Background:Following the decline of malaria transmission in many countries and regions,serological parameters have become particularly useful for estimating malaria transmission in low-intensity areas.This study evalu...Background:Following the decline of malaria transmission in many countries and regions,serological parameters have become particularly useful for estimating malaria transmission in low-intensity areas.This study evaluated a novel serological marker,Malaria Random Constructed Antigen-1(M.RCAg-1),which contains 11 epitopes from eight Plasmodium falciparum antigens,as a tool for assessing malaria transmission intensity along the border area of China-Myanmar.Method:Serum from Plasmodium falciparum and P.vivax patients was used to detect the properties of M.RCAg-1 and antibody responses.Cross-sectional surveys were conducted at the China-Myanmar border and in Hainan province in 2012 and 2013 using cluster sampling.Filter blood spot papers were collected from all participants.Antibodies against M.RCAg-1 were detected using indirect ELISA.The Mann–Whitney test and Spearman’s rank correlation test were performed to analyze antibody data.P.falciparum malaria transmission intensity was estimated using a catalytic conversion model based on the maximum likelihood of generating a community seroconversion rate(SCR).Results:M.RCAg-1 was well-recognized by the naturally acquired anti-malaria antibodies in P.falciparum patients and had very limited cross-reactivity with P.vivax infection.The total amount of IgG antibodies was decreased with the decrease in parasitemia after taking medication and lasted several weeks.In a population survey,the antibody levels were higher in residents living close to the China-Myanmar border than those living in non-epidemic areas(P<0.0001),but no significant difference was observed between residents from Hainan and non-epidemic areas.The calculated SCR was 0.0128 for Jieyangka,0.004 for Susuzhai,0.0047 for Qiushan,and 0.043 for Kayahe.The estimated exposure rate obtained from the anti-M.RCAg-1 antibody level correlated with traditional measures of transmission intensity derived from altitude.Conclusion:Our study demonstrates that M.RCAg-1 is potentially useful as a serological indicator of exposure to P.falciparum malaria,especially for malaria surveillance in low transmission areas.展开更多
基金supported in full by the National Special Science and Technology Project for Major Infectious Diseases of China(No.2012ZX10004220).
文摘Background:Following the decline of malaria transmission in many countries and regions,serological parameters have become particularly useful for estimating malaria transmission in low-intensity areas.This study evaluated a novel serological marker,Malaria Random Constructed Antigen-1(M.RCAg-1),which contains 11 epitopes from eight Plasmodium falciparum antigens,as a tool for assessing malaria transmission intensity along the border area of China-Myanmar.Method:Serum from Plasmodium falciparum and P.vivax patients was used to detect the properties of M.RCAg-1 and antibody responses.Cross-sectional surveys were conducted at the China-Myanmar border and in Hainan province in 2012 and 2013 using cluster sampling.Filter blood spot papers were collected from all participants.Antibodies against M.RCAg-1 were detected using indirect ELISA.The Mann–Whitney test and Spearman’s rank correlation test were performed to analyze antibody data.P.falciparum malaria transmission intensity was estimated using a catalytic conversion model based on the maximum likelihood of generating a community seroconversion rate(SCR).Results:M.RCAg-1 was well-recognized by the naturally acquired anti-malaria antibodies in P.falciparum patients and had very limited cross-reactivity with P.vivax infection.The total amount of IgG antibodies was decreased with the decrease in parasitemia after taking medication and lasted several weeks.In a population survey,the antibody levels were higher in residents living close to the China-Myanmar border than those living in non-epidemic areas(P<0.0001),but no significant difference was observed between residents from Hainan and non-epidemic areas.The calculated SCR was 0.0128 for Jieyangka,0.004 for Susuzhai,0.0047 for Qiushan,and 0.043 for Kayahe.The estimated exposure rate obtained from the anti-M.RCAg-1 antibody level correlated with traditional measures of transmission intensity derived from altitude.Conclusion:Our study demonstrates that M.RCAg-1 is potentially useful as a serological indicator of exposure to P.falciparum malaria,especially for malaria surveillance in low transmission areas.
