An Indian team has developed a highly sensitive and specific assay for detection of dengue viruses. The assay promises to be useful in differential diagnosis of dengue fever when a number of other clinically indistinguishable infectious diseases like malaria, Chikungunya, rickettsia and leptospira occur1 .
The ability of the assay to detect Dengue virus serotype-2 in inoculated mosquitoes makes it a potential tool for detecting it in field-caught mosquitoes.
Recognising the need for a rapid, sensitive and high throughput method for detection of dengue virys in the early stages of the disease, the researchers used the new generation TaqMan Minor Groove Binding (MGB) probe approach to develop an improved real time RT-PCR (qRT-PCR) for the virus.
They designed a single MGB probe and a single primer pair for all the four serotypes of the virus. The specificity and sensitivity of the assay was 100% when tested with a panel of 39 known positive and negative samples. Viral RNA could be detected and quantitated in infected mouse brain, cell cultures, mosquitoes, clinical samples as also in patients even after seroconversion till 10 days post onset of infection.
The researchers found no overlap with Japanese Encephalitis (JE), West Nile (WN), Chikungunya (CHK) viruses or with Leptospira, Plasmodium vivax, Plasmodium falciparum and Rickettsia positive clinical samples.
