Influenza virus presentation on biology. What is the flu? Influenza is an acute infectious disease of the respiratory tract that is caused by the influenza virus. How do you get the flu?

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Slide 2 Acute infection respiratory tract caused by influenza virus; Included in the group of acute respiratory viral infections (ARVI); Known since late XVI
century;

Flu

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History of the discovery of influenza
The first mention of influenza was noted many centuries ago - back in 412 BC. - It was then that Hippocrates described a flu-like disease.

The first documented influenza pandemic, which claimed many lives, occurred in 1580.

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An epidemic is a widespread spread of an infectious disease.

A pandemic is an epidemic characterized by the spread of an infectious disease throughout the entire country, the territory of neighboring states, and sometimes many countries of the world.

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Year Subtype Distribution
1889 – 1890 H2N8 Severe epidemic
1900 – 1903 H3N8 Moderate epidemic
1918 – 1919 H1N1 Severe pandemic (Spanish flu)
1933 – 1935 H1N1 Medium epidemic
1946 – 1947 H1N1 Medium epidemic
1957 – 1958 H2N2 Severe pandemic (Asian flu)
1968 – 1969 H3N2 Mild pandemic (Hong Kong flu)
1977 – 1978 H1N1 Medium pandemic
1995 – 1996 H1N1 and H3N2 Severe pandemic
2009 A(H1N1), so-called "swine flu" Moderate pandemic

History of epidemics, influenza A

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The influenza virus has a spherical shape with a diameter of 80-120 nm.

Influenza virus

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Virus structure

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Influenza A virus Causes moderate to severe illness. It affects both humans and some animals (horse, pig, ferret, birds). It is influenza A viruses that are responsible for the emergence of pandemics and severe epidemics.

Electron micrograph of influenza A virus

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Spreading Everyone is susceptible to the flu age categories of people. The source of infection is a sick person who releases the virus by coughing, sneezing, etc. The patient is contagious from the first hours of the disease until the 3rd - 5th day of the disease. High-risk groups are children, the elderly, pregnant women, people with chronic diseases

heart, lungs, as well as individuals with chronic renal failure.

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Routes of transmission of the virus
Characterized by an aerosol transmission mechanism and extremely rapid spread

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Physiological acts Number of particles formed, thousand Particle ratio, % Particle ratio, %
Physiological events Number of particles formed, thousand more than 100 microns less than 100 microns
Sneezing (strong, with open mouth) 100–800 50 50
Sneeze (held, with mouth closed) 10–15 80 20
Cough medium strength 10–50 90–85 10–15
Number and ratio of bacterial aerosol particles during coughing and sneezing

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Clinical manifestations
All manifestations of the disease can be divided into several groups: Fever – i.e. increased body temperature, usually with chills. Sweating occurs when the temperature drops quickly.

Intoxication. Catarrhal phenomena lead to a runny nose, cough, lacrimation, etc. Signs of damage to the respiratory tract.

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Treatment

drinking plenty of water; antipyretics; vasoconstrictors to facilitate nasal breathing; antitussives; in the first days of illness, steam inhalations are recommended; ascorbic acid, multivitamins; antihistamines - tavegil, suprastin; in the first days of the disease - natural drugs that support immunity (interferon, aflubin).

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Prevention measures

1. The main method of prevention against influenza is active immunization, vaccination, when a particle of an infectious agent is introduced into the body.

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2. One of the most common and accessible means of flu prevention is a cotton-gauze bandage (mask).

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Slide 16 3. It is necessary to take ascorbic acid and multivitamins, which help increase the body's resistance. Largest quantity
Vitamin C is found in sauerkraut, cranberries, lemons, kiwi, tangerines, and oranges.

4. For prevention during flu epidemics, you can take 2 - 3 cloves of garlic daily. It is enough to chew a clove of garlic for a few minutes to completely cleanse your mouth of bacteria. Eating onions also has a positive effect.

Completed by: Nazarchuk Yu.E. Group: LD2-S12B

Parainfluenza

Etiology There are 4 types of parainfluenza viruses (PG-1, PG-2, PG-3, PG-4). Parainfluenza viruses contain RNA and are unstable in external environment

, are completely inactivated when heated to 50°C for 30–60 minutes, under the influence of disinfectants.

Epidemiology

The source of infection is humans. The disease is transmitted by airborne droplets and occurs in the form of epidemic cases or sporadically. The greatest increase in incidence is observed in the autumn-winter and spring months.

The gateway of infection is the mucous membranes of the respiratory tract, especially the larynx and nose, where the virus reproduces, causing inflammatory changes. As a result of swelling and inflammation of the laryngeal mucosa, children may experience false croup.

