A saliva test for the Zika virus: experts say it’s time

The Zika virus, whose recent outbreak has caused the World Health Organization (WHO) to declare it a global public health emergency, is known to be transmitted mainly by mosquitoes and to a lesser extent either through sexual contact or from pregnant mother to fetus. So far, the virus has been detected in human blood, semen, urine and saliva. And while researchers around the world are working on developing a vaccine for Zika virus, predictions are that we are still years away from making one available for public use.

The article published in the journal Brazilian Oral Research claims that until a vaccine is available, early detection using saliva-based diagnostics will be key to preventing further spread of the disease. Led by Dr. Walter Luiz Siqueira of the Schulich School of Medicine & Dentistry at the University of Western Ontario in London, Ontario, the article says saliva-based testing for diseases is becoming more common due to the recent development of new highly sensitive technologies for measuring biomarkers in saliva.

Already, research is underway on the use of saliva for the identification of various cancers and for renal and pulmonary diseases. “Saliva is becoming more recognized as a diagnostic fluid,” say the study’s authors.

And because saliva sampling is noninvasive, painless and low cost, saliva-based diagnostics have huge potential for use worldwide, especially in developing countries where diseases like the Zika virus have their greatest impact.

Beginning in 2014, the current outbreak of Zika virus in South America has caused public alarm, in the main due to the discovered association between the disease and microcephaly, the underdevelopment of a newborn’s brain which can drastically affect intellectual and motor functioning.

Recent evidence also points to a link between Zika and meningitis. According to the New England Journal of Medicine an 81 year-old man was admitted to hospital in France with meningoencephalitis after a 4-week cruise to New Caledonia, Vanuatu, the Solomon Islands and New Zealand.

As of this week, the WHO reports Zika virus transmission in 59 countries and territories worldwide, with Cuba and Dominica being the latest to confirm transmission. Five states have now reported that their outbreaks of Zika are over while three others (France, Italy and the United States) have reported infections separate from known mosquito infection -likely due to sexual transmission.

Experts are currently divided on how to advise residents in Zika-prone areas concerning the potential for salivary transmission. Last month, a research institute in Brazil suggested that pregnant women should refrain from kissing people who may be infected with the virus. This was countered by Rubio Soares Campos, who co-identified the first case of Zika virus in Brazil, stating, “The warning is crazy and unnecessary. Just because the virus is present in saliva does not mean it can be transmitted that way.”

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