Human influenza viruses are divided into A, B, C-III. Influenza A (A) virus, the most common culprit is an influenza pandemic. B (B) only in small-scale spread of the pathogen is one of the winter flu. Hepatitis C (C) is not important. Two kinds of influenza virus surface antigen --- H (hemagglutinin) and N (neuraminidase) have been in the event of mutation, when there is a qualitative change, resulting in a new subtype, because people are not immune to it, it possible pandemic.
Influenza is not a person-specific, many animals also have the flu, but generally do not transmission. Large animal influenza viruses do not infect humans, occasionally arise from human to human transmission does not occur, like the recent emergence of highly pathogenic avian influenza virus, although the pathogenicity very strong, even can be transmitted to close contacts of those who caused fatal pneumonia, but fortunately it is a bad communication between people, otherwise it will result in disaster. Swine influenza is not normally infect humans, only a very small number of pigs in close contact with people who have pockets of infection, human infection example is the individual. But the human influenza virus animal influenza virus in animals, genetic reassortment took place, the emergence of new subtypes, there are likely to lead to a pandemic.
There are many subtypes of swine influenza viruses, which infect humans mainly H1N1. Since the beginning of this outbreak of swine influenza as a result, a number of countries and their products for pigs panic, some countries ordered the slaughter pigs. In fact, the source of the Influenza A H1N1 influenza is not clear, not directly from the pigs to infect humans, only because this gene is a new virus from pigs, poultry and human influenza virus genes formed. In order to avoid misunderstanding, innocent bystander, was renamed the World Health Organization influenza A H1N1 influenza, which is right.
Behavior and epidemiology of influenza viruses the performance of the most difficult to predict what will be a new influenza does not occur in a serious global epidemic, is still unable to jump to assert. In 1976 the U.S. Army base in New Jersey, a swine flu outbreak, hundreds of soldiers were infected, a death of young people. U.S. authorities believe that a serious pandemic is imminent, then spent 135 million U.S. dollars creating a vaccine, by President Ford signed an order in the nation-wide vaccination. This program started a few weeks, the vaccine appeared caused by multiple nerve root inflammation, and soon there were 30 people died of the disease. As the mass protests, the U.S. federal government terminated the project, but are worried about an influenza pandemic has not happened. Therefore, excessive response, may also have negative effects, it is a lesson.
Influenza spreads rapidly through the respiratory tract, prevention and control is very difficult. At present the most important strategies and measures are the patients and their viruses of influenza surveillance and outbreak timely sharing of information and publishing. Viral antigen components of the research is safe and effective vaccine preparation of the basis for preparation of a new vaccine takes at least 4-6 months. The departments concerned should be proper dissemination of knowledge to the public, the public information released by the departments concerned should accept the guidance of departments, without tension, not hearsay, panic-stricken.