A review of loiasis and its vectors in Gabon.

Loiasis colloquially known as tropical eye worm is a neglected tropical helminthic disease that affects the rural poor population of Gabon. A systematic review of 51 documents (45 peer reviewed papers and six dissertations) over four decades has documented many knowledge gaps on loiasis and its vectors. Higher prevalence and high microfilaremia is typical wherever Chrysops vectors occur. The two main vectors were C. silacea and C. dimidiata along with the savanna species C. longicornis. The two main vectors were only caught around forested national parks at low density (<1 Chrysops per trap per day). Chrysops longicornis was trapped in the savanna zone at higher numbers at a cattle ranch in Nyanga province. Leukoconcentration and Field's stain for L. loa diagnosis performed well as diagnostic tools. However, studies on diagnostic efficacy remain scant, and no study has focused on the evolution of L. loa at the wildlife-human interface of Gabon.