McMahon J E, Sowa S I, Maude G H, Kirkwood B R
London School of Hygiene and Tropical Medicine, London, UK.
Trans R Soc Trop Med Hyg. 1988;82(4):595-600. doi: 10.1016/0035-9203(88)90524-x.
Very little of the original primary forest remains in Sierra Leone and the savanna is mainly woodland or a forest-savanna mosaic. The prevalence of microfilariae of Onchocerca volvulus, nodules and moderate or severe skin lesions was higher in forest than savanna villages. In forest villages the prevalence of microfilariae was 71.8% at the iliac crest, 36.6% (outer canthus), 12.8% (cornea) and 34.1% in the anterior chamber of the eye. Corresponding figures for the savanna villages were 51.9%, 20.5%, 5.6% and 21.8%. The overall prevalence of nodules in the forest and savanna was 70.5% and 53.2% respectively, while the prevalence of head and upper body nodules was 14.8% (forest) and 11.0% (savanna). The prevalence of moderate or severe skin lesions was 17.7% in forest and 13.0% in savanna villages. Lesions of the groin and scrotum were few in both zones. In persons aged 30 years or more the prevalence rates of severe eye lesions--sclerosing keratitis, iritis, optic atrophy and choroidoretinitis--were 4.3%, 16.1%, 13.9% and 14.8% respectively in forest villages. Corresponding figures for the savanna villages were 3.7%, 8.7%, 14.2% and 11.3%. Males were more commonly affected than females. At least one of these lesions was found in 32% persons in forest and 24% in savanna villages.
塞拉利昂现存的原始原生林极少，稀树草原主要为林地或森林 - 稀树草原镶嵌地貌。盘尾丝虫微丝蚴、结节以及中度或重度皮肤病变在森林村庄中的患病率高于稀树草原村庄。在森林村庄中，髂嵴处微丝蚴患病率为71.8%，外眦为36.6%，角膜为12.8%，眼前房为34.1%。稀树草原村庄的相应数据分别为51.9%、20.5%、5.6%和21.8%。森林和稀树草原中结节的总体患病率分别为70.5%和53.2%，而头部及上身结节的患病率在森林中为14.8%，在稀树草原中为11.0%。森林村庄中中度或重度皮肤病变的患病率为17.7%，稀树草原村庄为13.0%。两个区域腹股沟和阴囊的病变都很少。在30岁及以上人群中，森林村庄中严重眼部病变（硬化性角膜炎、虹膜炎、视神经萎缩和脉络膜视网膜炎）的患病率分别为4.3%、16.1%、13.9%和14.8%。稀树草原村庄的相应数据分别为3.7%、8.7%、14.2%和11.3%。男性比女性更容易受到影响。在森林村庄中，32%的人至少患有其中一种病变，在稀树草原村庄中这一比例为24%。
