Postnatal Identification of Zika Virus Peptides from Saliva

Abstract

We explored the potential to diagnose Zika virus (ZIKV) infection by analyzing peptides in saliva during a convalescent phase of infection, long after resolution of acute disease. A 25-y-old woman clinically diagnosed with Zika fever in the first trimester was enrolled with her dizygotic twins for a 3-mo postnatal sample of saliva (9-mo after maternal infection). The female baby (A) had microcephaly while the male baby (B) was born healthy. Peptidomic analysis was completed by mass spectrometry (MS/MS), and ZIKV peptides were identified using the National Institutes of Health Zika Virus Resource database, then aligned and mapped to the ZIKV polyprotein to determine proteome coverage and phylogenetic studies. A total of 423 (mother), 607 (baby A), and 183 (baby B) unique ZIKV peptides were identified in saliva by MS/MS, providing a coverage of 67%, 84%, and 45%, respectively, of the entire ZIKV polyprotein (>3,400 amino acids). All peptides were aligned to other flaviviruses that are circulating in Brazil (dengue and yellow fever) to discard false-positive matches. Nine peptides identified were highly conserved to dengue virus. Alignment of a contiguous peptide sequence for mother/babies with the 74 ZIKV sequences suggested that the virus may have entered the oral cavity through the salivary glands, leading to an infection that persists into the postnatal period (vertical transmission). Furthermore, we identified 9 sequence variations that were unique to the baby with microcephaly (not found in the mother or the twin). This sequence information could provide a template for future neuropathogenic studies. A much larger sample size is required to determine whether sequence variation in the envelope protein significantly associates with microcephaly. Finally, from a public health perspective, it will be important to determine whether viral replication is still taking place after birth and whether the virus can be transmitted through salivary contact.

Guidelines for dental care provision during the COVID-19 pandemic

“…Even after patient recovery, recusancy during the convalescence period was reported (D. Chen et al, 2020). This is plausible since the presence of some virus strains in saliva for as long as 29 days have been reported in the literature (Barzon et al, 2016;Zuanazzi et al, 2017).…”

“…It is unclear yet, but COVID-19 recusancy might be possible and some virus strains can be present in saliva for as long as 29 days (Barzon et al, 2016;D. Chen et al, 2020;Zuanazzi et al, 2017). 4.…”

Rapid diagnosis of Zika virus through saliva and urine by Loop-mediated isothermal amplification (LAMP)

“…Although saliva appears to be a useful sample to diagnose ZIKV infection during the acute phase, other studies have reported a low risk of transmission through this fluid [10,12,24]. …”

“…Since the first report of ZIKV in saliva [9], studies have suggested that saliva could be an important alternative sample to detect ZIKV infection [5,9–12]. Saliva collection is easy, non-invasive, involves safe handling and requires less processing than blood greatly simplifying the assay, and justifying efforts to develop diagnostic techniques through the use of this fluid.…”

Coronavirus COVID-19 impacts to dentistry and potential salivary diagnosis

“…Diagnosis of COVID-19 can theoretically be performed using salivary diagnosis platforms. Some virus strains have been detected in saliva as long as 29 days after infection [18,19], indicating that a non-invasive platform to rapidly differentiate the biomarkers using saliva could enhance disease detection. [20] Saliva samples could be collected in patients who present with oropharyngeal secretions as a symptom [12,13].…”