Abstract
Effective influenza management requires early testing to guide time-sensitive antiviral therapy, the indiscriminate use of which may promote drug resistance. Reverse transcriptase polymerase chain reaction (RT-PCR) testing is constrained by laboratory infrastructure needs and a turnaround time of several hours. Point-of-care nucleic acid amplification tests (NAATs) and digital immunoassays (DIAs), though rapid, remain costly and are not widely available in low- and middle-income countries (LMICs). This standard operating protocol provides practical guidance for managing seasonal and zoonotic (avian) influenza, primarily based on WHO recommendations. Oseltamivir is reserved for severe influenza, with empirical use permitted only if RT-PCR results are delayed beyond 24 h. For non-severe illness, Baloxavir is recommended in patients at high risk of hospitalisation, but only after a positive NAAT or DIA; however, its access and affordability remain limited in LMICs. Post-exposure prophylaxis is reserved for specific high-risk exposures.
Flowchart Algorithm: Testing and Treatment
N.B.:
Antiviral treatment should be started as early as possible and within 48 h of symptom onset.1–3 RT-PCR and NAAT have high sensitivity and specificity. DIA (antigen-based) has high specificity but lower sensitivity. Preferred sample for testing is a nasopharyngeal (± throat) swab or aspirate. Pregnancy, diabetes, and malignancy are considered additional risk factors for hospitalisation but are not included in the primary high-risk group for antiviral therapy eligibility. Avoid: antibiotics (except in superadded bacterial infection), corticosteroids (except in selected cases of acute respiratory distress syndrome), and nonsteroidal anti-inflammatory drugs.
Abbreviations: DIA: digital immunoassays; NAAT: nucleic acid amplification test; RT-PCR: reverse transcriptase polymerase chain reaction.
Post-exposure prophylaxis for influenza
Indications
Extremely high-risk individuals exposed to seasonal influenza
- Defined as: Age ≥ 85 years, or any age with multiple high-risk factors (cardiovascular, neurological, respiratory, and immunocompromised) and/or additional risk factors (pregnancy, diabetes, and malignancy). - Not recommended in low-risk individuals due to limited benefits.
Any person exposed to avian/zoonotic influenza (e.g. H5N1, H5N6, and H7N9).
Footnotes
Author contributions
The author conceived the idea and drafted and revised the manuscript.
Declaration of conflicting interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author received no financial support for the research, authorship, and/or publication of this article.
