"Bird's" flu
Description:
High species specificity is characteristic of influenza viruses. It means that viruses, the infecting separate types (people, certain bird species, pigs, horses and seals) remain "are faithful" to these types and only in rare instances go beyond their limits and other types infect. However the problem is that if the influenza virus of animals after all breaks a specific barrier and infects the person, the organism is absolutely unprotected and unadapted to such disease. In fact, it is a new virus which is unknown to our immune system, so, it is very dangerous. The infection proceeds hard, atypically and leads to many complications. Besides, the modern medicine is so far almost powerless in fight against such flu.
Symptoms of "Bird's" flu:
Clinical picture of bird flu will cause a stir in big variability, at the same time usually the disease is followed by heavy respiratory insufficiency and development of viral pneumonia which cause disease severity.
The incubation interval lasts from 2 to 8 days. Initial symptoms are similar to usual flu: muscle pains, cold, cough, sometimes diarrhea, vomiting, pain in a stomach and a breast and bleeding from a nose and gums. The patients infected with the H5N1 virus have a bystry clinical deterioration. The period between emergence of symptoms of a disease and development of acute respiratory insufficiency made about six days. In total more than a half of all of the laboratory confirmed cases ended with death.
Reasons of "Bird's" flu:
To cause epidemic among people, the virus needs not only "to learn" to pass from a sick bird, but also from the person to the person. While the virus does not mutate and will not gain the property necessary for this purpose, epidemic of bird flu to us is not terrible.
During the first registered outbreak of an infection of H5N1 among people which happened in Hong Kong in 1997 18 human cases matched on time the outbreak of highly pathogenic bird flu caused by almost identical virus on poultry farms and the markets of a live bird. During the comprehensive investigations of human cases it was revealed that a source of an infection was direct contact with sick poultry. During the researches conducted among members of the families and other persons which had contacts with patients and also among the health workers giving them help and coalminers of birds it was revealed that if transfer of a virus from the person to the person took place, it was very limited. Infection of people stopped after operational (within three days) destructions of all populations of the poultry in Hong Kong containing about 1,5 million heads.
Treatment of "Bird's" flu:
In an arsenal of doctors there is a number of antiviral drugs which have some therapeutic effect at an early initiation of treatment. For the rest, symptomatic therapy is used.
Now bird flu H5N1 remains, substantially, a disease of birds. The specific barrier is rather high: the virus is not transmitted freely from birds to the person. Despite infection from the middle of 2003 of tens of millions of poultry on huge geographical spaces, there are less than 200 laboratory confirmed human cases.
