Typhoid Fever Resistance to Antibiotics Is Growing and Spreading, Scientists Warn

A new study recently showed that the bacterium causing typhoid fever is evolving extensive drug resistance, and it is quickly replacing strains that are not resistant.

As indicated in a ScienceAlert report, typhoid fever might be a rare disease in developed countries, although this so-called ancient threat, believed to have existed for millennia, remains much of a danger in this modern world.

Currently, antibiotics are the only way to treat typhoid effectively, caused by the bacterium Salmonella enterica serovar Typhi or S Typhi.

Yet, over the past 30 years, the resistance of the bacterium to oral antibiotics has been growing, not to mention spreading.

S. Typhi Strains

Arranging the genomes of more than 3,400 S Typhi strains contracted between 2014 and 2019 in Pakistan, India, Pakistan, and Bangladesh, researchers of the study published in The Lancet Microbes journal discovered a recent increase in extensive drug-resistant or XDR Typhi.

Essentially, XDR Typhi is not just impervious to frontline antibiotics such as chloramphenicol, ampicillin, and trimethoprim/sulfamethoxazole, although it is growing resistant as well to newer antibiotics such as the third-generation cephalosporins and fluoroquinolones. Even worse, said the study investigators, such strains are spreading worldwide at such a fast rate.

While most XDR Typhi cases stem from south Asia, the study authors identified almost 200 cases of international transmission since 1990.

Most variants have been exposed to Southeast Asia and East and Southern Africa. However, typhoid superbugs have also been detected in the United States, the United Kingdom, and Canada.

Warning About Drug-Resistant Typhoid Strains

According to Jason Andrews, an infectious disease specialist from Stanford University, "the speed at which highly-resistant strains of S. Typhi" have occurred and spread in recent years is a real cause for concern and emphasizes the need for urgently expanding prevention measures, specifically in nations at greater risk.

Scientists have cautioned about drug-resistant typhoid strains for years, although the new study is the most extensive genome analysis on the bacterium to date, a similar True Viral News report said.

Historically, most XDR typhoid strains have been combatted with third-generation antibiotics such as cephalosporins, macrolides, and quinolones.

Nevertheless, by the early 2000s, mutations conferring resistance to quinolones accounted for over 85 percent of all cases in Singapore, India, Nepal, Pakistan, and Bangladesh. At the same time, cephalosporin resistance was taking over, as well.

At present, only one oral antimicrobial drug is left-the macrolide azithromycin. This drug might not work for much longer, though.

Typhoid Conjugate Vaccines May Help Avoid Future Outbreaks

This new research discovered that mutations conferring resistance to azithromycin are spreading as well, threatening the efficacy of all oral antimicrobials for typhoid treatment.

While XDR S Typhi has not yet adopted such mutations, if they are, "we are in serious trouble," warned the infectious disease specialist.

If the disease is untreated, the researchers said, up to 20 percent of typhoid cases can be deadly, and at present, there are 11 million cases of typhoid each year.

With typhoid conjugate vaccines, future outbreaks can be avoided to some degree, although if access to such jabs is not expanded worldwide, the entire world could soon have another health crisis.

Easy Transmission

South Asia might be the main hub for typhoid fever, with 70 percent of all reported and recorded cases. However, if COVID-19 has taught the world anything, it is that variants of diseases in his modern, globalized world are easily transmitted.

To avoid that from happening, health experts have contended notions need to expand access to typhoid vaccines and invest in new antibiotic studies.

For instance, recent research in India estimated that if children are vaccinated against typhoid in urban places, it could prevent up to 36 percent of typhoid cases and fatalities.

Lastly, antibiotic resistance is among the leading causes of death worldwide, claiming more people's lives than malaria or HIV/Aids. Wherever available, vaccines are some of the best tools available today to prevent catastrophes in the future.

Related information about the threat of antibiotic resistance is shown on the Centers for Disease Control and Prevention's YouTube video below:

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