Western University researchers say they have discovered a new, more effective way, to test patients for exposure to Zika virus.
They’ve identified a specific protein signature for the mosquito-borne virus by analyzing the saliva of a pregnant mother infected with Zika and her twins, one born with microcephaly and one without.
Microcephaly is a birth defect in which a baby’s head and brain are smaller than normal.
“The gold standard now is to test and detect if you have Zika virus or not in the first four days after infection. With our method, we can increase this window for detection and we can discover if the person has the Zika virus after 20 days of infection, ” said Dr. Walter Siqueira, a dental clinician-scientist and associate professor from the School of Dentistry at Western’s Schulich School of Medicine and Dentistry.
The current diagnostic test used by the Centers for Disease Control and Prevention uses blood tests to look for changes to RNA. The drawback to this method is that it can only detect the virus up to one week after exposure. Siqueira points out because proteins are more stable than RNA, saliva proteomics can detect the virus far longer after exposure than with the traditional method.
“We can identify the proteins and the peptides that come directly from the virus and these stay longer in the body than RNA. The window to detect whether or not someone has the Zika infection increases to more than 20 days. In the case of our paper, it was nine months after infection.”
Siqueira says discovering how to detect Zika beyond a week after infection is crucial, as the symptoms of Zika are very common, and it’s hard to tell in three or four days if you specifically have the Zika virus.
The study published online in the Journal of Dental Research, also suggests a vertical transmission of the virus between mother and baby. It also showed mutations in the amino acid sequence of the peptides that were different for each twin, suggesting these mutations may play a role in whether or not a baby will develop microcephaly.