The value of IgG to IgM ratio in predicting secondary dengue infection

Abstract

Background The determination of primary or secondary dengueinfection using hemagglutination inhibition (HI) test is time-con-suming. The IgG to IgM ratio which can be obtained earlier wasused by several studies to differentiate secondary from primaryinfection, but they still reported various cut-off points.Objective To find the diagnostic value and best cut off point ofIgG to IgM ratio for predicting secondary dengue infection.Methods This was a prospective study carried out between July2003 and June 2004. Children with suspected dengue hemor-rhagic fever (DHF) were tested for HI during acute and convales-cent phase. The IgG and IgM titer were examined during the acutephase using ELISA method.Results Sixty-two children were recruited, 48 with secondary in-fection and 14 with primary infection. The prevalence of second-ary infection was 77%. The best cut off point of the IgG to IgM ratioto predict secondary infection was >1.1 with sensitivity of 87.5%,specificity 92.9%, likelihood ratio 12.3, and post test probability97.7%.Conclusion The IgG to IgM ratio of >1.1 is a good predictor forsecondary infection

Immunoglobulin G (IgG) to IgM ratio in secondary adult dengue infection using samples from early days of symptoms onset

“…A study using samples from IgM and IgG titer-negative sera found a cut off IgM/IgG OD ratio that was comparable with studies previously [ 9 , 24 ]. This study also used samples from IgM and IgG titer-negative sera and also found a cut off IgG/IgM ratio comparable to a study previously [ 23 ].…”

“…A study in Bali, Indonesia found IgG/IgM ratio of ≥ 1.1 on the day 5–7 of disease is a good predictor of secondary dengue infection. This study was done on children hospitalized for suspected DENV infection, with mean age of 6 year-old [ 23 ]. Study in Thailand using HI test as the gold standard found that the best cut off point of IgG/IgM ratio for secondary infection was ≥ 1.78 [ 9 ].…”

“…This study found that IgG/IgM ratio of ≥1.14 as the best cut off point to determine secondary DENV infection, with sensitivity of 80.56 % and spesificity of 91.67 %. Different ratios found in these studies might be due to different settings and seroepidemiologics [ 9 , 10 , 20 , 23 ].…”