An almost defeated infectious disease seems to be returning. 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 going evolve.
Diphtheria it is caused by certain strains of bacteria Corynebacterium diphtheriae. It spreads mainly through respiratory drops and, less frequently, 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. EArid symptoms include sore throat and mild fever. In a few days, the toxin can destroy enough cells along the throat to cause a revealing wheataccumulation of dead debris that makes it difficult for victims to breathe. Sufferers may also develop a swollen “bull’s neck” caused by enlarged lymph nodes. If left untreated, the toxin can seep into the blood and other organs, causing massive internal damage that kills about half of its victims.
Although diphtheria has killed people for centuries, the emergence of antitoxins, antibiotics and an extremely effective vaccine in the first half of the twentieth century has greatly neutralized it. From 1980 to 2000, following the impetus of the World Health Organization for universal vaccination of children in the 1970s, incidence of new cases of annual diphtheria fell 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 US
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There are still pockets in the world where access to effective treatments and vaccines is more limited, in any case. The incidence of diphtheria has also gradually started to rise recently. Ia new study published On Monday, in Nature Communications, scientists say there is evidence that diphtheria bacteria are likely to 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 (both toxin-producing and non-toxin-producing strains) over the last 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 graph the evolution of these bacteria over time.
There are signs that researchers have found that bacteria begin 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 their “tox” gene, responsible for producing the deadly the toxin has also increased recently. They identified 18 different variants of the tox gene, some of which could conceptually change the basic structure of the toxin, which could make existing treatments less effective..
There may also be antibiotic-resistant strains of diphtheria bacteria makes it more difficult for doctors to treat infections. Meanwhile, the diphtheria vaccine works by training the body to recognize the toxin specifically. Aany significant change in its structure could weaken how well our immune system will prevent it, as well as the potency of the antitoxin drugThat being said, these findings do not show that diphtheria is now impervious to antibiotics or vaccines. Mutations found in its toxic gene do not appear to impact the effectiveness of our current vaccine, while there are 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 they may one day “learn” how to better avoid vaccines, antitoxins and antibiotics. And against the background of current trends, it is certainly worrying. In 2018, more than 16,000 cases of diphtheria were reported worldwide – the highest annual number recorded in the last 22 years –and 2019 was equal worse. And in the last year, the covid-19 pandemic has halted 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 beginning to fail. But researchers warn that we need to continue to study and start preparing for these possibilities now, before it is too late and diphtheria to follow in the footsteps of other vaccine-preventable diseases, such as measles, which have caused a frightening rebirth Lately.
“[I]It is more important than ever to understand this historically important disease, in order to prevent it from becoming a major global threat again in its original form or in a modified, better adapted form, ”the authors wrote.