Pathogen & epidemiology

• Onchocerca volvulus

Life-cycle

• Black fly (genus Simulium) takes a blood meal and larvae enter wound

• Adults in s/c tissues, produce microfilariae typically found in skin and lymphatics of connective tissue (occasionally in blood, urine, sputum)

• Blackfly takes a blood meal and ingests mf

Clinical

Triad

• Skin nodules (adult worms)

• Dermatitis: Skin itch (leopard skin)

• Eyes: 5% blind

• 
  

• Association with Nodding syndrome

Diagnosis

• Skin snip

• Clinical, Eosinophilia, eye (slit lamp)

• Mazzotti DEC test

Treatment

• Doxycycline for 4-6 weeks (wolbachia)

• Ivermectin every 3-6 months (not if Loa Loa)

Prevention

• MDT

• Disease control