Russell Richard C, Webb Cameron E, Davies Neil
Department of Medical Entomology, University of Sydney and ICPMR, Westmead Hospital, Australia.
J Med Entomol. 2005 Nov;42(6):1045-56. doi: 10.1093/jmedent/42.6.1045.
Populations of Aedes aegypti (L.) and Aedes polynesiensis (Marks) on Moorea Island, French Polynesia, the local vectors of dengue and filariasis, respectively, were sampled by landing/biting collection at nine localities on the east, north, and west coasts, during the late dry season, early and late wet season (September-May) 2003 and 2004, to investigate epidemiologically important features of the populations and compare them between regions and months. Biting rates of both species tended to increase (but not always significantly) for each species in each region each month from the late dry season to the late wet season, and the north coast region had significantly higher biting rates of Ae. aegypti. Insemination rates of Ae. polynesiensis females (94.5-98.8%) were consistently greater than those of Ae. aegypti (87.5-93.5%) throughout the study, but there was no significant difference in the insemination rates of either species between months and regions. Parity rates were generally highest in north coast samples and lowest in west coast samples for both species and generally increased (albeit not always significantly) by month for each species, with a range of 52.9-88.8% for Ae. polynesiensis and 28.6-53.6% for Ae. aegypti, although the high gravid rate (15.8-45.9%) of Ae. aegypti samples (reflecting its feeding more than once in a gonotrophic cycle) confounded both intraspecific and interspecific comparisons. Filarial infection was rare in Ae. aegypti, although both W. bancrofti and D. immitis were recorded, and infection rates in Ae. polynesiensis increased through the study period in each region for both filarias, with up to 4.6% infected and 1.4% infective for W. bancrofti and up to 6.3% infected and 2.5% infective for D. immitis. For W. bancrofti, infection rates were significantly lower on the west coast and also in the dry season, whereas rates for infective stages were significantly greater in the late wet season. For D. immitis there was no significant difference in infection rates between regions, but rates were significantly greater in the late wet season. Rainfall in all months sustains populations of both vectors and explains the relatively few significant differences between seasons; however, the wet season may provide for increased vector abundance and longevity, and present a potentially increased risk for transmission. Although the differences shown between regions also were limited in a statistical sense, there were increased risks for the northern and eastern regions, where both locals and tourists are concentrated and where the seaports and airport are located, and these areas should be priority targets for disease surveillance and vector control.
法属波利尼西亚莫雷阿岛上的埃及伊蚊（L.）和波利尼西亚伊蚊（Marks）种群，分别是登革热和丝虫病的本地病媒。于2003年和2004年旱季后期、雨季早期和晚期（9月至5月），在该岛东、北、西海岸的9个地点，通过着陆/叮咬采集法对这两种蚊虫进行采样，以调查种群在流行病学方面的重要特征，并比较不同区域和月份之间的差异。从旱季后期到雨季后期，每个区域每个月这两种蚊虫的叮咬率均呈上升趋势（但并非总是显著上升），且北海岸地区埃及伊蚊的叮咬率显著更高。在整个研究期间，波利尼西亚伊蚊雌蚊的受精率（94.5 - 98.8%）始终高于埃及伊蚊（87.5 - 93.5%），但这两种蚊虫在不同月份和区域的受精率均无显著差异。两种蚊虫的产过卵比率通常在北海岸样本中最高，在西海岸样本中最低，并且通常每个月都会上升（尽管并非总是显著上升），波利尼西亚伊蚊的产过卵比率范围为52.9 - 88.8%，埃及伊蚊为28.6 - 53.6%，不过埃及伊蚊样本的高怀卵率（15.8 - 45.9%）（反映其在一个生殖营养周期内多次吸血）混淆了种内和种间比较。埃及伊蚊中丝虫感染很少见，尽管记录到了班氏吴策线虫和犬恶丝虫，而在整个研究期间，每个区域的波利尼西亚伊蚊中这两种丝虫的感染率均有所上升，班氏吴策线虫的感染率高达4.6%，感染期比率为1.4%，犬恶丝虫的感染率高达6.3%，感染期比率为2.5%。对于班氏吴策线虫，西海岸以及旱季的感染率显著较低，而感染期比率在雨季后期显著更高。对于犬恶丝虫，不同区域的感染率无显著差异，但在雨季后期感染率显著更高。各月的降雨维持了这两种病媒的种群数量，并解释了季节之间相对较少的显著差异；然而，雨季可能使病媒数量增加且寿命延长，从而使传播风险可能增加。尽管区域间显示出的差异在统计学意义上也很有限，但北部和东部地区风险增加，这些地区是当地人和游客的集中地，也是海港和机场所在之处，这些区域应成为疾病监测和病媒控制的优先目标。
