Systemic tick borne infection

Rarely, systemic tick-borne infections may be transmitted by tick bite; these include rickettsial infections and, less commonly, infection by Coxiella burnetii, which causes Q fever. Transmission of systemic infection generally requires that the tick has been attached for at least 24 hoursEisen, 2018.

A dry necrotic black eschar at the site of tick bite (see Image of eschar and surrounding inflammation associated with rickettsial infection of a tick bite site) can be present in rickettsial infection transmitted by ticks.
Figure 1. Image of eschar and surrounding inflammation associated with rickettsial infection of a tick bite site.

[NB1]

Note:

NB1: A dry necrotic black eschar is a full thickness skin wound that may be a sign of rickettsial infection at the site of a tick biteGraves, 2020.

Reproduced with permission from Thomas SA, Wu J. Queensland tick typhus (Rickettsia australis) in a man after hiking in rural Queensland. Aust J Gen Pract 2018;47(6):359-60Thomas, 2018.

For clinical features and diagnosis of rickettsial infections, see information on rickettsial infections (Victorian Department of Health). For antibiotic recommendations for rickettsial infections, see Rickettsial infections .

For information about infections due to Coxiella burnetii, see Q fever . Q fever is, however, less likely to be transmitted by ticks than by inhalation of aerosols.

Lyme disease is caused by Borrelia species, transmitted to humans via tick bite; for information, see Lyme disease.