Editorial Commentary: "Late" Treatment With Neuraminidase Inhibitors for Severely Ill Patients With Influenza: Better Late Than Never?

(See the Major Article by Louie et al on pages 1198–204.) It has been estimated that, globally, seasonal influenza epidemics result in 3–5 million severe infections, excessive hospitalizations, and 250 000 − 500 000 deaths each year [1]. During the pandemic in 2009, there were increased hospitalizations, and a recent study estimated that about 284 400 (range 151 700−575 400; respiratory and cardiovascular) deaths had occurred worldwide in the first 12 months [2]. Not only do severe, complicated influenza infections occur in young children, older adults, and those with underlying medical conditions, evidence also documents severe disease in obese persons, pregnant women, and adults <65 years old with no apparent risk factors. Such patients often require hospital care and seem to be at increased risk of death. Among hospitalized patients, about 5%– 17% of those with seasonal influenza and 9%– 34% with A/H1N1pdm09 influenza may require intensive care unit (ICU)–level care, with fatal outcomes in 3%– 12% and 2%– 15%, respectively [3]. Typically, influenza lower respiratory tract infection and pneumonia occur 2–3 days after the initial onset of symptoms; in some patients, there is rapid progression in the following few days, resulting in respiratory failure and other complications [3]. Studies have shown that >40% of patients with seasonal influenza who require hospitalization actually present >48 hours after symptom onset, with a median delay of about 2 days [4–6]; in patients with A/H1N1pdm09 influenza, the median time delay is about 3–4 days [3, 7–10]. Patients who develop critical illness requiring ICU care commonly have the longest delay in presentation (median, 5–7 days) [8, 10–13].