Phillips-Howard P A, Radalowicz A, Mitchell J, Bradley D J
Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine.
BMJ. 1990 Feb 24;300(6723):499-503. doi: 10.1136/bmj.300.6723.499.
To identify which British residents travelling abroad are at greatest risk of malaria infection, and to determine the efficacy of malaria chemoprophylaxis for preventing P falciparum infections in tropical Africa.
Prospective cohort study (case-base linkage) with routine national surveillance systems. Denominators (base population) were obtained from monitoring a random sample of returning British travellers with the international passenger survey. Numerators (cases) were obtained from reports of malaria infections in British residents, through the Malaria Reference Laboratory network.
International passenger survey conducted at passport control of international airports in Britain. Malaria reports received nationally were collated centrally in London.
2948 British residents (0.2%) returning to Britain in 1987 randomly selected and questioned and 1052 British residents with microscopically confirmed malaria infections in 1987, whose case reports were reviewed and on whom additional data were collected by postal survey.
Annual incidence subdivided by categories of risk. Chemoprophylactic efficacy for east and west Africa by principal regimens and compliance.
Annual rates of reported infection per 100,000 travellers to Oceania were 4100; to west and east Africa were 375 and 172 respectively; to Latin America, the Far East, and the Middle East were 12, 2, and 1 respectively. Immigrants visiting friends and relatives in Ghana and Nigeria were at greatest risk (1303 and 952 per 100,000 respectively) in west Africa. Business travellers to Kenya experienced the highest attack rates in east Africa (465 per 100,000). Age-sex specific attack rates varied by region. No prophylaxis was reported to have been used by 23% of British visitors to west Africa, 17% to east Africa, 46% to central or southern Africa, and 58% visiting south Asia. The efficacy of chloroquine plus proguanil against P falciparum infection was 73% and 54% in west and east Africa respectively. Lower values were obtained for chloroquine alone and proguanil alone. The efficacy of Maloprim (pyrimethamine-dapsone) was 61% in west Africa, but only 9% in east Africa. Visitors to west Africa who did not comply with their chemoprophylactic regimen were at a 2.5-fold higher risk of infection than fully compliant users. Non-compliant visitors to east Africa had similar rates of infection as non-drug users.
In 1987 chloroquine plus proguanil was the preferred chemoprophylactic regimen for P falciparum infection in Africa; antimalarial drugs must be taken regularly to be effective.
确定哪些出国旅行的英国居民感染疟疾的风险最高，并确定疟疾化学预防措施在预防热带非洲恶性疟原虫感染方面的效果。
采用常规国家监测系统进行的前瞻性队列研究（病例对照关联研究）。分母（基础人群）通过对随机抽取的回国英国旅行者样本进行国际旅客调查获得。分子（病例）通过疟疾参考实验室网络获取英国居民疟疾感染报告。
在英国国际机场的护照检查处进行国际旅客调查。全国收到的疟疾报告在伦敦集中整理。
1987年随机抽取并接受询问的2948名回国英国居民（占0.2%），以及1987年经显微镜确诊患有疟疾的1052名英国居民，对其病例报告进行审查，并通过邮政调查收集更多数据。
按风险类别细分的年发病率。按主要用药方案和依从性划分的东非和西非化学预防效果。
每10万名前往大洋洲的旅行者中，报告的年感染率为4100；前往西非和东非的分别为375和172；前往拉丁美洲、远东和中东的分别为12、2和1。在西非，前往加纳和尼日利亚探亲访友的移民风险最高（分别为每10万人1303例和952例）。前往肯尼亚的商务旅行者在东非的发病率最高（每10万人465例）。特定年龄和性别的发病率因地区而异。前往西非的英国游客中有23%、前往东非的有17%、前往中非或南非的有46%、前往南亚的有58%报告未使用任何预防措施。氯喹加氯胍预防恶性疟原虫感染的效果在西非为73%，在东非为54%。单独使用氯喹和单独使用氯胍的效果较低。马洛普明（乙胺嘧啶-氨苯砜）在西非的预防效果为61%，但在东非仅为9%。在西非，未遵守化学预防方案的游客感染风险比完全遵守方案的游客高2.5倍。在东非，未遵守方案的游客感染率与未用药者相似。
1987年，氯喹加氯胍是非洲预防恶性疟原虫感染的首选化学预防方案；抗疟药物必须定期服用才能有效。
