As follows from the epidemiology of influenza (that is, the science that studies this disease), the pathology is one of the acute ones, provoked by viruses, manifests itself as severe symptoms, severe general poisoning of the body.
general information
According to epidemiology, the flu manifests itself as heat and pain in the joints, muscles. The patient complains of a headache, chills him. With flu, the airways suffer. Complications are frequent with such a disease, even severe enough. Usually they are explained by secondary bacterial invasion.
To learn more about the disease, you should study the epidemiology of influenza. The etiology of the disease, in particular, is as follows: macro viruses that contain RNA provoke a pathological condition. Currently, scientists know three main groups of microorganisms: A, B, C. Although they are morphologically close, the antigenic composition of viruses is quite different. Type A is most prone to mutations - its antigenic composition is constantly being adjusted. This is due to the transformation of surface antigens. As soon as both antigens change, we can talk about a new subtype, which means the likelihood of a pandemic.
In the epidemiology of influenza, special attention is paid to the fact that type A is common both among people and among animals, birds, while the other two groups are found strictly in humans.
Beginning and course: general view
You can get the flu if you have contact with a sick person. The transmission of the virus is carried out by airborne droplets. From the epidemiology of influenza, it is known that susceptibility to it is extremely high. The maximum risk of infection, if in contact with the patient at the height of the disease. This period lasts from four to ten days - depends both on the nuances of the pathogen and on the characteristics of human health.
The incubation period varies from half a day to three days. From the epidemiology of the influenza virus, it is known that the disease usually comes unpredictably, all of a sudden. The patient feels a fever, he is shivering, his head hurts, and his joints ache. The patient feels weak, there is an increased sensitivity to light, stuffy nose.
To be ill or not to be ill?
To somewhat alleviate the patient’s condition, you need to drink a lot and take vitamins. Ascorbic acid is most useful. If the patient has a fever, it is necessary to take funds to relieve the heat, as well as the practice of procedures to lower the temperature. With influenza, bed rest and etiotropic therapy are indicated. Epidemiology, diagnosis, treatment, prevention of influenza is the area of knowledge and responsibility of qualified doctors, so if you suspect this disease, you should call a doctor at home.
Influenza is a common problem, and epidemics of this disease from season to season disable a huge number of people. In addition, there is a risk of death. For this reason, one of the most important parts of influenza epidemiology is prevention. Those who wish can receive a vaccine, however, from a specific form of the virus. Unfortunately, vaccination will not save from mutated varieties.
In the presence of chronic infectious diseases, it is important to regularly treat foci in order to exclude the development of pathological microflora. Constantly practiced hardening, gymnastics, procedures to strengthen the body, proper nutrition can reduce the risk of the disease. Below are the risks of getting sick from those who are not inherent in bad habits.
Relevance of the issue
Etiology, epidemiology, clinic, flu prevention are current issues for modern medicine. These figures illustrate: the number of patients from year to year is literally horrifying - it’s tens of millions of victims. Influenza is not only a specific person’s problem, but also a costly disaster for any country. The state is forced to bear significant costs for vaccines, doctors' salaries. It is necessary to maintain hospitals that, during the epidemic, still cannot satisfy the demand for medical services, as well as pay sick leave and take other measures in order to support patients and prevent the spread of the disease even more widely. However, for a simple person, flu is no less a problem, because you have to buy expensive medicines, take sick leave and lose your salary. The risk of complications is high, which means that you can get pneumonia and meningitis. There is a risk of death.
As part of a study of the epidemiology and prevention of influenza and SARS, it was revealed that on average about 41 million people are sick in our country alone per year, about a thousand patients die. There is a higher risk of getting sick in children older than three years of age and before the end of the school period. For the first time after having contracted the flu, a person receives immunity to it, but it applies only to a certain type of pathogen. Influenza-provoking viruses constantly mutate, so you can get the flu literally right after an outbreak.
