Mansonella Perstans - Case Study

Case Study

A 36-year-old man was admitted to the outpatient clinic at the Goundi Missionary Hospital in the south of Chad in May 2001. He complained of visual impairment in the left eye, ocular and abdominal pruritus, and abdominal pain. He had previously been treated with DEC for M. perstans infection five months prior to his visit. A blood sample was taken at 11:00 am, and examined microscopically as a thick blood film stained with Giemsa's solution. The thick blood film revealed the presence of M. perstans, and no other parasites were found. He had 3% eosinophilia. A visual acuity test showed a reduction of visual acuity to 4/10 for the left eye, while the right eye was 9/10. However, no abnormalities were observed during examination of the anterior left eye chamber. Upon examination of the fundus of his left eye, a narrow, white, motionless, and linear lesion of 6–7 mm was found. He was then treated with a second course of DEC (400 mg daily in two doses for eight days, after a three-day dosage increase), and by the end of treatment, he did not have pruritus, but his visual impairment was unchanged. The M. perstans burden was significantly reduced, and the peripheral eosinohpil count decreased to 1%. He was then treated with mebendazole (100 mg twice a day, for 14 days), and at the end of his treatment, his visual impairment was the only symptom remaining. After a week, with no further treatment, his vision improved and acuity was increased to 8/10 in the left eye. While ocular symptoms occur quite frequently in symptomatic M. perstans infection, intraocular localization had not been described prior to this study. This case also is an example of the difficulty of treating mansonelliasis, and shows that combined drug regimens can be more effective than treatment using a single drug.