The initial bite may be the least of your worries.

By Maggie O'Neill
August 25, 2020
Advertisement

When people talk about sand fleas, they may be talking about a few different organisms: Sand flies, which live in and around aquatic habitats, and sand or mole crabs, which are actually crustaceans that live on the beach and don't bite humans. Really, "any flea that comes out of a sandy area, people call a sand flea," Nancy Hinkle, Ph.D, a professor at University of Georgia’s Department of Entomology, tells Health.

But true sand fleas are technically known as chigoe fleas, or Tunga penetrans, according to the Centers for Disease Control and Prevention—and they're actually quite detrimental to human health, but not necessarily from a bite. Luckily, these sand fleas are extremely rare in the US, but that doesn't mean you'll never come across them, especially if you travel outside the country at some point.

To help you with everything you need to know about sand fleas, Health spoke to Hinkle, an entomologist (aka, a bug expert)—here's what we found out about sand fleas, sand flea bites, and what other damage these parasites can cause.

What are sand fleas (aka, chigoe fleas), and where do they live?

Chigoe fleas are known by quite a few different names: jiggers, niguas, chicas, picos, piques or suthis, according to the CDC, which says that adult female fleas pose the most risk to humans. While both adult male and female fleas feed on warm-blooded hosts, like humans, the adult mated females actually burrow into the skin of humans (more on that later).

These sand fleas are mainly found on Caribbean beaches, as well as beaches in South America, Hinkle says. The fleas originally came from Africa, and Hinkle says sand fleas are common on African beaches as well. The CDC adds that the fleas normally occur in sandy climates, including beaches, stables and farms.

Just because we don’t currently see Tunga penetrans in the US doesn’t mean we couldn’t: If you were to travel to a beach in the Caribbean, for instance, and come into contact with the fleas, you could potentially pick them up there. And then, if you walked around a beach the US after coming into contact with sand fleas, you could introduce them to the area. “That is a risk—[if] you have been walking along a Florida beach, you could start an infestation of chigoe fleas in Florida,” Hinkle says.

What do sand flea bites look and feel like?

Here's where things get interesting: Sand fleas reproduce with the help of humans. Female sand fleas burrow into the skin (usually the feet) and male sand fleas briefly meet them there to mate, Hinkle says. This is technically called tungiasis, or an infestation by the Tunga penetrans. The female’s head will be burrowed into the skin but her rear end isn’t, which allows her to expel eggs to the ground after mating. The female dies after expelling eggs—about 100 or so over a two-week period, per the CDC—and then will fall out of the foot, to the ground.

Usually, people don’t notice sand flea bites as they’re happening. The fleas are small, and they usually attach themselves to the ankles or feet, meaning you might not even notice when they first make contact with the body. In fact, per the CDC, the initial symptoms of a sand flea infection usually start to develop only after the females are in their engorged state. “That’s the risk there: You have this lovely vacation, you get back on the plane—a couple of days later you notice irritation on your big toe, [and] it’s hurting to walk around,” Hinkle says. This inflammation and ulceration may become severe, the CDC says, and multiple lesions can cause difficulty walking

But the bite itself—and even strictly the burrowing—isn’t necessarily the problem, it’s the aftermath. The opening created when the female burrows into the skin can put you at risk of contracting infections. The female sand flea “creates this opening that allows bacterial infection.” This can lead to a tetanus diagnosis, or one of gangrene, Hinkle says. In severe cases, people have to have toes amputated as a result of a sand flea bite. The treatment prescribed if your doctor diagnoses you with sand flea bites hinges on the damage done.

Your takeaway: The next time you do find yourself planning a vacation, it can’t hurt to look ahead to see if sand fleas are problematic on the beaches you plan on visiting. The World Health Organization reports that repellents, such as DEET-containing bug sprays, can be effective in keeping fleas away, as can coconut oil. That said, it’s important to check the label of your preferred bug spray to see how frequently you need to apply it to make sure you’re constantly protected.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter