Parasitiformes (ticks) and Acariformes (mites) vectors and their vertebrate host diversity: A global scoping review

While the infection ecology and epidemiology of some vector-borne pathogens have received extensive research focus, many tick- and mite-borne zoonoses, particularly in the global South, have been largely neglected. The current scoping review aims to understand the global state of knowledge for the infection ecology and epidemiology of tick- and mite-borne pathogens, contextualised by their maintenance community composition, in the landscapes in which these pathogens circulate.

Online databases were searched with keyword combinations to gather evidence on the relationship between vertebrate host species diversity and the occurrence of tick- and mite-borne diseases. Information related to pathogen, vector species involved in transmission, geographic location, and ecological and epidemiological relationships between host species diversity and tick- and mite-borne disease was recorded.

A total of 5510 papers were initially selected for screening based on this search with a final total of 36 papers included in the review. The review found that the literature is highly skewed toward Lyme disease (29 out of 36 studies) and focused on the global North regions (32 out of 36 studies). A general lack of studies on mite-borne diseases globally was evident. Additionally, 42 % of all studies reported evidence for the dilution effect whereby greater species richness in the maintenance community appeared to diminish pathogen transmission, while 31 % of the studies identified both dilution and amplification effects in the disease systems.

While there has been an increase in studies on tick-borne diseases other than Lyme disease in the past decade, the current scoping review has identified an urgent need to study tick- and mite-borne diseases in the global South. The state of knowledge on these unique vector-pathogen systems with respect to relevant maintenance communities is sparse and requires targeted investigation in regions of the global South experiencing rapid habitat loss and subsequent changes in vertebrate species diversity.