Incubation period – 2–7 Clinic days. The disease often begins gradually, with moderate intoxication, low-grade fever, after which catarrhal syndrome develops, which is the leading syndrome in parainfluenza. The occurrence of laryngitis should be considered typical, which is accompanied by a dry “barking” cough, hoarse voice, and often aphonia. The cough persists for a long time, sometimes up to the 12th–21st day of illness. Quite often, parainfluenza laryngitis occurs without fever and begins with hoarseness or aphonia.

On examination, hyperemia of the pharynx, soft palate, and posterior pharyngeal wall is detected.

In children, parainfluenza is complicated by croup. In these cases, the disease begins acutely with high temperature, rough cough, hoarseness. Laryngeal stenosis develops suddenly, often at night, and lasts several hours. Other complications of parainfluenza are viral bacterial pneumonia, as well as otitis media and damage to the paranasal sinuses.

Diagnostics

similar to that for all acute respiratory viral infections. During epidemic outbreaks, diagnosing influenza is not difficult. Sporadic cases of the disease require laboratory confirmation, which is carried out in the same way as for influenza - by immunofluorescence, RSK.

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Deytiforin acts on the PG-3 virus (see “Influenza”). Pathogenetic and symptomatic agents are usually used. Antigrippin, thermal procedures, and desensitizing agents are used. For laryngeal stenosis, it is necessary to provide first aid - distractions (hot foot baths), and prescribe desensitizing and antispasmodic drugs. Hospitalization is indicated. Specific prevention has not been developed.

FLU

an extremely contagious acute infectious disease characterized by symptoms of specific intoxication and catarrh of the upper respiratory tract.

Influenza was first described by E. Pasquier in 1403; since that time, 18 pandemics have been registered, which mainly originated on the Asian continent.

Thus, the influenza pandemic in 1918-1919. called the “Spanish Flu” claimed more than 20 million lives, i.e. 2 times more than the first World War. In 1957, the Asian flu pandemic swept the world. The losses from the epidemic amounted to about 1 million lives.

Parainfluenza

Influenza pathogens belong to the orthomyxovirus family, which includes 3 genera of influenza viruses: A, B, C. Influenza viruses contain RNA, an outer shell, which contains 2 antigens - hemagglutinin and neuraminidase, which can change their properties, especially in type A viruses. Changes in hemagglutinin and neuraminidase causes the emergence of new subtypes of the virus, which usually cause more severe and more widespread diseases.

According to the International Nomenclature, the designation of virus strains includes the following information: genus, place of isolation, isolate number, year of isolation, type of hemagglutinin (H) and neuraminidase (N). For example, A/Singapore/l/57/H2N2 denotes a genus A virus isolated in 1957 in Singapore, which has the H2N2 antigen variant.

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Influenza epidemics occur annually, usually during the cold season, and affect up to 15% of the population globe. Influenza and ARVI make up 95% of all infectious diseases in the world. Every year, up to 500 million people get sick in the world, 2 million of whom die. In Russia, from 27.3 to 41.2 million cases of influenza and other acute respiratory viral infections are registered annually (WHO data).

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Influenza (lat. Influentia): an acute infectious disease of the respiratory tract caused by the influenza virus. Included in the group of acute respiratory viral infections (ARVI). Periodically spreads in the form of epidemics and pandemics.

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The name of the disease comes from the Russian word “wheezing” - the sounds made by patients. During the Seven Years' War (1756-1763), this name spread into European languages, denoting the disease itself, and not a separate symptom. Then there was a secondary borrowing into the Russian language from the French “grippe”.

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The first mention of influenza was noted many centuries ago - back in 412 BC. a description of the influenza-like illness was made by Hippocrates. Influenza-like outbreaks were also noted in 1173. The first documented influenza pandemic, which claimed many lives, occurred in 1580. People talk about an epidemic when people get the flu at the same time. a large number of people in one country.

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The duration of an influenza epidemic is usually 3-6 weeks. In the event of a pandemic, influenza affects a large number of people simultaneously different countries. In this case, the disease is caused by new serotypes of the influenza virus, to which the vast majority of the population is susceptible. Therefore, the virus spreads very quickly high speed and causes very severe disease.

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Transmission of infection occurs by airborne droplets. The virus is released from the mucous membranes of the respiratory tract when breathing, sneezing, coughing, or talking in huge concentrations and can remain suspended for several minutes. There is also a possibility of transmission of infection through household items, pacifiers, toys, underwear, and dishes.

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The “infectious” period reaches its maximum 1-2 days after the onset of the disease. After the 5-7th day of illness, the concentration of the virus in the exhaled air decreases sharply, and the patient becomes practically harmless to others (Pokrovsky V.I., “Epidemiology and Infectious Diseases”).

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In 1918-1920 the infamous “Spanish Flu” (H1N1 influenza virus) claimed, according to conservative estimates, more than 20 million lives. In 1957 – 1958 The pandemic called “Asian flu” (H2N2 influenza virus) killed more than 70 thousand people in the United States alone.

