Israel Medical Association Journal

Background: In March 2009 the pandemic influenza A (H1N1) strain was identified. The disease initially appeared to be accompanied by complications and high mortality rates. It became an endemic virus during the influenza season in our region, along with the classical seasonal H3N2.

Objectives: To identify the burden of pandemic influenza, its effect in pediatric patients, and complicated hospitalizations, compared to seasonal influenza years after the pandemic.

Methods: A retrospective observational study was conducted at a tertiary hospital. Data were collected from the medical records of all children who were hospitalized from April 2009 to 2011 with laboratory-confirmed influenza.

Results: Of 191 patients with influenza, 100 had the 2009 pandemic influenza, 62 had seasonal influenza, and 29 had H1N1 in 2010–2011. Patients with the 2009 H1N1 were characterized by older age, more co-morbidity conditions and more symptoms including fever, cough and rhinitis on admission. No significant differences in outcomes between the groups were recorded. Of patients hospitalized with pandemic influenza in 2009, 28% had complicated hospitalizations, compared with 17.7% of patients hospitalized with seasonal influenza in 2010–11. Children with pandemic influenza received more oseltamivir (Tamiflu®) (94% vs. 19.4%, P < 0.001) and more antibiotics than the other groups.

Conclusions: The type of influenza had no effect on outcome. There were no significant differences between groups in the percentages of in-hospital mortality, admission to intensive care units, prolonged hospitalization (> 9 days), or the development of complications during hospitalization.

 

Background: Recent studies show that vaccination of health care workers (HCW) might reduce influenza transmission and mortality among hospitalized patients. No studies have compared the incidence of laboratory-proven influenza in vaccinated versus unvaccinated hospital HCW. 

Objectives: To evaluate the effectiveness of influenza vaccination among hospital HCW and to examine the attitudes of this population towards influenza vaccination.

Methods: We performed a prospective cohort study between 1 January and 30 April 2014 of 1641 HCW at our medical center; 733 were vaccinated and 908 not vaccinated. A random sample of 199 subjects was obtained: 97 vaccinated and 102 non-vaccinated. Participating individuals were contacted on a weekly basis during the flu season and were asked to report any respiratory or flu symptoms and, if positive, to undergo a polymerase chain reaction (PCR) test for influenza. 

Results: In the general HCW population, vaccination was more frequent among physicians 298/498 (58%) than among nurses (324/862 (38%) and among males than females. Flu symptoms were reported by 20 of 199 participants, 13 in the non-vaccinated group (12.7%) and 7 in the vaccinated group (7.2%). A positive PCR test for influenza A virus was present in 4 of 20 people tested (20%). All positive cases were from the non-vaccinated group (P = 0.0953). 

Conclusions: Non-vaccinated HCW showed a higher, although not statistically significant, tendency for contracting laboratory-proven influenza than the vaccinated population. The main reasons for vaccination and non-vaccination were personal beliefs and habits. Education efforts are needed to improve compliance. Larger studies could further clarify this issue.