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

A nearly conquered infectious disease seems to be making a comeback. In a new article this week, scientists warn that cases of diphtheria have gradually increased in recent years, as there are signs that antibiotics and vaccines against the bacteria could be in danger of losing their potency as a germ keep on going to evolve.

Diphtheria is caused by certain strains of the bacteria Corynebacterium diphtheriae. It is mainly spread by respiratory droplets and, more rarely, through skin contact with infected wounds. The damage caused by these bacteria does not usually come from the infection itself but from the toxin they can produce. EThe main symptoms include a sore throat and a slight fever. Within days, the toxin can kill enough cells along the throat that it causes a graaccumulation of dead debris that prevents victims from breathing. People with the condition may also develop a swollen ‘bull neck’, caused by enlarged lymph nodes. If left untreated, the toxin can seep into the bloodstream and other organs, causing massive internal damage that kills about half of its 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 has largely sterilized it. From 1980 to 2000, following the World Health Organization’s campaign for universal childhood immunization in the 1970s, the impact of new annual cases of diphtheria have fallen by more than 90%. Today, about 85% of the world’s population is vaccinated against diphtheria, and the disease is virtually extinct in many countries including United States

There are still pockets of the world where access to effective treatments and vaccines is more limited, however. The incidence of diphtheria has also started to increase recently. Ia new study published On Monday in Nature Communications, scientists say there is evidence that diphtheria bacteria may change 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 (toxin-producing and non-toxin-producing strains) over the past century. , studying samples taken from patients in 16 countries.. This included India, where the majority of annual cases of diphtheria worldwide now occur.. They used this data to trace the evolution of these bacteria over time.

There are signals that the bacteria are starting to adapt to our weapons, the researchers found. They found a substantial 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 the production of the mortal toxin, has also increased recently. They identified 18 different variants of the tox gene, some of which could alter the basic structure of the toxin, which could make existing treatments less effective..

Antibiotic-resistant strains of diphtheria bacteria could also make it difficult for doctors to treat infections. Meanwhile, the diphtheria vaccine works by training the body to specifically recognize the toxin. Aa significant change in its structure could weaken the ability of our immune system to repel it, as well as the strength of the antitoxin drugs. However, these results do not show that diphtheria is now impermeable to antibiotics or vaccines. The mutations found in its tox gene do not seem to have an impact on the effectiveness of our current vaccine, although there were no evidence of substantial resistance to the antibiotics most commonly used to treat infection.

The growing diversity of these bacteria suggests that it could one day “learn” how to better evade our vaccines, antitoxins and antibiotics. And in the context of current trends, it’s really worrying. In 2018, more than 16,000 cases of diphtheria were reported worldwide – the highest annual toll in 22 years –and 2019 was same worst. And over the past year, the covid-19 pandemic has disrupted vaccination efforts against diseases like diphtheria.

Even in the worst-case scenario, vaccines and antitoxins can be changed as needed, and there are other antibiotics that doctors can use if the forehead-Line drugs for these still rare infections are also starting to fail. But researchers warn that we must continue to study and start preparing for these possibilities now, before it is too late and diphtheria follows in the footsteps of other vaccine-preventable diseases, such as measles, which have made a scary resurgence recently.

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