Summary of WHO clinical practice guidelines for influenza

ABOUT THIS GUIDELINE: Rapid Recommendation is a summary of a World Health Organization guideline published 12 September 2024. The full guideline is available in MAGICapp and in PDF on the WHO website. The WHO guideline is primarily for healthcare providers and takes a patient-centred perspective on benefits and harms. Other considerations include resource implications, acceptability, feasibility, equity, and human rights of relevance to healthcare systems. Recommendations were developed according to standards and methods for trustworthy guidelines by a panel of non-conflicted experts, as delineated in the WHO handbook (https://www.who.int/publications/i/item/9789241548960). CLINICAL QUESTIONS: What is the role of medications in treating non-severe and severe influenza including zoonotic disease (novel influenza A), and in preventing infection among contacts? Which diagnostic testing strategies best enable rapid and accurate treatment decisions? CONTEXT AND CURRENT PRACTICE: New randomised controlled trial (RCT) evidence, ongoing concerns about zoonotic disease, and the increasing availability of rapid diagnostic tests require updated guidance. RECOMMENDATIONS: apply to seasonal influenza and zoonotic influenza. There are 29 recommendations; 21 related to antiviral medications and six to adjunctive therapies to prevent and treat influenza. Recommendations are stratified by severity of disease and risk of disease progression. For seasonal influenza, WHO conditionally recommends treatment within 48 hours of symptom onset with oseltamivir for severe illness, and baloxavir for patients at high risk of progression from non-severe to severe illness. WHO also conditionally recommends prophylaxis (using baloxavir, laninimavir, oseltamivir, or zanamivir) for anyone exposed to zoonotic influenza, and for those exposed to seasonal influenza who are at extremely high risk. The panel issued recommendations against the use of adjunctive therapies in patients with non-severe influenza (strong recommendation against antibiotics) and severe influenza (conditional recommendation against corticosteroids, macrolides, mTOR inhibitors, non-steroidal anti-inflammatory drugs, and passive immune therapy). A recommendation is made for diagnostic testing strategies in non-severe and severe influenza disease. THE EVIDENCE: Four systematic reviews of RCTs provided low to very low certainty evidence on benefits and harms of antiviral medications and adjunctive therapies. A systematic review of prognostic factors provided baseline risk estimates and information on individual risk factors for disease progression. A decision analysis model informed recommendations for testing based on alternative potential diagnostic pathways.