International Journal of Infectious Diseases and Therapy 2017; 2(1): 9-14 http://www.sciencepublishinggroup.com/j/ijidt doi: 10.11648/j.ijidt.20170201.13 Serological Diagnostic Assays for Detection of Ns1 Antigen, IGM and IGG Antbodies to Dengue Virus Purimitla Usha Rani, Payala Vijayalakshmi * Department of Microbiology, GITAM Institute of Medical Sciences and Research, GITAM University, Visakhapatnam, Andhra Pradesh, India Email address: bavisettyvijayalakshmi2@gmail.com (P. Vijayalakshmi) * Corresponding author To cite this article: Purimitla Usha Rani, Payala Vijayalakshmi. Serological Diagnostic Assays for Detection of Ns1 Antigen, IGM and IGG Antbodies to Dengue Virus. International Journal of Infectious Diseases and Therapy. Vol. 2, No. 1, 2017, pp. 9-14. doi: 10.11648/j.ijidt.20170201.13 Received: December 18, 2016; Accepted: January 10, 2017; Published: February 15, 2017 Abstract: Complications in managing the dengue virus infections include the lack of rapid diagnostic procedures and at the same time the symptoms of dengue infection are often confused with those of other diseases. Two commercial rapid serological diagnostic kit methods (Dengue Day 1 test, J Mitra and Co. Pvt. Ltd., New Delhi, ImmunoComb II Dengue IgM/IgGBispot kit (Orgenics Pvt. Ltd., Israel)were evaluated for the detection of NS1 antigen, Immunoglobulin IgG and IgM specific to dengue virus in the serum samples of patients suffered with dengue acute primary infection and secondary infection. The total assay time was 20 min-2hrs. The results of these methods were compared with the gold standard assay methods Dengue IgM-Capture Microplate ELISA and Dengue Indirect IgG ELISA (Pan Bio, Brisbane, Australia). The total assay time was 6-7hrs. Nine serum samples were positive to NS1 antigen and negative to IgG and IgM by Dengue day 1 test. The results of Bispot assay method revealed that, the number of IgG positive samples was 11, IgM positive samples were 31 and both IgG and IgM positive samples were 8. Majority of the positive cases were noticed in the age group 35-68 years and males were more prone to dengue infection while comparing with females. By performing IgM MICROLISA, 34 samples were positive which in turn indicated that, three of them were false negative by the immune comb bispot method giving a sensitivity of 91.17%. Through indirect IgG ELISA, the number of positive samples was 15 and four of the 15 positive samples of IgG were false negative by the immuo comb bispot method giving a sensitivity of 73.33%. The gold standard ELISA methods were more efficient than rapid serological tests and gave an overall sensitivity of 99%. Thus the alternative of an assay that is to be used in the diagnosis of dengue infections depends on factors like laboratory infrastructure, preference and availability of equipment. The allied performance of the Rapid test, followed by confirmation with MAC-ELISA on those samples, ensures both speediness as well as quality of reported results. Keywords: Dengue, NS1 Antigen, IgM, IgG, Primary Dengue, Secondary Dengue, ELISA 1. Introduction Dengue is caused by four serologically related flaviviruses called dengue-1, dengue-2, dengue-3 and dengue-4 [1]. Infection to one serotype confers immunity only to that particular infecting serotype [2]. Subsequent infection with one of the three remaining serotypes results in immune-enhanced disease in the form of severe hemorrhagic fever or dengue shock syndrome. Of the more than 100 million cases of dengue fever, 250, 000 cases result in dengue hemorrhagic fever, resulting in approximately 25, 000 deaths annually [3]. These viruses found in most tropical parts of the world [4]. Dengue normally affects adults and older children. Dengue presents as an acute febrile illness with chills, head-ache, retro- ocular pain, body aches and anthralgia in more than 90% of apparent cases, with nausea or vomiting and a maculopapular rash resembling measles lasting for 2-7 days in about 60% of cases [5]. Illness persists for 7 days, fever remitting after 3-5 days followed by relapse (Saddleback fever) and pains in the body muscles and joints sufficiently severe to earn the breakbone fever. When the fever falls, some patients present bleeding manifestations, thrombocytopenia and hemoconcentration [6]. Hepatomegaly can also be observed. Rash occurs more