Final answer:
Borrelia recurrentis is transmitted by the body louse Pediculus humanus, causing louseborne relapsing fever, while Borrelia hermsii is transmitted by the soft-bodied tick Ornithodoros hermsi, causing tickborne relapsing fevers. Both require vectors for transmission and can lead to recurrent fever episodes treatable with antibiotics.
Step-by-step explanation:
Transmission of Borrelia Species
The transmission of Borrelia recurrentis and Borrelia hermsii is categorized as vector transmission, which is similar to how Lyme disease is transmitted through ticks. B. recurrentis is known to cause louseborne relapsing fever and is transmitted by the body louse Pediculus humanus. Lice become infected with this bacterium when they feed on humans carrying the spirochetes. On the other hand, B. hermsii is responsible for tickborne relapsing fevers and is transmitted by the soft-bodied tick Ornithodoros hermsi, which acquires the spirochetes from rodent reservoirs. Infection in humans occurs when the Borrelia in the tick's saliva or excreta enters the skin as the tick bites.
Both diseases involve bacteremia, causing recurrent fever episodes that can be alleviated with antibiotic treatment. The cyclical nature of symptoms arises from the bacteria's ability to evade the immune system through antigenic variation. These fevers, if left untreated, can result in significant health issues.