Loa Loa: The “African Eye Worm”

Loa Loa migrating through eye

Loa Loa migrating through eye

Nicknamed “the African eye worm”, Loa loa is one of those tropical parasites that myths and legends are made of.  A medically important parasite from Africa, this is commonly a disease of local people but can effect travelers and adventurers in the endemic areas.

 Basics:

Also known as “African Eye Worm”. Filarial worms migrate through all tissues of the body. Transient swellings and itching are most common symptoms and can take years to appear.

 

Location:

African rainforests and especially Central Africa

 

Transmission/ Incubation:

Transmitted by the bite of an infected Deer Fly (Chrysops species)

Prevention:

Standard flying insect precautions, vector control, 300 mg once per week DEC (diethylcarbamazine) for high risk persons

 

Diagnosis:

Demonstration of microfilariae in daytime drawn blood smear

 

Treatment:

Diethylcarbamazine (DEC) 5-10 mg/kg three times per day for 3-4 weeks generally kills larvae and eliminates adult worms. Treat possible histamine/allergic based reactions with antihistamines/steroids. Albendazole and ivermectin may have a slower kill of larvae, causing a less severe treatment reaction.

 

Chrysops fly

Chrysops fly

This parasite is very similiar to the other nematodes including W. bancrofti.  however, this worm likes to move through tissues, without setting up a real permanent residency.  Soem trouble with this infection can occur when treatment begins.  Use of medications often used to treat other parasitic infections, found in the same geographic area, can cause bad reactions.  Caution should be used with ivermectine (treatment for onchocerciasis) as encephalitis/brain swelling can occur.  Common treatment reactions with DEC can involve histamine and typically respond well to antihistamines and/or steroids.

 

distribution of common parasitic infection

distribution of common parasitic infection

 

 

 

 

 

 

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