Dermacentor variabilis, also known as the American dog tick or wood tick, is a species of tick that is known to carry bacteria responsible for several diseases in humans, including Rocky Mountain spotted fever and tularemia (Francisella tularensis). It is one of the most well-known hard ticks. Diseases are spread when it sucks blood from the host, which could take several days for the host to experience some symptoms.

Disease transmission

Symptoms of Rocky Mountain spotted fever can first be noted by the appearance of a rash around the wrists and ankles that moves slowly up to the rest of the body and develops within 2–5 days. Symptoms of Tularemia can usually be noticed within 3–5 days but can take up to 21 days before symptoms appear. Oftentimes patients will experience chills, swollen lymph nodes, and an ulceration at the site of the bite.[5]

Fortunately, when a tick bites you, it does not automatically transfer diseases to their host. Instead, they need to be attached to the host around 6–8 hours before they are capable of transferring the disease.[5] This gives the host an opportunity to remove this parasite before disease transmission occurs.

Source: Wikipedia