An almost defeated infectious disease looks set to reappear. In a new paper this week, scientists warn that diphtheria cases have gradually increased in recent years, while there are signs that antibiotics and vaccines against bacteria it could be in danger of losing its potency as a germ keep on evolve.
Diphtheria it is caused by certain strains of bacteria Corynebacterium diphtheriae. It spreads mainly through respiratory droplets i, more rarely, by 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. ESymptoms include sore throat and mild fever. After a few days, the toxin can kill enough cells along the throat that cause a revealing grainaccumulation of dead debris that makes it difficult for victims to breathe. People who suffer may also develop an swollen “bull’s neck” caused by an increase in 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 advent of antitoxins, antibiotics, and a highly effective vaccine in the first half of the twentieth century castrated it. From 1980 to 2000, after the impetus of the World Health Organization for universal childhood vaccination during the 1970s, the incidence of the new annual cases of diphtheria fell more than 90%. Today, about 85% of the world’s population is vaccinated against diphtheria and the disease is virtually extinct in many countries included The USA
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There are still bags in the world where access to effective treatments and vaccines is more limited, despite this. The incidence of diphtheria has also begun to gradually increase recently. Join the new study published On Monday in Nature Communications, scientists say there is evidence that diphtheria bacteria are at risk of changing genetically enough to weaken the effectiveness of antibiotics and vaccines used against them.
The study, which involved researchers from the United Kingdom, India and the World Health Organization, examined the genetic diversity of these bacteria (both toxin-producing and non-toxin-producing strains) over the past century. by studying samples collected from patients in 16 countries.. This included India, where most of the world’s annual diphtheria cases now occur. They used this data to track the evolution of these bacteria over time.
There are signs that indicate that researchers found that bacteria are beginning to adapt to our weapons. They found a substantial increase in the average number of antimicrobial resistance genes carried by diphtheria bacteria in the last decade, compared to previous decades. The diversity of its “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 change the basic structure of the toxin, which could make existing treatments less effective..
There may also be strains of antibiotic-resistant diphtheria bacteria make it difficult for doctors to treat infections. Meanwhile, the diphtheria vaccine works by training the body to specifically recognize the toxin. Aif a significant change in its structure could weaken the degree of resistance of our immune system, as well as the strength of the antitoxin drugs. That said, these findings do not show that diphtheria is now impervious to antibiotics or vaccines. Mutations found in their tox gene do not seem to affect the effectiveness of our current vaccine there is no evidence of substantial resistance to the most common antibiotics used to treat the infection.
The growing diversity of these bacteria suggests that one day we could “learn” to better evade our vaccines, antitoxins, and antibiotics. And in the context of current trends, this is certainly worrying. In 2018, more than 16,000 cases of diphtheria were registered worldwide —the highest annual toll recorded in 22 years—and in 2019 it was even worse. And, 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 modified if necessary, and there are other antibiotics that doctors can use ifline drugs for these still rare infections are also starting to fail. But researchers warn that we must continue to study and begin to prepare for these possibilities now, before it is too late and diphtheria is following in the footsteps of other vaccine-preventable diseases such as measles. frightening resurgence lately.
“[I]It is more important than ever to understand this historically important disease, to prevent it from becoming a major global threat again in its original form or in a modified, better adapted form, ”the authors wrote.