Acute respiratory viral infection

Acute respiratory infections (ARI) are the most common diseases in the world. Each person succumbs to the infection, approximately 2 times per year. Infectious diseases (virus – SARS or bacterial) affect people of all ages, however, their frequency in the pediatric population is much higher.

The spread of SARS also contributes to the cold and wet season. Thus, it is in the fall-spring it is good to exercise maximum attention to the signs of infectious tion of diseases. In some cases, it comes to massive spread of the disease, which takes the form of the epidemic; in General, these outbreaks causing acute respiratory viral infection (ARVI) and influenza type A or B. these viruses in the past have caused pandemics responsible for millions of lives. One of them is known as the Spanish flu, which had 4 times more victims than the World war that preceded the pandemic. The UN estimates that in 2013, possible flu pandemic could claim the lives of up to 150 million people.

Respiratory disease is very contagious, they spread quite bit of air, the viruses can easily penetrate into the respiratory system of the human body. Seasonal respiratory diseases include a large number of viral diseases with similar symptoms and similar phenomena. Many of them, though, and may have the character of the epidemic, however, as a rule, are quite banal. For respiratory disease may also have a different – from the symptoms of the common cold to severe cases with complications.

1. Acute respiratory infection affecting the upper respiratory tract and include rhinitis, sinusitis, tonsillitis and laryngitis, mostly of viral origin, i.e. of viral respiratory infection (ARVI).
2. Diseases of the lower respiratory tract – inflammation of the trachea, acute bronchitis or pneumonia in addition to viruses, are caused also bacteria.

In the colder months, also a number of other respiratory infections, which are often incorrectly referred to as "flu". It's – diseases that affect not only children but also adults. They have the same course, accompanied by fever, cough, fever and systemic symptoms. However, the duration can be shorter and the General condition of the patient is not as sharp. The reasons for the spread of respiratory diseases is very diverse. An important role in this regard can play a large variety of viruses, bacterial infections, yeast, fungi, but also, for example, inhalation of irritating gases and dust.

One of the most common symptoms of viral infections of the upper and lower Airways is cough. At first it is dry and irritating, later develops into a cough.

General symptom

Common symptoms include:

• swelling and burning in the nose,
• increasing the temperature to fever,
• fatigue,
• joint and muscle pain,
• chest pain,
• loss of appetite.

Children may experience other symptoms, which in the case of adults occur very rarely and usually in combination with other types of diseases. In this population, may experience vomiting, the child has, in addition to this, frequent loose stools. Respiratory diseases often affect people with a weakened immune system.

Risk, who are often sick with respiratory diseases, including children under 5 years people over 65, people with diabetes, cardiac or renal insufficiency, patients with asthma, COPD, multiple sclerosis, smokers.

Prevention is important, but it is difficult to draw. Effective prevention including vaccination against influenza. In the first place, must, to the extent possible, to avoid places where you may focus infection. Against children this includes kindergartens, where the spread of respiratory diseases is very difficult to prevent. In old age, these places represented doctor's offices, and all confined and poorly ventilated areas, where there is a crowd of people – vehicles, public transport, offices…

Visiting such a place, of course, does not automatically mean disease, butincreases the likelihood that the disease will invade the body. An important action in terms of prevention is regular hand washing. When blowing your nose are the best option disposable paper handkerchiefs, which after use is discarded. It is also necessary to provide food, rich in vitamins, avoid fruits and vegetables that is crucial, especially in children. Finally, it is important to dress well, do not underestimate the weather conditions and remember to hardening of the body!

If "respiratory" disease struck the child, you should immediately visit a doctor. In adults, as a rule, there is no need at the first sign to run to the specialist. A visit to him is necessary when the symptoms persist for 3-4 days, as the signs accompanying acute respiratory disease may occur in conjunction with other, more serious, diseases. In this case, it is good to do a blood test for degree of inflammation and sedimentation.

Viral diseases usually do not require hospitalization. A hospital stay is needed only in complicated influenza or other viral infections. Most people manage to cope with the disease by using common medications, several days of bed rest and consuming sufficient amounts of fluid.

Respiratory tract infection

Infections of the upper and lower respiratory tract occur throughout the year but during the cold months are a much more common phenomenon. Often they are referred to as the flu, although the disease causing infectious agents, low temperature outdoor air. High incidence of the disease is a frequent cause of physician visits, disability, and absence of adults and children in preschools and schools, in the workplace.

Sporadic occurrence of respiratory infections from the end of the autumn months until early spring alternates with large-scale outbreaks or even epidemics that regularly (almost every year) is caused by influenza viruses.

