| Summary: | Background. Malaria is distributed in almost all provinces in Indonesia in
different levels of endemicity and transmission. In this study, antibody responses
against Plasmodium falciparum Merozoite Surface Protein-1 (P.f.MSP-1) and
Apical Membrane Antigen-1 (P.f.AMA-1) is measured in populations living in
low and medium endemic malaria areas in Indonesia to evaluate the level of
malaria endemicity in the region.
Methods. Serum antibody are measured from blood samples collected from
people living in low endemic malaria in Purworejo and medium endemic malaria
in South Lampung during high transmission season (November 2008-January
2009 in Purworejo, December 2008-February 2009 in Lampung) and during low
transmission season (May 2009-July 2009) in both regions. Blood samples are
grouped in age groups as 0-5, 6-10, 11-20, 21-30, 31-40 and >41 years. Antibody
titer is measured by indirect ELISA method using recombinant P.f.MSP-119 and
P.f.AMA-1. The samples are considered seropositive if the titer is above cut off
value (mean +3SD) titers of seronegative cluster from minimal of 120 samples).
Percentage of seropositive individuals from both regions is analyzed with Mantel-
Haenzel and Chi-Square, differences of mean antibody titer is analyzed with
Kruskal-Wallis and Mann-Whitney, significances of correlation between antibody
titers and age is analyzed with Pearson Correlation.
Results. During high and low transmission season, seroprevalence of anti P.f
MSP-1 and anti P.f AMA-1 antibodies in most of age groups in Purworejo is
lower than in Lampung. In Purworejo, mean antibody titers and correlation of
antibody titer with age of anti P.f MSP-1 and anti P.f AMA-1 antibodies during
high and low transmission season are not different. Meanwhile, in Lampung,
mean antibody titers and correlation of antibody titer with age of anti P.f MSP-1
and anti P.f AMA-1 antibodies during high and low transmission season shows a
significant difference.
Conclusion. Antibody anti P.f MSP-1 and anti P.f AMA-1 response as titers and
seroprevalence gives an image that Purworejo is an unstable malaria area and
Lampung is a stable malaria area. This study is analogous to previous theories that
seroprevalence is a good parameter for assessing malaria transmission levels.
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