Avian and swine flu symptoms , treatment, prevention
Avian influenza - a viral infection, it is highly contagious, which can affect all species of birds.
flu - is a virus that strange creature, stuck between the worlds of the living and the nonliving.It floats in the air in microdroplets, settles on clothes, computers or the skin, but is truly alive, only infect other living form.Infestation is necessary for its survival.Unlike bacteria, which are complex, organisms capable of reproducing itself, the virus is not self-sufficient.He was there to breed, and can do so only by cunning or force injected into the body.
It is this elusive creature evolved hundreds of millions of years, and we are struggling with both a source of avian influenza.Almost every day in the news in the newspapers and on television there is new information about the disease, and people are more and more concerned about the ease with which it spreads.We have become accustomed to the idea that from the flu every winter dies a number of elderly people, but the infection, which we encou
The main feature of the influenza virus is associated with the fact that it is carried through the air.Once in the cells lining the inside of the lungs, throat and nose, it creates a lot of tiny particles (virions), which fly at high speed in the composition of mucus, if you sneeze, or moisture droplets when you cough or speak.In one experiment, it was able to show that the virus particles can move in a subway car at a speed of 128 kilometers per hour.Such is the power of an ordinary sneeze.That is why the habit of closing the nose and mouth when you sneeze - not just a requirement of etiquette: it prevents diseases that are flying away at high speed, to infect the people around.
influenza virus can be on the skin.You can easily get an infection if to shake hands with the carrier of the virus, and then rubbed his hand over his eyes, nose or mouth.On the surface of toys, doorknobs, computer keyboards - will suit any hard surface - virions can live up to 48 hours.They kill disinfectant solution.Even ordinary washing with soap and water is likely to destroy the majority of the particles.They destroy the sunlight and dry air.If the virus got on raw meat, he will be killed by heat treatment in cooking.
From the most common strains of influenza, many people are protected natural immunity.However, those with immune system disorders, and respiratory diseases such as asthma, are more vulnerable.Influenza results in an aggravation of diabetes and cardiovascular disease.After an illness can occur as a complication of respiratory diseases such as bronchitis, as well as secondary infections such as otitis media, which is especially common in children.One of the main causes of death from the flu is pneumonia.It occurs when the lungs get inflamed causing bacteria, such as Staphylococcus aureus, which is possible if the flu virus will damage the tiny hairs (tsiliyu), in normal circumstances, protects the lungs from dust, dirt and bacteria.For the treatment of pneumonia or other secondary bacterial infections prescribe antibiotics, but they do not help against influenza of which is carried by a virus.
In most countries of the northern hemisphere seasonal influenza outbreak lasts from six to eight weeks a year and happens every winter, it often peaks in January.According to the UK Department of Health, one in five ill refers to your doctor.If within a week to the doctor treated 200 new patients per 100 000 population, say that the flu has reached epidemic threshold.
Nevertheless, there is always the probability of a new strain against which people were not protected.Avian influenza is a problem with the fact that, if it begins to spread among humans, it will be particularly powerful strain, against which there is no ready-made vaccine or natural immunity.
etiology. influenza virus type A has two antigen - hemagglutinin (H) and neuraminidase (N).15 known subtypes of hemagglutinin and nine neuraminidase subtypes.The avian influenza virus is H5N1-antigens is characterized by high rate of variability, which increases its virulence and contribute to a new ecological niche occupation - human.Resistant in the external environment.Thus, in poultry manure is stored several months.At a temperature of -70 ° C. is maintained for several months.Dies in infected meat at high temperatures.Not excluded recombination of avian and human influenza viruses.
Epidemiology. Migratory waterfowl are the natural hosts of influenza virus, it is transferred in the intestines and release into the environment with saliva, respiratory and fecal material.Among the most susceptible poultry chickens and turkeys.Possible infection of pigs.The usual way to spread by the fecal-oral, but can pin airborne.Transmission of the virus from a person not currently described to man.
2005-2006.recorded outbreak of avian influenza in Asia, Europe, and in some areas of Russia.
pathogenesis. Entrance gate - mucosa of the upper respiratory tract, possibly bowel.In place of introduction of developing serous inflammation.Subsequently formed viremia with dissemination to the virus and lung damage, vascular endothelium.Rapidly growing toksinemiya gross metabolic, vascular disturbances leading to DIC, infection-toxic shock, cerebral edema and pulmonary.
