International researchers have created a new test able to quickly and cost-effectively identify Zika virus infection up to 9 months’ post-exposure.
The new test examines proteins and peptides in saliva using proteomics, the study of proteomes and their functions. According to a press release on the research, published in the Journal of Dental Research (JDR), this is the first time proteomics has been used in this way “to accurately detect exposure to the Zika virus.”
For the study, the researchers looked at 3-month postnatal saliva samples from a 25-year-old women, “clinically diagnosed with Zika fever in the first trimester,” according to the study, and her dizygotic twins. (The mother had been infected with Zika 9 months prior.) The male twin was born healthy, while the female twin was born with microcephaly. Mass spectrometry was used to complete peptidomic analysis and the authors used the National Institutes of Health Zika Virus Resource database to identify Zika virus peptides. These peptides were, “then aligned and mapped to the Zika virus polyprotein to determine proteome coverage and phylogenetic studies,” according to the study. In total, 423 unique Zika virus peptides were identified from the mother, 607 from the female baby, and 183 from the male baby. Study authors write that, “all peptides were aligned to other flaviviruses that are circulating in Brazil (dengue and yellow fever) to discard false-positive matches, [and] 9 peptides identified were highly conserved to dengue virus.”
After analysis, the researcher discovered sequence types that suggest the Zika virus, “may have entered the oral cavity through the salivary glands, leading to an infection that persists into the postnatal period (vertical transmission).” In addition, the female baby, with microcephaly, had 9 unique sequence variations that were not found in her brother or mother. These unique sequences may hold the clue to “how the virus passes from mother to baby and its role in the development of microcephaly,” according to the press release.
JDR Editor-in-Chief, William Giannobile, spoke on the significance of these findings in the press release, remarking, “We are very excited to publish findings that shed light on the transmission of Zika virus and present an innovative approach to assessing the presence of Zika virus. This research has the potential to positively impact global health. By detecting the virus, the infected individuals can have their symptoms and the virus progression properly monitored, as well as take action to stop the spread of the virus which causes these devastating craniofacial defects in newborns.”
A provisional US patent was given to the researchers “to develop a simple device that can be used to identify the Zika virus peptides in saliva outside of the laboratory.”
On the transmission of the Zika virus via saliva, experts have determined that the likelihood of infection is low because it would take an extremely high number of particles to infect another person, and infected individuals are not able to produce the amount that is needed.