History and Facts
The etiology, epidemiology of influenza, the issues of preventing the disease, minimizing the negative consequences - all this attracts the attention of scientists from around the world. Traditionally, the greatest attention is paid to the varieties H1N1, H2N2, H3N2 from class A. The entire population of the planet does not simultaneously have the flu, and each individual receives immunity after the disease for a while - this parameter is unique to humans. At times, an immune layer forms, for which the susceptibility of new viruses is especially high. It is created by people whose body does not have immunity to viruses.
Certain varieties of virus A are the most active forms that can provoke a global epidemic. As the knowledge bases accumulated during the study of the epidemiology of influenza and SARS show, the average frequency of global pandemics is 30–40 years. Each time it is provoked by a new form of the pathogen. The most severe were observed in 1918, 1957, 1995.
World epidemics: historical nuances
The first pandemic of influenza was established in 1918. The disease was called Spanish. It is she who is considered the most disastrous. This case is the most famous flu epidemic in human history. From the epidemiology of influenza and SARS, we know that the Spaniard spread extremely quickly around the planet, affecting almost every third person. The number of victims is estimated at approximately 40 million.
Currently, more common species are H3N2, H1N1. The main percentage of the world's population has contacted them at least once, which means it has immunity. It is believed that these types are relatively safe.
In 2009, the pathogen A / H1N1 / 2009 was first detected in America. He was called - California. Over time, the form was renamed swine flu. This is due to its proximity to the form of the flu, which affects a pig on this continent. It is believed that the infection has spread from a pig farm owned by Smithfieldfoods. The epidemiology of Michigan influenza is close to the California form of the disease - this is one of the subspecies of swine flu.
In 2003, H5N1 flares were first recorded. Infection is known in at least 62 countries. The disease is considered quite rare, and you can get it from birds. Doctors recorded 486 episodes of the disease, of which 287 were fatal.
The epidemic: how is everything going?
The epidemiology of influenza, the clinic of the manifestations of the disease have been studied well, so doctors, by indirect signs, can understand that a major outbreak of the disease is approaching. So, it has been established precisely that influenza A usually begins abruptly, and the peak number of patients is observed by the second, sometimes the third week of the epidemic. The duration of the incident is up to a quarter of a year. The conclusion is usually as sharp and unexpected as the beginning.
As is known from the epidemiology of influenza, in 2018, as in any other year, one can suspect an approaching epidemic to increase the number of cases of acute respiratory infections, and a febrile state in children. Gradually, this is replaced by similar cases among the adult population. The third stage is an increase in the number of hospitalized with pneumonia, insufficient heart function, as well as with acute relapses of chronic pulmonary diseases caused by the transferred flu.
During the epidemic, the number of disabled people is growing sharply, and schoolchildren and students cannot attend educational institutions for health reasons. Closer to the end of the epidemic, as is known from the science devoted to the clinic, the prevention of influenza and SARS (epidemiology), the frequency of deaths is increasing.
Figures and observations
Scientists involved in the epidemiology of influenza, the clinic and the prevention of this disease know that on average the incidence rate during the epidemic varies between 10-20%, although the years mentioned above were noted by a much more complicated situation. For example, in 1957 it was recorded that up to half of all city dwellers had the flu A, and even half as many fell ill with it in an erased form. The incidence rate is higher within or close to closed institutions, especially if the community is highly susceptible to illness.
Many works of prominent scientists were devoted to the problem of the disease in question (for example, OI Kiselev was engaged in this). Epidemiology, diagnosis, treatment, prevention of influenza - topics that are relevant for medicine in any part of the world. It is known that more often the epidemic occurs in the winter months, although the virus can also be infected at other times of the year. Currently, there is no accurate information about where and how the virus is stored in between epidemics. Presumably, it circulates among people, while the level of infection is quite low. Some scientists suggest that the virus can persist in the body of the animal. Both hypotheses have no evidence. However, it has been established for certain that the spread of the influenza virus in recent years is explained by the movement of people.
