Two distinct genetic clades of seasonal influenza A(H1N1) viruses have cocirculated in the recent seasons: clade 2B oseltamivir-resistant and adamantane-susceptible viruses, and clade 2C viruses that are resistant to adamantanes and susceptible to oseltamivir. We tested seasonal influenza A(H1N1) viruses collected in 2008-2010 from the United States and globally for resistance to antivirals approved by the Food and Drug Administration. We report 28 viruses with both adamantane and oseltamivir (dual) resistance from 5 countries belonging to 4 distinct genotypes. Because of limited options for antiviral treatment, emergence of dual-resistant influenza viruses poses a public health concern, and their circulation needs to be closely monitored.

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Knowledge from early outbreaks is limited regarding the virus detection and illness duration of the 2009 pandemic influenza A (H1N1) infections. During the period from April to May 2009 in Texas, we collected serial nasopharyngeal (NP) and stool specimens from 35 participants, testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) and culture. The participants were aged 2 months to 71 years; 25 (71%) were under 18. The median duration of measured fever was 3.0 days and of virus detection in NP specimens was 4.2 days; however, few specimens were collected between days 5-9. The duration of virus detection (4.2 days) was similar to the duration of fever (3.5 days) (RR, 1.14; 95% CI, .66-1.95; P = .8), but was shorter than the duration of cough (11.0 days) (RR, .41; 95% CI, .24-.68; P < .001). We detected viral RNA in two participants' stools. All cultures were negative. This investigation suggests that the duration of virus detection was likely similar to the seasonal influenza virus.

BackgroundSince 2001, Nigeria has collected information on epidemic-prone and other diseases of public health importance through the Integrated Disease Surveillance and Response system (IDSR). Currently 23 diseases are designated as “notifiable” through IDSR, including human infection with avian influenza (AI). Following an outbreak of highly pathogenic avian influenza A(H5N1) in Nigerian poultry populations in 2006 and one laboratory confirmed human infection in 2007, a study was carried out to describe knowledge, perceptions, and practices related to infectious disease reporting through the IDSR system, physicians’ preferred sources of heath information, and knowledge of AI infection in humans among public sector physicians in Nigeria.MethodsDuring November to December 2008, 245 physicians in six Nigerian cities were surveyed through in-person interviews. Survey components included reporting practices for avian influenza and other notifiable diseases, perceived obstacles to disease reporting, methods for obtaining health-related information, and knowledge of avian influenza among participating physicians.ResultsAll 245 respondents reported that they had heard of AI and that humans could become infected with AI. Two-thirds (163/245) had reported a notifiable disease. The most common perceived obstacles to reporting were lack of infrastructure/logistics or reporting system (76/245, 31%), lack of knowledge among doctors about how to report or to whom to report (64/245, 26%), and that doctors should report certain infectious diseases (60/245, 24%). Almost all participating physicians (>99%) reported having a cell phone that they currently use, and 86% reported using the internet at least weekly.ConclusionsAlthough the majority of physicians surveyed were knowledgeable of and had reported notifiable diseases, they identified many perceived obstacles to reporting. In order to effectively identify human AI cases and other infectious diseases through IDSR, reporting system requirements need to be clearly communicated to participating physicians, and perceived obstacles, such as lack of infrastructure, need to be addressed. Future improvements to the reporting system should account for increased utilization of the internet, as well as cell phone and email-based communication.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-014-0568-3) contains supplementary material, which is available to authorized users.