Will the controversy surrounding Lyme disease finally end? The High Authority for Health (HAS) published, on February 18, an update of its recommendations For the management of this infection caused by the transmission of the Borrelia Burgdorferi bacteria during a bite of a tick. The text was particularly expected by the scientific community and patient associations, especially since the previous version, which dated from 2018, had caused a rare imbroglio by being rejected both by learned societies and patient associations.
Already at the time, the central point of discussions concerned the “post-burreliosis syndrome of Lyme treated”, better known by the term chronic Lyme, or Lyme Long. Except that the mechanisms to explain this persistence are not entirely understood by science. This shadow zone has fed controversies whose magnitude is almost unequaled in the medical world, as L’Express recently told.
In its current form, Lyme disease results in 95 % of cases by migrant erythema, a rash around a bite of the tick. It can, more rarely, evolve in neuroborreliosis – The attack of the central nervous system – or take the form of painful inflammatory rheumatism. The treatment indicated is taking an antibiotic, most often doxycycline or amoxicillin, for fourteen days. The prevalence of the disease has hardly changed for almost thirty years. According to the most recent figures in public health France, almost 40,000 infections are diagnosed On the national territory each year, for 700 hospitalizations.
But the disease can also take a chronic form which is characterized by very varied symptoms: great fatigue, diffuse pain, memory disorders and concentration which persist at least six months after treatment. It would affect 6 to 20 % of patients in Europe, according to HAS. Patient associations helped by “Lyme Doctors” are convinced that this chronic form is caused by the persistence of the bacteria in the human body, or even by the tick transmission of other bacteria and viruses. According to them, implementing shock treatments sometimes sometimes sometimes sometimes including around twenty drugs prescribed for months, or even for life.
However, no serious scientific publication has never demonstrated these theories. Updating the HAS recommendations recognizes the persistence of symptoms, but offers other hypotheses to explain it, such as a disturbance of the immune system caused by initial infection, which would promote secondary or opportunistic infections; or chronic inflammation promoting the development of autoimmune phenomena. The authority also underlines that the treatment prolonged by antibiotic is ineffective and dangerous.
Listen better at patients
In any case, specialists are on one point: patient symptoms and sufferings are very real. The causes and solutions are, however, more difficult to make heard. “All the doctors of France have already met a patient consultant for an alleged long Lyme with a similar profile: fatigue, pain, depression, sometimes an inability to work, assures Anne Scherrer, Responsible for oncological medicine and infectious referent at the Ambroise Paré – Hartmann (Neuilly) clinic. And explaining to them that this was not necessarily linked to Borrelia is often difficult. “
These sometimes conflicting relationships have also been one of the main reproaches made by associations. Some white blouses have been tempted to see these patients as imaginary and time -consuming patients. “The previous generations were perhaps more dressed in the aura of the doctor whose speech was of Gospel. But I think that today, we are more vigilant when the patient is needed and more empathic, and C ‘is a good thing, “admits Yves Hansmann, an infectiologist at the National Reference Center for Lyme disease, in Strasbourg.
Robust scientific evidence
Doctors’ speech has also been strengthened through the accumulation of scientific data. In recent years, a dozen international studies that explore diagnosed diseases in patients coming to consult A long Lyme have brought solid evidence. Three French studies published in 2018 and 2019 and relating to 1,000 people show, for example, that only 12 % to 15 % of patients actually have a confirmed or possible Lyme disease. An American study (1,261 people) published in 2019 reveals that only 14 % of patients have active or recent Lyme disease. And two Dutch studies published in 2023 and 2024 still strengthen these results.
“Conclusions converge and overlap: 80 to 90 % of patients who consult do not suffer from a long Lyme, but other rheumatological, neurological, psychiatric or linked diseases in disorders linked to large situations Psychological or ill-being distress, “sums up Pr. Éric Caumes, infectiologist at the Hôtel-Dieu in Paris. His team and published him A study in 2019 which also shows that prolonged antibiotic treatments fail in 80 % of cases.
News supported, a vaccine in testing
The fact remains that these patients must still be treated. In its recommendations, the HAS calls for “personalized” and “multi-disciplinary” management. She rests on the work undertaken by several hospitals which have set up specialized teams. The Hôtel-Dieu, in Paris, has developed a protocol that integrates three disciplines: internal medicine, sports medicine and psychiatry.
“Our multidisciplinary approach is not reserved for post-infectious syndromes, because we are convinced that we must be interested in transdiagnostic mechanisms of persistence of symptoms, whatever the initial cause. Indeed, in all diseases , some patients suffer from persistent symptoms despite organic healing, “said Professor Cédric Lemogne, head of the adult psychiatry department The Paris hospital, which participated in the HAS working group. The purpose of this approach is, in particular, to determine whether the persistence is linked to mechanisms specific to each pathology or if there are psychological or behavioral factors that predispose patients to keep symptoms.
Treatment always starts with attentive listening to patients, who have often been in medical wandering for years. Then doctors explain how the brain can sometimes promote the persistence of symptoms. They illustrate this mechanism by citing studies which consist in making different odors feel in participants and increasing the rate of CO2 each time they smell a particular odor. After several repetitions, the brain combines the smell with asphyxiation … and the participants feel short of breath each time they feel it, even if the CO2 rate is normal. “The brain learns from his experiences and reacts according to what he thinks is good for his survival: in case of doubt, he is always alarmed with excess and this alarm, these are the symptoms”, explains the pr . In the same way, the body can continue to protect itself from a disease while the bacteria or the virus has been eradicated. The symptoms felt are very real and can be painful, but are not dangerous.
Doctors detail, finally, how avoidance behaviors can maintain symptoms. For example, in case of great fatigue, the first reflex will be to rest. The benefit is obvious in the short term. But in the long term, physical tasks are becoming more and more exhausting. It is a vicious circle. In the same way, focusing on a disturbing bodily sensation can amplify it by causing a wedding effect, the opposite of the placebo effect. Above all, Prof. Lemogne tries to convey an essential message: “In understanding of the general public, and often health professionals, symptoms are either psychological or physical, but that does not make sense: these are the two”. The experience of smells demonstrates this: if there is not a triggering physical factor – the increase in CO2 in this case – there would not be symptoms maintained by the brain.
The Hôtel-Dieu teams are currently carrying out several studies, the results of which should be known soon. In the meantime, doctors assure that the feedback is positive: the state of many patients improves significantly. “Some are even in complete remission, which is a very great source of motivation for us,” said Pr. Lemogne.
On the drug side, no new antibiotics is being developed. But a vaccine could soon see the light of day. Developed by the Valneva and Pfizer laboratories, it targets the external surface of a protein present on the Borrelia bacteria in order to prevent it from entering the human body. The vaccine is currently tested in two clinical trials of phase three, ultimate tests before a possible marketing. What reassure the most worried, and perhaps soften the inflamed debates that surround this infection.
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