why is Creutzfeldt-Jakob disease once again a public health issue?
On November 6, a retired technician from INRAE in Toulouse (Haute-Garonne) died of Creutzfeldt-Jakob disease. This case raises the question of its possible contamination in his professional environment and that of safety in the research units working on the prion. It refers to the mad cow crisis during the 90s and raises the hypothesis of a second wave of the disease.
The Creutzfeld-Jacob disease (CJD) is a rare disease. Between 1993 and 2019, 3,091 people died from it in France (Public Health Data France, update of July 31, 2019). According to scientists, its origin is most often unknown (so-called sporadic CJD). It can also have its source for genetic reasons, or even be caused by a medical treatment, such as growth hormone treatments, for example.
But these are the people infected with variant Creutzfeldt-Jakob disease (vCJD), after eating upstart meat bovine spongiform encephalopathy (BSE), also called mad cow disease, who made the most of them during the 90s.Appeared in the United Kingdom in 1986, nearly 200,000 cattle and more than 200 people were victims in Europe. In France, 25 cases (and deaths) have been observed, the last death occurring in 2009. There is no cure for this disease.
The death of Emilie Jaumain, on June 17, 2019 and that of Pierrette C., on November 6, 2021, both technicians from INRAE working in contact with biological tissues infected with prions, the agent responsible for transmissible spongiform encephalopathies (TSE), caused a real shock wave.
As the “Safety expertise mission in infectious prion research laboratories“having delivered its conclusions in September 2020:
To date, no CJD or vCJD of professional origin has been documented in France or elsewhere according to the three studies available to the knowledge of the mission, knowing that the origin of CJD or vCJD is complex to trace. . The incubation period can reach several decades and is asymptomatic up to a few months before death, the diagnosis of the type of TSE can only be established post-mortem.
Safety expertise mission in infectious prion research laboratoriesIGESR September 2020
The origin of the contamination having acquired Emilie Jaumain’s is not definitively defined. The incubation period of the disease, extremely long and exceeding 50 years, makes the investigations very complex. But strong suspicions relate to an accident that occurred in 2010 when the young woman cut herself while handling fragments of the brains of mice infected with prions, in another INRAE unit., in Jouy-en-Josas.
A recent scientific publication and the death of Pierrette C. further strengthen this hypothesis. From union sources, the technician from Toulouse also declared, in 2004 and 2005, two accidents at work during handling with the prion where she cut herself.
The subject is all the more sensitive as the risk of contamination by aerosols was also highlighted in research published in 2011.
Faced with this situation, the authorities decided, after the disappearance of Emilie Jaumain, to review “the security measures planned and implemented in the laboratories concerned.“
In France, nine research teams and a concentration of agents are working on prions *.
According to the IGÉSR report of September 2020, the number of accidents in these laboratories are few. The mission thus learned of “five agents pricked or cut with contaminated syringes or blades, seven agents pricked or cut without contact with infected materials and five agents bitten and having undergone projections a priori without seriousness because without contact with contaminated material. “Figures to be taken with caution. According to several unions”these types of accidents are not always reported in laboratories. Sometimes we can even prevent their statements.“
But the mission of the IGÉSR also underlines “that certain practices“within these research units”still need to be improved. “Personal protective equipment (PPE), such as masks or visors, overshoes, aprons and / or coveralls are not there”systematically used.“
Seven recommendations had been formalized which do not seem always applied today.
Research on prions is an important issue. According to researchers, Creutzfeldt-Jakob disease may once again impact public health. Three risks are identified:
– The appearance of a new wave of people affected by the variant of Creutzfeld-Jakob disease, resulting from the “mad cow” crisis, is not ruled out, due to the long incubation period.
– The resistance of the infectious prion to decontamination on reusable medical equipment.
– The recent discovery in Europe of a form of animal prion disease affecting wild cervids, but whose transmissibility to humans has not yet been demonstrated.
A moratorium on research and experimentation relating to prion diseases is imposed by the government until the end of 2021.