Pathology. changes found in both the upper and the lower respiratory tract.Most often avian influenza virus causes necrosis in the nasal cavity, the trachea, bronchi and bronchioles.
Clinic. incubation period of avian influenza is 1 to 7 days.The clinical course is very similar to bird flu hypertoxic form of flu.
diagnosis of avian influenza is carried out based on the following criteria:
While that person is very difficult to catch from birds.Meanwhile, the majority of cases were in very close contact with ducks or chickens.If the virus is transmitted easily hundreds of thousands of people have already been infected, as in Southeast Asia, the infection is transferred millions of ducks, chickens and wild birds.
bird flu virus can live in droppings, saliva and nasal secretions of birds.Wild birds - carriers of the virus (mainly waterfowl, flying between the rivers and lakes) may develop without showing any symptoms.Meanwhile, left on their places of recreation manure can infect other birds.
Of particular concern is the fact that one of the strains of avian flu, known as the H5N1, can become pathogenic (disease causing) to humans and cause a new pandemic.Until 1997, scientists thought that avian flu can not be transmitted directly to the person, but it is now clear that they were wrong.
Soon even bigger breakthrough was made after that.It so happened that a sick ferret sneezed researcher in the face - and two days later, the same man flu.It confirmed the possibility of transmission of the virus from animals to humans.Studies have shown that flu can be transmitted between the very different types.Two years later, Wilson, Smith found that the influenza virus can be cultivated in chicken embryos.This discovery paved the way for the development of vaccines.
Of particular concern is the likelihood of the H5N1 bird flu mutation, which is why it can easily be transmitted from person to person.That has not happened yet, and it is impossible to predict when there will be.Nevertheless, experts are afraid that someday such a mutation will arise.John Oxford, Professor of Virology, who works in the School of Medicine and Dentistry behalf of Queen Mary, University of London, explained one possible scenario: "If a child brings to the market an infected chicken, and this chicken will be put to death in the back yard of a house, chances are that someonefamily infected by the bird.If this man is the bearer of a common virus ordinary flu, the H5N1 could mix their genes from this common form, and we'll get a brand new strain against which there is no immunity.Common among people, it can evolve by acquiring new properties.For example, the new strain may become somewhat less fatal, since the virus is important that its media-people did not die too fast, and had time to pass it on to others.But it will still be very powerful strain, from which we have no defense. "
Mankind had never before faced with the H5N1, and it is impossible to predict the extent of its lethality, although our vulnerability in this sense can be quite high, because we have a natural immunity to this strain.The fact that it can be transmitted between different species of animals, including tigers, peacocks, cats, pigs and several species of birds, means that its transfer from birds to humans can become very real.
Mutation of H5N1 subtype in a fully humanized form will likely trigger a pandemic and simply because large reservoir of the disease - are now too many wild and domestic birds carry the virus.Inhaled avian influenza virus become ill very quickly.If the patient gets to the hospital, he was prescribed medication and it is connected to the ventilator system, but still sick often die.-
Action infections on the human body can be disastrous.Dr. Dominique Duayr, a virologist and a member of the Australian National Committee for the planning of preventive measures against the pandemic, said: "The virus enters the lungs.The body reacts to a very strong immune response.In the fight against infection lungs fill with fluid, rich in proteins and cells.As a result, they are crowded, and the person can not breathe.The patient dies from respiratory failure, since it can not get enough oxygen, which means the end. "
In some countries, there are cases when the disease is not limited to only the defeat of the respiratory system.
In February 2004, in Vietnam from encephalitis brain dead four year old boy and his nine year old sister.According to information provided by doctors from Ho Chi Minh City, and published in the New England Journal of Medicine Journal, during postmortem examination in these children have found the H5N1 virus in the cerebrospinal fluid, blood, throat and intestines.Both children were taken to hospital with severe diarrhea, but soon their condition worsened, convulsions, have fallen into a coma followed by death.
