| Diagnostic methods | Pros and cons |
| Parasitological diagnosis | |
Microfilariae can be found in day blood (peak between noon and 2 p.m.). However, many infected individuals are amicrofilaraemic due to immunity to microfilariae (“occult loiasis”). Standard procedure: membrane filtration or lysis of blood (Knott’s method).
Adult worms may be seen migrating through the conjunctiva. Fugitive swellings (calabar oedema) are characteristic for loiasis. | - Sensitivity of parasitological methods unsatisfactory due to long pre-patent period and immunity to microfilariae
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| Molecular diagnosis | |
| PCR methods detecting two repetitive DNA sequences of Loa loa in whole blood have been described but are not yet standardized. | |
| Antigen detection | |
| Attempts to develop a sensitive antigen detection assay have been unsuccessful so far | |
| Antibody detection | |
| Serological tests detect circulating antibodies in loiasis lack specificity (cross-reacting antibodies from Mansonella perstans and other filarial infections) and are unable to distinguish between past and current infection | - No specific test so far available
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