Can Fleas Pass Disease To Humans?

The constant itching sensation of a flea bite is enough to drive anyone crazy, but the real threat posed by these tiny blood-sucking pests comes in the form of infectious disease. It’s a common assumption that fleas are merely a nuissance, with bites that only cause minimal pain, itching and inflammation. Along with these unpleasant symptoms, however, fleas are capable of transmitting a variety of infectious diseases to humans.

Black Plague

Yersinia pestis, or what’s more commonly known as the Black Plague, is a bacterium-based disease that’s spread by fleas. It was responsible for killing an estimated 25-30 million people in Europe during the 14th century and 200 million people worldwide through history. Rats carried the fleas into cities, homes and dwellings, spreading the disease like wildfire.

I know what you’re probably thinking: isn’t the black plague long gone by now? This short answer is no, it’s not gone. There are still several cases of black plague reported each year, usually occurring in the southwest. Modern-day antibiotics are highly effective at treating the black plague, but it can still kill an otherwise healthy adult in 7 days if left untreated. It’s critical that people exhibiting signs of the black plague seek medical attention immediately.

Black Plague Symptoms:

  • Headache
  • Fever
  • Lethargy
  • Weakness
  • Lack of energy
  • Swollen lymphnodes


Another disease that’s transmitted to humans by fleas is murine typhus.  Much like the Black Plague, murine typhus is carried by rat-infested fleas. The fleas attach themselves onto the furry coat of rats, at which point they are transported throughout the surrounding region. Murine typhus can be found throughout much of the U.S., although it’s especially problematic in Texas and the surrounding southern states.

Typhus Symptoms:

  • Headaches
  • Red rash
  • Body aches
  • Weakness
  • Infection

Typhus responds well to a treatment of antibiotics, but again, it’s critical that people suffering from this disease seek medical attention immediately. Allowing the disease to progress will significantly reduce the chance of a positive outcome.


Although this is technically a parasite, not a disease, it’s still worth mentioning that tapeworms can be transmitted to humans by fleas. In order for a flea to transmit a tapeworm to a human host, however, the human must consume the flea (a bite won’t transmit tapeworms).

Fleas transmit a variety of diseases to human hosts.

Fleas transmit a variety of diseases to human hosts.

Have you experienced illness or disease as a result of a flea bite? Let us know about it in the comments section below!