Focks D A, Chadee D D
Center for Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture, Gainesville, Florida, USA.
Am J Trop Med Hyg. 1997 Feb;56(2):159-67. doi: 10.4269/ajtmh.1997.56.159.
This report documents the results of a country-wide pupal survey of Aedes aegypti (L.) conducted in Trinidad. The survey was designed to identify the important Ae. aegypti-producing containers, importance being a function of a container's abundance and its productivity. Results are summarized on a country-wide basis and by county: urban versus rural comparisons are also made. Numerically, the most common water-filled containers positive for the larvae or pupae of Ae. aegypti (foci) were outdoor drums, water storage tanks and buckets, laundry tubs, discarded tires, and small miscellaneous containers such as drink bottles and cans. The island-wide average number of foci per hectare was 287 and ranged between 65 and 499. The average standing crop per container of Ae. aegypti pupae was 9.5 and ranged 12-fold, the most and least productive being the flower pot (> 30) and the small indoor vase (< 3), respectively. In terms of production by type of container, four of the 11 types, outdoor drums, tubs, buckets, and small containers, accounted for > 90% of all Ae. aegypti pupae: the remaining seven types were responsible for < 10%. If targeted source reduction programs were directed by how important various container types were in the production of Ae. aegypti, environmental sanitation efforts designed to actually eliminate the ubiquitous small receptacle and tires would reduce mosquito densities by 43%; the provision of an adequate water supply system precluding the need for water storage in drums and buckets would have the potential to eliminate an additional 38%. Combined, these two measures have the potential to reduce the sources responsible for > 80% of Ae. aegypti production in the country. In our survey, the traditional Stegomyia indices used to document the density of Ae. aegypti and predict the threat of dengue transmission, the House, Container, and Breteau indices, were seen to have virtually no correspondence with the actual number of pupae per hectare or per person. We conclude that pupal survey is more appropriate for assessing risk and directing control operations.
本报告记录了在特立尼达进行的一项全国范围的埃及伊蚊蛹调查结果。该调查旨在确定重要的埃及伊蚊滋生容器，重要性是容器数量及其繁殖力的函数。结果在全国范围内以及按县进行了总结：还对城市和农村进行了比较。从数量上看，对埃及伊蚊幼虫或蛹呈阳性的最常见盛水容器（孳生地）是室外桶、储水箱和水桶、洗衣盆、废弃轮胎以及诸如饮料瓶和罐头之类的小型杂物容器。全岛每公顷孳生地的平均数量为287个，范围在65至499个之间。每个容器中埃及伊蚊蛹的平均存量为9.5个，范围相差12倍，繁殖力最高和最低的分别是花盆（>30个）和小型室内花瓶（<3个）。就按容器类型的繁殖情况而言，11种类型中的4种，即室外桶、盆、水桶和小型容器，占所有埃及伊蚊蛹的90%以上：其余7种类型占比不到10%。如果针对性的源头减少计划根据各种容器类型在埃及伊蚊繁殖中的重要性来指导，旨在实际消除无处不在的小型容器和轮胎的环境卫生措施将使蚊虫密度降低43%；提供充足的供水系统从而无需使用桶和水桶储水，有可能再消除38%的蚊虫。综合起来，这两项措施有可能减少该国80%以上埃及伊蚊繁殖的源头。在我们的调查中，用于记录埃及伊蚊密度并预测登革热传播威胁的传统白纹伊蚊指数，即房屋指数、容器指数和布雷图指数，与每公顷或每人的实际蛹数几乎没有对应关系。我们得出结论，蛹调查更适合评估风险并指导控制行动。