Factors and Information
What irreplaceable information can be drawn from influenza epidemiology? In 2018, for example, at what point will a new epidemic begin, and when will it end? Unfortunately, at the moment, scientists can only give approximate forecasts, since no factors have been identified due to which the epidemic begins and ends. The severity of most cases, the number of patients is determined primarily by the immunity of people living in a particular area, but extensive infection is possible if a new antigen is formed. The existing immune layer is too small or the population, in principle, does not have immunity.
The complexity of influenza prevention in epidemiology is also explained by the possibility of forming such a strain to which no one on the entire planet has immunity. Such a disease spreads rapidly across all countries, and travels across the states in waves for several years. Stops a pandemic the formation of collective immunity. However, there will still be epidemics of this strain in the future, since the virus is characterized by antigen drift. The situation is stable until a new type is formed, which means that a pandemic will begin. However, there are also known cases when epidemics faded on their own, although the number of people susceptible to the virus was high.
There is no single scenario
The formation of a new strain does not always lead to a major epidemic. A good example: the events of 1976 when swine flu was recorded in America, the pathogen antigens being identical to the virus that triggered the pandemic in 1918. The outbreak was probably explained by the influence of swine flu on several closely interacting people, and the pathogen did not spread beyond this group. Scientists believe that some forms of the pathogen are less virulent in relation to different people, even those who do not have immunity, which means that the disease is easier, the frequency of cases is less. In addition to immunity, other factors play a role in influenza epidemiology, which have not yet been established.
Influenza happens different
As part of the diagnosis of influenza, epidemiology takes into account that, in addition to the type A described above, there are two others that are found somewhat less frequently. For example, influenza B rarely causes numerous cases of the disease, and the pathology itself is much easier. Scientists suggest that this is due to rare and weak changes in the antigens of the virus. Usually, outbreaks of such flu are characteristic of military, educational institutions, nursing homes. Virus B can cause Reis syndrome. This complication is the most difficult of all possible.
Virus C is quite rare, although antibodies to it are present in the body of many people. Scientists suggest that many suffer from this type of flu without symptoms.
What does it lead to?
Currently, the number of complications, lethal outcomes caused by influenza, is quite high. More often they are associated with other diseases, due to which the flu provokes complications. For every 100 thousand patients, as doctors estimate, 800 are hospitalized. More often complications concern those who are inherent in cardiac and pulmonary chronic diseases. This is more common in the elderly. Slightly less than among those suffering from heart diseases, the frequency of deaths in patients with kidney pathologies, metabolic problems, as well as lack of immunity.
Among other people, the flu often provokes severe complications. Scientists estimate that in the 60s of the last century in America, economic losses for each of the three epidemics estimated varied between $ 1.5-3.5 million. These days, these numbers are becoming even more significant.
Bird flu
The epidemiology of this disease is a particularly interesting topic because of its danger. Infectious pathology is characteristic of birds, it is provoked by different strains of the virus, of which the main percentage for humans is not dangerous. An exception is H5N1, an aggressive disease in which the patient's condition worsens suddenly and quickly. The probability of death with this diagnosis is extremely high. Additional difficulties are created by the lack of information about the pathogen, as well as the lack of well-developed approaches to the treatment of the disease.
Avian influenza is characterized by prolonged incubation - from a week to 17 days. As it is completed, the fever reaches 38 degrees, the symptoms as a whole resemble ordinary flu. A person suffers from a digestive tract disorder, he is sick and vomits, hurts in the stomach, blood flows from the gums and nose. Intoxication manifests itself as pain in muscle tissue, joints. Symptoms may indicate a malfunction of the respiratory system.
Two days after the onset of the acute phase, breathing becomes more difficult, a typical "gurgle" appears, when you try to speak, a person wheezes, and a cough is accompanied by sputum separation with blood inclusions.
Where does the disease come from?
