Additional molecular testing of saliva specimens improves the detection of respiratory viruses

Kelvin Kw To, Lu Lu, Cyril Cy Yip, Rosana Ws Poon, Ami My Fung, Andrew Cheng, Daniel Hk Lui, Deborah Ty Ho, Ivan Fn Hung, Kwok-Hung Chan, Kwok-Yung Yuen, Kelvin Kw To, Lu Lu, Cyril Cy Yip, Rosana Ws Poon, Ami My Fung, Andrew Cheng, Daniel Hk Lui, Deborah Ty Ho, Ivan Fn Hung, Kwok-Hung Chan, Kwok-Yung Yuen

Abstract

Emerging infectious diseases in humans are often caused by respiratory viruses such as pandemic or avian influenza viruses and novel coronaviruses. Microbiological testing for respiratory viruses is important for patient management, infection control and epidemiological studies. Nasopharyngeal specimens are frequently tested, but their sensitivity is suboptimal. This study evaluated the incremental benefit of testing respiratory viruses in expectorated saliva using molecular assays. A total of 258 hospitalized adult patients with suspected respiratory infections were included. Their expectorated saliva was collected without the use of any special devices. In the first cohort of 159 patients whose nasopharyngeal aspirates (NPAs) tested positive for respiratory viruses during routine testing, the viral load was measured using quantitative reverse transcription PCR. Seventeen percent of the patients (27/159) had higher viral loads in the saliva than in the NPA. The second cohort consisted of 99 patients whose NPAs tested negative for respiratory viruses using a direct immunofluorescence assay. Their NPA and saliva specimens were additionally tested using multiplex PCR. In these patients, the concordance rate by multiplex PCR between NPA and saliva was 83.8%. Multiplex PCR detected viruses in saliva samples from 16 patients, of which nine (56.3%) had at least one virus that was not detected in the NPA. Decisions on antiviral or isolation precautions would be affected by salivary testing in six patients. Although NPAs have high viral loads and remain the specimen of choice for most patients with respiratory virus infections, supplementary molecular testing of saliva can improve the clinical management of these patients.

Figures

Figure 1
Figure 1
Study design. nasopharyngeal aspirate, NPA; quantitative PCR with reverse transcription, qRT-PCR. aRoutine clinical testing was performed using antigen detection by the DFA, which included the influenza A and B viruses, parainfluenza virus types 1–3, respiratory syncytial virus, human metapneumovirus and adenovirus. From 1 March to 8 April 2015 (during the peak influenza A virus season), monoplex real-time RT-PCR for the influenza A M gene was performed for patients admitted to the general medical ward. bPatients whose NPA specimens either tested negative for respiratory viruses by DFA or had insufficient NPCs for DFA during routine clinical testing. Insufficient NPCs is defined as <20 NPCs in the entire well.
Figure 2
Figure 2
Viral loads in the NPA and the saliva specimens for all patients in the first cohort. The number of patients infected with each of the respiratory viruses is outlined in Table 2. (A) Comparison of viral loads between the NPA and saliva specimens. (B) Comparison of the saliva viral load of influenza A and influenza B in patients with saliva collected before and after oseltamivir treatment. (C) Comparison of the saliva viral loads in patients with or without pneumonia. Medians, quartiles, and ranges are shown. nasopharyngeal aspirate, NPA.

