A woman lived with an eye parasite for years before seeking treatment

By Claire Wolters | Fact-checked by Davi Sherman
Published April 24, 2024

Key Takeaways

  • Parasites can cause silent but severe health problems; a recent case involves a woman who had a parasite living in her eye for 2 years before seeking medical treatment.

  • She was eventually diagnosed with the zoonotic disease ocular pentastomiasis, which can cause blindness—that’s why detecting and removing parasites right away is crucial.

  • In the exam room, ask questions about travel and hygiene and administer tests as needed to help detect a parasite early in at-risk patients, such as those who have recently traveled.

When parasites burrow into the body, they can cause severe health problems. To treat existing damage and stop the parasite from causing more harm, the best course of action is to find and remove the bug from the body. This is often easier said than done, however, as some parasites hide in hard-to-reach places, and others can go undetected for years, causing silent disruptions.

One particularly harrowing case involves a woman who harbored a parasite in her eye for 2 years before seeking medical care.[][] 

Hiding in plain sight

The patient, living in the town of Basankusu in the Democratic Republic of the Congo, presented to the hospital for an uncomfortable mass that had developed in her eye. Doctors eventually found out it was a larval form of a pentastomid parasite, which typically infects reptiles and is not usually detected in humans, but can be passed to different hosts through the food chain. 

The presence of the parasite in the patient’s eye contributed to an eventual diagnosis of the zoonotic disease ocular pentastomiasis. The ocular subtype of pentastomiasis is particularly rare in humans, as the parasite is most likely to be found in the abdominal region. Her doctors deduced she most likely contracted the parasite after eating crocodile meat.

Health risks of ocular parasites

Parasites in the eye can cause a variety of symptoms, including inflammation and scarring of the eye, and can even pose risks of blindness.[] Once detected, surgical removal of larval parasites from the eye can be necessary for helping the body heal. However, some damage may remain.[]

Despite the trauma it can cause to the eye, an ocular parasite may be easier to remove than one buried within internal organs, where removal requires more invasive surgery. Ocular parasites may, in some cases, also be easier to find.

Doctors should encourage patients to seek medical attention for problems with vision or pain in their eyes. Although parasites in the eye are rare, they are not nonexistent. A patient may still need medical interventions for their symptoms even if they are not experiencing an ocular parasite.

Doctors can help patients get a head start on treatment by diagnosing parasites early.

Conducting thorough physical exams, including eye exams, and asking questions about patients’ recent travel, dietary choices, and hygiene habits can help you get a sense of whether they are at risk for infection caused by a parasite and whether this might explain any curious health symptoms they are experiencing. 

Diagnosing parasites

Diagnosing parasites can require a combination of asking questions and administering tests. Providers can ask patients questions on the following topics:[]

  • Recent travel history: Some parasites are more common in some countries than in others.

  • Dietary choices: Some parasites can be passed through food sources, like unsanitary water, raw meat, or fruit washed in unsanitary water.

  • Interactions with pets or animals: Some parasites can be passed to humans from living animals or animal feces.

  • Suspected bug bites: Some insects can pass parasites to humans through bites.

  • Hygiene practices: Proper hygiene can reduce the risk of infections, including those caused by parasites.

Providers can conduct the following tests to diagnose a parasite:[]

  • Fecal or stool exams: These can be used to look for a parasite causing symptoms such as diarrhea, loose or watery stool, cramping, gas, or other abdominal illnesses, according to the CDC.

  • Colonoscopies and endoscopies: These procedures can be used to look for a parasite causing symptoms like diarrhea, loose or watery stool, cramping, gas, or other abdominal illnesses, particularly if a previous stool sample did not identify a parasite.

  • X-rays, MRIs, or CAT scans: These tests can help identify some parasitic diseases that cause lesions in organs.

  • Blood tests: Blood tests can be conducted to look for specific parasites but can’t give a comprehensive picture of every parasite.

Two available blood tests for parasites include a serology test, which is used to look for parasite antigens, and a smear test, which is used to look for parasitic diseases in the blood, such as filariasis, malaria, or babesiosis.

Administering additional tests may be helpful when dealing with a case in an unusual location, such as the eye. 

Chris McDermott, MSN, APRN-IP, AGPCNP-C, CLCP, a nurse practitioner, suggests that doctors utilize “advanced imaging techniques tailored to the suspected location of the parasite,” like optical coherence tomography (OCT), to help with a suspected ocular parasite diagnosis.

“[OCT] can provide high-resolution images of ocular structures, aiding in the detection of subtle abnormalities caused by parasitic infestations,” McDermott tells MDLinx. “These imaging modalities enable clinicians to visualize the affected areas with precision, facilitating accurate diagnosis and prompt initiation of appropriate treatment measures to mitigate potential complications.”

What this means for you

Parasites can cause harm to the body, which often can only be stopped through surgical or non-surgical removal. Doctors can help patients get a head start on parasite treatment by detecting cases early. Ask your patients about travel history and hygiene practices, in addition to conducting tests, if they appear to be at risk of a parasitic disease.

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