Saliva is a hypotonic fluid in nature. the major salivary glands admire the parotid glands, submandibular glands and sublingual glands secrete close to 90% of secretion. The secretion glands have high permeability and are encircled by abundant capillaries, blood and acini, which may exchange molecules. 

    Hence, biomarkers within the blood circulation will infiltrate acini and ultimately secreted into the saliva

    Oral cavity is an entrance and an outlet of body, and saliva is meant to play a job in early diagnosis and shut contact transmission in infectious diseases

    In response to the COVID-19 pandemic, early, accurate, and sensitive diagnosing for each symptomatic and well patients could give efficient and timely disease control, significantly in distinguishing potential “super-spreaders”.

    prevalence of well patients, and also the mechanism of however they drive this pandemic, stay unknown.

    In this blog we see how saliva as diagnostic factor for covid-19

    In my previous blog I posted about coronavirus, structure, sign and symptoms and diagnosis if want to see that please click the below 


    • Non-invasive, economical.
    • Safer to administer than serum sampling (no needles).
    • Real-time diagnostic values.
    • No would like for trained medical workers.
    • Multiple samples may be obtained simply.
    • Collection and screening may be done at home.
    • Minimizes the risks of cross-contamination.
    • More economical sampling, shipping and storage compared to serum.
    • Requires lesser manipulation throughout diagnostic procedures compared to serum.
    • Commercial availability of screening assays.
    • Saliva doesn't clot and might be manipulated more simply than blood.


    The standard methodology of COVID-19 detection is reverse transcription enzyme chain reaction (RT-qPCR), typically used to find viral ribonucleic acid from nasopharyngeal and oropharyngeal swabs or sputum samples. 

    Rapid identification and publication of the virus’ genome sequence have expedited the event of diagnostic ways, still because the race to develop a vaccine.  

    Qualitative reverse transcription polymerase chain reaction (RT-qPCR) assays are easier to validate than quantitative assays and are most well-liked for diagnostics. 

    Furthermore, a chest X-ray could be a helpful diagnostic tool to find bilateral pneumonia, presenting as multilobar ground-glass opacities with a peripheral, asymmetric, and posterior distribution.
    • CT is also an useful diagnosis of covid-19 some of the feature that seen in CT scan are 
      • Ground glass appearance
      • Crazy paving pattern
      • Mass consolidation 
    As of nineteen March 2020, a medical science protein take a look at to find IgG (IgG) and immune globulin was approved by the authority as a point-of-care test, tho' isn't nonetheless wide used.


    The collection of those specimen types needs close contact between healthcare staff and patients and poses a risk of transmission of the virus, causes discomfort and will cause bleeding, particularly in patients with condition corresponding to thrombocytopenia. 

    Hence, nasopharyngeal or oropharyngeal swabs aren't fascinating for sequential observance of viral load

    rRT-PCR, however, isn't a perfect screening procedure to be adopted for massive screening, because it implies the patient's reside home or in hospital till diagnosing, thus inflicting the crowding of the centers appointed to gather specimens.


    saliva specimen collection has the benefits of being additional acceptable for patients and more secured for healthcare workers for diagnosing of coronavirus. 

    Specimen are often collected by the patients themselves and therefore reduces the chance of infection to the healthcare workers

    Oral swabs are in all probability applicable in early detection.

    saliva specimens can eliminate the waiting time, and thus the results would be available abundant sooner, It conjointly reduces the time and value related to the collection of specimen. 

    Saliva incorporates a high consistency rate of greater than 90% with nasopharyngeal specimens within the detection of respiratory viruses, together with coronaviruses.

    Coronaviruses, together with the SARS-CoV, are detected previously in saliva, nearly in par with the amount found in cavum specimens. 

    saliva samples, it had been reportable from completely different clinical studies that 87%, 91.6%, and 100 percent of COVID-19 patients were known as being infectious agent positive, respectively, suggesting that saliva may be a powerful specimen source for the diagnosing of the SARS-CoV-2 virus.

