Medical Academic (MA): Many patients, particularly young children and some elderly individuals, struggle to swallow capsules. How do you approach antiviral treatment in these patients, and what is the importance of being able to open capsules when necessary?

Prof Keertan Dheda (KD): Oseltamivir remains the most commonly used antiviral for influenza. In everyday practice, a common challenge is that young children and some elderly patients are unable to swallow capsules. In these situations, the capsule can be opened and mixed with a small amount of sweetened liquid or soft food. This can be particularly helpful when a liquid (syrup) formulation is unavailable. The ability to administer treatment in this way is important because antiviral therapy works best when started early. Delays in treatment may reduce the potential benefit of therapy.

MA: Parents and caregivers often ask whether antiviral medication should be taken with meals. What advice do you provide regarding food intake when prescribing oseltamivir, and can taking it with food improve tolerability?

KD: Oseltamivir may be taken with or without food. However, taking it with food often reduces nausea and stomach upset, which are common side effects. For this reason, I usually advise patients to take the medication after a light snack. This simple measure can improve tolerability and help patients complete the full course of treatment.

MA: We often hear that antiviral treatment should be initiated within the first 48-hours of symptom onset. Why is early intervention important, and what practical advice do you give patients who present later than expected?

KD: Influenza virus replication is greatest during the early phase of illness. Antiviral treatment is therefore most effective when started within the first 48-hours after symptom onset. In otherwise healthy outpatients, treatment during this period may shorten the duration of illness (by about a day) and reduce the risk of complications and hospitalisations (the major benefit). Patients should be encouraged to seek medical attention early if they develop symptoms consistent with influenza, particularly if they are older, pregnant, immunocompromised, or have chronic medical conditions.

MA: In real-world practice, many patients do not seek medical attention within the first 24- to 48- hours. How do you assess whether antiviral therapy may still provide benefit beyond this period, particularly in patients at risk of complications?

KD: The decision depends on the individual patient. In a young, otherwise healthy outpatient who is already improving after several days of illness, antiviral therapy will not provide much benefit. However, treatment may still be worthwhile in patients at increased risk of complications. This includes adults aged ≥65-years and older, particularly those >75-years of age, pregnant women, immunocompromised individuals, and patients with significant chronic heart, lung, kidney, liver, neurological, or metabolic disease. Hospitalised patients and those with influenza pneumonia should generally also receive antiviral treatment even if they present beyond 48-hours. Clinical judgement remains important, and treatment decisions should be based on the patient's overall risk profile rather than a rigid time cut-off.

MA: Antimicrobial stewardship has become increasingly important in healthcare. How can clinicians promote the rational use of antiviral therapy while ensuring appropriate patients receive timely treatment?

KD: Antiviral stewardship means identifying those patients most likely to benefit from treatment while avoiding unnecessary prescribing. Not every patient with a winter respiratory illness has influenza. Respiratory syncytial virus (RSV), SARS-CoV-2, rhinovirus, adenovirus, parainfluenza virus, and human metapneumovirus may all produce similar symptoms.

Where testing is available and affordable, it can help guide treatment decisions. Traditional rapid antigen or lateral-flow assays generally have sensitivities of ~60%-70%, although performance varies between manufacturers and settings. Specificity is generally high. Rapid molecular tests have substantially better performance, with sensitivities usually exceeding 90%-95% and with similarly high specificity. Results are often available the same day. Clinicians should familiarise themselves with the performance characteristics of the assays used by their local laboratory or practice.

Vaccination is also an important part of antimicrobial stewardship. Preventing viral illness reduces consultations, hospital admissions, secondary bacterial infections, and unnecessary antibiotic use.

MA: Influenza viruses continue to evolve from season to season. Have you observed any recent trends in circulating strains, and are there concerns regarding increased transmissibility or changes in disease severity?

KD: Influenza viruses undergo continual genetic change. This process, known as antigenic drift, is one of the reasons why annual vaccination remains necessary. Different strains may dominate in different seasons and in different parts of the world.

From a clinical perspective, influenza remains a highly transmissible respiratory infection. It spreads readily through close contact, respiratory droplets, contaminated hands, and surfaces, and through short-range aerosols in poorly ventilated indoor environments. The severity of illness depends not only on the circulating strain but also on factors such as age, comorbidities, immune status, and vaccination status.

MA: How do you distinguish influenza from other common viral respiratory infections in clinical practice?

KD: This can be challenging. Influenza often presents with abrupt onset of fever, headache, muscle aches, cough, sore throat, and marked fatigue (all of these symptoms might be present). However, many other respiratory viruses can produce an almost identical clinical picture.

In reality, it is impossible to reliably distinguish influenza from RSV, SARS-CoV-2, adenovirus, rhinovirus, parainfluenza virus, or human metapneumovirus on clinical grounds alone. Diagnostic testing remains the most reliable way to confirm the diagnosis when the result will influence management.

Multiplex molecular assays can detect several respiratory viruses simultaneously, but results must always be interpreted in the clinical context. Detection of a virus does not necessarily mean that it is the sole cause of the patient's symptoms.