Viral diseases of the respiratory tract, usually cause a local inflammatory changes of individual organs, such as the nasopharynx, middle ear or bronchi; more rare but life-threatening are invasive infections of the respiratory tract, such as pneumonia bacteriemia.

Pathogens of these diseases are numerous respiratory viruses, and some bacteria, often complicated by viral infection.

Studies conducted in recent years showed that during a short time known atypical bacteria – Mycoplasma and chlamydia – can also be pathogens of the upper and lower respiratory tract. The incubation period for viral respiratory infections typically is short, and is only 1-3 days, infection caused by atypical bacteria have a long incubation period.

Clinical symptoms caused by respiratory viruses, are very similar and in mild course of the disease called acute respiratory infection (runny nose, cough without fever), at the time, as with a more severe course (with fever and General symptoms) are called "flu-like" infection or "influenza-like-illness" (ILI). Regularly occurring symptoms of "influenza-like illnesses" include:

• cough,
• stuffy nose,
• fever,
• feeling of fatigue,
• headache,
• pain in muscles.

Since the above symptoms can occur with most viral infections of the respiratory tract, it is impossible on clinical grounds in particular cases to establish a causal diagnosis. When the viral infection is accompanied by bacterial superinfection, then, first, the serous discharge from the nose, purulent change. Ancillary laboratory tests (creative protein, sedimentation of erythrocytes, blood) viral infections are usually within the normal range or only slightly elevated. In contrast, during acute bacterial infections caused by typical pathogens, such as streptococci and pneumococci (tonsillitis, otitis, pneumonia) insights creative protein and sedimentation of erythrocytes was increased to high values also indicates an increase in the number of leukocytes, usually with considerable appearance of younger forms.

With the development of diagnostic methods during the last century has gradually been discovered respiratory viruses or virus groups, how to identify them and explore their properties, including distribution methods.

First of all, and identified the influenza virus in 1933 – influenza virus type A, in 1939 – In the type, and in 1950 – the type C. it was Then discovered and cultivated in tissue cultures of other respiratory viruses: adenoviruses (1953) – currently there are more than 50 subtypes of adenoviruses, shortly after this – 4 of parainfluenza virus, in 1956 – the first of rhinoviruses, of which there are over 100 subtypes, immediately thereafter syncytial virus (RS virus) respiratory, in 1958 – respiratory Coxsackie virus and echo virus, in 1960 – respiratory coronavirus and finally, in 2001, metapneumovirus.

Some of these viruses primarily affect specific organs (RS virus – the bronchioles in infants, rhinoviruses – the nasopharynx, the influenza viruses in the trachea), but can cause pathological changes in other organs.Other viruses, such as, for example, subtypes of adenoviruses cause diseases of different organs in different age groups.

Infections of the upper respiratory tract

Rhinites

Perhaps the most common clinical entity which occurs each of us from childhood to old age, is rhinitis acuta is an acute infectious rhinitis. Despite the fact that the disease occurs at all times of the year, vastly affects the cold months.

Most often, diseases cause rhinoviruses, but due to the fact that subtypes of rhinoviruses there are more than 100, and between them there is cross-resistance, rhinitis several times a year, with its various subtype may affect a single person. In addition, the acquired immunity is only temporary.

Entry of infection is the nasal mucosa and conjunctiva. After an incubation period (12-72 hours) viruses multiply rapidly on the mucous membranes of the nasopharynx lead to the secretion of a watery mucus, which contains a large number of viral particles. Simultaneously, there is conjunctivitis with abundant lacrimation.

Rhinoviruses survive well at temperatures around 35°C, with watery secretions stick to the fingers and are easily transferred to different objects.

For more severe frosts almost the same symptoms caused by the respiratory coronaviruses, which for acute rhinitis, especially in adults, are responsible of approximately 30% of cases. In summer, these infections do not occur.

Unlike rhinoviruses, coronaviruses are spread contaminated air droplets, and incubation period is about 2 days, slightly longer than those of rhinoviruses.

Coronavirus infection increases the likelihood of acute exacerbations of chronic bronchitis in the elderly.

Protection from rhinovirus or coronavirus infection in a vaccination is not yet known, and a crucial preventive factor is frequent hand washing, and avoiding (whenever possible) of contacts with patients. Acute infectious rhinitis can, in a small percentage of cases, be caused by other respiratory viruses.

In addition, nasopharyngitis, the vast majority due to respiratory viruses, in which prolonged rhinitis accompanies fever, sore throat and cough no significant expectoration. An objective examination shows subfebrile, children may notice a slight fever and redness of the sky. In addition, in this disease, not found laboratory signs of inflammation.

