Molecular and entomological studies on dengue

Abstract

A novel molecular-based assay (Reverse Transcription-Polymerase Chain Reaction-based Liquid Hybridization (RT-PCR-LH)) was developed and validated for early detection of dengue virus in clinical specimens. Possible risk factors affecting transmission of dengue were studied in dengue hot-spots. Soluble fragment of dengue virus in clinical samples were sequenced and gene and protein sequences were compared with available sequences. The novel assay was found to be more sensitive than the other diagnostic techniques for early and definitive laboratory diagnosis. Further, the assay could detect dengue virus in field-caught Aedes albopictus specimens. Ae. albopictus acts as an important vector of dengue in some urban and semi-urban areas. Some socio-ecomonic and other factors directly affect transmission of dengue in the hot-spot. Risk maps developed in the study are important to predict impending dengue epidemics so that limited resources could be utilized in a cost effective manner to control the disease. Sequence analysis of dengue virus indicated that dengue 2 serotype of Indian ancestry had been introduced to Sri Lanka. All districts in Sri Lanka were hyperendemic to dengue with signs of rapid rate of in situ evolution of dengue 3 serotype.