Analysis of specific IgM responses in secondary dengue virus infections: levels and positive rates in comparison with primary infections.
BACKGROUND
Dengue viruses are a serious cause of illness in tropical and subtropical areas of the world. Laboratory diagnosis is essential for confirmation of dengue virus infections. Detection of specific IgM by IgM-capture enzymed-linked immunoassay (ELISA) has been widely used as a main serological diagnostic technique.


OBJECTIVE
The levels of specific IgM in secondary dengue virus infections were compared with those in primary infections.


METHODS
A total of 1780 samples collected from 924 confirmed dengue cases were tested for anti-dengue IgM by IgM-capture ELISA.


CONCLUSIONS
Specific IgM was detected in all the cases with primary dengue virus infection on disease day 9 or later. However, specific IgM cannot be detected in 28% (204/716) of the cases in secondary infections. The average titers of IgM were higher in primary infections than in secondary infections. The results confirmed that IgM detection is a reliable serological diagnostic test in primary dengue virus infections. Although IgM detection is also a useful test, other serological diagnostic tests or tests for dengue virus detection are necessary for confirmation of all the secondary dengue virus infections.
Department of Medical Sciences, National Institute of Health, Ministry of Public Health, 88/7 Tivanond Road, Muang, Nonthaburi 11000, Thailand. sn111139@dmsc.moph.go.th
Sumalee
S
Chanama
Surapee
S
Anantapreecha
Atchareeya
A
A-nuegoonpipat
Areerat
A
Sa-gnasang
Ichiro
I
Kurane
Pathom
P
Sawanpanyalert
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000175:diagnosis* / Q000821:virology; D003716:Dengue Virus / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D007223:Infant; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D000914:Antibodies, Viral; D007075:Immunoglobulin M