A brief review: the prevalence of tick-borne pathogens in urban and suburban areas

Abstract

Ticks are widely distributed blood-sucking ectoparasites and vectors for numerous zoonotic pathogens that cause infectious diseases in humans and animals. The increase in the incidence of tick-borne diseases (TBD) is partially associated with climatic changes, such as shorter and warmer winters, prolonged growing seasons, and also with increasing urbanisation. In recent decades, a rising number of established populations of medically important ticks have been reported in urban and suburban areas such as city parks or suburban forests over many regions in Europe. The transformation of natural ecosystems into urban areas becomes actual significant problem because it could affect the circulation of tick-borne pathogens and increase the risk of infection for humans and domestic animals. Tick-borne pathogens, including Borrelia burgdorferi s. l., Rickettsia spp., Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis, and Babesia spp., have been detected in urban tick populations in Europe. Such places as parks, leisure-time areas, green spaces, and gardens become endemic zones of tick-borne pathogens. This review describes the investigations on the prevalence of tick-borne pathogens in urbanised areas conducted in Europe during the last fifteen years (2005–2020).

Prevalence of pathogens in sympatric <i>Ixodes ricinus</i> and <i>Dermacentor reticulatus</i> ticks in Eastern Poland and their potential impact on oral-anal contacts between ticks

“…The prevalence of Borrelia burgdorferi s.l. in questing I. ricinus adults in other regions of Europe most often ranges from 6.8% -25% [10]. In some areas, however, the percentage of infected I. ricinus adult ticks is substantially higher; for example, Borrelia spirochetes were identified in 48.9 ± 8.4% of adult I. ricinus ticks [58] in Finland, and 49.1% of adult stages were infected by the bacteria in northern Germany (Western Pomerania) [56].…”

“…Over the last two decades the distribution range of I. ricinus [5] and D. reticulatus [6] in Europe has expanded substantially. Currently, these ticks can be found not only in natural habitats but also in parks and other recreation areas inside or near cities [7][8][9][10]. This phenomenon is associated with climate change and environmental changes, which influence the development, survival, and phenology of ticks and the behaviour of their potential animal hosts.…”

Altitudinal Distribution, Seasonal Dynamics and Borrelia burgdorferi Sensu Lato Infections in Hard Ticks (Acari: Ixodidae) in Different Forest Communities in Inland Croatia

“…Such increase is a result of different environmental and social factors, e.g., climate changes (prolonged growing seasons, warmer and shorter winters, etc.) [8][9][10], loss of predators [11], reforestation of agricultural lands, woodland expansion [12,13], urbanization, human mobility and population growth [14][15][16]. The higher risk of TBDs is typically associated with woodland habitats that provide ticks with the most favorable microclimatic conditions and high availability of hosts [17][18][19].…”

“…The higher risk of TBDs is typically associated with woodland habitats that provide ticks with the most favorable microclimatic conditions and high availability of hosts [17][18][19]. Even so, a rising number of medically important tick species populations are also being recorded in urban and suburban areas across Europe [10]. One tick species well-known for its high abundance and wide distribution in Europe and Croatia is Ixodes ricinus (Castor bean tick, Sheep tick, Deer tick, Forest tick) [20].…”

“…In Croatia, it has shifted from 255 to more than 400 reported human cases per year in the last 20 years [34]. It is recognized now that Borrelia burgdorferi exists at quite variable rates wherever the vector exists and that maximum prevalence is recorded in large regions of Central Europe, where the infection rates of Ixodes ricinus ticks range from 3% to 45% [10,35,36]. While there is an environmental niche that accounts for the prevalence of the causative agents, such as Borrelia burgdorferi s.l.…”