Seasonality and anatomical location of human tick bites in the United Kingdom

Tick bites on humans can occur in a variety of habitats and may result in the transmission of tick-borne pathogens, such as the causative agent of Lyme borreliosis (LB), Borrelia burgdorferi sensu lato. As the risk of transmission of this pathogen to the host increases with the duration of tick feeding, the recognition and removal of ticks as soon as possible following attachment is important for reducing the risk of infection. Performing a thorough body examination for ticks following potential exposure is recommended by tick awareness campaigns. Knowledge of where on the body feeding ticks are frequently found, and at which times of year peak tick exposure occurs, provides important information for public health messaging and may aid those bitten by ticks to engage more effectively with tick-checking behaviour. This paper summarizes human tick bites in the United Kingdom (UK) during 2013-2018 reported to Public Health England's passive Tick Surveillance Scheme and further examines the anatomical location and seasonality of bites from the most commonly encountered tick and LB vector Ixodes ricinus. A total of 1,328 tick records from humans were received of which 93% were I. ricinus. Humans were most commonly bitten by I. ricinus nymphs (70% bites). Tick bites were recorded on all parts of the body, but there were significant differences in their anatomical location on adults and children. Most tick bites on adults occurred on the legs (50%), whereas on children tick bites were mostly on the head and neck (43%). Bites from I. ricinus were recorded throughout the year but were most numerous during May to August. This study adds to the body of research on the seasonality and anatomical location of human tick bites in temperate Europe and highlights the importance of data collected through passive surveillance in addition to research and epidemiological studies.