PREVALENCE OF ANTIBODIES TO THE REPEAT EPITOPE OF THE CIRCUMSPOROZOITE PROTEIN OF PLASMODIUM-VIVAX IN SAN-LUIS-POTOSI, MEXICO

The prevalence of antibodies against the repeat epitope of the circums porozoite protein (cs) of the standard (PV210) and variant (PVK247) st rain of Plasmodium vivax was determined by ELISA in 1170 sera from ind ividual residents of seven localities of the Region Huasteca of San Lu is Potosi, Mexico, The capture antigens were the synthetic peptides DD AAD and (ANGAGNQPG)(4) that correspond to the repeats of the PV210 and PVK247 cs proteins, respectively, Of the analyzed serum samples, 34.1 % (400/1170) were positive with one or both of these antigens, Of the sera, 18.2% (214/1170) reacted with the DDAAD peptide and 6.6% (78/117 0) were positive with the variant synthetic peptide, Additionally, 9.2 % (108/1170) of the samples reacted with both peptides, A sample of 10 % of positive sera for the variant cs repeat (18/78) was tested with t he cs repeat peptide of P. malariae/P. brasilianum (NAAG); almost all of them (16/18, 89%) being positive, These results confirm that the tr ansmission of the variant strain of P. vivax is a common phenomenon in endemic regions in Latin America, as well as in other tropical region s of the world, These findings may have implications for the developme nt of aP. vivax vaccine since that based on the standard cs repeat onl y would not be universally protective.