What

Spread by biting black flies, onchocerciasis (oncho) is a vector-borne nematode parasitic disease that causes severe disability. 

Who

Approximately 33 million people

Where

30 countries in sub-Saharan Africa (with small foci in Latin America and Yemen)

Symptoms

Blindness and severe skin disease

DOLF Project’s contributions 

The current onchocerciasis treatment approach of annual mass drug administration with ivermectin is useful for preventing severe disease but is unlikely to eliminate onchocerciasis before 2050. We have conducted several clinical trials to evaluate the safety and efficacy of new drug combinations. One study found that a single dose of IDA was partially effective for killing the adult worms and more effective than ivermectin. This was a step forward, but there is more work to be done. A current clinical trial is testing new drug combinations and a different treatment schedule in hopes of improving efficacy.

Additional information

Several programs and developments — including the Onchocerciasis Control Programme (ended in 2002), the African Programme for Onchocerciasis Control (ended in 2015), and the Mectizan Distribution Programme — have greatly helped to control and prevent the disease. Now, the goal is permanent elimination. The Onchocerciasis Elimination Program for the Americas (OEPA) has nearly eliminated onchocerciasis in the Americas, and the World Health Organization and the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) manage onchocerciasis elimination in Africa. 

While local elimination of onchocerciasis in isolated areas in Africa can be achieved in the near future with periodic mass administration of ivermectin, computer modeling studies predict that it may take several decades to eliminate onchocerciasis across Africa. More effective treatments — options for which the DOLF Project is studying — could greatly accelerate this process.

Learn more about onchocerciasis from the Centers for Disease Control and Prevention and the World Health Organization.

Larval onchocercal worms in the eye of an infected study participant.