The environment is filled with a huge number of "residents", among which there are various microorganisms: viruses, bacteria, fungi, protozoa. They can live in absolute harmony with a person (non-pathogenic), exist in the body without harm under normal conditions, but become activated under the influence of certain factors (conditionally pathogenic) and be dangerous to humans, causing the development of the disease (pathogenic). All these concepts relate to the development of the infectious process. What is an infection, what are its types and features - discussed in the article.
Basic concepts
Infection is a complex of relationships between various organisms, which has a wide range of manifestations - from asymptomatic carriage to the development of the disease. The process appears as a result of the introduction of a microorganism (virus, fungus, bacteria) into a living macroorganism, in response to which a specific protective reaction arises from the host.
Features of the infectious process:
- Contagiousness is the ability to quickly spread from a sick person to a healthy one.
- Specificity - a specific microorganism causes a specific disease, which has its characteristic manifestations and localization in cells or tissues.
- Frequency - each infectious process has periods of its course.
Periods
The concept of infection is also based on the cyclical nature of the pathological process. The presence of periods in development is characteristic of each similar manifestation:
- The incubation period is the time that elapses from the moment the microorganism is introduced into the body of a living creature until the first clinical signs of the disease appear. This period can last from several hours to several years.
- The period of prodromation is the appearance of a general clinic, characteristic of most pathological processes (headache, weakness, fatigue).
- Acute manifestations are the peak of the disease. During this period, specific symptoms of infection develop in the form of rashes, characteristic temperature curves, tissue damage at the local level.
- Reconvalescence is the time of the extinction of the clinical picture and the patient's recovery.
Types of Infectious Processes
To consider in more detail what the infection is, you need to understand what it is. There are a significant number of classifications depending on the origin, course, location, number of microbial strains, etc.
1. By the method of penetration of pathogens:
- exogenous process - characterized by the penetration of a pathogenic microorganism from the environment;
- endogenous process - the activation of its own opportunistic microflora occurs under the influence of adverse factors.
2. By origin:
- spontaneous process - characterized by the absence of human intervention;
- experimental - the infection is removed artificially in a laboratory.
3. By the number of microorganisms:
- monoinfection - caused by one type of pathogen;
- mixed - several types of pathogens are involved.
4. By order:
- the primary process is a newly emerging disease;
- secondary process - accompanied by the addition of an additional infectious pathology against the background of the primary disease.
5. By localization:
- local form - the microorganism is located only in the place through which it entered the host organism;
- generalized form - pathogens spread throughout the body with further subsidence in certain favorite places.
If microbes spread with blood flow, but do not multiply there, this condition is called viremia (pathogen - virus), bacteremia (bacterium), fungemia (fungi), parasitemia (protozoa). In the case of the multiplication of pathogenic microorganisms in the blood, sepsis develops.
6. With the flow:
- acute infection - has a vivid clinical picture and lasts no more than a few weeks;
- chronic infection - characterized by a sluggish course, can last for decades, has exacerbations (relapses).
7. By age:
- "childhood" infections - affect children mainly from 2 to 10 years of age (chickenpox, diphtheria, scarlet fever, whooping cough);
- the concept of "adult infection" as such is not present, since the children's organism is also sensitive to those pathogens that cause the development of the disease in adults.
There are concepts of reinfection and superinfection. In the first case, a person who has fully recovered after an illness becomes infected again with the same pathogen. With superinfection, re-infection occurs even during the disease process (pathogen strains overlap each other).
Hit paths
There are the following ways of penetration of microorganisms, which provide the transfer of pathogens from the external environment to the host organism:
- fecal-oral (consists of alimentary, water and contact-household);
- transmissible (blood) - includes sexual, parenteral and through insect bites;
- aerogenic (airborne dust and airborne droplets);
- contact-sexual, contact-wound.
Most pathogens are characterized by the presence of a specific pathway to the macroorganism. If the transmission mechanism is interrupted, the disease may not appear at all or worsen in its manifestations.
Localization of the infectious process
Depending on the area of damage, the following types of infections are distinguished:
- Intestinal. The pathological process occurs in the departments of the gastrointestinal tract, the pathogen penetrates the fecal-oral route. These include salmonellosis, dysentery, rotavirus, typhoid fever.
