Clinical and demographic characteristics of confirmed cases in H1N1 [2009] influenza

Presentation of pandemic H1N1 influenza [H1N1] is widely evolving as it continues to involve different geographic locations and populations. This study was conducted to improve the precision of clinical diagnosis of H1N1 [2009] influenza infection in an outpatient setting. A prospective cross-sectional study was conducted among adult patients [age >15 years] with influenza-like illnesses [ILI] from November 2009 to February 2010. Clinical, laboratory and epidemiological findings in the first week of illness were collected using a standardized datasheet. Influenza testing was performed by real-time reverse-transcriptase polymerase chain reaction [rRT-PCR]. Thirty nine [24%] patients were positive for H1N1 and 123 [76%] were negative for any subtype of influenza A virus. Whilst otalgia [14% vs. 0 p= 0.01] was more prevalent in non-influenza A cases, cough [90% vs. 72% p = 0.03] and shortness of breath [67% vs. 47% p = 0.02] were more often associated with H1N1-infection. Comparative analysis of coexisting conditions and demographic factors of patients revealed no other significant differences between the two groups. The clinical presentation of H1N1 [2009] infection is largely indistinguishable from other acute respiratory diseases. Although previous studies suggested significant differences in demographic and co-existing conditions of H1N1 infected patients, our study shows that as the pandemic spreads worldwide and affects the majority of the population, H1N1 diagnosis based on clinical presentation and demographic characteristics has become less practical and much more difficult in tertiary care centers

Prevalence of oseltamivir-resistant 2009 H1N1 influenza virus among patients with pandemic 2009 H1N1 influenza infection in NRITLD, Tehran, Iran

Oseltamivir-resistant cases were reported during the 2009 pandemic influenza outbreak and therefore, widespread emergence of oseltamivir-resistant 2009 H1N1 virus is imaginable. Underlying medical conditions like immunosuppression increase the chance of oseltamivir resistance. In a retrospective cross-sectional study, respiratory tract specimens of confirmed cases of 2009 H1N1 influenza referred to the Masih Daneshvari Hospital were analyzed for presence of H275Y mutation. From November 2009 through March 2010, oseltamivir-resistant 2009 H1N1 infection was observed and confirmed in 4 patients [including 2 immunocompromised patients] by performing H275Y mutation molecular testing. Close monitoring of resistance to neuraminidase inhibitors is essential in tertiary care centers. The H275Y mutation [oseltamivir-resistant genotype] could appear in the absence or presence of selective drug pressure