Swine influenza A( H1N1) - Causes, symptoms and treatment. MF.
Jun 13, 2018
Swine flu is an acute, highly infectious disease caused by the pandemic influenza A( H1N1) virus, transmitted from the pig and human to human, having a high susceptibility among the population with a pandemic and characterized by fever, respiratory syndrome and severe lethal outcome.
The swine flu virus itself was discovered in 1930 by Richard Shope( USA).For 50-60 years this virus was found and circulated only among pigs in North America and Mexico. Then the swine flu was recorded occasionally in humans, mainly among workers in pig farms, veterinarians.
All of us remember the latest well-known epidemic of swine flu in 2009( the so-called California / 2009), which emotionally and persistently informed the population of the media. The epidemic was spreading since March 2009.The first cases of infection with an unknown strain of the virus were recorded in Mexico City, and then in Canada and the United States. Many countries have been involved in the epidemic process: the USA, Canada, Mexico, Chile, Great Britain, France, Germany, Australia, Russia, China, Japan and many others. As of the end of October, according to the World Health Organization( WHO), 537,248 cases of swine flu were laboratory-confirmed. The greatest susceptibility was noted among a group of people from 5 to 24 years, in second place children under 5 years. In the course of the epidemic, the virus was assigned a 6th hazard class( that is, the registration of a pandemic of swine flu, which is easily transmitted from person to person, and the disease is captured by many countries and continents).According to official WHO information, the deaths following the pandemic( California / 2009) were 17, 4 thousand people. In Russia, a pandemic came in the autumn of 2009, the peak occurred in late October - early November. In total, more than 2500 patients with confirmed diagnosis were registered. There were lethal outcomes.
The causative agent of the swine flu
There are several subtypes of the influenza virus in pigs( H1N1, H1N2, H3N2, H3N1), but the highly pathogenic properties and the ability to transmit from person to person acquired only the subtype H1N1.The influenza A( H1N1) virus is the result of the crossing of the human influenza A( H1N1) virus and the swine flu virus, as a result the virus mutated and became highly pathogenic, and it is called the pandemic California virus 2009.Just like a normal human influenza virus, a pandemic virus has hemagglutinin in the envelope( contributes to the attachment of the virus to the cell) and neuraminidase( contributes to the penetration of the virus into the cell).
Swine flu virus
Causes of swine flu spread
Source of infection - pigs( sick or carriers of the virus) and a sick person. The sick person becomes infectious the day before the onset of the symptoms of the disease and even during the week of illness. Accordingly, potential patients at the end of the incubation period are of great epidemiological importance. Up to 15% of patients on the background of treatment continue to secrete the virus within 10-14 days.
Mechanisms of infection:
- aerogenic( airborne) - dangerous discharge of the patient when sneezing, coughing - in a diameter of 1.5-2 meters;
- contact-household - dangerous allocation of the patient on the hands of others, as well as on household items( tables, surfaces, towels, cups) - the virus retains its properties for 2 hours or more( you can bring the virus from the hands to the mucous membranes of the mouth and eyes).
Susceptibility to infection is universal. There are risk groups for the development of severe forms of swine flu:
- children under 5 years;
- adults over 65 years;
- pregnant women;
is a person with concomitant chronic diseases( chronic lung diseases, oncology, blood diseases, liver, urinary system, heart disease, diabetes mellitus, and infectious immunodeficiencies, for example, HIV).
Symptoms of swine flu
Clinical symptoms of swine flu are similar to those of normal seasonal flu with small features. The incubation period( from the moment of infection to the appearance of the first complaints) with swine flu lasts from day to 4 days on average, sometimes prolonged to a week. Patients are troubled by symptoms of intoxication( high temperature to 38-39 °, severe weakness, muscle pains, nausea, vomiting of the central genesis, that is against a background of high fever, body aches, lethargy).
Another group of complaints is related to the development of the respiratory syndrome ( dry cough, pronounced throat swelling, feeling of lack of air), and the likelihood of rapid development of one of the complications is the development of early pneumonia( 2-3 days of illness).
Sore throat indicates the activity of pathogenic microorganisms, which will help to destroy the procedure of irrigation of the nasopharyngeal mucosa with a drug with antibacterial action. Such a means can be a Bioparox aerosol containing an antibiotic of natural origin, fusafungin, which reduces inflammation and accelerates the healing process. The drug will stop the reproduction of harmful bacteria and will not harm normal microflora.
