The dominant circulating Flu strain for 2018-19 season has been identified as Influenza A(H1N1).
Zanamavir should be used first line for patients that are severely immunosuppressed instead of Oseltamivir (Tamiflu).
Further information available link to guidance.
For prophylaxis see:
Annual vaccination is essential for all those at risk of influenza. For otherwise healthy adults antivirals not recommended.
Treat ‘at risk’ patients with oseltamivir 75md BD for 5 days, when influenza is circulating in the community and ideally within 48 hours of onset (do not wait for lab report) or in a care home where influenza is likely. At risk: pregnant (including up to two weeks post-partum), 65 years or over, chronic respiratory disease (including COPD and asthma), significant cardiovascular disease (not hypertension), immunocompromised, diabetes mellitus, chronic neurological, renal or liver disease, morbid obesity (BMI>=40). Use 5 days treatment with oseltamivir. If resistance to oseltamivir or severe immunosuppression, use zanamivir 10mg BD (2 inhalations by diskhaler for up to 10 days) and seek advice. See PHE Influenza guidance for treatment of patients under 13 years or in severe immunosuppression (and seek advice).