Respiratory tract infections

Respiratory infections were responsible for 11.3 million deaths worldwide in 2021,⁴ and are caused by a wide variety of pathogens. Viruses like influenza A and B, respiratory syncytial virus (RSV), and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) command much attention, but similar symptoms may also be presented by other pathogens, including viruses like enterovirus and rhinovirus and bacteria like Streptococcus and Mycobacterium tuberculosis (MTB, TB).

Influenza: Influenza is a seasonal respiratory illness that occurs annually, usually peaking in winter. It affects 5-10% of adults and 20-30% of children each year.⁵ Seasonal outbreaks can result in hospitalisation and death mainly among high-risk groups (the very young, elderly, or chronically ill). Worldwide, annual epidemics are estimated to result in 3–5 million cases of severe illness and 290,000–650,000 deaths.⁶

RSV: RSV is an acute respiratory viral infection that is thought to infect almost all children before the age of two years and can result in severe disease and death. It is estimated that it accounts for 3.2 million hospital admissions, and up to 149,400 deaths annually.⁷ There is a disparity in the burden of disease between countries with 95% of infection episodes in young children occurring in low- and middle-income countries.⁸ RSV can also affect adults and is increasingly recognised as a cause of severe illness in adults over 60.⁹

SARS-CoV-2 (COVID-19): To date, COVID-19 has accounted for more than seven million deaths globally.¹⁰ Although no longer considered a global health emergency, the virus continues to circulate and change, with continued severe consequences for some such as hospitalisation and death. The WHO reported a 42% increase in hospitalisations and a 62% increase in intensive care unit admissions in December 2023 compared with November 2023, and nearly 10,000 deaths from COVID-19 in the same period.¹¹

Group A Streptococcus (GAS): GAS is carried in human throats or skin with infections peaking during the winter months and commonly affecting school-aged children. Illnesses are usually mild, such as tonsillitis, pharyngitis, and impetigo. However, in rare cases, GAS infection can lead to invasive GAS which causes life-threatening conditions such as necrotising fasciitis and streptococcal toxic shock syndrome. GAS is responsible for more than 500,000 deaths globally each year.¹²

Tuberculosis: As the world’s deadliest infectious disease, in 2023 tuberculosis (TB) infected 10.8 million people, including 1.3 million children, and accounted for >1.25 million deaths. Caused by the bacillus Mycobacterium tuberculosis (MTB), TB co-infection with HIV and other pathogens further complicates diagnostic and treatment strategies for patients. While TB infects humans globally, the disease is prevalent in 30 high TB-burden countries which account for 87% of the TB infections worldwide.¹³

Identifying the underlying cause of a respiratory infection is essential to ensure appropriate treatment and effective use of resources. However, this can be challenging for a number of reasons.

Similar signs and symptoms

The non-specific clinical presentation of respiratory infections poses a considerable challenge to the differential diagnosis of pathogens. For example, influenza symptoms (including fever, headache, sore throat, muscle pains, body aches, runny nose, fatigue, and dry cough) overlap with many upper and lower respiratory infections caused by other bacterial and/or viral pathogens. This makes diagnosis based on symptoms alone challenging for clinicians.¹⁴

Overprescribing of antibiotics

In primary care settings, empiric treatment with antibiotics is frequently initiated—even when a viral infection is a strong possibility—leading to unnecessary or inappropriate prescribing of antibiotics.¹⁵ An early and accurate diagnosis is essential to identifying the cause of a respiratory infection and ensuring appropriate antimicrobial therapy. For example, the use of molecular Point of Care testing that can reliably detect viral and/or bacterial pathogens would result in enhanced care, less antibiotic empiricism, and reduced patient and societal costs of illness.

Complexity and sensitivity of testing

Bacterial culture was the traditional gold standard of diagnosis. However, there are drawbacks to this method as it can be labour-intensive, requires a high level of technical expertise, and has a long time to result.¹⁶ To optimise time-to-treatment, the diagnosis of acute respiratory tract infections cannot rely on the traditional method of culture alone. Therefore, other methods of detection have been developed to improve sensitivity, specificity, and detection time of pathogens causing respiratory tract infections.

