MorLo Project

Rationale

Loiasis, an infectious disease caused by the parasitic worm Loa loa, affects more than 20 million individuals in central Africa, and more than 100 million people are potentially exposed to infection. Since its first description in 1770, the international scientific community has considered this filarial disease as benign. As a result, loiasis is not considered a Neglected Tropical Disease (NTD), according to the list edited by the WHO; with the impact of the absence of programs to fight this disease.

The main clinical features associated with loiasis are chronic hypereosinophilia, joint pain, temporary joint edema (named “Calabar’s swelling”), pruritus, and occasional passage of the worm under the skin as well as under the conjunctiva of the eye (also known as "eye worm" disease). However, loiasis is known to be one of the main reasons for consultations in endemic areas. And recently, we demonstrated that loiasis significantly reduces the life expectancy of infected people, which should lead to further studies to understand this result.

While some more severe complications are suspected, no studies to date have demonstrated the reality of loiasis-related complications. Serious clinical conditions result of several interacting mechanisms. The main hypothesis is that loiasis induces a chronic pathology possibly related to the very stable microfilarial levels. Most clinical sequelae may be indirect and unspecific, and this might explain why direct links have not been demonstrated so far.

Last, more generally, representative data on the prevailing morbidity in rural communities of Central Africa is dramatically lacking. This is particularly true for loiasis, but also for cardiac and kidney diseases in general. Thus, beyond its main objectives focusing on loiasis, the present project will contribute to the collection of invaluable information on the prevalence of complications of various infectious and non-infectious diseases.