Comparison of a rapid immunochromatography assay with an enzyme linked immunosorbent assay (ELISA) for anti-dengue virus IgM detection

Abstract

ObjectivesThe current study was undertaken to compare the sensitivity, specificity, positive predictive value and negative predictive values of a dengue IgM rapid immunochromatography (ICT) assay with a dengue IgM capture ELISA for the detection of anti-dengue virus IgM in patients clinically suspected of having dengue fever (DF). MethodsBlood samples (n=119) were collected from paediatric and adult patients suspected of having DF at Teaching Hospital, Peradeniya (THP) after 5 days of fever. The samples were analyzed for the presence of anti-dengue virus IgM using a commercial rapid dengue IgM ICT assay (Hexagon dengue, Human, Germany) and a commercial IgM capture ELISA (Panbio Diagnostics Inc, Australia) provided to THP by the Ministry of Health for the diagnosis of dengue fever. ResultsWhen tested using the rapid dengue IgM ICT assay, 80 blood samples were positive and 39 were negative for anti-dengue virus IgM. When tested using the dengue IgM ELISA, 100 sera were positive and 19 were negative for dengue IgM. Using the IgM capture ELISA as the comparator, the sensitivity and the specificity of the rapid assay were 79% and 94.7% respectively with a positive (PPV) and negative (NPV) predictive value of 98.8% and 46.2%. ConclusionIn comparison with the results of the IgM capture ELISA, the low sensitivity and NPV for antidengue virus IgM detection by the rapid dengue IgM ICT assay was noted. The low sensitivity and NPV means that patients with DF will be missed when using this test. In contrast, the high specificity and PPV indicate that this rapid assay is able to detect true positives. Since preliminary screening of DF is carried out widely using these rapid tests, the strengths and limitations of this and other similar tests require validation before use in diagnostic laboratories.

Characterization of dengue virus infections in a sample of patients suggests unique clinical, immunological, and virological profiles that impact on the diagnosis of dengue and dengue hemorrhagic fever

“…DENV viremia lasts for about 5–6 days followed by the progression to an immunological phase. In Sri Lanka, anti‐DENV IgM and IgG detection after day 5 of the onset of symptoms/fever remains the major laboratory tool to diagnose DENV infection [Senaratne and Noordeen, ; Senaratne et al, ]. Additionally, since dengue is endemic in Sri Lanka, anti‐DENV IgG sero‐positivity is high and anti‐DENV IgM levels may be detected for months following an infection.…”

Comparison of a rapid immuno-chromatography assay with a standard ELISA for the detection of IgM and IgG antibodies against dengue viruses

“…No significant difference was noted (p [ 0.05) in the accuracy indices for anti-DENV IgM and IgG detection by the ICT assay between the DF and DHF patients ( Table 3). A recent study conducted by Senaratne et al in a different region of Sri Lanka tested only 119 samples for anti-DENV IgM and IgG and incidentally this study also has used the same ELISA (Panbio Diagnostics, Australia) for validating a different ICT assay [8]. The sensitivity, specificity and the PPV of the ICT assay used by Senaratne et al for anti-DENV IgM detection were higher than those observed in the current study indicating the differences in the accuracy indices of different ICT assays.…”

“…Moreover, the difference between different ICT assays for detecting a particular marker using the same ELISA comparator indicates the importance of validating rapid ICT assays. Previous studies report a wide variation in the detection sensitivity and specificity ranging from 20 to 100% for the detection of anti-DENV IgM and anti-DENV IgG for some commercially available rapid ICT assays [2,3,5,6,8]. Moreover, sensitivity of anti-DENV IgM detection is significantly low in secondary infections [10] and thus the low sensitivity for anti-DENV IgM detection by the ICT assay in the current study is not surprising, as more than 60% of the study sample had secondary DENV infections.…”

“…The ICT assays do not require any specialized equipment or training and the results are available within 25 min [4]. However, some studies questioned the ability of the ICT to discriminate between primary and secondary DENV infections [6,8].…”