LOAISIS (AFRICAN EYE WORM)

LOAISIS also called African eye worm by most people, is caused by the parasitic worm Loa loa. It is passed on to humans through the repeated bites of deerflies (also known as mango flies or mangrove flies) of the genus Chrysops.
Loa loa is the filarial nematode species that causes Loa loa filariasis. Loa loa actually means "worm worm", but is commonly known as the "eye worm", as it localizes to the conjunctiva of the eye. Loa loa is commonly found in Africa. It mainly inhabits rain forests in West Africa and has native origins in Ethiopia
Loa Loa is endemic in eleven West and Central African countries, as follows;
Angola, Cameroon, Central African Republic, Chad, Congo, Democratic Republic of Congo, Equatorial Guinea, Ethiopia, Gabon, Nigeria, Sudan.

• WHAT ARE THE SIGNS AND SYMPTOMS?
Parasitic eye infections don’t always cause symptoms, which can make them hard to recognize.
When symptoms do occur, they can include:
✓ eye pain
✓ redness or inflammation in the eye
✓ excessive tear production
✓ blurry vision
✓  presence of floaters (small spots or lines) in your field of vision
✓ sensitivity to light
✓ crusting around the eyelids and eyelashes
✓ redness and itching around the eye
✓retinal scarring
✓ loss of vision and blindness

• HOW DO YOU GET INFECTED?
You get infected by being bitten by an infected deerfly of the genus Chrysops. Deerflies become infected when they eat blood from an infected person. Travelers are more likely to become infected if they are in areas where they are bitten by deerflies for many months, though occasionally they get infected even if they are in the area for less than 30 days.

• CAN LOIASIS BE SPREAD PERSON TO PERSON?
No. If you are infected you cannot pass the infection on to other people.

• HOW IS IT DIAGNOSED?
If you have traveled to an area where infected flies are found and you develop symptoms, your health care provider may order a blood smear.  Blood is put on a microscope slide and examined for the larvae of the parasite.  Additionally, loaisis can be diagnosed by a health care provider if they see an adult worm on the surface of your eye.  Sometimes, if your health care provider is concerned that you may be infected but your tests are normal, he or she may order a specialized blood test.

• WHAT IS THE TREATMENT?
Treatment of loiasis can be dangerous, so your health care provider may want to talk to an expert in tropical medicine before giving you any medication to treat loiasis. If you have an eye worm, the worm can be surgically removed to provide immediate relief while your health care provider determines if it is safe to treat you with medication to kill the parasite. Removing the worm from your eye does not cure the infection, as the parasite is often found in other parts of your body. A medication called diethylcarbamazine, or DEC, can be used to kill the parasites in your body. Because there is a small risk of serious side effects related to killing the parasites, your health care provider will do tests to be sure that it is safe to treat you. Sometimes people need special treatments before it is safe to give medication and sometimes treatment with medications is not recommended.

CREDIT: CENTER FOR DISEASE CONTROL AND TREATMENT (CDC)