Researchers at the Center for Research and Advanced Studies (Cinvestav) in Mexico have developed a cDNA microarray chip that allows detection of the RNA strand of the dengue fever virus.

The genetic information pinpoints the exact serotype of malaria that an infected person or mosquito is carrying  and allows analysis of the complementary strand of DNA (cDNA) obtained from the dengue fever virus being carried by the infected patient. The cDNA is covalently linked to a slide (substrate) that can be a glass or paper.

Through probes marked with fluorescent elements, called fluorochromes, they can perceive in the chip different colors according to the serotype of dengue fever the patient is bearing. Additionally, the cDNA microarray can display more than one color if the patient carries two serotypes.


cDNA microarray on a chip for rapid detection of dengue fever. Credit: Investigación y Desarrollo

According to Maria de Lourdes Muñoz Moreno, researcher at the Department of Genetics and Molecular Biology at Cinvestav, the problem is that sometimes dengue fever cases are diagnosed improperly. "A simple flu could be mistaken for dengue fever; or on the contrary, the latter could be diagnosed as a cold." 

Muñoz Moreno added that a mis-diagnosis of dengue fever could trigger the progression of the disease. "If a painkiller or an antihistamine are prescribed to the patient infected by the virus, such drugs could cause a thinning of the blood vessels walls, thus triggering hemorrhagic fever" the researcher said.

Knowing the precise serotype of dengue fever virus the patient is carrying, the progression of the disease would stop and an optimal follow up of the treatment would be held. "When it comes to a second infection with another serotype, the antibodies that protect the body from dengue fever in the first infection, could now adhere to the virus of a new serotype, causing the cells to be more easily infected," explained Muñoz Moreno.

Currently, the research group at Cinvestav is working to achieve a microarray that differentiates dengue fever from Chikungubya, a viral disease recently reported in Latin America that is transmitted in a dengue-like manner, causing an acute febrile phase lasting two to five days. (Agencia ID).