Current diagnostic methods commonly used are point-of-care rapid antigen tests, molecular Point of Care tests and lab-based polymerase chain reaction (PCR) tests.^17,18 Clinicians must consider which test is most appropriate as although PCR tests are highly sensitive, the turnaround time for results is longer than an antigen test. On the other hand, antigen tests are generally less sensitive and have the potential to show false negatives.

Accuracy in testing is important as false negative results may pose a serious medical risk for patients and could lead to further spread of the virus to others. On the other hand, false positive results may lead people to believe they have been exposed to the virus and have developed antibodies, when in fact they have not.

Underdiagnosis

During the past 20 years in the US, only a small percentage of those presenting with influenza-like illness were tested and, of those tested, only 23% to 43% during peak activity were associated with a positive test for influenza.¹⁹ Therefore, while testing has a clear role to play in the accurate diagnosis of respiratory illness, it is not always utilised. Reasons for this discrepancy can be related to funding, access to appropriate tests, and even perception of the dangers of respiratory viruses.¹⁹

Underdiagnosis poses a major challenge to the World Health Organization (WHO)’s goal of eliminating TB by 2030. In 2023, only 63% of people who were newly diagnosed with pulmonary TB were biologically confirmed with a molecular test. This translates to 3 million TB patients who did not receive a molecular test to confirm diagnosis.²⁰ To reach these TB-elimination goals, healthcare agencies, national governments, and other stakeholders have emphasised the need for innovative diagnostics so clinicians can receive the information they need to properly diagnose infections, improve treatment access and reduce disease transmission.

The primary care setting plays a critical role in the diagnosis and management of respiratory infections, with respiratory symptoms being the most common reason for primary care consultations.²³

Roche ’s cobas® liat platform offers targeted and near-patient multi- and single-target assays with results in minutes. Quick respiratory testing enables clinicians to provide appropriate advice, guidance, and treatment at the right time and place. Moving respiratory testing to local clinics and the community could also reduce pressure on primary and secondary care providers

Roche cobas® liat system delivers gold-standard PCR testing at the point of care:^21,22

• Rapid frontline multiplex testing covering common respiratory targets
• Easy to use with less than 1 minute of hands-on time and intuitive easy-to-use interface
• Clinically actionable results for flu A/B and SARS-CoV-2 are available in 20 minutes
• Small design made to fit any clinic, urgent care, or satellite location

In complex cases, clinicians need diagnostic confidence for the most appropriate treatment and prescribing.

Roche offers comprehensive coverage that can identify infections beyond influenza, SARS-CoV-2, and RSV and even identify co-infections. Results can be used to guide isolation recommendations to prevent the spread of infection to other patients.

Roche cobas® eplex provides comprehensive, fast syndromic testing of 20+ respiratory targets for high-risk patients^21,22

• Easy-to-use workflow with less than 1 minute of hands-on time
• Urgent, actionable results for high-risk patients
• Random and continuous access to perform testing on all shifts
• Modular and scalable

Easing the burden on under-pressure physicians and laboratory staff is particularly important during a winter surge. Multiplex testing enables under-pressure lab staff to focus on priority cases.

Roche offers flexible, high-throughput, syndromic testing that can be customised. Clinicians can order respiratory tests that are optimised for settings and address seasonality, local dynamics, and patient cohorts.

Roche cobas® Respiratory flex for use on cobas® 5800/6800/8800 systems delivers gold-standard PCR technology offering focused and first-of-its-kind flexible and reliable respiratory testing^21,22

• Multiplex testing in hospitals for 12 most common viral respiratory pathogens
• Pre-calibrated ready-to-use reagents and automation require minimal technician interaction
• Highest throughput and the longest walk-away time available among automated molecular platforms