Diagnosis is made by directly observing the thin and unsheathed microfilariae, approximately 190 to 200 μm in length, in peripheral blood (2). PCR can be useful in differentiating among various nematodes, including Brugia malayi, Loa loa, M. perstans, and Wuchereria bancrofti (4). Unlike those of other nematodes that have diurnal periodicity, M. perstans microfilariae are consistently present in peripheral blood. Infection is notoriously difficult to eradicate, but in those species that harbor endosymbiotic Wolbachia, doxycycline can reduce microfilarial burden (5). In our patient, with a potentially long-standing infection, it was unclear whether he had acquired M. perstans in Uganda, where endosymbiotic Wolbachia is less common, or the Democratic Republic of Congo. In cases in which Wolbachia is epidemiologically unlikely, anthelminthic drugs are the mainstay of treatment, including the combination of diethylcarbamazine and mebendazole (1). Treatment can typically be deferred, as most patients are asymptomatic, and there are few long-term sequelae to untreated infection.
展开▼
