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Review
. 2018 Apr 3:9:43-48.
doi: 10.2147/RRTM.S132380. eCollection 2018.

Loa loa infection detection using biomarkers: current perspectives

Jean Paul Akue  1 , Elsa-Rush Eyang-Assengone  1   2 , Roland Dieki  1
Affiliations
Review

Loa loa infection detection using biomarkers: current perspectives

Jean Paul Akue et al. Res Rep Trop Med. .

Abstract

Loa loa is originally a restricted filarial worm from central Africa and some west African countries. However, numerous imported cases are being reported throughout the world due to human movement. Traditionally, its diagnosis is based on identification of microfilariae in the peripheral blood or the passage of the adult worm under the conjunctiva. However, few patients have microfilariae in their peripheral blood, while the majority of infected people are amicrofilaremic (without microfilariae in their blood), despite clinical symptoms suggesting L. loa infection. This situation suggests that diagnoses based on the presence of microfilariae in the blood or the ocular passage of an adult worm, are not sensitive. Therefore, it seems necessary to search for biomarkers to remedy this situation. Furthermore, L. loa is a major obstacle in the control of other filarial worms in areas where these filariae are co-endemic. To develop a diagnostic tool based on a biomarker, several approaches have been considered using antibodies, antigens or nucleic acid detection. However, none of the diagnostic techniques in loiasis based on biomarkers has reached the point of care as have microscopic detection of microfilariae or observation of ocular passage of a worm.

Keywords: DNA; Loa loa; antibody; antigen; diagnosis.

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Conflict of interest statement

Disclosure The authors report no conflicts of interest in this work.

Figures

Figure 1
Figure 1
Natural distribution of Loa loa. Map of Africa showing the area of endemicity for L. loa (circled in red). Adapted from Sayre et al, A New Map of Standardized Terrestrial Ecosystems of Africa. NatureServe. 2013.
Figure 2
Figure 2
Loa loa microfilariae. Group of microfilariae purified from a hypermicrofilaremic individual stained with May-Grumwald Giemsa (A). Note the unstained sheath of microfilaria during exsheathment, see arrows (B). The cephalic extremity of microfilaria without nuclei; but unstained sheath, see arrow (C). The tail of microfilaria with nuclei extending to the end of the tail indicated by arrow (D).
See this image and copyright information in PMC

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