Scientists warn that diphtheria is on the rise and could once again become a major global threat

An almost conquered infectious disease appears to be making a comeback. In a new article this week, scientists warn that cases of diphtheria have gradually increased in recent years, while there are signs that antibiotics and vaccines against the bacteria can be in danger of losing their potency as a germ continues evolve.

Diphtheria is caused by certain strains of bacteria Corynebacterium diphtheriaeIt is mainly spread through respiratory droplets and, rarer through skin contact with infected wounds. The damage these bacteria cause usually doesn’t come from the infection itself but from the poison they can produce. E.The most common symptoms include a sore throat and mild fever. Within days, the poison can kill enough cells along the throat, causing a telltale grainyish build-up of dead debris making it difficult for victims to breathe. Patients may also develop a swollen “bull’s neck” caused by enlarged lymph nodes. If left untreated, the toxin can seep into the bloodstream and other organs and cause massive internal damage that kills about half of the victims.

Although diphtheria has been killing people for centuries, the emergence of antitoxins, antibiotics, and a highly effective vaccine in the first half of the 20th century strongly neutered it. From 1980 to 2000, following the World Health Organization’s commitment to universal vaccination for children in the 1970s, the incidence of the annual new cases of diphtheria decreased by more than 90%. Today that is about 85% of the world’s population vaccinated against diphtheria, and the disease is virtually extinct in many countries, including The United States.

There are still parts of the world where access to effective treatments and vaccines is more limitedhowever. The incidence of diphtheria has also started to gradually increase recently. Iafter a new study published Monday in Nature Communications, scientists say there is some evidence that diphtheria bacteria are at risk of altering genetically enough to weaken the effectiveness of antibiotics and vaccines used against them.

The study, which involved researchers from the UK, India and the World Health Organization, looked at the genetic diversity of these bacteria (both toxin and non-toxin producing strains) over the past century by examining samples collected from patients in 16 countries.This also included India, which now has a majority of the world’s annual cases of diphtheriaThey used this data to map the evolution of these bacteria over time.

There are signs that the bacteria are beginning to adapt to our weapons, the researchers found. They found a significant increase in the average number of antimicrobial resistance genes carried by diphtheria bacteria over the past decade, compared to previous decades. The diversity of their “tox” gene, responsible for producing the deadly toxin, has also increased recently. They identified 18 different variants of the tox gene, some of which could potentially alter the basic structure of the toxin, making existing treatments less effective.

Antibiotic-resistant strains of diphtheria bacteria could, too make it more difficult for doctors to treat infections. Meanwhile, the diphtheria vaccine works by training the body to specifically recognize the toxin. AAny meaningful change in structure could weaken how well our immune system will defend it, as well as the power of anti-toxin drugss. That said, these findings do not demonstrate that diphtheria is now refractory to antibiotics or vaccines. The mutations found in the tox gene do not seem to affect the effectiveness of our current vaccine, when they did no evidence of substantial resistance to the most common antibiotics used to treat infection.

However, the growing diversity of these bacteria suggests that they could one day ‘learn’ how to better avoid our vaccines, antitoxins and antibiotics. And against the backdrop of current trends, this is certainly worrying. In 2018, more than 16,000 cases of diphtheria were reported worldwide – the highest annual toll in 22 years –and 2019 was even worseAnd over the past year, the Covid-19 pandemic has disrupted vaccination efforts for diseases such as diphtheria.

Even in the worst case, vaccines and antitoxins can be changed if necessary, and there are other antibiotics that doctors can use as the front-line medications for these still-rare infections are also starting to fail. But the researchers warn that we should continue to study and prepare for these opportunities now, before it is too late and diphtheria follows in the footsteps of other vaccine-preventable diseases such as measles that cause frightening resurgence lately.

[I]Understanding this historically significant disease is more important than ever to prevent it from ever becoming a major global threat in its original or modified, more adapted form, ”the authors wrote.