Bacterial Agents Detected in 418 Ticks Removed from Humans during 2014-2021, France

Area of Science:

• Medical Entomology
• Infectious Diseases
• Microbiology

Background:

• Tick-borne diseases pose significant public health challenges, necessitating robust monitoring and diagnostic strategies.
• Accurate identification of tick vectors and their carried pathogens is crucial for effective prevention and management of associated diseases.

Purpose of the Study:

• To identify tick species and detect bacterial pathogens in ticks removed from patients in Marseille, France.
• To assess the contribution of tick and pathogen identification to the diagnosis of tick-borne illnesses.

Main Methods:

• Analysis of 418 ticks collected from 359 patients between 2014 and 2021.
• Tick identification using morphology, molecular methods, and MALDI-TOF mass spectrometry.
• Bacterial DNA detection and pathogen identification within ticks.

Main Results:

• Ixodes (47%), Dermacentor (33%), and Rhipicephalus (16%) were the predominant tick genera identified.
• Bacterial DNA was detected in 58% of ticks, with Rickettsia spp. (R. raoultii, R. slovaca, R. massiliae) and Borrelia spp. being the most frequent pathogens.
• Tick identification and pathogen detection supported the diagnosis of tick-borne diseases in 26 patients, including scalp eschar and neck lymphadenopathy and Lyme borrelioses.

Conclusions:

• Integrated tick and pathogen identification methods are valuable tools for clinical diagnosis and surveillance of tick-borne diseases.
• The study highlights the importance of entomological surveillance in understanding local tick populations and their pathogenic potential.
• Early and accurate diagnosis facilitated by rapid identification contributes to timely treatment and improved patient outcomes.