Unexpected winter questing activity of ticks in the Central Midwestern United States.

Ram K Raghavan,Roger W Stich,Ali Hroobi,Roman Ganta,John Harrington,Gunavanthi Boorgula,Gary Anderson,Zoe L Koestel,Doug Goodin,Daniel Becker

doi:10.1371/journal.pone.0259769

Abstract

Unexpected questing activity of ticks was noted during the winter months of January and February in the Central Midwestern states of Kansas, Missouri, Oklahoma, and Arkansas. From nine geographically distinct locations, four species of ticks were collected using the flagging method, of which the lone star tick, Amblyomma americanum, was most abundant, followed by the American dog tick, Dermacentor variabilis, the Gulf coast tick, Amblyomma maculatum, and the Black legged tick, Ixodes scapularis. More A. americanum nymphs were caught questing than male or female adults. The winter activity of these medically important ticks in this region poses concern for public health and offers an insight into future tick activity in light of ongoing climate change. More studies on the seasonality of these tick species, and how different climate parameters affect their seasonal activity in this region are warranted and would be expected to benefit for both human and veterinary medicine.

Highlights

Tick-borne diseases in the Central Midwestern United States—roughly corresponding to the states of Kansas, Missouri, Oklahoma, and Arkansas—have been increasing steadily over the past decade [1,2]
A. americanum, A. maculatum, D. variabilis and I. scapularis were caught in this study during the winter months of 2017
With the ongoing climate change, it can be expected that the seasonal activity of medically significant tick species in the central midwestern US will change, with these tick species becoming more active throughout the year

Summary

Introduction

Tick-borne diseases in the Central Midwestern United States—roughly corresponding to the states of Kansas, Missouri, Oklahoma, and Arkansas—have been increasing steadily over the past decade [1,2]. This includes human ehrlichiosis [3], feline tularemia and cytauxzoonosis [4,5] transmitted by lone star ticks, Amblyomma americanum. Two novel tick-borne viral diseases of humans, caused by Heartland Virus (HRTV) and Bourbon Virus (BRBV), were recently identified in this region and were shown to be transmitted by this tick species [6–. Incidences of human and animal disease agents transmitted by other tick species in the region are on the rise. Rocky Mountain spotted fever [2], which are caused by rickettsial pathogens vectored by Dermacentor variabilis, have indicated a strong year-to-year and county-to-county spread.

Methods

Results

Discussion

Conclusion