Seasonal Influenza

The 2009 flu pandemic is a global outbreak of a new strain of an influenza A virus subtype H1N1, referred to as the "novel H1N1" first identified in April 2009, and commonly called "swine flu."  It is thought to be a reassortment of four known strains of influenza A virus: one endemic in (normally infecting) humans, one endemic in birds, and two endemic in pigs (swine).

The outbreak began in Mexico and in early June, as the virus spread globally, the World Health Organization (WHO) declared the outbreak to be a pandemic.  The virus spreading with "unprecedented speed" and many clinics were soon overwhelmed testing and treating patients.  The virus typically spreads from coughs and sneezes or by touching contaminated surfaces and then touching the nose or mouth.

Vaccines may soon be available but may be limited and given first to healthcare workers, pregnant women, and other higher risk groups.  Two or three injections will be required for maximum immunity from both the swine flu and seasonal flu.  There is also concern if the new virus mutates further, it could become more virulent and less susceptible to any new vaccine.

The WHO predicts an "explosion" of swine flu cases during the remainder of 2009 and into 2010.  Because the global spread of swine flu will endanger more lives as it speeds up in coming months, they are alerting governments to boost preparations for a swift response.  There will soon be a period of further global spread of the virus, and most countries may see swine flu cases double every three to four days for several months until peak transmission is reached.  The CDC estimates that as many as 40% of the workforce, in a worst-case scenario, might be unable to work at the peak of the pandemic due to the need for many healthy adults to stay home and care for an ill family members.

Viruses are masters of interspecies navigation.  Mutating rapidly and often swapping genetic material with other viruses, they can often jump from animals to humans.  Avian and human influenza viruses can exchange genes when a person is simultaneously infected with viruses from both the common human influenza virus and the avian type.  This process of gene swapping inside the human body can give rise to a completely new type of the influenza virus to which few, if any, humans would have any natural immunity.  If the new virus contains sufficient human flu virus genes, transmission directly from person to person can occur.

Avian flu has spread from Southeast Asia to China, Russia and now Europe.  Human cases of avian influenza have been reported in Thailand and Vietnam.  Researchers believe the deadly H5N1 form of bird flu has split into two distinct strains, a development that could make it harder to develop vaccines to stop the spread of the disease.

In 2003 the Severe Acute Respiratory Syndrome (SARS) virus infected over 8,200 people in 29 countries, resulting in over 700 deaths worldwide.  The World Health Organization (WHO) has repeatedly warned that SARS could return and the world must be on the alert for the resurgence of the virus.  During the epidemic, SARS spread rapidly by person-to-person contact in hospitals and public transportation hubs, and there was a great need to screen large groups of people for fever, a primary symptom of SARS.  Conventional body temperature measurement using oral and ear thermometers, however, were too slow and inconvenient to use for mass screening.  A method of fever detection was needed that was fast, accurate, and non-obtrusive and thermal imaging was the technology chosen.

Between April 23 and June 4 of 2003, 30 million travelers were screened using thermal imagers;  9,292 were assessed as having elevated temperatures and were further evaluated, 38 people were suspected as SARS virus carriers, and 21 were finally diagnosed as having SARS.

back to top