'Ancient Killer' Typhoid Rapidly Gaining Antibiotic Resistance, Scientists Warn

Typhoid fever, a disease that has plagued humanity for centuries, is once again raising global alarm. Though rarely seen as a major threat in developed countries, health experts say the bacterium behind the illness is rapidly developing resistance to antibiotics, leaving doctors with shrinking treatment options in 2026.

Typhoid is caused by Salmonella enterica serovar Typhi (S Typhi) and spreads through contaminated food and water.

Antibiotics remain the only effective treatment. However, a landmark 2022 study published in The Lancet Microbe found that extensively drug-resistant (XDR) strains are increasingly replacing non-resistant ones.

Dr Vijayalaxmi Mogasale,  Joint PhD Candidate at the London School of Hygiene & Tropical Medicine and Nagasaki University said: "Drug-resistant typhoid fever remains a serious public-health threat in India, with implications beyond national borders. Tackling this problem does not lie solely in moving to newer antibiotics, but calls for timely preventive action, including responsible antibiotic use and the introduction of the typhoid vaccine into the national immunisation programme, prioritising high-burden age groups and regions."

Resistant Strains Spreading Globally

Researchers analysed 3,489 samples collected between 2014 and 2019 from Nepal, Bangladesh, Pakistan and India. They identified a sharp rise in XDR Typhi strains resistant to older frontline drugs such as ampicillin and chloramphenicol, as well as newer antibiotics including fluoroquinolones and third-generation cephalosporins.

Since 1990, nearly 200 international transmission events have been recorded, with resistant strains detected not only in South Asia but also in parts of Africa, Southeast Asia, the UK, the US and Canada.

The first XDR typhoid strain was identified in Pakistan in 2016 and had become the dominant strain there by 2019.

Azithromycin Resistance Raises Fresh Fears

Today, azithromycin is the last widely effective oral antibiotic against typhoid. But researchers have found mutations that could make the bacterium resistant to this drug as well. If XDR strains acquire this resistance, experts warn treatment options could become severely limited.

According to the World Health Organization, typhoid remains endemic in many low- and middle-income countries. South Asia accounts for around 70 percent of global cases. In 2024 alone, more than 13 million cases were reported worldwide. Untreated, the disease can be fatal in up to 20 percent of cases.

Vaccines Seen As Key Defence

Health authorities are urging wider use of typhoid conjugate vaccines. The World Health Organization has prequalified four such vaccines, and several endemic countries have introduced them into routine immunisation programmes.

Pakistan became the first country to roll out routine typhoid vaccination nationwide, a move experts say could significantly curb infections. A 2021 modelling study in India suggested that vaccinating children in urban areas could reduce cases and deaths by up to 36 percent.

Scientists say expanding vaccine access and investing in new antibiotics are critical to preventing a larger global health crisis. In an era of easy international travel, experts warn that drug-resistant typhoid cannot be viewed as a regional problem.

As antibiotic resistance continues to claim millions of lives globally each year, researchers caution that time is running out to contain this ancient disease.