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.
Chanama
Sumalee
S
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
Anantapreecha
Surapee
S
A-nuegoonpipat
Atchareeya
A
Sa-gnasang
Areerat
A
Kurane
Ichiro
I
Sawanpanyalert
Pathom
P
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