On supervision of Dr. James Campbell, an expert on influenza and associate professor of pediatrics at the University of Maryland Medical Faculty, the flu is sometimes accompanied by encephalitis."Strangely, that these cases of encephalitis were observed without respiratory symptoms, - he wrote in the New England Journal of Medicine Journal.- If such a method is shown bird flu infection, we should treat it differently than just as a respiratory disease. "
if bird flu mutated, will spread among people, it is likely to become a pandemic.The latter can be defined as an epidemic sweeping the more than one continent.Pandemic influenza is much more aggressive than usual, with her ill 20 to 30% of the population, up to 50% of children, sometimes there is a relatively high mortality rate.For example, as described in Chapter 2 of pandemic influenza "Spanish flu" killed in 1918, 2.5% of all cases.Other pandemic is not as dangerous, for example, lost 0.37% of all infected during the outbreak in 1957.
From Influenza pandemics are not always the first to suffer the elderly - sometimes young people are at greater risk.Today, the task of scientists is to find out about H5N1 as much as possible and as quickly as possible to find any of his mutation, which gives the virus an opportunity to spread among humans.At least then the doctors will know what fight.
new influenza virus A (HINl) of swine origin emerged in the spring of 2009 among the population of Mexico and spread by travelers around the world, which led to the first influenza pandemic in 1968
strains associated with outbreaks of the so-called "swineflu ", found among influenza A viruses of subtypes of serotype C and serotype A (A / HINl, A / H1N2, A / H3N1, A / H3N2 (Finnish flu) and A / H2N3).These strains are known collectively as the "swine flu virus".
Swine flu is common among domestic pigs in the United States, Mexico, Canada, South America, Europe, Kenya, Mainland China, Taiwan, Japan and other Asian countries.The virus can be circulated among people, birds and other species;This process is accompanied by its mutations.
virus is transmitted both through direct contact with infected organisms and airborne.
entrance gate is a virus of the respiratory tract epithelium.The characteristic features of pathogenesis are severe toxicity, which is caused by massive cell death due to the virus invasion.As a result of intoxication occurs vascular damage, reduced their tone, increased brittleness, increases the likelihood of bleeding.The virus has a neurotropic, which leads to the typical flu neurological symptoms.
significant role in the pathogenesis of lung injury and plays the bronchi due to increased expression of a number of factors - inflammatory mediators (. TLR- 3, y-IFN, TNFa, etc.), which causes multiple damage the alveoli, necrosis and hemorrhage.High pathogenicity and virulence of this strain of virus may be due to non-structural protein NS1 ability (inherent in the virus) to inhibit type I interferon production by infected cells.The defective gene in this virus are much less pathogenic.
The incubation period is about 2-3 days, but can be up to seven days.The severity of the disease, from mild to severe, usually of moderate severity.
Clinically influenza caused by the pandemic strain of the virus, characterized by fever (62% patients), tickling in the oropharynx (30%), dry cough (16%), cough with sputum (8%), headache (14%), nasal congestionand obstruction of the nasal respiration (10%), myalgia (14%), pain in joints (8%), nausea (3%), vomiting (29%), diarrhea (3%), dyspnea (3%), rales in the lungs(1%), konyunktivitom (2%), epistaxis (1%).Perhaps the appearance of symptoms and signs indicating the development and build-up of respiratory or cardio-pulmonary failure: shortness of breath (under load or at rest), shortness of breath, cyanosis, blood in the sputum, or colored sputum, chest pain and low blood pressure, hypoxia onpulse oximeter readings.Significant role in the pathogenesis of respiratory lesion plays an increase in the expression of factors, mediators of inflammation, resulting in damage to multiple alveolar hemorrhagic necrosis, and the development of the syndrome.For some patients can observe the symptoms and warning signs of CNS: altered mental status, loss of consciousness, drowsiness or difficulty in waking up and recurring or persistent seizures, mental confusion, severe weakness or paralysis.
The vast majority of patients with symptoms of the disease caused by the influenza virus A (H1N1) California / 04/2009, do not have any fundamental clinical differences from those of seasonal flu.For some patients in the first 2-4 days of illness noted the development of viral pneumonia and respiratory distress syndrome, accompanied, as it is known, acute respiratory failure.
In newborns and young children often have less typical compared to older children flu symptoms: low body temperature, rapid breathing, cyanosis, excessive drowsiness, lethargy, lack of appetite and dehydration.These symptoms are non-specific.The diagnosis can not be put solely on the basis of these characteristics.During the circulation of the pandemic virus A (H1N1), clinicians should exercise increased vigilance and be aware of the possibility of ILI among those who have been in contact with the child, to facilitate the clinical diagnosis and to avoid delays in the start of antiviral treatment in children.