Differentiating Viral from Bacterial Infections
Estimates claim that over 1.2 million people died in 2019 as a direct result of an antibiotic-resistant bacterial infection. Statistics show that up to 4.95 million deaths in the same year were associated with antimicrobial resistance (AMR)1. The overuse and misuse of antibiotics is considered to be the largest contributing factor to the rise of AMR. Antibiotics are effective at treating a wide range of bacterial infections, however, when used to treat viral infections, they have little to no effect. Even still, many physicians continue to prescribe so-called empirical antibiotics as an all-encompassing treatment strategy. In their defence, differentiating viral from bacterial infections can be troublesome. Traditional testing takes the form of paired serology, which requires patients to visit a healthcare facility twice during a 2–4-week period. Many of these infections have distressing symptoms, making this an unreasonable time-to-diagnosis period. Novel molecular techniques can reduce the time to result in the determination of many infections. However, some of these methods are associated with high false positive rates and low specificity resulting in further misuse of antibiotics.
Mxyovirus resistance protein A (MxA) is a biomarker associated with viral infections. It displays antiviral activity against positive, double-stranded RNA viruses and some DNA viruses2. In a study from earlier this year, MxA was used to differentiate viral from bacterial infections in a cohort of 61 adults with an AUROC of 0.9 and a sensitivity and specificity of 92.3% and 84.6% respectively3. An additional study, known as the TREND study, found that a cut-off of 430μg/L could effectively differentiate bacterial and viral infections with an AUROC of 0.9, a sensitivity of 92% and a specificity of 100%4.
C-reactive protein (CRP) is a non-specific acute phase protein which is associated with bacterial infection. However, CRP levels have also been shown to be elevated in response to various viral infections such as Influenza virus, malaria5 and SARS-COV-26, limiting its utility in differentiating the aetiology of an infection.
Using both biomarkers in combination can help physicians determine the true aetiology of infection with high specificity, supporting antimicrobial stewardship and reducing the harmful use of these drugs. Available on the VeraSTAT, Randox provides tests for MxA and CRP, which together provide a fast and accurate method of detection and differentiation of bacterial and viral infections from a small sample.
We have provided an educational guide which describes these biomarkers and their usefulness in the arena of viral and bacterial detection. If you’re interested in learning more, you can find our educational guide here.
Differentiating Viral from Bacterial Infections
- Murray CJL, Ikuta KS, Sharara F, et al. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. The Lancet. 2022;399(10325):629-655. doi:10.1016/S0140-6736(21)02724-0
- Liao S, Gao S. MxA: a broadly acting effector of interferon-induced human innate immunity. Visualized Cancer Medicine. 2022;3:2. doi:10.1051/vcm/2022002
- Metz M, Gualdoni GA, Winkler HM, et al. MxA for differentiating viral and bacterial infections in adults: a prospective, exploratory study. Infection. Published online February 3, 2023. doi:10.1007/s15010-023-01986-0
- Rhedin S, Eklundh A, Ryd-Rinder M, et al. Myxovirus resistance protein A for discriminating between viral and bacterial lower respiratory tract infections in children – The TREND study. Clinical Microbiology and Infection. 2022;28(9):1251-1257. doi:10.1016/j.cmi.2022.05.008
- Joseph P, Godofsky E. Outpatient Antibiotic Stewardship: A Growing Frontier—Combining Myxovirus Resistance Protein A With Other Biomarkers to Improve Antibiotic Use. Open Forum Infect Dis. 2018;5(2). doi:10.1093/ofid/ofy024
- Paranga TG, Pavel-Tanasa M, Constantinescu D, et al. Comparison of C-reactive protein with distinct hyperinflammatory biomarkers in association with COVID-19 severity, mortality and SARS-CoV-2 variants. Front Immunol. 2023;14. doi:10.3389/fimmu.2023.1213246
Identification and Differentiation of Viral and Bacterial Respiratory Infection to Guide Antibiotic Stewardship
The development of point-of-care testing is critical in the identification and differentiation between bacterial and viral respiratory infections. Defining the indications of infection to improve antibiotic stewardship, ensures that patients are protected from unnecessary antibiotic use and antibiotic resistance. It has been shown that particular protein biomarkers, such as myxovirus resistance protein (MxA) and C-reactive protein (CRP), differentiate infections between bacterial and viral. Using point-of-care platforms, such as Randox’s VeraSTAT, for detection of these protein biomarkers may provide more rapid and cost-effective discriminating tools.
The treatment of bacterial and viral infections can differ significantly, however people are often treated with empirical antibiotics due to a lack of paid and accurate testing. Although early intervention of infection is urgent, current diagnostic methods are either time intensive or inaccurate. The challenges clinicians are faced with in the differentiation of viral or bacterial respiratory infection can lead to delayed diagnosis, misappropriation of antibiotics and increased healthcare costs.
MxA protein has the potential to greatly enhance the rapid detection of viral respiratory infections as it increases significantly when there is actuate viral infection. CRP is the dominant acute phase protein often used to guide treatment of a bacterial infection or inflammation associated with tissue injury, inflammatory disorders, and associated diseases.
CRP & MxA together, allow clinicians to make appropriate decisions in supporting antimicrobial stewardship and guide the appropriate use of antibiotics, saving time performing unnecessary tests, providing unnecessary treatment which missing the opportunity to provide the right treatment in a timely manner.
The Randox VeraSTAT is a simple, accurate, portable point of care device which delivers rapid results via the use of patented cathodic electrochemiluminescence technology (C-ECL). Designed with the aim of offering users the next generation of rapid diagnosis, the VeraSTAT eliminates the requirement to send samples to a laboratory and instead returns results in as little as 6 minutes.
- Eliminates delays in sending samples to the lab and facilitate immediate decision making at the point of care.
- Lightweight, portable and convenient, the Randox VeraSTAT can be used in a variety of locations to deliver results as required, such as a GP surgery or Emergency Department.
- Intuitive user interface guides the operator through the entire testing process.
- All necessary reagents are conveniently included in each single use, sealed cassette with no preparation required. All necessary consumables are supplied with the kit.
- The Randox VeraSTAT allows for results to be exported via Bluetooth connectivity.
- Flexible test menu comprising of a range of immunoassay, protein, inflammatory, diabetes & infectious disease markers.
Novel testing approaches identifying the type of infection at the point of care are essential in accurately guiding appropriate antibiotic treatment. Although these tests can’t determine what type of viral or bacterial infection a patient has, it will determine whether the infection is viral or bacterial, further testing is then carried out to determine what type of pathogen the patient has via PCR – the gold standard. The ability to distinguish between viral and bacterial infections is the most effective guide for clinical decision making and is an innovative tool for antibiotic stewardship.
1 – Fleming-Dutra K.E., Hersh A.L., Shapiro D.J. Prevalence of inappropriate antibiotic prescriptions among US ambulatory care visits, 2010–2011. JAMA. 2016;315:1864–1873. doi: 10.1001/jama.2016.4151.
2 – Cals JW, Hopstaken RM, Butler CC, Hood K, Severens JL, Dinant GJ. Improving management of patients with acute cough by C-reactive protein point of care testing and communication training (IMPAC3T): study protocol of a cluster randomised controlled trial. BMC Fam Pract. 2007;8:15.
3- New report calls for urgent action to avert antimicrobial resistance crisis [Internet]. World Health Organization. World Health Organization; 2019
4 – Hutchings MI, Truman AW, Wilkinson B. Antibiotics: past, present and future. Curr Opin Microbiol. (2019) 51:72–80. doi: 10.1016/j.mib.2019.10.008