The latest edition of the New England Journal of Medicine (NEJM) has a great summary article detailing the most contemporary thinking on the H1N1 pandemic and its clinical aspects.  Well written and easy to follow for those non-medical types too!

Risk factors for complications of H1N1

As of March 2010, almost all countries had reported cases, and more than 17,700 deaths among laboratory-confirmed cases had been reported to the World Health Organization (WHO). The number of laboratory-confirmed cases significantly underestimates the pandemic’s impact. In the United States, an estimated 59 million illnesses, 265,000 hospitalizations, and 12,000 deaths had been caused by the 2009 H1N1 virus as of mid-February 2010. This article reviews virologic, epidemiologic, and clinical data on 2009 H1N1 virus infections and summarizes key issues for clinicians worldwide.

Symptom profiles of H1N1 worldwide

The article highlights some of the key takeaways.  A large amount of information about the natural history and clinical management of 2009 H1N1 virus infection has been obtained in a remarkably short period of time (thanks to the Internet), but considerable gaps remain.

  • · The uncertain evolution of this virus among humans and potentially other species highlights the need for continued virologic surveillance for antigenic changes, viral reassortment, antiviral resistance, and altered virulence. Improvements in the global capacity for detection of influenza viruses by molecular analysis, such as RT-PCR assay, and by viral isolation are needed.
  • · A simple, inexpensive, highly accurate rapid influenza diagnostic test that is easily deployable worldwide has yet to be developed.
  • The burden and character of disease in low-resource settings are still incompletely understood, especially with respect to disadvantaged populations, including marginalized, refugee, and aboriginal populations.
  • Poverty, homelessness, illiteracy, recent immigration, language barriers, and cultural factors may impede access to care, with the potential for more serious outcomes of influenza. Thus, public health efforts reduce risk factors and to identify at-risk populations for the purpose of providing immunization and early care, including the use of antiviral drugs, should focus on social as well as clinical factors.
  • Both experience with previous pandemics and recent modeling efforts indicate that the age bias observed for outbreaks of 2009 H1N1 virus infection may shift in coming months toward older persons, with implications for the allocation of public health resources.
  • Major gaps exist in our understanding of viral transmission, pathogenesis of disease, genetic and other host factors related to susceptibility or disease severity, and optimal management of severe illness. The development of new antiviral regimens with improved effectiveness, combinations with targeted adjunctive therapies, and improved management of influenza-associated ARDS are priorities, along with better prevention, recognition, and treatment of invasive bacterial coinfections.
  • Available findings highlight the importance of early use of antiviral drugs and antibiotics in the treatment of serious cases and of the potential value of influenza-specific and pneumococcal vaccines for prevention.
  • Both the gaps in knowledge and the experience to date underline the urgent need for better international collaboration in clinical research, particularly in the case of diseases with pandemic potential, for which rapid detection, investigation, and characterization of clinical syndromes are prerequisites for improved mitigation of their public health consequences.