Doxycycline to Treat Mansonella Perstans Infection in Patients With and Without Lymphatic Filariasis

This study will examine: 1) the safety and effectiveness of the drug doxycycline in reducing the number of Mansonella perstans (Mp) worms in the blood of infected patients, and 2) the effects of doxycycline followed by albendazole and ivermectin treatment for lymphatic filariasis, caused by the parasitic worm Wuchereria bancofti (Wb).

Both Mp and Wb very small filarial worms that are spread by mosquitoes. Some people are infected with both Mp and Wb. Although most people do not become ill from infection with these parasites, some develop symptoms. Wb can cause swellings in the arms, legs, breast, and scrotum, and can progress to permanent swelling of the legs or arms called elephantiasis. Mp can cause itching, swelling, fever, headache, or other symptoms. Ivermectin and albendazole are medicines used to treat lymphatic filariasis. They eliminate the Wb parasite from the blood but do not affect Mp. Doxycycline is used to treat many kinds of infections and has also recently been shown to reduce the number of filarial worms in several types of filarial infections. The drug may be useful in Mp infections as well.

Residents of Sabougou and nearby villages in Mali who are infected with the Mp parasite, are between 14 and 65 years of age, are in good health, are not pregnant or breastfeeding, and weigh at least 40 kg (88 lb) may be eligible for this study. They may or may not also be infected with Wb. Candidates are screened with a brief medical history and physical examination and blood tests to look for infection with Mp and Wb.

Participants undergo a complete physical examination and medical history. Blood is drawn for routine blood tests. Participants are then randomly assigned to one of four treatment groups, as follows: 1) doxycycline for 6 weeks; 2) doxycycline for 6 weeks followed by a single dose of albendazole and ivermectin given 6 months after the beginning of doxycycline treatment; 3) a single dose of albendazole and ivermectin given 6 months after the beginning of doxycycline treatment; or 4) no treatment. Only patients infected with Wb receive albendazole and ivermectin treatment.

All participants, whether or not they receive doxycycline, come to the clinic every day for 6 weeks. Every 2 weeks during this time, they have a blood test and, in women of childbearing age, a urine pregnancy test. After 6 months, they have a medical history, physical examination, and blood tests. Subjects in the albendazole/ivermectin treatment group are given the pills to take at that time. One year and three years after beginning the study, participants return to the clinic for a final history, physical examination, and blood tests.

At the end of the first year of the study, all participants who tested positive for lymphatic filariasis but did not receive ivermectin and albendazole will be offered treatment with these medicines Ivermectin and albendazole will also be distributed by the Mali government to everyone in the villages as part of a program to eliminate lymphatic filariasis in the country.