The difference from seasonal influenza is the presence of dyspeptic syndrome in 30-45% of patients - the patients have constant nausea, repeated vomiting, and stool disruption.
Manifestations of severe forms of swine flu
In the early days of the disease, intense headaches, pain in the eyeballs, photophobia, which increases with the movement of the eyes. Possible the development of serous meningitis, encephalitis. Muscle pain is one of the most pronounced symptoms of the disease.
One of the dangerous complications of swine flu is the development of pneumonia. Inflammation of the lungs may be due to influenza virus( primary, may be associated with the attachment of secondary bacterial flora( secondary), may be a consequence of the action of the virus and the concomitant stratification of the bacterial flora( mixed)
Primary pneumonia develops on the second to third days from the beginningdisease and is characterized by the development of symptoms of acute respiratory failure: the patient often breathes( about 40 breaths per minute at a rate of 16), in the act of breathing, the auxiliary muscles actively participate(diaphragm, abdominal muscles), pronounced dry or unproductive cough( discharge mucous and transparent), pronounced dyspnea, blue skin( cyanosis) When listening to the lungs: wet wheezing in the lower lungs mainly at the inspiration height, dullness of the percussion sound at the tapping of the lungs
Primary pneumonia often leads to the formation of a respiratory distress syndrome( development of pulmonary edema) with possible fatal outcome.
Secondary pneumonia occurs on the 6-10 day from the onset of the disease. The most common is pneumococcal seeding( in 45% of patients), less often Staphylococcus aureus( no more than 18%), and also a hemophilic rod. The peculiarity of this pneumonia is the intensification of cough: it becomes painful, almost constant, against the background of coughing the patient has a second wave of fever and intoxication, the patient practically does not take food. Increases pain in the chest with coughing and even breathing. Separated lungs( phlegm) is no longer transparent, but has a purulent hue. At a roentgenography - the centers of an inflammation in lungs. The course of secondary pneumonia is long, patients can not recover for a month and a half. Often, staphylococcal pneumonia leads to the formation of lung abscess.
Pneumonia in swine flu
Mixed pneumonia has clinical symptoms of both one and the second pneumonia, flowing for a long time( progradiently), difficult to treat.
Other complications of swine flu include:
pericarditis, infectious allergic myocarditis, hemorrhagic syndrome.
What are the alarming "swine flu" symptoms you need to see a doctor?
- Frequent breathing, difficulty breathing movements;
- Bluish shade of the skin of the limbs and trunk;
- Refusal to eat and drink;
- Repeated vomiting( vomiting "fountain", as well as frequent regurgitation in infants - the equivalent of vomiting at this age);
- Drowsiness and drowsiness of the child;
- On the contrary, excitement, resistance even when taking a child in his arms;
- The appearance of a second wave of symptoms with increased cough and shortness of breath.
- Dyspnea and exacerbation of it within 24 hours;
- Pain in the chest during breathing and coughing;
- Severe dizziness, appearing suddenly;
- Periodically confused consciousness( forgetfulness, loss of individual events from memory);
- Multiple and profuse vomiting;
- The second wave with temperature, cough, dyspnea.
Immunity after the transferred swine flu is type-specific and short( 1 year).
Diagnosis of swine flu
Preliminary diagnosis of is difficult due to the similarity of the symptoms of the disease with the usual seasonal flu. To help the doctor will have the following features:
- contact with a sick flu, as well as coming from a swine-influenza-endemic zone( the countries of North America);
- the patient's complaints about gastrointestinal disorders against the background of temperature and respiratory syndrome;
- unexplained or absence of sore throat against a background of strong cough predominantly dry;
- development on 2-3 day of pneumonia with characteristic symptoms( described above).
The final diagnosis of is possible after laboratory confirmation of the disease:
- PCR diagnosis of nasopharyngeal mucosa samples for detection of influenza A( H1N1) virus RNA California / 2009;
- Virological method of sowing nasopharyngeal mucus, sputum for certain media.
Treatment of swine flu
The main goal of the treatment is to reduce the number of patients with severe and complicated swine flu.
1. Organizational-regime measures of - at the time of the preliminary diagnosis, hospitalization is performed according to clinical indications( severe forms, and also moderate in children, elderly people and persons with chronic comorbidities).When laboratory confirmation of the diagnosis of swine flu is mandatory hospitalization with the appointment of specific therapy. For the entire febrile period and 5-7 days of normal temperature, bed rest is prescribed to prevent complications.