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In 1968-1969 A moderately severe “Hong Kong flu” (H3N2 influenza virus) occurred, which killed more than 34 thousand people over 65 years of age. The emerging bird flu pandemic, according to various sources killed about 40 million people. The majority of those who died were healthy young people between 25 and 45 years old, which is an extremely alarming sign.

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In April of this year, news about the epidemic of a new deadly looking H1N1. The virus that affects pigs is similar to humans, and its mutation can occur quite quickly. Moreover, pigs are often infected with different influenza viruses, after which they become a kind of “laboratories” for crossing strains that are dissimilar to each other.

Influenza epidemics occur every year
usually in the cold season and
affect up to 15% of the world's population
ball. Flu and ARVI make up 95%
all infectious diseases in
world. Every year, up to
500 million people, 2 million of
who die.
In Russia, every year they register from
27.3 to 41.2 million sick with influenza and
other ARVI (WHO data).

Influenza (lat. Influentia): acute
infection
respiratory tract, caused
influenza virus.
Included in the group of acute respiratory
viral infections (ARVI).
Periodically distributed in the form
epidemics and pandemics.

The name of the disease comes from
Russian word "wheezing" - sounds,
published by patients. During
The Seven Years' War (1756-1763) is
the name spread to
European languages, denoting already
the disease itself, and not a separate symptom.
Then a secondary thing happened
borrowing into Russian from
French "grippe".

The first mention of influenza was
noted many centuries ago - back in 412
BC description of influenza-like
disease was made by Hippocrates.
There have also been flu-like outbreaks
noted in 1173. First
documented influenza pandemic
which took many lives, happened in 1580
year. People talk about an epidemic when
get the flu at the same time
a large number of people in one
country.

Duration of the influenza epidemic
usually 3-6 weeks. IN
In case of a pandemic, influenza strikes
a large number at the same time
people in different countries. In this case
the disease is caused by new
serotypes of influenza virus, to which
the vast majority are susceptible
population. Therefore the virus
spreads from very high
speed and causes disease in
very severe form.

The infection is transmitted by airborne droplets. Virus from the respiratory mucosa
paths when breathing, sneezing, coughing, talking
is released in huge concentrations and can
be in suspension somewhat
minutes. There is also a possibility of transmission
infections through household items, pacifiers, toys,
linen, dishes.
Scatter
aerosol particles
when sneezing

Flu symptoms

In the case of typical development of infection,
the following flu symptoms:
- a sharp rise in body temperature (within
several hours) to high numbers (38-40 °C)
(reaches its maximum on the first or second day
diseases)
- chills
- dizziness
- muscle pain
- weakness
- headache

The “contagious” period reaches its maximum
1-2 days after the onset of the disease. After the 5-7th day of illness, the concentration of the virus in the exhaled breath
air drops sharply, and the patient becomes
practically harmless to others
(Pokrovsky V.I., “Epidemiology and infectious diseases
disease").
Localization of symptoms
flu

In 1918-1920 infamous
The Spanish flu (H1N1 influenza virus) carried away
according to the most conservative estimates, more
than 20 million lives.
In 1957 – 1958 from the pandemic under
called "Asian flu" (virus
H2N2 influenza) killed only in the USA
more than 70 thousand people.

In 1968-1969 happened on average
severity of the "Hong Kong flu" (virus
influenza H3N2), which killed
more than 34 thousand people over 65
summer age.
The emerging bird flu pandemic
according to various sources carried away
lives of about 40 million people.
Most of the dead are healthy
young people aged 25 to 45 years,
which is extremely worrying
sign.

In April of this year, all news agencies covered
news about the epidemic of a new deadly species H1N1.
The virus that affects pigs is similar to humans, and
its mutation can occur quite quickly.
Moreover, pigs often become infected with various
influenza viruses, after which they become
unique “laboratories” for crossing
strains that are dissimilar to each other.

Flu prevention

1) Vaccination
2) Wash your hands often, especially before
food
3) Wear a mask
4) Do not touch your face with your hands
5) Rinse your nose
6) Cleaning of premises
7) Limit space to the maximum,
where there are a lot of people
8) Healthy image life
- sufficient and varied
nutrition
- emotional comfort
- general strengthening of the body
(sports, gymnastics,
hardening)

Flu treatment

1. Bed rest.
2. Daily ventilation, wet cleaning if possible
premises.
3. Sufficient water regime. Give as much to drink as possible
liquids, 2-3 liters per day is a must.
4. Reduce the temperature. Temperatures above 38.5 °C are reduced to
without fail, these are no longer useful, but harmful to the body
numbers. We reduce it with paracetamol or ibuprofen (ibufen).
NEVER use aspirin!!! Aspirin increases permeability
vascular wall and can lead, when used, to
complications of influenza, as well as pulmonary edema. Particularly dangerous to use
aspirin to reduce fever in children - may lead to
severe complications, such as Raynaud's syndrome.
5. Nutrition. Light food (porridge, broth)
6. Expectorants.