Evaluation of a New Multiplex Quantitative PCR Technique for the Diagnosis of Echinococcosis

Echinococcosis is a severe parasitosis caused by the development of the tapeworm larva Echinococcus multilocularis, responsible for alveolar echinococcosis (AE) or Echinococcus granulosus, responsible for cystic echinococcosis (CE). The treatment is based on surgery (only possible in 30 to 40% of cases) and/or on a benzimidazole antiparasitic treatment, especially albendazole. Albendazole is only parasitostatic, it slows down the development of the parasite but does not kill it. It is often prescribed for life. Monitoring the effectiveness of the treatment is therefore necessary, requiring radiological and serological monitoring once or twice a year. Being a chronic disease whose treatment is not always curative, patients quality of life is impacted, with a high level of anxiety described in some patients.

The diagnosis, evoked on radiological arguments, is then confirmed by serological techniques, whose sensitivity for EA diagnosis is good (95%) in the absence of immunosuppression (now observed in 25% of EA patients). Sensitivity is lower for CE diagnosis (70% or even less than 50% in certain clinical forms).

Quantitative real-time PCR (QPCR) techniques on blood samples are now used in many infectious pathologies to quantify the circulating DNA load, and improve diagnosis and therapeutic monitoring. The presence of circulating parasitic DNA has been reported in both types of echinococcosis.

A new Echinococcus spp.multiplex QPCR technique (QPCR-Echino) allowing the detection of DNA from E. multilocularis and different species of the E. granulosus complex of European occurrence, in different types of biological samples, has recently been developed in the French National Reference Center for Echinococcosis laboratory.

The investigators wish to evaluate QPCR-Echino for the detection of DNA in tissues, as well as in blood, for the diagnosis of Echinococcosis. This technique could improve the sensitivity of biological diagnosis, especially in immunocompromised patients, who often experience significant diagnostic delays, and could also provide information on the virulence and viability of the strains involved.