What is the tick that causes rickettsiosis? - briefly
The bacteria responsible for rickettsial disease are transmitted by several tick genera, chiefly Dermacentor, Rhipicephalus and Ixodes. Dermacentor variabilis (the American dog tick) is the primary vector of Rocky Mountain spotted fever in North America.
What is the tick that causes rickettsiosis? - in detail
The primary vector of rickettsial disease in humans is the brown dog tick, Rhipicephalus sanguineus. This ectoparasite completes its life cycle on a single host species—domestic dogs—yet it readily feeds on humans when dogs are absent. Its role in transmitting Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, is well documented in temperate and subtropical regions.
Key biological features of R. sanguineus:
- Three developmental stages (larva, nymph, adult) each requiring a blood meal.
- Ability to survive for months without feeding, permitting persistence in indoor environments.
- Tolerance of a wide temperature range (10 °C–40 °C), enabling establishment in diverse climates.
- Transovarial transmission of Rickettsia spp., allowing infected offspring to emerge already carrying the pathogen.
Geographic distribution covers most of the world’s temperate zones, with high prevalence in the United States, Mediterranean countries, and parts of South America and Africa. Indoor infestations are common in kennels, veterinary clinics, and households with pet dogs, creating a direct pathway for human exposure.
Transmission dynamics:
- Infected tick acquires Rickettsia during larval or nymphal feeding on a bacteremic host.
- Pathogen replicates in the tick’s salivary glands and ovaries.
- During subsequent blood meals, the tick inoculates the bacterium into the host’s dermis.
- Human infection can occur within hours of attachment; prompt removal reduces bacterial load but does not eliminate risk.
Control measures focus on eliminating tick habitats, regular acaricide treatment of dogs, and environmental decontamination. Monitoring programs track tick density and infection rates, informing public‑health advisories during peak activity seasons (late spring to early autumn).