Use of Dengue Blot IgG Test as an Epidemiological Tool for Assessing Incidence of DHF in Communities By
Faisal Yatim Communicable Diseases Research Centre National Institute of Health Research and Development Ministry of Health, Jakarta, Indonesia
D
uring 1990, the Blot IgG test for DHF serology, which was developed by Dr M. Jane D. Cardosa and marketed by M/s Diagnostic Biotechnology Ltd., Singa-pore, was further modified and standardized by Dupen Diagnostics Division. A field evaluation of this test kit was undertaken by the National Institute of Health Research and Development in collabo-ration with the DHF Control Programme. This paper presents the sensitivity and specificity of this kit. One thousand specimens of acute and canvalescent DHF cases were collected from four provincial health laboratories. The specimens were obtained from clinically suspected DHF patients who had been hospitalized in district hospitals. Sera samples were divided into two, and each set was tested by IgG blot for comparison with haemaglutinin test (HI). The results of the trials are summarized in Table.
Table. Result of the Dengue Blot test Positive Hi Test Positive Negative Total 713 39 752 Negative 98 225 323 Total 811 364 1175
Sensitivity: 713/752 = 94.8% Specificity: 225/323 = 69.66%
From the results, it is apparent that the Blot test captured only the IgG antibodies which reflects that the patients had previous dengue infection, and hence can assay the incidence in the community. However, for detection of recent infection, it must be combined with Blot IgM. Addition of Blot IgM will not, however, make this test cost-effective.
References 1. Prasittisuk C and Andjaparidze AG. Dengue haemorrhagic fever prevention and control activities in South-East Asia Region. WHO/ SEARO, Dengue Bulletin, Vol 20,1996 : 25. 2. Gubler DJ. Serological diagnosis of dengue haemorrhagic fever. WHO/SEARO, Dengue Bulletin, Vol 20, 1996 : 20-23.
Dengue Bulletin – Vol 21, 1997
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Historical Account of Dengue Haemorrhagic Fever in Sri Lanka
Dengue Bulletin – Vol 21, 1997
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