Cobelens F G, Verhave J P, Leentvaar-Kuijpers A, Kager P A
Department of Internal Medicine, Academic Medical Center, University of Amsterdam, The Netherlands.
Am J Trop Med Hyg. 1998 Jan;58(1):75-80. doi: 10.4269/ajtmh.1998.58.75.
The purpose of this investigation was to assess the role of serology for establishing incidences of Plasmodium falciparum malaria and of exposure to P. falciparum in epidemiologic studies of travelers using chemoprophylaxis. The design was a prospective cohort study involving 548 short-term Dutch travelers to areas endemic for P. falciparum malaria. Sera were collected before departure and, together with the medical history, 2-6 weeks after return. All sera were tested for anti-circumsporozoite (CS) antibodies by an R32tet32-ELISA; sera of subjects reporting febrile illness during travel or after return or with anti-CS responses were tested for anti-blood-stage antibodies by an indirect fluorescence antibody test (IFAT). Five subjects (0.9%) reported P. falciparum malaria confirmed by thick blood smear examination (documented cases) and six (1.0%) reported treatment for malaria without a documented diagnosis (presumptive cases). Conversions in the IFAT were detected in six subjects, including all five documented cases and one presumptive case. Anti-CS antibodies were detected in seven subjects (1.3%), including three documented cases and four of 442 subjects with no history of fever or malaria treatment (0.9%). Incidence rates per 1,000 person-months of travel (95% confidence interval) of infection with P. falciparum, whether or not suppressed by chemoprophylaxis, were 16.9 (8-31) for all destinations and 91.6 (33-200) for West Africa. In epidemiologic studies of P. falciparum malaria in travelers, testing for antibodies to blood stages can increase the sensitivity and specificity of case detection; testing for antibodies to sporozoites may be useful for the assessment of exposure to P. falciparum in travelers using chemoprophylaxis, but the sensitivity is limited.
本调查的目的是评估血清学在使用化学预防的旅行者流行病学研究中，对于确定恶性疟原虫疟疾发病率以及接触恶性疟原虫情况的作用。研究设计为前瞻性队列研究，涉及548名前往恶性疟原虫疟疾流行地区的短期荷兰旅行者。出发前采集血清，并在返回后2至6周连同病史一起采集。所有血清均通过R32tet32-ELISA检测抗环子孢子（CS）抗体；报告旅行期间或返回后发热疾病或有抗CS反应的受试者血清，通过间接荧光抗体试验（IFAT）检测抗血期抗体。5名受试者（0.9%）报告经厚血涂片检查确诊为恶性疟原虫疟疾（确诊病例），6名（1.0%）报告接受了疟疾治疗但无确诊记录（推定病例）。在6名受试者中检测到IFAT转换，包括所有5例确诊病例和1例推定病例。在7名受试者（1.3%）中检测到抗CS抗体，包括3例确诊病例和442名无发热或疟疾治疗史的受试者中的4名（0.9%）。无论是否被化学预防抑制，每1000人月旅行感染恶性疟原虫的发病率（95%置信区间），所有目的地为16.9（8 - 31），西非为91.6（33 - 200）。在旅行者恶性疟原虫疟疾的流行病学研究中检测血期抗体可提高病例检测的敏感性和特异性；检测子孢子抗体可能有助于评估使用化学预防的旅行者接触恶性疟原虫的情况，但敏感性有限。
