Potential use of saliva samples to diagnose Zika virus infection

Article:  https://www.arca.fiocruz.br/bitstream/icict/16381/2/Tauro%20LB%20Potential%20….pdf

Summary:  Since the Zika virus is relatively new and is spreading to various areas of the world, it is essential to stop its advance before the number of cases gets too high. One way of doing this is designing a vaccine, or finding an effective cure, but another way that is now being developed is an accurate way to diagnose the infection. The Zika virus presents with fever, fatigue, exanthema and headache. These symptoms are not specific and could be linked to many other illnesses. Also, viremia (virus in the blood) is short-lived and low and the presence of antigens can no longer be detected after a few days. Saliva and urine samples, however, present with a much higher load and make the diagnosis faster and more accurate. At the moment they are testing for antigens with ELISA and for viral RNA with RT-PCR (polymerase chain reaction, using reverse transcriptase since the genome of Flavivirus is RNA and has to be converted back to DNA to be detected).

Connections:  This connects to the ELISA testing we did in lab and talked about in class  as well, and also to the Dan Stinchcomb lecture, which focused on the Zika virus and vaccine specifically.

Analysis:  Research on Zika virus has progressed at a fast pace, considering that Zika emerged in 2016 and that we are already developing a vaccine and a way to diagnose the virus efficiently. This article is just a preliminary study on some patients that had no viral load in their blood but resulted positive for infection when their saliva, urine and serum were analyzed. Overall it seems promising and it might help preventing the spread of the virus by informing people of their infection, and shining some light on whether or not the virus can be spread with sexual contact.

Questions:  Why is viremia so short-lived and low? If the virus is present in bodily fluids, can it also be spread through them? What are the preventive measures taken to avoid the spread of the virus?