Treatment is symptomatic with bed regime and the relief of subjective symptoms with antipyretics and cough medicines.

Anginas

In contrast, angina (tonsillitis) can have diagnostic and therapeutic problems. Despite the fact that the disease occurs throughout the year, but both bacterial and viral sore throats are more common during the winter months.

A typical course has a strep sore throat. After a short incubation period starts with a sudden high fever, sometimes with chills, older children may experience febrile convulsions, sweating, pain in the throat, when swallowing. Submandibular lymph nodes are enlarged and painful on palpation, tongue white-coated, the tonsils swollen, red.

Inflammatory parameters, as a rule, increase to high values. When conducting a smear from the tonsils can be isolated Streptococcus pyogenes, always well sensitive to penicillin. Less often found Arcanobacter or other gram-positive cocci.

The drug of first choice is penicillin. It is also possible the use of oral cephalosporins 1st generation. Fundamentally the all forms aminopenicillins.

If angina occurs in young children, as a rule, the causative agent is adenovirus.

Infectious mononucleosis

Among older children and adolescents is quite common infectious mononucleosis. The disease is caused by Epstein-Barr; less likely to have the syndrome of infectious mononucleosis, which is caused by the cytomegalovirus.

These infections affect mainly adolescents begin rather slow-growing fever and significant swelling of the submandibular lymph nodes.

Upon physical examination, usually noticeable yellowish coating on the enlarged tonsils, which almost blocks the entrance to the throat. On the hard palate are visible tiny petechiae, enlarged liver, and sometimes spleen. In the leukocyte blood picture appears significant lymphocytosis with a large number of lymphoid monocytes, there are signs of increased liver function.

Inflammation of the middle ear and inflammation of the sinuses
Bacterial origin also have a middle ear infection and inflammation of the sinuses. Both of these infections are usually preceded by catarrhal inflammation of the virus. Purulent lesion, in most cases, cause Streptococcus pneumoniae and Haemophilus influenzae, rarely Moraxella catarrhalis. Rarely extremely painful inflammation of the tympanic membrane – miringa – may cause Mycoplasma pneumoniae.

The first attack of otitis media acuta one third of children takes under 2 years. The disease begins with pain in the affected ear, the baby is crying, there is a fever. Studies confirm the OTO -insights with redness of the tympanic membrane (catarrhal inflammation), or its bulge (purulent inflammation).

Infections of the lower respiratory tract

Laryngotracheitis

Laryngotracheitis in hospitalized children causes throughout the year, but more often in the spring, parainfluenza viruses. Inflammatory changes in the trachea can cause various respiratory viruses, but the most significant pathogens in this location – a influenza viruses, particularly type A.

Flu

Currently, different seasonal flu, which almost every year during the winter months, causing the human strains of influenza A H1N1, A H3N2 and H2N2 or one of the strains of influenza virus B. a few weeks, the virus affects 10-20% of the population, causing both overt and asymptomatic infections.

If it comes to the development of the disease, its course is characterized by the degree of severity from mild to moderate, the complications and fatal cases occur in people at risk.

Avian influenza

Until the mid ' 90s was human infection by avian influenza viruses is exceptional. In 1997, an outbreak of avian influenza among poultry in Hong Kong; the disease was caused by a highly pathogenic strain of influenza virus A H5N1. For several years the infection has affected numerous poultry farms across Southeast Asia, gradually this pansooti spread on poultry farms not only in Asia but also in Africa and Europe.

Malignant infection caused significant economic losses, leading to the extinction of many millions of land and water birds. Through close contact with diseased birds have been hundreds of cases of human infection by avian influenza virus, which more than half of the cases ended fatally due to a viral pneumonia. These outbreaks to a limited extent still is today, to humans the disease is always characterized by a serious course.

Swine flu

With 30 years of the 20th century, the famous swine flu, which is caused by strains of influenza A, mainly A H1N1. So far was described a few human infections caused by viruses, the actual swine flu. Since April of last year (i.e. in the off-season for flu) in Mexico and the United States, an outbreak of rapidly spreading influenza caused by influenza virus A H1N1, which was very similar to the swine virus. The infection spread quickly to all continents and has acquired the characteristics of a pandemic virus.

Although infection with this virus occurs in the same way as with seasonal flu, there are certain differences. The incubation period may be longer, from 1 to 5 days, have digestive problems, including diarrhea, the virus is also in the feces, increasing the possibility of contact transmission.

In mild form of infection is quite symptomatic treatment at home with bed regime. People with risk of serious course introduces the antiviral drugs Oseltamivir (Tamiflu) or Zanamivir (relenza) for 5 days.