Comparative evaluation of dengue NS1 antigen rapid test and IgM ELISA in a tertiary care hospital in VIMS, Ballari

Abstract

Dengue virus infection is becoming a major public health problem in recent decades because of the mortality and morbidity associated with it. Dengue is endemic in many parts of India and epidemics are frequently reported from various parts of India and abroad. The mortality rate in patients with dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) is as high as 44%. Hence early and rapid laboratory diagnosis of dengue is crucial. Appropriate clinical management can save the lives of DHF and DSS patients and mortality can be reduced to less than 1%. It is also worthwhile for planning appropriate control strategies. The present communication reports the seroprevalence of dengue infections occurred in Central India.To detect Dengue infection by NS1 Antigen Rapid detection and by IgM ELISA and compare Rapid NS1 Antigen detection test and IgM ELISA test.Blood samples from 5273 suspected cases were collected from January 2016 to December 2016. Sera were separated and subjected for NS1 antigen detection testing by the solid phase immunochromatographic assay, a commercial dengue virus rapid test kit. and antidengue IgM antibody ELISA in the Department of Microbiology, VIMS, Ballari. All samples were put for ELISA.3036 samples were tested for NS1 Antigen detection rapid method.2272 samples were tested for both rapid test and ELISA. Out of 5273 cases, 446 (8.46%) were found to be positive by IgM ELISA. 3036 samples WHICH were tested for NS1 Antigen detection by rapid method 208 (6.85%)samples were positive. The most affected age group was 5-10yrs with 284 cases, out of which 29 were positive, followed by the age group 0f 15yrs and above with 8.74%. Males were affected more than females with a percentage of 9.2 and 7.4 respectively. The highest number of suspected dengue patients admitted was in the month of November, i.e., 459 with 68 positive (14.81%) followed by August (12.16%) and September (11.03%), i.e., 28 with 7 (25%) positive. For the 2272 samples for which both tests were done, 153 cases were positive for rapid test and 137 cases were positive by ELISA. Dengue cases were more during September to November in the post monsoon season which is useful to plan special preventive strategies. The study draws attention toward the male, young and adult age group. To conclude, in countries lacking infrastructure for the diagnostic labs especially in the rural and remote areas, the rapid dengue ICT tests can play a major role in diagnosis and in patient management of acute dengue infection. The rapid ICTs are very simple, easy to perform, and can be used as point of care tests. We suggest that the rapid ICT for NS1 Ag detection may be used in patients presenting with fever less than 5 days