By the early 1920s, it was generally agreed that the filaria in Africa and Central America were morphologically indistinguishable and the same as that described by ONeill 50 years earlier.Robles hypothesized that the vector of the disease was the day-biting black fly, Simulium. Scottish physician Donald Blacklock of the Liverpool School of Tropical Medicine confirmed this mode of transmission in studies in Sierra Leone. Blacklocks experiments included the re-infection of Simulium flies exposed to portions of the skin of infected subjects on which nodules were present, which led to elucidation of the life cycle of the Onchocerca parasite. Blacklock and others could find no evidence of eye disease in Africa. Jean Hissette, a Belgian ophthalmologist,  discovered in 1930 that the organism was the cause of a "river blindness" in the Belgian Congo. Some of the patients reported seeing tangled threads or worms in their vision, which were microfilariae moving freely in the aqueous humor of the anterior chamber of the eye. Blacklock and Strong had thought the African worm did not affect the eyes, but Hissette reported that 50% of patients with onchocerciasis near the Sankuru river in the Belgian Congo had eye disease and 20% were blind. Hisette Isolated the microfilariae from an enucleated eye and described the typical chorioretinal scarring, later called the "Hissette-Ridley fundus" after another ophthalmologist, Harold Ridley, who also made extensive observations on onchocerciasis patients in north west Ghana, publishing his findings in  1945. Ridley first postulated that the disease was brought by the slave trade.
Achilles bursitis is bursitis (inflammation of synovial sac) of bursa situated above the insertion of tendon to calcaneus. It results from overuse and wearing of tight shoes. References


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