Climate change impacts on ticks and tick-borne infections

Abstract

Evidence climate change is impacting ticks and tick-borne infections is generally lacking. This is primarily because, in most parts of the world, there are no long-term and replicated data on the distribution and abundance of tick populations, and the prevalence and incidence of tick-borne infections. Notable exceptions exist, as in Canada where the northeastern advance of Ixodes scapularis and Lyme borreliosis in the USA prompted the establishment of tick and associated disease surveillance. As a result, the past 30 years recorded the encroachment and spread of I. scapularis and Lyme borreliosis across much of Canada concomitant with a 2-3 °C increase in land surface temperature. A similar northerly advance of I. ricinus [and associated Lyme borreliosis and tick-borne encephalitis (TBE)] has been recorded in northern Europe together with expansion of this species’ range to higher altitudes in Central Europe and the Greater Alpine Region, again concomitant with rising temperatures. Changes in tick species composition are being recorded, with increases in more heat tolerant phenotypes (such as Rhipicephalus microplus in Africa), while exotic species, such as Haemaphysalis longicornis and Hyalomma marginatum, are becoming established in the USA and Southern Europe, respectively. In the next 50 years these trends are likely to continue, whereas, at the southern extremities of temperate species’ ranges, diseases such as Lyme borreliosis and TBE may become less prevalent. Where socioeconomic conditions link livestock with livelihoods, as in Pakistan and much of Africa, a One Health approach is needed to tackling ticks and tick-borne infections under the increasing challenges presented by climate change.

The dynamics of the microbiome in Ixodidae are shaped by tick ontogeny and pathogens in Sarawak, Malaysian Borneo

“…Furthermore, temperature changes could affect the tick life cycle and activity, which could have a profound effect on tick-borne pathogens. However, little is known about the impact of raised temperatures on the tick microbiota, as a long-term study is required to obtain such evidence [87]. Other than Borrelia , several other bacteria species such as Anaplasma sp., Ehrlichia sp., Bartonella spp., R. heilongjiangensis, and Coxiella and Francisella -LE were also identified from different tick species (; and S5).…”

Models of spatial analysis for vector-borne diseases studies: A systematic review

“…Studies considering the future projections of VBDs generally predict expansions as a response under scenarios of climate change, along with changes in external environmental conditions (Table -1). This trend can be observed across different taxonomic groups, as shown by long-term field studies, which have demonstrated that some species have recently moved to higher latitudes and altitudes as a response to global warming [80][81][82][83][84][85]. Regarding the methodology used, the distribution range of a species was a conditioning factor.…”

Sequential expression of small heat shock proteins contributing to the cold response of Haemaphysalis longicornis (Acari: Ixodidae)

“…[6][7][8] However, ticks exhibit an extraordinary supercooling capacity to withstand cold stress. 9,10 For example, a decrease in water content and an increase in glycerol and total protein content enhance H. longicornis tolerance to cold stress. 10 In addition, various physiological processes, such as the expression of heat shock proteins (Hsps), are associated with cold tolerance in ticks.…”

“…10 In addition, various physiological processes, such as the expression of heat shock proteins (Hsps), are associated with cold tolerance in ticks. 9,11 Hsps are a superfamily of proteins that protect cells from stress in insects. 12,13 Based on their molecular masses, amino acid sequences, and functions, Hsps are mainly classified into four families: HSP90, HSP70, HSP60, and small Hsps (sHsps).…”

“…The geographical distribution and expansion of ticks are largely influenced by climatic factors, especially in temperate areas where extreme winter temperatures can affect tick development and survival 6–8 . However, ticks exhibit an extraordinary supercooling capacity to withstand cold stress 9,10 . For example, a decrease in water content and an increase in glycerol and total protein content enhance H. longicornis tolerance to cold stress 10 .…”