Imported loiasis in France: a retrospective analysis of 47 cases

Background: French physicians occasionally encounter travelers (immigrants, expatriates, others) seeking care for loiasis.

Methods: We describe the clinical and biological patterns and treatment of 47 cases of imported loiasis seen at three French hospitals over a 15-year period (1998-2012).

Results: Most patients acquired their infection in Cameroon, Gabon, and Central African Republic. Overall, Calabar swellings were observed in 63% patients, and eye worm migration in 29%. Peripheral blood microfilariae were detected in 48% of patients and eosinophilia in 90% respectively. Calabar swellings and eosinophilia were more common among expatriates and travelers, whereas African immigrants were more likely to present with eye worm migration and have microfilaremia. First-line treatment was ivermectin in most cases (51%), followed by diethylcarbamazine (23%), albendazole (8%) or a combination of drugs (8%). Forty-one patients underwent clinical and parasitological follow-up for a mean period of 422 days [range 30-3600 days]. Clinical relapse and/or persistence/reappearance of blood microfilaria occurred in 10 patients.

Conclusions: Clinical and biological features were comparable with the largest monocentric series of imported loiasis. There was a marked rate of failure after first-line treatment and rare adverse effects were reported. The treatment of patients with imported loiasis would benefit from standardization with guidelines for the choice of first and second line drugs, the length of follow-up and criteria for cure.