METHODS: A case of PCR-confirmed P. malariae recurrence in a 52-year old Italian man was observed 5 months after a primary attack. In the interval between the two observed episodes of malaria the patient denied any further stay in endemic areas except for a visit to Libya, a country considered malaria-free. Genomic DNA of the P. malariae strain using five microsatellites (PM2, PM9, PM11, PM25, PM34) and the antigen marker of circumsporozoite (csp) was amplified and sequenced. Analysis of polymorphisms of the P. malariae csp central repeat region showed differences between the strains responsible of the first and second episode of malaria. A difference in the allele size was also observed for the sequence analysis of PM2 microsatellites.
CONCLUSIONS: Plasmodium malariae is a challenging human malaria parasite and even with the use of molecular techniques the pathogenesis of recurrent episodes cannot be precisely explained.
方法:一名52岁意大利男子在初次发作后5个月观察到PCR证实的疟原虫复发病例。在两次观察到的疟疾发作之间的间隔中,除了访问利比亚外,患者否认在流行地区有任何进一步的停留,一个被认为没有疟疾的国家。使用五个微卫星(PM2,PM9,PM11,PM25,PM34)和环子孢子(csp)的抗原标记物扩增并测序。对疟原虫csp中央重复区域多态性的分析显示,造成第一和第二次疟疾发作的菌株之间存在差异。对于PM2微卫星的序列分析也观察到等位基因大小的差异。
结论:疟原虫是一种具有挑战性的人类疟疾寄生虫,即使使用分子技术,也无法准确解释反复发作的发病机理。