Your actions in case of suspected swine flu:
- If you find the symptoms of swine flu stay at home, do not go out to places of congestion.
- At home to protect those around you from the spread of infection - put on a mask and change it every 4 hours.
- Call a doctor at home. If you come from endemic countries( Mexico, USA), then tell the doctor about it.
To enhance the body's resistance, a physiologically complete diet with a sufficient amount of protein and a high content of vitamins A, C, and Group B is shown. To reduce fever, a sufficient amount of liquid is indicated( preferably blackcurrant, dogrose, chokeberry, lemon).All products are appointed in a warm form, avoiding sharp, fatty, fried, salted, pickled dishes.
2. Drug therapy includes:
Antiviral agents - oseltamivir( Tamiflu) and zanamivir( Relenza), which significantly affect the release of new viral particles from cells, which leads to the cessation of the multiplication of the virus. Reception of tamiflu and relenza is recommended in the following cases:
1) If the patient has one of the listed symptoms( fever, nasal congestion, cough, shortness of breath);
2) Laboratory-isolated influenza A / 2009 virus( H1N1);
3) Age group is less than 5 years old;
4) Persons of advanced age - over 65;
5) pregnant women;
6) people with severe concomitant diseases and immunodeficiency;
The usual course of treatment is 5 days, sometimes more depending on severity.
Light and medium-sized forms of swine flu admit administration of the following antiviral drugs: arbidol, interferon alfa-2b( influenza, viferon), interferon alfa-2a( reaferon lipid) and gamma interferon( inharone), ingavirin, kagocel, cycloferon.
In the emergence of bacterial pneumonia, antibacterial drugs( cephalosporin III-IV generation, carbapenems, fourth generation fluoroquinolones, vancomycin) are prescribed.
Pathogenetic therapy includes infusion detoxification therapy, glucocorticosteroids, sympathomimetics to reduce intoxication, facilitate breathing( performed in the hospital).At home, with a mild form of swine flu, there is an abundant drink( mors, tea, honey water).
Symptoms: antipyretic drugs( paracetamol, ibuprofen), vasoconstrictive for nasal( nasol, tizin, nasivin, otrivin and others), for cough relief( tussin, stoptussin, ambroxol, acetis and others), antihistamines( claritin, zodak).
Special attention is paid to children and pregnant women. For children, taking aspirin-containing drugs is prohibited because of the risk of development of Ray's syndrome( encephalopathy with edema of the brain and development of liver failure), therefore paracetamol, nurofen, is given preference from the group of antipyretic drugs. From antiviral agents are shown - tamiflu, relenza, viferon 1, influferon, reaferon lipid, kagocel with 3 years, anaferon.
Pregnant - plentiful drink in the absence of edema;
- in mild forms - from antiviral agents - viferon in candles, influferon, arbidol, when it is not possible to take tablets( vomiting) - administration of panavir intramuscularly;with severe forms of tamiflu, relenza, viferon;
- to reduce the severity of fever - paracetamol, ascorutin;
- with the development of bacterial pneumonia - cephalosporins III-IV generation, macrolides, carbapenems;
- during the epidemic, mandatory admission to all pregnant women with severe intoxication is indicated.
Prevention of swine flu
Measures for healthy( as recommended by WHO):
• Wash your hands often with soap and alcohol-containing solutions.
• Avoid close contact with sick people.
• Avoid hugs, kisses and handshakes.
• If you are sick, stay at home and limit contact with other people.
• If you have flu symptoms, seek medical advice immediately. If you are sick, stay at home for 7 days after identifying the symptoms in order to avoid infection of others.
For nonspecific drug prevention , the following drugs are used: kagocel, arbidol, anaferon, influferon, viferon for pregnant women, Tamiflu.
For , the specific prevention of has been developed to date with the vaccine for the highly pathogenic swine flu virus( H1N1).This vaccine protects against influenza B, and strains of A / H1N1( swine) and H3N2 influenza A( Grippol plus), that is, from swine flu and seasonal influenza. It is impossible to get sick after vaccination, since it does not contain a whole virus, but contains only surface antigens of viruses, which can not themselves cause the disease. The vaccine is administered annually.
The doctor infektsionist Bykova N.I.