Layton M, Parise M E, Campbell C C, Advani R, Sexton J D, Bosler E M, Zucker J R
Bureau of Communicable Disease, New York City Department of Health, NY 10013, USA.
Lancet. 1995 Sep 16;346(8977):729-31. doi: 10.1016/s0140-6736(95)91503-6.
In August, 1993, 3 cases of Plasmodium falciparum malaria in people without recent travel histories or bloodborne exposure were reported in New York City. An epidemiological investigation confirmed the absence of risk factors for acquisition of malaria in two cases. The third case could not be definitively classified as locally acquired malaria because the patient had travelled to Thailand two years before malaria was diagnosed. The 3 individuals lived in separate houses in the same neighbourhood of Queens, New York and had onset of illness within a day of each other. The investigation consisted of patient interviews, active case finding, reviewing recent New York flight and shipping arrivals, and an entomological survey for anopheline mosquitoes and breeding sites. No other cases were identified. The 3 patients lived several miles from air and sea ports and prevailing winds would have carried any mosquitoes at those sites away from the patient's homes. By the time of the environmental investigation (September, 1993), the area was dry and neither adult nor larval anophelines were found. However, weather conditions at the probable time of infection (July, 1993) were very different. Malaria was probably transmitted to these 2 patients by local anopheline mosquitoes that had fed on infected human hosts. Mosquito-control measures were not implemented because there was no evidence of ongoing transmission. The occurrence of mosquito-transmitted malaria in New York City demonstrates the potential for reintroduction of malaria transmission into areas that are no longer endemic and emphasises the need for continued surveillance and prompt investigations, if cases without risk factors are reported.
1993年8月，纽约市报告了3例无近期旅行史或血源暴露史的恶性疟原虫疟疾病例。一项流行病学调查证实，其中两例不存在感染疟疾的风险因素。第三例不能明确归类为本地获得性疟疾，因为该患者在被诊断出疟疾的两年前曾前往泰国。这3个人住在纽约皇后区同一街区的不同房屋里，发病时间相隔不到一天。调查包括对患者进行访谈、主动病例搜索、查阅纽约近期的航班和航运抵达记录，以及对按蚊和繁殖地进行昆虫学调查。未发现其他病例。这3名患者居住的地方距离机场和海港有数英里远，当时的盛行风会把这些地方的任何蚊子吹离患者的家。到环境调查时（1993年9月），该地区天气干燥，未发现成年或幼虫按蚊。然而，在可能的感染时间（1993年7月），天气状况却大不相同。疟疾可能是由叮咬过受感染人类宿主的本地按蚊传播给这两名患者的。由于没有持续传播的证据，所以未实施蚊虫控制措施。纽约市出现蚊媒传播的疟疾表明，疟疾传播有可能重新引入不再流行疟疾的地区，并强调如果报告了无风险因素的病例，需要持续监测和及时调查。
