in it, so it is currently known as M. perstans. The adult worms of M. perstans were first recovered during post mortem examination of two aboriginal Indians in British Guiana from their mesentery and subpericardial fat. While an insect vector was hypothesized, it took many years of investigation before the true vector of M. perstans was discovered. Clinical presentation in humans While Mansonella infections are often asymptomatic, they can be associated with angioedema (similar to Calabar swellings of loaisis), recurrent pruritic subcutaneous lesions, fever, headaches, arthralgia, and neurologic manifestations. Eosinophilia, headache, fever, or abdominal pain may also be present. M. perstans may also present with a condition known as kampala, or Ugandan eye worm. This occurs when adult worms of M. perstans invade the conjunctiva or periorbital connective tissues in the eye. This condition was first attributed to M. perstans in Uganda, when six patients presented with nodules in the conjunctiva. The adult worms were identified as adult female M. perstans in five of these six cases. The symptoms of M. perstans may be confounded with those of other filarial infections, such as onchocerciasis, lymphatic filariasis and loiasis, because coinfection often occurs. 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 eosinophil count decreased to