MA: Antiviral therapy is only one component of patient management. What role do hydration, adequate nutrition, and rest play in supporting recovery from influenza?

KD: Supportive care remains fundamental. Fever, sweating, reduced oral intake, and fatigue can lead to dehydration and delayed recovery, particularly in young children and older adults.

Adequate hydration, good nutrition, and rest, support recovery and help reduce complications. Antiviral therapy should be viewed as an adjunct to, rather than a replacement for, these basic principles of care.

MA: What practical advice do you provide to patients and caregivers regarding hydration, nutrition, and recovery during influenza?

KD: Patients should be encouraged to drink fluids regularly and avoid becoming dehydrated. Small, frequent meals are often easier to tolerate than large meals, particularly when appetite is poor. Soups, fruit, yoghurt, and other easily digestible foods are helpful.

Patients should rest until fever has resolved and energy levels are improving. They should seek medical attention if they develop shortness of breath, chest pain, confusion, worsening symptoms, inability to maintain oral intake, or signs of dehydration.

MA: Which patient groups are at greatest risk of developing influenza-related complications, and how does this influence your decision to initiate antiviral treatment?

KD: Patients at highest risk include adults aged ≥65-years, especially those >75-years of age, pregnant women, young children, residents of long-term care facilities, immunocompromised individuals, and patients with chronic medical conditions.

These patients warrant a lower threshold for testing and treatment. In higher-risk individuals, early antiviral therapy is more likely to provide benefit than in otherwise healthy adults with mild disease.

MA: Influenza often spreads rapidly within households. What measures can families take to reduce transmission when one member becomes infected, and what role can antiviral prophylaxis play in selected cases?

KD: Simple measures remain effective. Good ventilation, hand hygiene, respiratory etiquette, and avoiding close contact with vulnerable household members can reduce transmission. Where possible, the infected individual should remain at home during the most symptomatic phase of illness. The infected individual could also wear a mask to prevent transmission to others.

Antiviral prophylaxis is not required for most household contacts. However, it may be considered for selected high-risk individuals, such as severely immunocompromised patients or frail elderly contacts following significant exposure.

Special considerations in South Africa: Do not miss tuberculosis (TB)! While influenza is an important cause of seasonal respiratory illness, clinicians in South Africa must remember that TB is the leading infectious cause of death and the leading cause of respiratory-related mortality in the country. There is also a recognised epidemiological interaction between influenza and TB. Influenza may increase susceptibility to TB disease through transient impairment of host immune responses, while underlying TB may predispose patients to more severe viral respiratory infections.

During influenza season, clinicians should maintain a high index of suspicion for TB, particularly in patients with persistent symptoms, weight loss, night sweats, haemoptysis, recurrent presentations, or any relevant epidemiological risk factors (even if the above-mentioned symptoms are absent). These include residence in TB hotspots, recent TB contact, previous TB, HIV infection, diabetes, and other immunocompromising conditions. Where TB is suspected, a rapid molecular nucleic acid amplification test on sputum should be performed. Importantly, influenza and TB may coexist, and a diagnosis of influenza should not discourage further investigation for TB when clinical suspicion remains moderate to high.

Conclusion

In the South African primary care setting, antiviral therapy should be targeted, pragmatic, and risk-based. Oseltamivir remains the principal antiviral treatment for influenza, but not every winter respiratory illness is influenza. Diagnostic testing can improve stewardship where available, although access and cost remain important considerations. Although COVID-19 remains an important respiratory pathogen, widespread population immunity through vaccination and prior infection has substantially reduced the frequency of severe disease and hospitalisation. Influenza, however, continues to cause significant morbidity and mortality each year. It is estimated to account for ~6000-12 000 deaths annually in South Africa, particularly among older adults, people living with HIV, pregnant women, and those with underlying medical conditions.

Antiviral prescribing must also be considered within the realities of the South African healthcare system. Around 85% of the population relies on the public healthcare sector, where access to diagnostic testing and antiviral medications may be limited. Clinicians therefore need to balance guideline recommendations with local realities and focus treatment on those most likely to benefit.

Finally, vaccination remains a highly effective antiviral stewardship intervention. Annual influenza vaccination should be encouraged in all eligible individuals, particularly those aged ≥65-years and those with chronic medical conditions. Appropriate use of COVID-19 and RSV vaccines in eligible populations can further reduce severe respiratory disease, hospital admissions, antibiotic prescribing, and healthcare utilisation.

Prof Keertan Dheda is Professor of Respiratory Medicine and Director of the Centre for Lung Infection and Immunity at the University of Cape Town, with a joint appointment at the London School of Hygiene and Tropical Medicine. He is internationally recognised for his leadership in tuberculosis diagnosis, transmission, and global health research. Prof Dheda has published more than 320 peer-reviewed papers, holds several patents related to TB technologies, and serves on numerous international advisory and editorial boards. His work spans multiple countries and focuses on advancing TB diagnostics, clinical trials, capacity building, and respiratory medicine across Africa and globally.

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