The virus spreads with birds. Upon contact with an infected individual, a person may become ill. More rarely, a pathological microorganism is carried by animals. Transmission is possible by airborne droplets, while the pathogen enters the human body through the respiratory and visual organs.
You must be careful when choosing food. For example, if a chicken is infected with the flu, the pathogen dies under the influence of high temperature, so the risk of infection is low. But in the absence of proper heat treatment, chicken can be dangerous to humans.
There are currently no data on cases of avian influenza after eating fresh chicken eggs. However, doctors are calling for preference for boiled as a safer product.
Treatment features
An on-time accurate diagnosis and a well-chosen treatment method provide the patient with the best chance of a full recovery. First, the patient is examined, questioned, samples of biological fluids are taken for laboratory research. Having identified which organs have become targets, they select the optimal treatment program. Children and adults should be treated equally. The patient is immediately isolated in hospital conditions, strictly personal dishes and linen, hygiene items are isolated. Contact with the patient is possible only when using personal protective equipment, dressings and dressing gowns.
Medicines that are effective for bird flu are drugs used for other forms of flu. Most commonly , neuraminidase inhibitors are prescribed . When the diagnosis is only made, means are added to combat viruses. The classic version is Tamiflu. A slightly less effective, but more affordable option is Arbidol. At first, the drugs are used in shock (doubled) dosage.
To reduce heat, prescribe drugs with paracetamol, Ibuprofen or Efferalgan. It is possible to stimulate the immune system by Laferon. Antimicrobial agents and aspirin are not used in bird flu, because the drugs are ineffective against the virus, but can cause serious consequences.
The nuances of the incidence
On average, up to 70% of all cases are fatal. Even after defeating the disease, a person does not receive immunity and, upon contact with an infected individual, can become ill again. Assuming you have bird flu, it is important to immediately contact a doctor for expert help. With this disease, urgent hospitalization is required. There is no alternative treatment for bird flu.
Many scientists are trying to invent a vaccine against bird flu. The work of leading medical universities around the world is devoted to this area. While specialists are working on a vaccine, people should take safety measures in order to minimize risks for themselves. In particular, birds should be avoided, no play with them, and children should not be allowed to do so. Do not touch dead birds. Having found the body in the yard, you should immediately bury it, using disposable gloves and a respirator during operation. At the end of the event, change clothes, take a shower. Poultry meat, eggs should be stored in a special compartment of the refrigerator, do not mix with other products.
If the above symptoms are observed, and before that there was contact with the birds, it is important to consult a doctor immediately. Currently, bird flu is quite rare, as infection occurs only from birds. If the virus begins to spread between people, a high probability of a catastrophic pandemic. If you suspect that you have the flu, treatment will have to be done in the isolation ward.
Flu Michigan
This flu is one of the varieties of swine. It has a high level of infectiousness, an increased risk of complications. The risk of death is high enough. The virus multiplies rapidly, barely in comfortable conditions, which explains the rapid course of the disease. Soon after the pathogen enters the body, the patient feels unwell, the temperature rises - up to 40 degrees. Lowering it is very difficult; medications are ineffective. Often it is not possible to achieve a weakening of the heat for three days or even longer. At the same time, there are cases when people with Michigan flu have not noticed any symptoms at all.
Influenza is spread by airborne droplets. When sneezing, coughing, the patient is surrounded by a cloud of the pathogen with a radius of about two meters.
Infection through contaminated items is possible. The virus can survive for a long time on a smooth, solid - up to two days.
The incubation period varies from four days to a week. If it is known that there was contact with the patient, but there are no symptoms, you must consult a doctor and take funds for the prevention of the disease. Immunocompromised individuals, children and the elderly, pregnant women and diabetics, as well as people suffering from diseases of the heart, blood vessels, and respiratory system are more likely to get the Michigan flu. You are more likely to get sick if a person has bad habits, a lack of vitamins, if not enough time is spent on sleep. The risks of getting the flu are more against the background of oncology or autoimmune pathologies.