Range Expansion of Tick Disease Vectors in North America: Implications for Spread of Tick-Borne Disease

Abstract

Ticks are the major vectors of most disease-causing agents to humans, companion animals and wildlife. Moreover, ticks transmit a greater variety of pathogenic agents than any other blood-feeding arthropod. Ticks have been expanding their geographic ranges in recent decades largely due to climate change. Furthermore, tick populations in many areas of their past and even newly established localities have increased in abundance. These dynamic changes present new and increasing severe public health threats to humans, livestock and companion animals in areas where they were previously unknown or were considered to be of minor importance. Here in this review, the geographic status of four representative tick species are discussed in relation to these public health concerns, namely, the American dog tick, Dermacentor variabilis, the lone star tick, Amblyomma americanum, the Gulf Coast Tick, Amblyomma maculatum and the black-legged tick, Ixodes scapularis. Both biotic and abiotic factors that may influence future range expansion and successful colony formation in new habitats are discussed.

A 117 year retrospective analysis of Pennsylvania tick community dynamics

“…Am. americanum is a competent vector of ehrlichiosis, tularemia, RMSF, multiple Borrelia species (Including B. lonestari, B. andersonii , and B. americanum ), and competent vector of heartland virus)[2,58,59]. Am.…”

“…We identified 4 additional submissions of this species in our database since 1968 from 1969, 1990, 1994, and 2004. In the last several decades, the range of this species has expanded westward into the Mid-west and northward into the Mid-Atlantic on migrating birds, including into neighboring states (Sonenshine 2018). Their establishment northward has been attributed to climate change, but because they require high humidity and higher temperatures, what has driven their movement inland and westward is not yet clear.…”

“…Changes in geographic variability and the temporal dynamics of tick species may influence tick-borne disease outcomes. Several endemic tick species have been expanding into new habitats across North America, posing novel risks to local communities [2]. Although there are many tick-borne pathogens, the vast majority of tick-borne disease cases are caused by Borrelia burgdorferi [1,3], the main etiological agent of Lyme disease in the USA.…”

“…encroachment may bring reservoir hosts such as groundhogs in closer proximity)[9,10]. Additionally, long-term surveillance data can also reveal shifts in temporal dynamics of tick populations and communities [2]. The seasonality of known tick species have been described, but year-to-year distribution of tick species may be influenced by inter-annual variability (e.g.…”

The impact of biological invasion and genomic local adaptation on the geographical distribution of Aedes aegypti in Panama

“…The establishment and persistence of vectors within new geographic locations poses a serious threat from emerging and endemic arboviral diseases (1,2). For example, shifts in the distribution of ticks and Culex mosquitoes are linked to the rise of West Nile Virus and tick-borne encephalitis viruses within North America (3)(4)(5). In addition, the introduction of invasive Aedes mosquitoes has facilitated the recent spread of Zika and Chikungunya viruses throughout the Americas (6,7).…”