Identification and Distribution of Human-Biting Ticks in Northwestern Spain

Abstract

Ticks transmit a wide diversity of pathogens to a great variety of hosts, including humans. We conducted a tick surveillance study in northwestern Spain between 2014 and 2019. Ticks were removed from people and identified. Tick numbers, species, development stages, the timeline, seasonal and geographical distribution and epidemiological characteristics of people bitten by ticks were studied. We collected ticks from 8143 people. Nymphs of I. ricinus were the most frequently collected. Rhipicephalus bursa, R. sanguineus s.l., Hy. marginatum, Hy. lusitanicum, D. marginatus, D. reticulatus and H. punctata were also found, with adults as the main stage. The number of collected Hyalomma spp. and R. bursa has been progressively increasing over time. Although bites occurred throughout the year, the highest number of incidents was reported from April to July. The distribution patterns of the tick species were different between the north and the south of the region, which was related to cases detected in humans of the pathogens they carried. Adult men were more likely to be bitten by ticks than women. Ticks were most frequently removed from adults from the lower limbs, while for children, they were mainly attached to the head. Epidemiological surveillance is essential given the increase in tick populations in recent years, mainly of species potentially carrying pathogens causing emerging diseases in Spain, such as Crimean–Congo hemorrhagic fever (CCFH).

Examining the gut microbiota from several human-biting tick species in Northwestern Spain

“…Our results are of great relevance, considering that the region of Castilla y León has increased reports of tick bites in humans in recent years (Vieira Lista et al 2022). This region has geographical and climatological characteristics that favor the proliferation of multiple tick species and the presence of F. tularensis, Rickettsia spp., Borrelia spp., and Crimean-Congo hemorrhagic fever virus (Portillo et al 2018, Monsalve Arteaga et al 2020, Mínguez-González et al 2021).…”

“…Likewise, a recent study showed fluctuating distribution patterns of ticks with their potential to transmit several pathogens throughout northwestern Spain. These findings demonstrate the importance of monitoring the dispersion of these arthropods and the pathogens transmitted (Vieira Lista et al 2022). To emphasize, in Spain, there are numerous reports of diseases, including Q fever and tularemia, which are caused by Coxiella burnetii and Francisella tularensis , respectively.…”

“…A total of 29 adult ticks were included in the present study, stored at the University of Salamanca, Spain. The samples were collected and preserved using the protocol described by Vieira et al (Vieira Lista et al 2022). Briefly, the ticks were gathered between 2015 and 2022 from individuals who attended primary healthcare centers and hospital services for tick removal (each one of the ticks was collected from a different person).…”

Multisectoral Perspectives on Global Warming and Vector-borne Diseases: a Focus on Southern Europe

“…A recent survey of ticks in Spain reveals an increasing number of tick vector with CCHF. Dermacentor-borne necrosis erythema and lymphadenopathy are becoming an emerging disease in Spain [ 105 ]. Furthermore, tick bites have become frequent in spring and winter in Spain, in line with warmer winter due to GW over the years [ 103 , 105 ].…”

“…Dermacentor-borne necrosis erythema and lymphadenopathy are becoming an emerging disease in Spain [ 105 ]. Furthermore, tick bites have become frequent in spring and winter in Spain, in line with warmer winter due to GW over the years [ 103 , 105 ]. In Portugal, Mediterranean spotted fever (MSF) is the most important TBD with several fatal outcomes since year 2000 [ 106 ].…”