Recent flu vaccination associated with decreased risk for severe disease
A study of hospital admission for severe acute respiratory infections (SARIs) in military personnel found that recent flu vaccination lowered the risk of severe disease, while occupational factors and comorbidities may increase SARI risk, according to findings yesterday in Vaccine.
An international team of researchers evaluated data on 11,086 hospitalizations due to pneumonia or influenza from 2000 through 2012 among US military personnel. Hospitalized people had a median age of 32 and were largely male (89.5%).
Among the patients, 512 progressed to severe disease and required significant supportive therapy. Receiving a flu vaccination within 180 days prior to illness was associated with a decreased risk of severe disease, even under multivariate analysis (relative risk [RR], 0.81).
Chronic disease was also associated with developing SARI following hospitalization. Comorbidities with the highest risk of progression toward severe disease included chronic renal or liver disease (RR, 4.98); circulatory system disease (3.1), diabetes mellitus (2.3), obesity (1.6), cancer (1.6), and chronic obstructive pulmonary disease (1.4).
Under multivariate analysis, factors still significant for risk of severe disease included renal and liver disease (RR, 3.6), circulatory disease (2.2), and service in the Coast Guard (1.9) or Air Force (1.5). Investigators cautioned, however, that risk associated with service branch may simply reflect differences in data reporting rather than physiologic risk.
The protective effect of flu vaccination and the risk of severe disease in the presence of chronic comorbidities suggest that vaccination should be prioritized for groups at severe risk of influenza and pneumonia complications, the investigators said.
Oct 20 Vaccine study
Neuraminidase inhibitors may benefit high-risk, hospitalized patients
A review of observational studies on neuraminidase inhibitors (NIs) found that oseltamivir administration may benefit high-risk and hospitalized influenza patients even when provided days or weeks after symptom onset, according to Oct 19 findings in JAMA Internal Medicine.
Investigators from the University of California, San Francisco (UCSF), reviewed seven observational studies on oseltamivir use, along with the 2006 and 2014 Cochrane Collaboration meta-analyses of randomized controlled trials that recommended oseltamivir use in influenza patients within 48 hours of symptom onset.
The UCSF researchers found that, while the Cochrane analyses were based on rigorous clinical study data, their findings of oseltamivir benefit were only applicable to a healthy outpatient population with less risk of developing severe disease.
The UCSF investigators found that people hospitalized with severe influenza and/or infected with novel strains may shed active virus for weeks and thus benefit from NI treatment. Patients who appear to benefit from oseltamivir administration after the 48-hour window include pregnant women, children, the elderly, immunosuppressed people, and hospitalized patients.
The literature review also identified observational evidence that NI treatment may prevent cytokine storm and progression toward multiple organ failure in patients infected with H5N1 avian flu. A 2015 individual patient analysis found that early oseltamivir treatment lowers the risk of lower respiratory tract infection and hospitalization among people with seasonal influenza symptoms.
Based on the growing body of observational studies, the researchers recommended NI treatment for high-risk and hospitalized patients with flu symptoms, even in the absence of positive test results.
Oct 19 JAMA Intern Med study
