Science Article

The influenza virus is very infectious. It passes from person to person easily through coughing, sneezing, and by shaking hands. New strains spread very quickly, and can infect millions of people. Although people don’t always think the flu is a serious illness, every year it causes many deaths, typically among those with weaker immune systems, such as the elderly and young children.

Each year, the influenza virus infects people throughout the world. In the past, some flu virus strains have caused more serious outbreaks called pandemics—outbreaks that are worldwide and affect millions of people. Pandemics are usually traced to influenza-A viruses. Researchers believe that animals may be the source of all the pandemic strains: a virus normally found in birds or pigs mutates, or changes, and infects humans.

Examples of other pandemics include the Asian flu (1957), the Hong Kong flu (1968), and the avian flu outbreaks in the late 1990s and early 2000s. The most serious influenza pandemic in recorded history occurred in 1918-19, when a particularly virulent influenza swept the world. This influenza sickened 500 million of the 1.5 billion people in the world, killing an estimated 40 to 50 million. Researchers studying the genome of this flu virus have linked it to the type-A avian flu viruses

What is H1N1 Flu?

In March 2009, there was an outbreak of H1N1 flu in Mexico, with a large number of cases reported in Mexico City. This strain of the flu virus (A/H1N1) was initially transmitted from pigs, in the saliva, nasal secretions, and feces, to people who had direct contact with pigs, for example on farms. In Mexico, the people infected have gotten very sick, and many have been hospitalized.

By June 2009, H1N1 flu spread throughout the world, with cases reported in every part of the world except sub-Saharan Africa. The rapid spread is attributed to the ease of international travel. The virus continues to be transmitted from person to person by coughing, sneezing, and hands. People infected outside of Mexico have not had any direct contact with pigs. At present, the death rate from H1N1 flu seems to be less than 10%.

When the outbreak began, health agencies around the world, such as the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention, were extremely concerned that the H1N1 flu virus would spread very quickly. The great fear was that the virus would infect people who have little or no immunity, sickening hundreds of millions of people and causing millions of deaths. However, the illness caused by the H1N1 virus has proved to be relatively mild in most people, and on a par with typical flu outbreaks. But because of the global spread of the illness, on June 11, 2009, the WHO officially declared the H1N1 outbreak a pandemic.

H1N1 Flu Symptoms

Like most influenza infections, the symptoms of H1N1 flu include a fever, aches and pains in the muscles and joints, fatigue, coughing, and in some cases diarrhea. The only way to be sure a person has H1N1 flu rather than another strain of the virus is to identify the virus in the lab.

Preventing H1N1 Flu

There are a number of ways to prevent infection with H1N1 flu. One of the most important things is to wash hands frequently, with soap and hot water. The virus spreads through contact, and clean hands will help limit exposure. It is important to avoid live chickens, ducks, and pigs, in farms or market places, since the illness came from these animals. In the areas with the most active outbreaks, such as Mexico, people are wearing surgical masks in public. Although these are of limited value, the masks do prevent a sick person who coughs or sneezes from spreading the virus to others around him.

There is no vaccine against H1N1 flu. However, the vaccine against the seasonal flu reduces the chance of getting that particular illness.

What to Do If You Are Sick

H1N1 flu develops anywhere from 2 to 8 days after exposure to the virus. The most important thing a person who develops flu symptoms can do is stay home. This prevents the infection from being passed to other people in the general public. Treatments include taking acetaminophen to reduce the fever, drinking plenty of fluids, and getting lots of rest. There are two antiviral medications that have shown some effectiveness if taken within 48 hours of the appearance of the first symptoms. Both Tamiflu© and Relenza© require a doctor’s prescription. Tamiflu is not a preventive medication. A person who develops respiratory problems should call their doctor.