1Department of Virology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
2Department of Pathology, Government Multispeciality Hospital, Chandigarh, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
The accurate diagnosis of acute dengue infection is important to provide timely information for the management of patients and for early public health control of dengue outbreaks. Detection of dengue specific IgM antibodies by capture ELISA forms the mainstay for the diagnosis of dengue infection in a routine diagnostic laboratory. However, IgM antibodies usually develop after 4–5 days of infection. The methods used for diagnosis of acute dengue infection include virus isolation and RT-PCR. The problem of transport of samples in cold chain and the sophistication associated with these techniques limits their application. Recently, a commercial dengue NS1 antigen capture ELISA has been developed for the early diagnosis of dengue virus infection. This diagnostic system was evaluated and compared with IgM detection in 89 acute samples (<5 days fever) from patients with clinically suspected dengue infection. In patients presenting with upto 3 days of fever duration (n=35), NS1 positivity was 51.4% while IgM was detected in 25.7% only. NS1 antigen could detect additional 15 (42.8%) cases which were missed by IgM. In patients presenting on day 4–5 of fever (n=54), NS1 positivity was 37% while IgM was 64.8%. In these cases, IgM could detect additional 20 cases (37%) which were negative for NS1 antigen. Hence, for patients presenting after day 4 of fever, IgM antibody detection is a better alternative for the diagnosis of early dengue infection.
