Wondering how the Swine Flu virus actually works? A study that was released yesterday showed that the Swine flu virus can infect cells deeper in the lungs than seasonal flu, thus helping to increase the severity of the illness.

Influenza viruses penetrate cells by attaching themselves to molecules (called receptors) that are located on the outside of the cell wall. Seasonal virus strains typically attach themselves almost exclusively to cells that are found in the throat, nose and upper airway, thus helping to cause some of influenza’s signature symptoms – scratchy throat, runny nose, a dry cough.

The swine flu virus however sticks to a greater range of receptors than seasonal virus strains, and so it can also breach cells deep in the lungs.

The swine flu study was funded by the European Union, and published in the journal Nature Biotechnology. It basically provides the first laboratory confirmation of reports from front-line doctors that some patients with swine flu (h1n1) virus tend to suffer worse symptoms compared to those with a normal seasonal flu.

According to a recent study that was done in Chicago, Illinois (USA), the Swine flu was four times more likely to send blacks and Hispanics to the hospital than whites. This study is one of the first that looks at how the virus has affected different racial groups. Notably, it corresponds to recent unpublished information from Boston, MA, that found three out of four Bostonians who were hospitalized from swine flu were black or Hispanic.

Health officials have said the reason for the difference is probably not genetic, and that more likely, it is because blacks and Hispanics suffer disproportionately from asthma, diabetes and other health problems that make people more vulnerable to the flu. It is also not clear if a racial or ethnic difference will hold up when more complete national stats become available.

Source of information for the Chicago study – researchers looked at over 1500 lab-confirmed swine flu cases reported to the Chicago Department of Public Health from late April 2009 through late July.