Recent Advances in Methods Detecting the Dengue Virus

Abstract

Dengue fever, caused by the Dengue virus (DENV), has emerged as a mild to lethal human infection. Globally, an estimated 400 million patients have been infected with DENV over the past 10 years, and this number is expected to increase in the coming years. The DENV, possessing a single positive- stranded RNA with five serotypes, is transmitted by mosquitos of the Flaviviridae family—particularly, the Flavivirus genus and Aedes species. The DENV genome encodes three structural and seven non- structural proteins. In the Kingdom of Saudi Arabia (KSA), serotype 2 of the dengue virus (DENV-2) emerged in 1994 and caused a major epidemic in Jeddah, KSA. Dengue outbreaks first appeared in Makkah in 2004, according to the characteristics studied in hospitalized patients. Major factors causing the wide and rapid distribution of the virus include increased urbanization, migration, global commerce, weather variation, inadequate mosquito control, the development of pesticide resistance in mosquitos, irregular use of insecticides, and shifting climatic circumstances. Detection methods currently used for DENV include the detection of viral antigens (Ag) (virus extraction and purification, immunofluorescence test, and NS1 detection assay), serological assays (plaque reduction neutralization titers (PRNT), IgM/IgG immunological assays), and RNA detection using RT-PCR. Low sensitivity, specificity, and accessibility of the detection protocols represent major challenges necessitating the advent of more amenable protocols. The Aedes mosquito is the primary vector for horizontal transmission of DENV. DENV-infected mosquitos infect people, and DENV passes from one human to another through this vector. Once acquired, the virus requires 5–7 days of incubation before the patient exhibits various symptoms of dengue fever; subsequently, uninfected mosquitoes that come in contact with infected patients feed on their blood and become infected. The DENV may also be spread through the mating of male and female Aedes mosquitoes. The reverse transcription loop-mediated isothermal application (RT-LAMP) has emerged as one of the most adaptable viral detection procedures. This method could prove to be an excellent pathogen detection tool because it is cheap, simple, sensitive, cost-effective, accessible, and fast. The method relies on the use of 4–6 primers to recognize eight different loci in the target sequence contained in the DENV clinical isolates with a 100% success rate and a sensitivity of about 93%. We strongly recommend the use of LAMP in detecting spots of virus spread, especially in urban regions where accessibility to detection methods is scarce.