Ali A, Ashford R W
Institute of Pathobiology, Addis Ababa University, Ethiopia.
Ann Trop Med Parasitol. 1994 Jun;88(3):289-93. doi: 10.1080/00034983.1994.11812869.
In a population of some 4600 people in southern Ethiopia, in which visceral leishmaniasis is endemic, 142 cases were recorded in an 8-year period to 1990. The cases were very unequally distributed between the six villages studied, with more than 90% in the four which were closest to the uninhabited valley of the Segen River. It was deduced that transmission occurs in the villages at lowest altitude, as well as in the Segen Valley. The youngest children were rarely affected and half as many cases were females as males. In a year-long intensive study, annual incidence of disease was estimated at 6.9/1000 in the whole population. Incorporating the results of previously published immuno-epidemiological studies, the annual incidence of disease in susceptible people was calculated as 1.9% while the rate of immunoconversion was 5.6 times greater. This indicates a high incidence of abortive or cryptic cases, but it remains to be demonstrated whether or not these cases are sources of infection.
在埃塞俄比亚南部约4600人的人群中，内脏利什曼病呈地方性流行，到1990年的8年期间记录了142例病例。这些病例在所研究的6个村庄中分布极不均衡，90%以上的病例出现在最靠近塞根河无人居住山谷的4个村庄。据推断，传播发生在海拔最低的村庄以及塞根山谷。最小的儿童很少受到影响，女性病例数量仅为男性的一半。在为期一年深入研究中，估计整个人群的年发病率为6.9/1000。结合先前发表的免疫流行病学研究结果，易感人群的年发病率计算为1.9%，而免疫转化率则高出5.6倍。这表明流产型或隐匿型病例的发病率很高，但这些病例是否为传染源仍有待证实。
