Cull et al.
Seasonality and anatomical location of human tick bites in the United Kingdom
Zoonoses Public Health 2019, in press, doi:10.1111/zph.12659
After the attachment of a tick infected with a pathogen, the risk of transmission of pathogens to the host increases with the duration of feeding. Therefore, the recognition and removal of ticks as soon as possible following attachment is important. Examination of the body to check for feeding ticks is a measure to reduce the risk to acquire tick transmitted diseases. Are there preferred places ticks bite on the body? This has been investigated by the Tick Surveillance Scheme (TSS) of Public Health England. Between 2013 and 2018, TTS analyzed the anatomical bite site location of 1,232 Ixodes ricinus ticks on the human body. Ticks were most frequently removed from the legs (45.9%), followed by the torso (24.2%) and head/neck (9.5%). There was a significant difference of bite locations between adults (over 18 years of age) and children (younger than 18 years). In adults, the preferred bite site were the legs (50.3%) compared to 11.3% in children. Otherwise, most ticks were found at the head/neck in children (43.3% vs. 4% in adults). These findings are likely due to behavioral and physiological differences between adults and children. The heads of children are usually at the height of vegetation where ticks are questing. Conversely, adults’ legs are at the questing height and therefore would be exposed to ticks while they walk through the vegetation. Detailed analyses are reported in this article for nymphs, larvae and adult ticks.
On birds, ticks are mostly found at the head. This strong preference for attaching on bird’s head can be seen even when the ticks are placed on other body parts. Different species of ixodid ticks have a consistent preference for attaching on the head of birds and move to the head when experimentally placed on other body parts (Fracasso et al., Int. J. Parasitol, 2019, in press).