The first known epidemic of extensively drug-resistant typhoid is spreading through Pakistan, infecting at least 850 people in 14 districts since 2016, according to the National Institute of Health Islamabad.
The typhoid strain, resistant to five types of antibiotics, is expected to disseminate globally, replacing weaker strains where they are endemic. Experts have identified only one remaining oral antibiotic — azithromycin — to combat it; one more genetic mutation could make typhoid untreatable in some areas.
Researchers consider the epidemic an international clarion call for comprehensive prevention efforts. If vaccination campaigns and modern sanitation systems don’t outpace the pathogen, they anticipate a return to the pre-antibiotic era when mortality rates soared.
Four deaths have been reported so far, according to the National Institute of Health Islamabad. At least one travel-related case has been detected in the United Kingdom.
Genetic sequencing revealed that a common, aggressive MDR typhoid strain called H58 interacted with another bacteria, likely E. coli, and acquired from it an additional DNA molecule, called a plasmid, that coded for resistance to ceftriaxone.
The 1948 discovery of antibiotic treatment for typhoid plunged the infection’s fatality rate from almost one in four to just one in 100, triggering “an epic thrust-and-parry duel” between powerful drugs and “a wily bacterial foe’s stepwise acquisition of resistance to them,” wrote Dr. Myron M. Levine and Dr. Raphael Simon.
Doctors still prescribe an estimated 50 million doses of antibiotics for typhoid globally each year. In Karachi, the capital of Sindh province, antibiotic resistance is increasing by 30 percent each year, according to the W.H.O.; at that rate, all typhoid cases in the city will be resistant to multiple drugs by 2020.
Experts are also reinforcing hygiene habits for prevention: washing hands frequently, boiling drinking water and eating well-cooked foods. In the longer term, modern sanitation infrastructure is needed.
GAVI, The Vaccine Alliance, a public–private global health partnership working to increase access to immunization, has pledged $85 million to ensure that typhoid vaccines reach developing countries.
“It’s a global concern at this point,” said Dr. Eric Mintz, an epidemiologist at the Centers for Disease Control and Prevention. “Everything suggests this strain will survive well and spread easily — and acquiring resistance to azithromycin is only a matter of time.”