NS1 Antigen Capture ELISA an Effective Method for Diagnosis of Early Dengue Infection - Report of an Outbreak at Angul District, Odisha, India
Background: An outbreak of dengue infection occurred in Angul district of Odisha in the month of August & September, 2011. The study was undertaken to detect NS1 antigen positivity among the study population, to compare IgM capture ELISA with NS1 antigen detection for diagnosis of dengue and...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
JCDR Research and Publications Private Limited
2014-08-01
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| Series: | Journal of Clinical and Diagnostic Research |
| Subjects: | |
| Online Access: | https://jcdr.net/articles/PDF/4697/8589_CE(Ra)_F(Sh)_PF1(SNAK)_PFA(P)_PF2(PAG).pdf |
| Summary: | Background: An outbreak of dengue infection occurred in Angul
district of Odisha in the month of August & September, 2011.
The study was undertaken to detect NS1 antigen positivity
among the study population, to compare IgM capture ELISA
with NS1 antigen detection for diagnosis of dengue and to
identify the predominant genotype of Dengue virus responsible
for the outbreak.
Materials and Methods: Total 1020 serum samples were
collected from clinically suspected cases of dengue from the
outbreak. All were subjected for NS1 antigen detection, 92
were selected based on their clinical severity of illness (fever,
rash, bleeding manifestation, arthralgia) for further study of IgM
ELISA and platelet count and 148 NS1 positive samples were
selected from different Blocks of Anugul district for RT-PCR at
NIV, Pune, India.
Results: Five hundred and thirteen (50.2%) samples were
positive for NS1 antigen (highly significant p-value <0.0001,
C.I - 95%) with 88% positivity during 1-5 days. The NS1 Ag
positivity was peaked to 86.9% on days 3 to 5 (Sensitivity & NPV
- 100% each) & declined to 6.2% during 6-10 days with a low
sensitivity of 7.14% but 100% specificity & PPV. However, the
IgM antibody positivity was 81.2% on days 6 to 10 and 87.5%
after 10 days (Sensitivity- 100%, Specificity-13.33%,PPV7.14% & NPV - 100%). RT-PCR resulted 32.4% positivity (6-
DEN1, 39 - DEN 2 & 3- DEN 3) among which 20% were in IgM
+ve & 68% in IgM -ve cases.
Conclusion: Therefore, early diagnosis of dengue could be
mainly by NS1 antigen detection whereas Ig M ELISA is a better
tool during the later stage of infection &RT-PCR is more effective
in IgM -ve cases.The predominant genotype responsible for the
outbreak was found to be DEN-2. |
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| ISSN: | 2249-782X 0973-709X |