Mak J W, Lim P K, Tan M A, Lam P L, Noor Rain A, Selvadurai G D, Hanjeet K
Acta Trop. 1987 Mar;44(1):83-9.
Malaria surveys in an Orang Asli (aborigine) and an adjacent Malay village showed significantly higher parasite rates in the age-group 0-9 years in the former. Parasite rates declined progressively from a maximum at 0-4 years in the Orang Asli to zero at 30-39 years while in the Malays it rose progressively with age. Indirect fluorescent antibody test (IFAT) titres against schizont antigens of Plasmodium falciparum and P. cynomolgi were higher in the Orang Asli in all age-groups with a statistically significant inverse relationship between IFAT titres and parasite rates. IFAT titres in the Malay population also increased with age but were very much lower. Antibody levels detected by the enzyme-linked immunosorbent assay (ELISA) using soluble schizont antigens were also much higher in the Orang Asli and values with P. cynomolgi were higher than those with P. falciparum antigens. These differences are attributed to the higher malaria transmission in the younger age-groups of the Orang Asli and presumably greater immunological experience to a wider diversity of antigens than the Malays, thus explaining the presence of "protective" antibodies in the former but not the latter group.
对一个原住民部落（奥朗阿斯利人）和附近一个马来村庄进行的疟疾调查显示，前者0至9岁年龄组的寄生虫感染率显著更高。在奥朗阿斯利人中，寄生虫感染率从0至4岁时的最高值逐渐下降，到30至39岁时降至零；而在马来人中，感染率则随年龄增长而逐渐上升。在所有年龄组中，奥朗阿斯利人针对恶性疟原虫和食蟹猴疟原虫裂殖体抗原的间接荧光抗体试验（IFAT）滴度更高，且IFAT滴度与寄生虫感染率之间存在统计学上显著的负相关关系。马来人群中的IFAT滴度也随年龄增加，但要低得多。使用可溶性裂殖体抗原通过酶联免疫吸附测定（ELISA）检测到的抗体水平在奥朗阿斯利人中也高得多，且针对食蟹猴疟原虫抗原的值高于针对恶性疟原虫抗原的值。这些差异归因于奥朗阿斯利人较年轻年龄组中更高的疟疾传播率，以及与马来人相比，他们可能对更广泛多样的抗原有更多的免疫经验，从而解释了前者存在“保护性”抗体而后者不存在的现象。
