Ixodes Scapularis - As Disease Vector

As Disease Vector

Ixodes scapularis is the main vector of Lyme disease in North America. It can also transmit other Borrelia species, including Borrelia miyamotoi.

Ixodes ticks also can transmit Ehrlichia, a gram-negative obligate intracellular bacteria that is responsible for Ehrlichiosis.

Ticks that transmit Borrelia burgdorferi to humans can also carry and transmit several other parasites, such as Theileria microti and Anaplasma phagocytophilum, which cause the diseases babesiosis and human granulocytic anaplasmosis, respectively. Among early Lyme disease patients, depending on their location, 2%–12% will also have HGA and 2%–40% will have babesiosis.

Co-infections complicate Lyme symptoms, especially diagnosis and treatment. It is possible for a tick to carry and transmit one of the co-infections and not Borrelia, making diagnosis difficult and often elusive. The Centers for Disease Control's emerging infectious diseases department did a study in rural New Jersey of 100 ticks, and found 55% of the ticks were infected with at least one of the pathogens.