Ticks infesting humans in Italy and associated pathogens

Area of Science:

• Veterinary Entomology
• Medical Entomology
• Molecular Biology

Background:

• Ticks transmit various pathogens causing diseases in animals and humans, known as tick-borne diseases (TBDs).
• Human TBD incidence in Italy is likely underestimated due to insufficient surveillance and limited research.
• Understanding tick populations and their pathogen carriage is crucial for public health in Italy.

Purpose of the Study:

• To investigate the prevalence and diversity of tick species and their associated pathogens in humans across Italy.
• To assess the risk of TBDs in different geographical areas of Italy.
• To provide baseline data for improved TBD surveillance and control strategies.

Main Methods:

• Collected 561 tick samples from humans in four distinct Italian geographical areas.
• Morphologically identified tick species and performed molecular testing for pathogens.
• Tested for pathogens including Rickettsia, Babesia, Theileria, Candidatus Neoehrlichia mikurensis, Borrelia, and Anaplasma.

Main Results:

• Identified 16 tick species, with Ixodes ricinus (59.5%) and Rhipicephalus sanguineus s.l. (21.4%) being most common.
• Nymphs (41%) were the most frequent life stage, followed by adult females (34.6%).
• Overall pathogen detection rate was 18%, including Rickettsia spp. (17.0%), Anaplasma phagocytophilum (0.8%), Borrelia afzelii (0.5%), Borrelia valaisiana (0.3%), Candidatus Neoehrlichia mikurensis (0.5%), and Babesia venatorum (0.6%).

Conclusions:

• Humans in Italy are at risk from diverse tick species carrying multiple TBD pathogens.
• The findings underscore the potential for co-infections, increasing disease complexity.
• Enhanced surveillance is necessary to accurately gauge the burden of TBDs in Italy.