Harmful effects
Transmission of Lyme disease
The disease (first identified in Lyme, Connecticut) is spread by the bite of ticks of the genus Ixodes that are infected with the bacterial species Borrelia burgdorferi. The spirochetes live in the gut and salivary glands of ticks and enter the skin of the host (companion animals and humans) at the site of the tick bite. They may spread to other organs in lymph or disseminate in blood. Lyme disease is characterized by nonspecific symptoms such as flu-like chills, fever, malaise, arthritis and lymphadenopathy. In humans, the first clinical sign of Lyme disease is a reddish rash at the site of the tick bite, appearing like a ring or bull's-eye (so-called erythema migrans), which fades after a few weeks. Borrelia burgdorferi spirochetes can be found within the central nervous system as early as twelve hours after entering the bloodstream. This is why even early infections require full dose antibiotic therapy with an agent able to penetrate all tissues in adequate concentrations to be bactericidal to the organism.
Transmission of Babesiosis
Babesiosis is a malaria-like illness with hemolytic anemia caused by intracellular protozoan parasites of the genus Babesia, which attack the host's red blood cells. They live in the salivary glands of Rhipicephalus and Dermacentor species. Clinical signs of babesiosis in host animals (and humans) are high fever, hemolytic anemia, hemoglobinuria, jaundice and splenic enlargement. Infections may be life-threatening and must be treated promptly.
Transmission of Ehrlichiosis
Ehrlichiosis in both companion animals and humans is caused by several intracellular bacterial parasites of the genus Ehrlichia, which attack the host's white blood cells. They live in the salivary glands of Rhipicephalus species and are often transmitted as a dual infection with Babesia canis. Clinical signs may include fever, headache, malaise, respiratory distress and occasionally confusion and other neurological deficiencies. Chronic disease is associated with anemia, hemorrhage and a tendency to secondary infections.
Transmission of tick-borne encephalitis (TBE)
TBE is a disease of the central nervous system caused by a flavivirus which is mainly transmitted by bites of Ixodes species. Early clinical signs are flu-like illness, followed about a week later by the appearance of signs of meningoencephalitis. Severe motor dysfunction and permanent disability may occur. Russian spring-summer encephalitis, which is characterized by violent headache, high fever, nausea and vomiting is extremely dangerous. Delirium, coma and death may follow (mortality rate 25% to 30%). The flavivirus is exclusively pathogenic to humans, and companion animals are mainly involved as intermediate reservoir. Since there is no chemotherapy or specific treatment, measures for tick control and prevention are absolutely mandatory.
Tick paralysis
This severe disease is caused by a neurotoxin, which is produced by females of Ixodes and Dermacentor species. The action of the neurotoxin may result in death due to respiratory paralysis.