Virological and Serological Markers in Dengue Patients from Venezuela and Nicaragua

Abstract

Latest estimates suggest 390 million infections of dengue occur each year, of which 100 million results in symptomatic disease. The new clinical classification proposed by WHO-TRD 2009 simplifies dengue fever (DF) into dengue (D) and severe dengue (SD) with an intermediary group of "dengue with warning signs" (DWS). Early, sensitive and specific diagnosis of dengue is needed for appropriate patient management as well as for early epidemic detection. Virological and serological markers in sera from dengue confirmed patients from Venezuela and Nicaragua were evaluated. A total of 232 sera collected in the acute (days 1 to 5 of fever onset) and convalescent (days 7 to 14) phases of illness were tested by Platelia NS1 antigen ELISA and IgM, IgA and IgE capture ELISA methods. NS1 was detected with highest OD values in the acute phase for primary and secondary cases. IgM was detected in primary and secondary groups but the highest OD figures were observed after defervescence day. IgA and IgE detection were almost absent for primary cases, contrary to secondary cases which showed higher values but after defervescence day. NS1 could be used as effective diagnostic marker in the acute phase of illness for primary and secondary dengue infections. IgM detection is still an invaluable tool for routine dengue diagnosis but delay. IgA detection could define secondary infection in early phase of illness. IgA/IgE could be evaluated as prognostic markers associated to SD cases.

Case Series of Seronegative Dengue Hemorrhagic Fever

“…In addition to that low level of IgG-dengue antibody was observed. However, in secondary infection dengue specific IgG antibody increase extremely rapidly to reach high level at days 1 to 2 after onset of symptoms [9]. Interestingly, dengue specific IgM antibody level are significantly lower in secondary dengue infections.…”