Swine Flu History and Symptoms

In late March and early April 2009, cases of human infection with this H1N1 virus were first reported in Southern California and near San Antonio, Texas. All U.S. states have since reported cases of H1N1 flu infection in humans. As part of the federal government response to the H1N1 virus, the Department of Health and Human Services issued a nationwide public health emergency declaration on April 26, 2009.

On June 11, 2009, the World Health Organization(WHO) signaled that a global pandemic of novel influenza A (H1N1) was underway by raising the worldwide pandemic alert level to Phase 6. This action was a reflection of the spread of the new H1N1 virus, not the severity of illness caused by the virus. At the time, more than 70 countries had reported cases of novel influenza A (H1N1) infection and there were ongoing community level outbreaks of novel H1N1 in multiple parts of the world.

Since the WHO declaration of a pandemic, the new H1N1 virus has continued to spread, with the number of countries reporting cases of novel H1N1 nearly doubling. The Southern Hemisphere’s regular influenza season has begun and countries there are reporting that the new H1N1 virus is spreading and causing illness along with regular seasonal influenza viruses. In the United States, significant novel H1N1 illness has continued into the summer, with localized and in some cases intense outbreaks occurring. The United States continues to report the largest number of novel H1N1 cases of any country worldwide, however, most people who have become ill have recovered without requiring medical treatment.

Human Infection with H1N1 Influenza Viruses

H1N1 flu viruses do not normally infect humans. However, sporadic human infections with H1N1 flu have occurred. Most commonly, these cases occur in persons with direct exposure to pigs (e.g. children near pigs at a fair or workers in the swine industry).

Human-to-human transmission of H1N1 flu can also occur. This is thought to happen in the same way as seasonal flu occurs in people, which is mainly through coughing or sneezing of people infected with the influenza virus. People may become infected by touching something with flu viruses on it and then touching their mouth or nose.

In the past, CDC received reports of approximately one human H1N1 influenza virus infection every one to two years in the U.S., but from December 2005 through February 2009, 12 cases of human infection with H1N1 influenza were reported. For the information on the number of H1N1 flu cases that have occurred since then, visit the Centers for Disease Control and Prevention (CDC) H1N1 Web site.

H1N1 influenza viruses are not transmitted by food. You cannot get H1N1 influenza from eating pork or pork products. Eating properly handled and cooked pork and pork products is safe. Cooking pork to an internal temperature of 160°F kills the H1N1 flu virus as it does other bacteria and viruses.

Symptoms

The symptoms of H1N1 flu in people are similar to the symptoms of regular human seasonal influenza and include fever, lethargy, lack of appetite and coughing. Some people with H1N1 flu have also reported runny nose, sore throat, nausea, vomiting and diarrhea.

Diagnosis

To diagnose H1N1 influenza infection, a respiratory specimen would generally need to be collected within the first 4 to 5 days of illness (when an infected person is most likely to be contagious). However, some persons, especially children, may be infectious for 10 days or longer. Confirmation on an H1N1 virus requires sending the specimen to CDC for laboratory testing.

Source : Flu.gov