References

    1. Jain S, Self WH, Wunderink RG et al. Community-acquired pneumonia requiring hospitalization among US adults. N Engl J Med 2015; 373: 415–427.
    1. Jain S, Williams DJ, Arnold SR et al. Community-acquired pneumonia requiring hospitalization among US children. N Engl J Med 2015; 372: 835–845.
    1. Prina E, Ranzani OT, Torres A. Community-acquired pneumonia. Lancet 2015; 386: 1097–1108.
    1. Luyt CE, Brechot N, Chastre J. What role do viruses play in nosocomial pneumonia? Curr Opin Infect Dis 2014; 27: 194–199.
    1. Cheng VC, To KK, Tse H, Hung IF, Yuen KY. Two years after pandemic influenza A/2009/H1N1: what have we learned? Clin Microbiol Rev 2012; 25: 223–263.
    1. To KK, Chan JF, Chen H, Li L, Yuen KY. The emergence of influenza A H7N9 in human beings 16 years after influenza A H5N1: a tale of two cities. Lancet Infect Dis 2013; 13: 809–821.
    1. Chen Y, Liang W, Yang S et al. Human infections with the emerging avian influenza A H7N9 virus from wet market poultry: clinical analysis and characterisation of viral genome. Lancet 2013; 381: 1916–1925.
    1. Pan M, Gao R, Lv Q et al. Human infection with a novel, highly pathogenic avian influenza A (H5N6) virus: virological and clinical findings. J Infect 2016; 72: 52–59.
    1. Chan JF, Lau SK, To KK, Cheng VC, Woo PC, Yuen KY. Middle East respiratory syndrome coronavirus: another zoonotic betacoronavirus causing SARS-like disease. Clin Microbiol Rev 2015; 28: 465–522.
    1. Rao S, Nyquist AC. Respiratory viruses and their impact in healthcare. Curr Opin Infect Dis 2014; 27: 342–347.
    1. Dobson J, Whitley RJ, Pocock S, Monto AS. Oseltamivir treatment for influenza in adults: a meta-analysis of randomised controlled trials. Lancet 2015; 385: 1729–1737.
    1. Muthuri SG, Venkatesan S, Myles PR et al. Effectiveness of neuraminidase inhibitors in reducing mortality in patients admitted to hospital with influenza A H1N1pdm09 virus infection: a meta-analysis of individual participant data. Lancet Respir Med 2014; 2: 395–404.
    1. Hung IF, To KK, Lee CK et al. Hyperimmune IV immunoglobulin treatment: a multicenter double-blind randomized controlled trial for patients with severe 2009 influenza A(H1N1) infection. Chest 2013; 144: 464–473.
    1. Gelfer G, Leggett J, Myers J, Wang L, Gilbert DN. The clinical impact of the detection of potential etiologic pathogens of community-acquired pneumonia. Diagn Microbiol Infect Dis 2015; 83: 400–406.
    1. Baron EJ, Miller JM, Weinstein MP et al. A guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a). Clin Infect Dis 2013; 57: e22–e121.
    1. World Health Organization. Clinical management of human infection with pandemic (H1N1) 2009: revised guidance. Available at (accessed on 22 December 2015).
    1. Ruuskanen O, Lahti E, Jennings LC, Murdoch DR. Viral pneumonia. Lancet 2011; 377: 1264–1275.
    1. Kim YG, Yun SG, Kim MY et al. Comparison between saliva and nasopharyngeal swab specimens for detection of respiratory viruses by multiplex reverse transcription-PCR. J Clin Microbiol 2016; 55: 226–233.
    1. Jeong JH, Kim KH, Jeong SH, Park JW, Lee SM, Seo YH. Comparison of sputum and nasopharyngeal swabs for detection of respiratory viruses. J Med Virol 2014; 86: 2122–2127.
    1. Azadeh N, Sakata KK, Brighton AM, Vikram HR, Grys TE. FilmArray respiratory panel assay: comparison of nasopharyngeal swabs and bronchoalveolar lavage samples. J Clin Microbiol 2015; 53: 3784–3787.
    1. To KK, Song W, Lau SY et al. Unique reassortant of influenza A(H7N9) virus associated with severe disease emerging in Hong Kong. J Infect 2014; 69: 60–68.
    1. Yu L, Wang Z, Chen Y et al. Clinical, virological, and histopathological manifestations of fatal human infections by avian influenza A(H7N9) virus. Clin Infect Dis 2013; 57: 1449–1457.
    1. Ramirez P, Valencia M, Torres A. Bronchoalveolar lavage to diagnose respiratory infections. Semin Respir Crit Care Med 2007; 28: 525–533.
    1. To KK, Wong SC, Xu T et al. Use of nasopharyngeal aspirate for diagnosis of pneumocystis pneumonia. J Clin Microbiol 2013; 51: 1570–1574.
