyderabad in Pakistan in November 2016 is still spreading, according to experts from Aga Khan University who worked with the Sanger team.

Official data on case numbers and deaths are not available, but local media reports say health authorities detected more than 800 cases of drug-resistant typhoid in Hyderabad alone in a 10-month period between 2016 and 2017.

The researcher found the bacterial strain causing the outbreak is now resistant to five antibiotics in total, more than seen in any outbreak before.

“This is the first time we have seen an outbreak of extensively drug-resistant typhoid,” said Elizabeth Klemm, who co-led the analysis work at the Sanger Institute.

“This outbreak was caused by a multidrug-resistant strain that had gone a step further and acquired an extra piece of DNA encoding additional genes for antibiotic resistance.”

Typhoid is a highly contagious infection caused by the Salmonella enterica serovar Typhi bacteria. It is contracted by consuming contaminated foods or drinks and symptoms include nausea, fever, abdominal pain and pink spots on the chest. Untreated, it can be fatal.

Published in Dawn, February 21st, 2018