Anong D N, Nkuo-Akenji T, Fru-Cho J, Amambua-Ngwa A, Titanji V P K
Department of Biochemistry and Microbiology, University of Buea, P.O. Box 63, Buea, Cameroon.
Ann Trop Med Parasitol. 2010 Jan;104(1):25-33. doi: 10.1179/136485910X12607012373876.
The influence of the genetic diversity of Plasmodium falciparum infection on the clinical presentation of human malaria was investigated in rural Bolifamba, Cameroon. Parasite DNA was obtained from the blood of 208 children (aged 1-15 years) with malarial infection. The prevalences of anaemia and symptomatic and asymptomatic malaria among these children were 57.7%, 51.4% and 48.6%, respectively. The frequencies of parasites carrying each of the block-2 allelic variants (MAD20, K1 and RO33) of merozoite surface protein 1 (MSP1) were compared among the symptomatic and asymptomatic cases of malaria, the anaemic and non-anaemic subjects, and in various age groupings. Although all three allelic variants were found in Bolifamba, 32.7% of the children investigated were co-infected with parasites carrying the RO33 and K1 variants. There was a significant difference in the prevalence of each MSP1 allelic variant both between age-groups and between the various categories of anaemia considered (P<0.0001 for each), with the highest number of alleles occurring in the children with severe anaemia. The combination of RO33/K1 co-infection and anaemia was detected in most (57.7%) of the children aged 3-<6 years. The RO33/K1 co-infection was also strongly associated with both fever and high levels of parasitaemia (P<0.0001 for each). Although the children of Bolifamba are exposed to all three allelic variants of MSP1, which occur either singly or in varying combinations in the infected children, RO33/K1 co-infections are particularly associated with fever and this association appears independent of age and parasite density. The preliminary data presented here should facilitate the design of future research towards the development and testing of malaria candidate vaccines in the study area.
在喀麦隆的博利凡巴农村地区，研究了恶性疟原虫感染的基因多样性对人类疟疾临床表现的影响。从208名患有疟疾感染的儿童（年龄在1至15岁之间）的血液中获取了寄生虫DNA。这些儿童中贫血、有症状疟疾和无症状疟疾的患病率分别为57.7%、51.4%和48.6%。比较了裂殖子表面蛋白1（MSP1）的block - 2等位基因变体（MAD20、K1和RO33）在有症状和无症状疟疾病例、贫血和非贫血受试者以及不同年龄组中的携带频率。虽然在博利凡巴发现了所有三种等位基因变体，但32.7%的受调查儿童同时感染了携带RO33和K1变体的寄生虫。各MSP1等位基因变体的患病率在年龄组之间以及所考虑的不同贫血类别之间均存在显著差异（每项P<0.0001），严重贫血儿童中出现的等位基因数量最多。在大多数（57.7%）3至<6岁的儿童中检测到RO33/K1共感染与贫血的组合。RO33/K1共感染也与发热和高寄生虫血症水平密切相关（每项P<0.0001）。尽管博利凡巴的儿童接触到MSP1的所有三种等位基因变体，这些变体在受感染儿童中单独或组合出现，但RO33/K1共感染尤其与发热相关，并且这种关联似乎与年龄和寄生虫密度无关。本文提供的初步数据应有助于设计未来在该研究地区开发和测试疟疾候选疫苗的研究。
