Iranian Journal of Microbiology 2016. 8(6):395-400.

Significance of IgG optical density ratios (index value) in single reactive anti-Dengue virus IgG capture ELISA
Shiv Sekhar Chatterjee, Ankush Sharma, Shilpee Chowdhury, Sushil Kumar Chumber, Mandeep Kaur, Ras Bage, Nittin Parkhe, Uma Khanduri


Background and Objectives: A single reactive IgG anti-Dengue virus ELISA test in the absence of IgM antibodies or NS1 antigen may denote current infection or past exposure to the virus. To determine whether IgG index value can be used to identify true current dengue infection we conducted a prospective observational study.

Materials and Methods: Suspected dengue patients (n =1745) were tested in their first specimen by MAC-ELISA, GAC-ELISA and NS1 antigen ELISA. Patients with MAC-ELISA and NS1Antigen non-reactive but GAC-ELISA reactive results (n =57) in their first test were followed up and repeated sampling was asked for IgG index values were calculated according to the manufacturer’s instruction and classified as: low (2.2-2.5), medium (2.5-4.0) and high (>4.0).

Results: 16 out of 57 patients (28.1%) had low IgG Index value whereas 26 cases (45.6%) were categorized as medium and 15(26.3%) were classified as patients with high IgG index. Nine patients with paired reactive serology or antigen positive status were categorised as serologically confirmed dengue fever, 11 patients as not dengue with categorical evidence of other infections while the rest 37 casas with clinical, radiological and laboratory parameters suggestive of dengue but no serological confirmation as possible dengue. Among confirmed, possible and non-Dengue cases, 33.3, 32.4 and 0.0% had high Index value in comparison with 22.2, 29.7 and 27.3% showing low Index values, respectively.

Conclusion: Our results suggested a high IgG response in favour of true dengue infection than past exposure while no conclusions should drawn from a low or medium reactive GAC-ELISA results in the absence of IgM antibodies and NS1 Ag.

Keywords: Dengue fever, IgG capture ELISA, Optical density ratio, Index value


Dengue fever; IgG capture ELISA; optical density ratios; Index value

Full Text:



Guo RN, Lin JY, Li LH, Ke CW, He JF, Zhong HJ, et al. The prevalence and endemic nature of dengue in- fections in Guangdong, South China: an epidemiologi- cal, serological, and etiological study from 2005-2011.PLoS One 2014; 9: e85596.

De Paula SO, Fonseca BA. Dengue: a review of the lab- oratory tests a clinician must know to achieve a correct diagnosis. Braz J Inf Dis 2004; 8: 390-398.

World Health Organization (WHO) and the special pro- gramme for research and training in tropical diseases. Dengue: Guidelines for diagnosis, treatment, preven- tion and control (2009). WHO, Geneva, Switzerland 3rd ed.

Lima Mda R, Nogueira RM, Schatzmayr HG, dos Santos FB. Comparison of three commercially avail- able dengue NS1 antigen capture assays for acute diagnosis of dengue in Brazil. PLoS Negl Trop Dis 2010; 4: e738.

Rossi CA, Drabick JJ, Gambel JM, Sun W, Lewis TE, Henchal EA. Laboratory diagnosis of acute dengue fe- ver during the United Nations Mission in Haiti, 1995-1996. Am J Top Med Hyg 1998; 59: 275-278.

Gyurech D, Schilling J, Schmidt-Chanasit J, Cassinotti P, Kaeppeli F, Dobec M. False positive dengue NS1 an- tigen test in a traveller with an acute Zika virus infec- tion imported into Switzerland. Swiss Med Wkly 2016;146: w14296.

Blacksell SD. Commercial dengue rapid diagnostic tests for point-of-care application: recent evaluations and future needs? J Biomed Biotechnol 2012; 2012:151967.

Andries AC, Duong V, Ngan C, Ong S, Huy R, Sroin KK, et al. Field evaluation and impact on clinical man- agement of a rapid diagnostic kit that detects dengue NS1, IgM and IgG. PLoS Negl Trop Dis 2012; 6: e1993.

Guzmán MG, Kourí G. Dengue diagnosis, advances and challenges. Int J Infect Dis 2004; 8: 69-80.

Prince HE, Matud JL. Estimation of dengue virus IgM persistence using regression analysis. Clin Vaccine Im- munol 2011; 18: 2183-2185.

Rubens Costa Lima J, Rouquayrol MZ, Monteiro Cal- lado MR, Florindo Guedes MI, Pessoa C. Interpretation of the presence of IgM and IgG antibodies in a rapid test for dengue: analysis of dengue antibody prevalence in Fortaleza City in the 20th year of the epidemic. Rev Soc Bras Med Trop 2012; 45: 163-167.

Ngwe Tun MM, Muta Y, Inoue S, Morita K. Persistence of neutralizing antibody against dengue virus 2 after 70 years from infection in Nagasaki. Biores Open Access 2016; 5: 188-191.

Azfar NA, Malik LM, Jamil A, Jahangir M, Tirmizi N, Majid A, et al. Cutaneous manifestations in patients of dengue fever. Journal of Pakistan Association of Der- matologists : JPAD 2012; 22: 320-324.

Gomber S, Ramachandran VG, Kumar S, Agarwal KN, Gupta P, Gupta P, et al. Hematological observations as diagnostic markers in dengue hemorrhagic fever-a re- appraisal. Indian Pediatr 2001; 38: 477-481.

Hati AK. Dengue serosurveillance in Kolkata, facing an epidemic in West Bengal, India. J Vector Borne Dis 2009; 46: 197-204.

Blacksell SD, Jarman RG, Gibbons RV, Tanga- nuchitcharnchai A, Mammen MP Jr, Nisalak A, et al. Comparison of seven commercial antigen and antibody enzyme-linked immunosorbent assays for detection of acute dengue infection. Clin Vaccine Immunol 2012;19: 804-810.

Groen J, Koraka P, Velzing J, Copra C, Osterhaus AD.Evaluation of six immunoassays for detection of den- gue virus-specific immunoglobulin M and G antibod- ies. Clin Diagn Lab Immunol 2000; 7: 867-871.

Prince HE, Yeh C, Lapé-Nixon M. Development of a more efficient algorithm for identifying false-positive reactivity results in a dengue virus immunoglobulin M screening assay. Clin Vaccine Immunol 2008; 15: 1304-1306


  • There are currently no refbacks.

Creative Commons Attribution-NonCommercial 3.0

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License which allows users to read, copy, distribute and make derivative works for non-commercial purposes from the material, as long as the author of the original work is cited properly.