- Respiratory The process takes place in the upper and lower respiratory tract, microorganisms "move" in most cases through the air (flu, adenovirus infection, parainfluenza).
- Outdoor. Pathogens contaminate the mucous membranes and skin, causing fungal infections, scabies, microsporia, and STDs.
- Blood. The infection gets through the blood, spreading further throughout the body (HIV infection, hepatitis, diseases associated with insect bites).
Intestinal infections
Consider the features of pathological processes as an example of one of the groups - intestinal infections. What is an infection that affects the human digestive tract, and what is its difference?
Diseases of the presented group can be caused by pathogens of bacterial, fungal and viral origin. Rotaviruses and enteroviruses are considered viral microorganisms that can penetrate into various parts of the intestinal tract. They are able to spread not only by the fecal-oral route, but also by airborne droplets, affecting the epithelium of the upper respiratory tract and causing herpes sore throat.
Bacterial diseases (salmonellosis, dysentery) are transmitted exclusively by the fecal-oral route. Infections of fungal origin occur in response to internal changes in the body that occur under the influence of prolonged use of antibacterial or hormonal drugs, with immunodeficiency.
Rotaviruses
Rotavirus intestinal infection, the treatment of which should be comprehensive and timely, in principle, like any other disease, accounts for half of the clinical cases of viral intestinal infectious pathologies. An infected person is considered to be dangerous to society from the end of the incubation period until complete recovery.
Rotavirus intestinal infection in children is much harder than in adults. The stage of acute manifestations is accompanied by the following clinical picture:
- abdominal pain;
- diarrhea (the stool is light in color, there may be blood impurities);
- bouts of vomiting;
- hyperthermia;
- runny nose;
- inflammatory processes in the throat.
Rotavirus intestinal infection in children is in most cases accompanied by outbreaks of the disease in school and preschool institutions. By the age of 5, most babies themselves have experienced the effects of rotaviruses. The following infections are not as severe as the first clinical case.
Surgical infection
Most patients in need of surgery are interested in the question of what is a surgical type of infection. This is the same process of interaction of the human body with a pathogenic pathogen, only arising during surgery or requiring surgical intervention to restore function in a particular disease.
There are acute (purulent, putrefactive, specific, anaerobic) and chronic processes (specific, non-specific).
Depending on the location of the surgical infection, the following diseases are distinguished:
- soft tissue;
- joints and bones;
- the brain and its structures;
- abdominal organs;
- organs of the chest cavity;
- pelvic organs;
- individual elements or organs (mammary gland, hand, foot, etc.).
Pathogens of surgical infection
Currently, the most frequent "guests" of acute purulent processes are:
- staphylococcus;
- Pseudomonas aeruginosa;
- enterococcus;
- E. coli;
- streptococcus;
- Proteus.
The entrance gates of their penetration are various injuries of the mucous membranes and integuments, abrasions, bites, scratches, ducts of the glands (sweat and sebaceous). If a person has chronic foci of accumulation of microorganisms (chronic tonsillitis, rhinitis, caries), then they become the cause of the spread of pathogens throughout the body.
Infection treatment
At the heart of getting rid of pathological microflora is etiotropic therapy aimed at eliminating the cause of the disease. Depending on the type of pathogen, the following groups of medicines are used:
- Antibiotics (if the pathogen is a bacterium). The choice of a group of antibacterial agents and a specific drug is made on the basis of a bacteriological study and determination of the individual sensitivity of the microorganism.
- Antiviral (if the pathogen is a virus). In parallel, they use drugs that strengthen the defenses of the human body.
- Antimycotic agents (if the pathogen is a fungus).
- Anthelmintic (if the pathogen is helminth or simplest).
Infections in children under 2 years of age are treated in a hospital setting to avoid the development of possible complications.
Conclusion
After the onset of a disease having a specific pathogen, the specialist differentiates and determines the need for hospitalization of the patient. Be sure to indicate the specific name of the disease in the diagnosis, and not just the word "infection". The history of the disease, which is instituted for inpatient treatment, contains all the data on the stages of diagnosis and treatment of a specific infectious process. If there is no need to hospitalize the patient, all such information is recorded in the outpatient card.