Assessment of the role of dengue 1g M maelisa test in assisting in the diagnosis of clinically suspected cases of dengue haemorrhagic fever

Abstract

The study group consisted of a total of 273 samples from clinically suspected DHF patients whose samples were sent to the MRI between March and September 1995.Out of these,244 were acute samples and 29 were convalescent samples. These were grouped into the following. Group 1-consisted of 29 paired sera clinically suspected of having DHF who had a four fold rise in the HI antibody titer, where there were 5 primary dengue infections and 24 secondary dengue infections. The acute samples were collected between 1-8 days of onset of illness and the convalescent samples were collected between 12-20 days of onset of illness. Group 2- consisted of 111 single sera with a HI titer of = 1:2560 collected between 2-8 days of onset of illness. Group 3- consisted of 64 single serum samples with a HI titer of 1:20 and 1:1280 with the collection of blood samples between 2-9 days of onset of illness. Group 4- consisted of 40 single sera with a HI titer of 1:20 and samples were collected between 1-9 days of the onset of the disease. No laboratory based study has been carried out using both HI and IgM MAC-ELISA tests in Sri Lanka. The serum samples were tested for both HI and IgM antibody. A commercially available IgM MAC-ELISA test kit (PanBio,Australia) was used. The appearance of IgM was seen in all 4 groups at a higher precentage in the 5-8 day than the 0-4 day of the onset of illness ie. the figures for group 1,2,3 and 4,on the 0-4th day of illness respectively were 25 per cent,17 per cent,18.2 per cent, and 12.5 per cent.On the 5-8th day of the illness it was 81.8 per cent,85.7 per cent,73.8 per cent and 20.8 per cent. This shows a similar response as with other studies done in puerto rico and brazil. Further studies should be done to see the persistence of IgM in the Sri Lankan population