Tick collection

The California Department of Public Health (CDPH), Vector-Borne Disease Section performs routine surveillance and testing of sylvatic Ixodes ticks for Borrelia spp. spirochetes. This includes relapsing fever group Borrelia (e.g., B. miyamotoi) and members of the B. burgdoferi sl complex [12]. Ixodes pacificus adults and nymphs were collected throughout the state of California from 2008 to 2015. Ticks were collected from low vegetation, leaf litter, or other substrates (e.g., rocks or downed logs) by CDPH and county public health agencies using 1-m² white double nap flannel “flag” attached to a 1.5-m wooden dowel. In most instances, ticks were collected from public lands such as regional or state parks. Ticks were collected all months of the year, with adult ticks most commonly collected in the winter months and the nymphs in the spring and summer months. Adult and nymphal I. spinipalpis ticks were collected opportunistically by flagging, during the same collection events; this tick species rarely attaches to people but parasitizes wildlife such as woodrats (Neotoma fuscipes and N. macrotis) and may be an important bridge vector for B. burgdorferi sl. Ticks were either maintained alive within 37-mL polystyrene containers (Fisher Scientific, USA) in sealed plastic bags with moistened paper toweling at 3°C or retained in 70% ethanol within 1.5-mL microcentrifuge snap-cap tubes.