UNSTABLE HYPOENDEMIC MALARIA IN RONDONIA (WESTERN AMAZON REGION, BRAZIL) - EPIDEMIC OUTBREAKS AND WORK-ASSOCIATED INCIDENCE IN AN AGROINDUSTRIAL RURAL SETTLEMENT
UNSTABLE HYPOENDEMIC MALARIA IN RONDONIA (WESTERN AMAZON REGION, BRAZIL) - EPIDEMIC OUTBREAKS AND WORK-ASSOCIATED INCIDENCE IN AN AGROINDUSTRIAL RURAL SETTLEMENT
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DOI：
10.4269/ajtmh.1994.51.16
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发表时间：
1994-07-01
影响因子：
3.3
通讯作者：
DASILVA, LP
中科院分区：
文献类型：
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作者：
MARCELO, L;CAMARGO, A;DASILVA, LP
1991年1月至1992年1月，在Rondonia州（巴西西亚马逊地区）的农村农工林业定居地Urupa农场进行了一项纵向研究，以确定疟疾的寄生虫学和临床特征。进行了三次横断面、寄生虫学和临床调查。在两次调查之间，通过每周两次对农场的医疗访问和长期的当地监测来监测疟疾病例。居民人口约为170人，具有高流动性的特点。横断面调查发现，总人口（间日疟原虫加恶性疟原虫）的载玻片阳性率分别为0.5、4.2和2.1。2-9岁儿童脾率均小于1%。然而，这种基本上是低地方性的疟疾情况并不稳定，在旱季结束时发生了典型的流行病爆发。1991年1月至12月记录的疟疾病例总数为163例，每年寄生虫指数为每1 000名居民970例。然而，病例的性别和年龄分布表明，婴儿疟疾发病率很少，10岁以下儿童发病率较低。16-40岁的男性成年人是主要的危险群体。观察到的病例聚集使我们能够确定工作地点是导致成人疟疾高发的一个因素。总体流行病学资料显示，当地按蚊媒介的室内疟疾传播很少或不存在。
A longitudinal study was conducted from January 1991 to January 1992 on the Urupa farm, a rural agro-industrial forestry settlement in Rondonia state (Western Amazon Region, Brazil) to define the parasitologic and clinical profile of malaria. Three cross-sectional, parasitologic, and clinical surveys were performed. In the intervals between surveys, malaria cases were monitored by twice a week medical visits to the farm and permanent local surveillance. The population of residents was approximately 170 and was characterized by high mobility. The slide positive rates found in the cross-sectional surveys were 0.5, 4.2 and 2.1, respectively, for the total population (Plasmodium vivax plus P. falciparum). Spleen rate values in children 2-9 years old were always less than 1%. However, this basically hypoendemic malaria situation was unstable, with occurrence of a typical epidemic outbreak at the end of the dry season. The total number of malaria cases recorded from January to December 1991 was 163, giving an annual parasite index of 970 per 1,000 inhabitants. However, sex and age distribution of cases showed rare incidence of malaria in infants and low incidence in children less than the age of 10. Male adults 16-40 years of age represented the main risk group. The observed clustering of cases allowed us to identify the place of work as a factor responsible for high incidence of malaria among adults. The general epidemiologic profile indicated that indoors transmission of malaria by the local Anopheles vector was low or absent.