2009 H1N1 Influenza

Abstract

Within 2 months of its discovery last spring, a novel influenza A (H1N1) virus, currently referred to as 2009 H1N1, caused the first influenza pandemic in decades. The virus has caused disproportionate disease among young people with early reports of virulence similar to that of seasonal influenza. This clinical review provides an update encompassing the virology, epidemiology, clinical manifestations, diagnosis, treatment, and prevention of the 2009 H1N1 virus. Because information about this virus, its prevention, and treatment are rapidly evolving, readers are advised to seek additional information. We performed a literature search of PubMed using the following keywords: H1N1, influenza, vaccine, pregnancy, children, treatment, epidemiology, and review. Studies were selected for inclusion in this review on the basis of their relevance. Recent studies and articles were preferred.

Mortality from Influenza A/H1N1 in a tertiary care teaching institution in North India

“…Most patients presented late in the illness, resulting in adverse outcomes. Another important finding is that most patients who died had at least some predisposing chronic illness, which is in agreement with the results of earlier studies on seasonal influenza [3]. Also significant is that the patients who died had tachycardia or tachypnea in most cases.…”

Infection by H1N1 flu virus revealing T-cell acute lymphoid leukaemia: about two cases

“…No secondary infections were observed, and neither patient experienced ARDS, perhaps due to the neutropaenia, despite the fact that previously reported deaths were mostly due to ARDS [2,3]. The only recommended treatment for the H1N1 virus is oseltamivir, and this treatment is highly effective [4][5][6][7]. We confirmed the efficacy in immuno-compromised patients.…”

Effect of short-term school closures on the H1N1 pandemic in Japan: a comparative case study

“…The new cases of H1N1 after a class/school closure were recorded starting on the date classes were resumed. Because the estimated incubation period for H1N1 virus is 1-7 days [20] and because viral shedding almost completely ceases 7 days after infection [21], the H1N1 cases in each class were recorded during the 7 days following the resumption of classes. Only the first closure of each class was utilized for H1N1 cases analysis to avoid the effect of increased immunization of children in classes closed more than once.…”