    1. White MR, Helmerhorst EJ, Ligtenberg A et al. Multiple components contribute to ability of saliva to inhibit influenza viruses. Oral Microbiol Immunol 2009; 24: 18–24.
    1. Bilder L, Machtei EE, Shenhar Y, Kra-Oz Z, Basis F. Salivary detection of H1N1 virus: a clinical feasibility investigation. J Dent Res 2011; 90: 1136–1139.
    1. Goff J, Rowe A, Brownstein JS, Chunara R. Surveillance of acute respiratory infections using community-submitted symptoms and specimens for molecular diagnostic testing. PLoS Curr 2015; 7: pii: ecurrents.outbreaks.0371243baa7f3810ba1279e30b96d3b6.
    1. Robinson JL, Lee BE, Kothapalli S, Craig WR, Fox JD. Use of throat swab or saliva specimens for detection of respiratory viruses in children. Clin Infect Dis 2008; 46: e61–e64.
    1. Sueki A, Matsuda K, Yamaguchi A et al. Evaluation of saliva as diagnostic materials for influenza virus infection by PCR-based assays. Clin Chim Acta 2016; 453: 71–74.
    1. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987; 40: 373–383.
    1. To KK, Lee KC, Wong SS et al. Lipid metabolites as potential diagnostic and prognostic biomarkers for acute community acquired pneumonia. Diagn Microbiol Infect Dis 2016; 85: 249–254.
    1. Hung IF, Cheng VC, Wu AK et al. Viral loads in clinical specimens and SARS manifestations. Emerg Infect Dis 2004; 10: 1550–1557.
    1. To KK, Hung IF, Li IW et al. Delayed clearance of viral load and marked cytokine activation in severe cases of pandemic H1N1 2009 influenza virus infection. Clin Infect Dis 2010; 50: 850–859.
    1. To KK, Chan KH, Li IW et al. Viral load in patients infected with pandemic H1N1 2009 influenza A virus. J Med Virol 2010; 82: 1–7.
    1. Chan KH, Yam WC, Pang CM et al. Comparison of the NucliSens easyMAG and Qiagen BioRobot 9604 nucleic acid extraction systems for detection of RNA and DNA respiratory viruses in nasopharyngeal aspirate samples. J Clin Microbiol 2008; 46: 2195–2199.
    1. Siegel JD, Rhinehart E, Jackson M, Chiarello L, Health Care Infection Control Practices Advisory C. 2007 Guideline for isolation precautions: preventing transmission of infectious agents in health care settings. Am J Infect Control 2007; 35 (10 Suppl 2): S65–164.
    1. Kumar S, Henrickson KJ. Update on influenza diagnostics: lessons from the novel H1N1 influenza A pandemic. Clin Microbiol Rev 2012; 25: 344–361.
    1. Somerville LK, Ratnamohan VM, Dwyer DE, Kok J. Molecular diagnosis of respiratory viruses. Pathology 2015; 47: 243–249.
    1. Chen JH, Lam HY, Yip CC et al. Clinical evaluation of the new high-throughput Luminex NxTAG respiratory pathogen panel assay for multiplex respiratory pathogen detection. J Clin Microbiol 2016; 54: 1820–1825.
    1. Chan KH, To KK, Chan JF et al. Assessment of antigen and molecular tests with serial specimens from a patient with influenza A(H7N9) infection. J Clin Microbiol 2014; 52: 2272–2274.
    1. Chan JF, Choi GK, Tsang AK et al. Development and evaluation of novel real-time reverse transcription-PCR assays with locked nucleic acid probes targeting leader sequences of human-pathogenic coronaviruses. J Clin Microbiol 2015; 53: 2722–2726.
    1. Li IW, Hung IF, To KK et al. The natural viral load profile of patients with pandemic 2009 influenza A(H1N1) and the effect of oseltamivir treatment. Chest 2010; 137: 759–768.
    1. Hansen KB, Westin J, Andersson LM, Lindh M, Widell A, Nilsson AC. Flocked nasal swab versus nasopharyngeal aspirate in adult emergency room patients: similar multiplex PCR respiratory pathogen results and patient discomfort. Infect Dis (Lond) 2016; 48: 246–250.
    1. Centre for Health Protection. Recommended Personal Protective Equipment (PPE) in hospitals/clinics for suspected or confirmed cases with Middle East Respiratory Syndrome (MERS) under different response levels. Available at (accessed on 17 November 2015).
    1. Esposito S, Scala A, Bianchini S et al. Partial comparison of the NxTAG respiratory pathogen panel assay with the Luminex xTAG respiratory panel fast assay V2 and singleplex real-time polymerase chain reaction for detection of respiratory pathogens. Diagn Microbiol Infect Dis 2016; 86: 53–57.

Source: PubMed

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