We thought they were relegated to the past, but they are resurfacing with sometimes worrying incidence: measles, whooping cough, syphilis, tuberculosis, etc. Diseases of the past are returning thanks to a lack of vaccination or insufficient prevention.
Forgotten illnesses that come back
Whooping cough is making a comeback in France. Nearly 6,000 cases of this respiratory infection were recorded in the first five months of the year, five times more than in 2023. The number of measles cases is exploding. In 2023, 117 cases (including 31 imported) were declared in France, compared to 15 in 2022. This highly contagious viral disease is often benign, but can cause serious, respiratory and neurological complications, sometimes fatal in babies.
Tuberculosis, although it remains at a low level, saw a rebound in cases in France in 2023 after three years of health crisis, with 4,728 cases declared. Transmitted by air, it is a very contagious bacterial infection most often affecting the lungs, but can spread to the brain.
Syphilis, a sexually transmitted infection infamous throughout the world for having infected artists like Baudelaire and Schubert, has long been relegated to the background of public policies, particularly in the face of the HIV epidemic. It saw its incidence jump by 110% between 2020 and 2022.
Scientists see this as a consequence of the cessation of barrier measures against the Covid pandemic, or a decline in collective immunity. But it is often insufficient vaccination coverage that is the cause.
Disease latency and mutation
« Never really, but they have transformed, spaced out over time. », underlines Mikael Askil Guedj, doctor of medical sciences and eye surgeon, who looked at all the diseases of the century in a book Doctors in spite of yourself, Portraits of 21st diseasese century (Grasset, 2023). “ This is the epidemic genius: there are cycles of a few years, sometimes a few decades, where diseases are forgotten, mutate a little, then reappear without warning. ».
These diseases ” have always been latent “, also notes Philippe Sansonetti, professor emeritus at the Pasteur Institute and the Collège de France. Syphilis, we saw it flare up with AIDS and then fall back at the same time as preventive measures; tuberculosis had diminished enough for vaccination to be stopped; as for measles and whooping cough, we live with irregular outbreaks. “, he specifies.
As with other germs, scientists see this as a consequence of the cessation of barrier measures against the Covid pandemic, or a decline in collective immunity. But it is often insufficient vaccination coverage that is to blame. The MMR vaccine in particular (measles-mumps-rubella) had been the victim of strong mistrust among parents due to false reports attributing cases of autism to it. Cases soared in the 2000s that this vaccination went from “recommended” to “mandatory” for all infants in 2018 in an attempt to stem the phenomenon.
More ” there are adult and adolescent measles cases among the unvaccinated or poorly vaccinated (one injection instead of the two required) “, underlines Mikael Askil Guedj. For tuberculosis, which mainly affects people in very precarious situations, ” There is a vaccine, BCG, which is no longer available in pharmacies. “. And who, moreover, “ does not protect very well “, he adds. Regarding whooping cough, it would be necessary to ” revaccinate in adulthood, especially pregnant women “to protect future babies, because” the current vaccine does not protect against infection for life », underlines Philippe Sansonetti.
As for syphilis, its return can be explained by the reduced use of condoms, since antiretrovirals have reduced the fear of AIDS. “ Many people carry it without knowing it, and continue to spread syphilis because the first symptoms are quite discreet or poorly identified. », adds Dr Guedj.
What are the recommendations for getting rid of it?
« Some countries have a more solid vaccination policy than France “, notes Philippe Sansonetti, who expects a lot from the future digital vaccination health record. Today, there are gaps and confusion about the real vaccination coverage » adults, he notes.
Without necessarily advocating compulsory vaccination for all, as is the case in pediatrics, the researcher questions the implementation of a better vaccination policy among adolescents and adults. For syphilis, “ the diagnosis is difficult, but as soon as there is any doubt, serological tests must be done », adds the scientist, who also pleads for “ major information and awareness campaigns ».
