Is African Eye Worm (Loiasis) Contagious?

No, Loiasis (African eye worm) is not contagious from person to person ^[1][2]. If you have an active infection, you cannot pass the parasite to your spouse, your children, or anyone else around you ^[2][3].

It is completely safe to touch, hug, and share a home with your loved ones ^[2]. The parasite cannot be spread through casual contact, sharing food or utensils, kissing, bodily fluids, or sexual intercourse ^[2][3].

How Loiasis Is Spread

To understand why your loved ones are safe, it helps to understand how the Loa loa parasite lives and grows. The African eye worm requires a very specific biological partner—a type of insect called the Chrysops fly, commonly known as the deer fly or mango fly ^[1][4].

The transmission process works like this:

• The Fly as an Incubator: When a Chrysops fly bites a person who has Loiasis, the fly ingests microscopic early-stage parasites (called microfilariae) that are circulating in the person’s blood ^[1][5].
• A Necessary Transformation: The parasite cannot simply jump to another person and survive. It must spend time developing inside the fly’s body to mature into an infective larva ^[1][5].
• Infecting a New Host: Only after the larva has matured inside the insect can the fly pass the infection to a new person during a future bite ^[1][5].

Because the parasite absolutely requires the Chrysops fly to transform and mature, it is physically impossible for the infection to spread directly from one human to another ^[1][2].

Understanding Your Symptoms and Your Family’s Risk

If you are currently managing an active Loa loa infection, you can focus fully on your own health and treatment without the emotional burden of worrying about infecting your family.

While the adult worms can occasionally migrate across the surface of the eye (which gives the disease its name), they also produce the microscopic baby worms that circulate in your bloodstream ^[1][5]. You may also notice Calabar swellings—temporary, localized swollen areas under your skin ^[1]. This is all a normal part of the infection.

Because the microscopic worms are in your blood, you should not donate blood or organs while you are actively infected, even though the parasite cannot grow into an adult without the fly vector ^[2].

Fortunately, Loiasis is highly treatable ^[1]. Your doctor can prescribe medications to eliminate the parasites from your body and resolve your symptoms safely ^[1].

Finally, if your family members have also been diagnosed with Loiasis, or if they develop symptoms like Calabar swellings or eye irritation, it is not because they caught the infection from you. Instead, it is because they were independently bitten by Chrysops flies if they traveled with you to regions in West or Central Africa where the flies live ^[6]. If you traveled together, they should monitor their own health and consult a doctor if they notice any symptoms ^[6].