    For salivary ribonucleic acid analysis, it had been discovered that saliva samples are often keep in Trizol for over 2 years at –80 °C while not adding rnase inhibitors, suggesting such specimens are often used for future diagnostics. 

    salivary viral RNA testing by RT-qPCR, we have a tendency to propose that secretion assay of IgM/IgG against SARS-CoV-2, SARS-CoV-2 double-membrane extracellular vesicles (EVs) isolation, anti-SARS-CoV-2 surface proteins, viral titres load, CD4+/CD8+ T cells derived EVs, and pro-inflammatory cytokines may be potential diagnostic and prognostic biomarkers for COVID-19 disease.

    The presence of Covid-19 in patients saliva suggests the probability of salivary gland infection.

    However, it ought to be noted that saliva specimens not only contain saliva secreted from major or minor secretion glands however conjointly contain secretions coming down from the nasopharynx or coming up from the respiratory organ via the action of cilia lining the airway

    Soon, salivary diagnostics may play a important role in detection of Covid-19 and may provide mass screening of the population.

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    • May 8,2020 the U.S. Food and Drug Administration authorized the first diagnostic test with the option of using home-collected saliva samples for COVID-19 testing.
    • Saliva samples self-collected by patients at home using the Spectrum Solutions LLC SDNA-1000 Saliva Collection Device.


    FDA approved saliva collection device

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    Saliva plays a very important role within the transmission of infection between persons by contact with the droplets expressed.

    Respiratory and salivary droplets seem to be the most transmission routes of COVID-19 disease through inhalation, ingestion, and/or direct mucous contact. 

    Saliva droplets are generated once breathing, talking, coughing, or sneeze and formed as particles during a mixture of moisture and droplet nuclei of microorganisms. 

    Three thousand saliva driblet nuclei may be generated by one cough, that nearly equals to the number made throughout a 5-min speak.

    Around 40,000 spittle droplets reaching several meters in air is generated by one sneeze.

    One normal exhalation will generate spittle droplets reaching the gap of 1 m in air.

    The ACE2 epithelial cells of the secretion glands are shown to be associate initial target for the SARS-CoV, early within the disease process, in rhesus macaques.

    These findings recommend that the oral cavity has high susceptibleness to COVID-19 infection. 

    The potential for transmission via salivary bioaerosols poses a very important danger to healthcare workers that operate in close proximity to the face and oral cavities, like dental practitioners; oral-maxillofacial surgeons; ear, nose, and throat (ENT) surgeons; and ophthalmologists, particularly once carrying out procedures that generate aerosols.

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    Use of personal protecting equipment, such as masks and respirators that may be effective in preventing the transmission mechanism of coronavirus RNA, must be tested in clinically relevant things wherever droplets and aerosols are generated from biofluids (including saliva) throughout medical procedures. 

    The role of pre-procedural rinsing with disinfectant mouthwash must be explored during this context. 

    High volume suction and use of filtration air-systems, particularly in clinical settings wherever aerosols (including those from saliva) are often generated by surgical procedures.


    Saliva offers several advantages as a diagnostic fluid because it is simple to collect, store and contains extremely smart quality desoxyribonucleic acid. Thus, saliva will be a perfect various for blood.

    Saliva as a supporter within the detection of the virus associated an individual’s immunity to it 

    Salivary diagnostics may play a crucial  role in detection of Covid-19 and may supply mass screening of the population.

    Saliva as a attacker within the battle against COVID-19 because of it being a prominent supply for disease transmission via droplets and probably aerosols.

    Indeed, non-invasive saliva sampling could also be another efficient technique for up the sensitivity and accuracy of large-scale detection of COVID-19 virus and/or immunity, therefore significantly decreasing the risk for medical professionals and patients.

    It is anticipated that the event of precise secretion diagnostic tools can build salivary medicine a reality within the future.


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