This United States Centers for Disease Control and Prevention (CDC) portal publishes news, statistics and guidance related to the A(H1N1) influenza virus, more commonly known as 'swine flu'. The CDC presents facts and figures on the virus, as well as information and advice for specific groups of people, including pregnant women, travellers, clinicians, laboratory workers and people with HIV/AIDS.

It publishes daily press briefings and situation updates as well as weekly morbidity and mortality reports. The website also hosts an image gallery, with pictures of the virus, and a range of social media, including online videos, podcasts and widgets.

This clearing house from The Lancet aggregates scientific articles, news reports and commentary from over 60 journals and societies on the scientific, clinical and public health aspects of A(H1N1) influenza, commonly known as 'swine flu'.

The site contains research articles on the diagnosis, epidemiology, pathogenesis, surveillance, virology, prevention and treatment of A(H1N1) among others. A podcast from John McConnell, editor of The Lancet Infectious Diseases, discusses issues surrounding swine flu. The site also links to relevant organisations and online sources of information about the virus.

This collection of material, from The New England Journal of Medicine (NEJM), includes news, original research, commentary and analysis on the A(H1N1) influenza virus, or 'swine flu', and related topics such as avian influenza, the 1976 swine flu epidemic and the 1918 Spanish flu pandemic.

The NEJM resource also publishes advice to practitioners and surveillance updates, including an interactive map of worldwide cases of A(H1N1) influenza. It also links to relevant public health organisations, professional societies and the United States Centers for Disease Control and Prevention's Twitter feed.

The Influenza Virus Resource, published by the National Center for Biotechnology Information (NCBI), presents gene sequence data from the 2009 A(H1N1) influenza virus, or 'swine flu', outbreak and tools for analysis and annotation. It aims to help scientists compare virus strains so that emerging variations can be more quickly identified and appropriate vaccines developed.

The NCBI site also links to other resources hosting flu sequences, relevant publications and general information about flu viruses, including flu epidemics and flu virus biology.

This news special, published by Nature, is a collection of news and commentaries on the 2009 A(H1N1) influenza virus outbreak, more commonly known as swine flu. It includes interviews with researchers and public health officials, and discusses issues such as the spread of the virus, its virology and its severity.

Nature are maintaining a timeline of the outbreak, and provide links to information and guidelines on broader issues such as dealing with pandemics and historical outbreaks of flu, including bird flu and the 1918 Spanish flu.

This information resource, published by the international public health agency Pan American Health Organization (PAHO), provides daily situation updates on the A(H1N1) influenza virus, or 'swine flu', including the number of confirmed cases reported in individual countries in the Americas and PAHO activities and recommendations.

The site publishes documents in English and Spanish that include background information on the virus as well as guidelines on laboratory procedures, surveillance, clinical management and infection control. It also links to videos of PAHO press conferences on influenza A(H1N1) and other online swine flu resources.

The Flu Wiki aims to help local communities prepare for and cope with a possible influenza pandemic by collecting information and encouraging discussion. It is a collaborative website that allows any user to edit content, and has an extensive list of other online resources relating to all aspects of avian flu and pandemic preparedness, and a popular online discussion forum.

This blog, from the journal Nature, rounds up news about A(H1N1) influenza, or 'swine flu', from sources around the world. The round-ups include reports and confirmations of cases, warnings and statements issued by public health agencies such as the WHO as well as news of government proposals and actions against swine flu. It also links to other relevant online resources, including commentary, analysis and outbreak maps.

This influenza A(H1N1) information resource from Thomson Reuters links to a daily briefing on the current status of, and future trends in, drug therapy for the disease, that includes basic facts about A(H1N1), more commonly known as 'swine flu'.

The website also provides an article on the threat of an A(H1N1) pandemic and information on the pipeline of influenza vaccines, including some vaccines for A(H1N1) that are under development.

The WHO's site on influenza A(H1N1), or 'swine flu', provides daily updates and maps of the spread of the 2009 outbreak of swine flu and official WHO statements on the virus, as well as background documents and regional information.

It publishes guidance for different groups of people, including individuals, communities, national authorities and health professionals, and presents answers to frequently asked questions about the disease, vaccines, antiviral drugs, levels of pandemic alert and travel.

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