By ULY CLINIC

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Onchocerciasis (river blindness)

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Onchocerciasis is a tissue parasitic infestation caused by a filarial worm, Onchocerca volvulus.

The microfilariae invade lymphatic system, subcutaneous and deep tissues producing acute inflammation and chronic inflammation at a later stage.  

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Diagnostic Criteria

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• They are caused by the chronic inflammation which presents with:

• Skin inflammation with papules

• Subcutaneous nodules

• Atypical skin lesions (scarred, saggy, hanging areas of skin, leopard skin)

• Skin nodules under the bony prominent areas

• Microfilaria in anterior chamber

• Scleritis and Keratitis leading to Impaired vision as well as blindness.

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Investigations

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• Rapid diagnostic test (OV-16 - Onchocerciasis IgG) 

• Skin snip for microscopic examination

• Slit lamp eye examination. 

 

Pharmacological Treatment

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Treatment is done in consultation with dermatologists and infectious disease specialists. Apart from WHO recommended mass treatment campaign to community at risk with annual preventive chemotherapy which polarize/paralyze the worm, treatment depends on individual patient presentation. 

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Ivermectin 0.15 mg/kg (PO) once every 12 months for 12–15 years 

Note:

• Patients with heavy ocular infestation require retreatment every 3 to 6 months. 

• Treatment will only arrest progression of the clinical features but not revese them

 

Dosage guidelines based on body weight