What parasite causes Lyme disease?

Lyme disease is caused by a specific type of bacteria called Borrelia burgdorferi, which is transmitted primarily through the bite of infected ticks. Ticks, particularly the black-legged tick (also known as the deer tick), are the primary vectors of this disease. When the tick bites a host, it can transfer the bacteria into the bloodstream, leading to infection.

Fleas, mites, and mosquitoes may carry other diseases but are not responsible for transmitting Lyme disease. Fleas are more commonly associated with diseases like plague or flea-borne typhus, while mites can cause conditions such as mange. Mosquitoes are known for spreading diseases like West Nile virus and heartworm in pets. Therefore, the role of ticks as the vectors for Lyme disease is paramount, making them the correct answer in this context.