Licensed books on medicine
<< Previous || Next >> |
The basic conditions necessary for the occurrence of an infectious disease
For the occurrence of an infectious disease, three prerequisites are necessary: the source of infection, the mechanism of transmission of infection and the susceptibility of the human body.
1. Sources of infection:
Sick person - refers to the most dangerous sources of infection, because it excretes in a large number of pathogens, moreover, in the most virulent state. Of particular danger are patients with atypical, erased forms of the disease, because they can be in contact with others for a long time, infecting them and environmental objects, including food products.
Sick animal - can be both a direct danger and the transmission of the pathogen through the "food chain" through food products received from it.
Infection carriers (bacterio-, virus- and parasitic carriers) - carriage often occurs after the transmission of infectious diseases, when both humans and animals release pathogens into the environment for some time.
2. The mechanism of transmission of infection is the evolutionarily acquired ability of microorganisms to spread from the source of infection to susceptible macroorganisms. A transmission mechanism is being implemented using pathways and transmission factors of infection.
Infection transmission factors are environmental elements that may be involved in the spread of disease pathogens. These include water, soil, air, food, household items, apparatus, equipment, containers, packaging, dishes, etc. Transmission factors determine the transmission of infection.
A contact transmission path is transfer through contact. There are direct contact - transmission of infection with direct contact of the skin and mucous membranes with the source of infection and indirect - through household and industrial items.
Airborne transmission - infection is transmitted through the air through an airborne droplet (the pathogen is transferred with droplets of mucus released from the respiratory tract of the patient or carrier) or by airborne dust (through infected dust).
Waterway - when drinking contaminated water, bathing in it, using it for industrial and household needs, for washing vegetables, dishes, equipment, etc.
The food route - differs from those listed above in that food products can not only transmit the infection, but also serve as a favorable breeding ground for the reproduction and accumulation of microbes. Food contamination occurs in various ways:
• directly from a sick animal from which this product is obtained (milk, meat, eggs);
• from a sick person or a carrier carrier when processing products, through equipment, utensils, water, air, hands, etc.
The transmissible path is the path of transmission through the bites of insect vectors (mosquitoes for malaria, ticks for tick-borne encephalitis, lice for typhus, etc.). In this case, the pathogen enters directly into the blood.
Depending on the factors and transmission routes, four mechanisms of transmission of pathogens are distinguished, according to which all infections are also divided into four groups:
• airborne droplet (aerosol) mechanism - transmission of infections of the upper respiratory tract and lungs;
• fecal-oral mechanism - the transmission of intestinal infections by food, water and the household;
• contact mechanism - transmission of infections of the external integument (skin and mucous membrane diseases);
• transmission mechanism - transmission of blood (vector-borne) infections.
Susceptibility of an organism - the ability of the human body to become ill when meeting a pathogen. Refractory persons may not become ill when in contact with infected objects or directly with patients or carriers.
The susceptibility of an organism is determined by resistance and immunity.
Resistance - this is nonspecific stability of the body, due to the action of general protective factors (conditions of nutrition, labor, life, rest, climate, social conditions, economic opportunities, etc.).
Non-specific protection factors play an important role in protecting the body against infectious disease pathogens: impermeability of the skin and mucous membranes for most microorganisms; the presence in the skin secret and acidic contents of the stomach of substances that adversely affect microorganisms; the presence in the blood and body fluids (saliva, tears, etc.) of enzyme systems that destroy microorganisms (lysozyme, etc.), etc.
Immunity is the specific resistance of an organism to infection. Specific immunity determines protection against only one infection and does not affect the susceptibility to other infections. Distinguish between natural and artificial immunity.
Natural immunity can be congenital (inherited) and acquired (as a result of an illness). Acquired immunity can be short-term, long-term or lifelong.
Artificial immunity - created artificially by introducing various drugs into the body. There are two types of artificial immunity:
• artificial active immunity - vaccines and toxoids (vaccine prophylaxis) are used to create it. Currently, there are two categories of vaccines: traditional (live, inactivated, i.e. killed and chemical vaccines) and new generation vaccines (synthetic, genetically engineered, etc.).
• artificial passive immunity - immune serums and immunoglobulins are used to create it (seroprophylaxis).
Thus, if at least one of the three links — the source of infection, transmission routes, and susceptibility of the population — is excluded from the epidemic chain, the pathogen’s circulation ceases and the disease does not spread further. This is the basis for the prevention of infectious diseases, including those transmitted through food products.
| << Previous || Next >> |
| = Skip to textbook content = |
The basic conditions necessary for the occurrence of an infectious disease
- GENERAL INFORMATION ABOUT INFECTIOUS DISEASES. CONDITIONS OF THE ORIGIN AND DISTRIBUTION OF INFECTIOUS DISEASES, GENERAL PRINCIPLES OF THEIR PREVENTION
The emergence and spread of various microbial diseases is due to the fact that some microbes under certain conditions can acquire the properties of pathogens. These are the so-called pathogenic microorganisms. Pathogenic microorganisms can cause various diseases, including infectious ones. It is known that pathogenic microorganisms are characterized by strict specificity, i.e.
- Characterization of the main aspects of the occurrence and development of acute respiratory disease
Characterization of the main aspects of the occurrence and development of acute respiratory
- The importance of personal hygiene for the prevention of infectious diseases
School is not only a “temple of knowledge”, but also a place of gathering of a large number of people. In the face of infection, the school can become one of the foci of the disease. This is due to the fact that children, not yet possessing strong and stable immunity, do not always adequately fulfill the requirements of personal hygiene. Teachers and parents need to remember: from how much children will be accustomed to monitor
- Infectious Disease Medicines
The drugs most commonly used to treat infectious diseases in newborns are listed in Table. 53-1. Side effects of antibiotics Allergic reactions (generalized and local). • Toxic effects (hematologic, neurological, nephrological, hepatotoxic, gastrointestinal and others, including those manifesting in follow-up). • Side effects
- KEY GROUPS OF INFECTIOUS DISEASES
BASIC INFECTIOUS GROUPS
- Conditions for the onset and development of diseases
Factors that influence the onset and development of diseases are called the conditions for the onset of the disease. Unlike the cause, conditions are not necessary for the development of the disease. If there is a cause, the disease can develop without the participation of certain conditions for its occurrence. For example, croupous pneumonia caused by pneumococcus of strong virulence can develop without hypothermia or
- Conditions for the emergence of negative mental states
The likelihood of developing negative mental states depends on the presence and degree of certain risk factors. They can be subdivided into conditions conducive to the development of such states, and into the causes that cause these states. An example of conditions is the fact that people with melancholic and choleric types of temperament are more prone to emotional tension. For reasons, in particular,
- The state of frustration and the conditions of occurrence in a military team
Frustration - the mental state of a person - is expressed in the appearance of imaginary barriers to the goal, which he estimates as complex, insurmountable. The difficulties and obstacles that arose during this do not allow the individual to fulfill his intentions and satisfy his needs. Such conditions reprint the state of frustration. Typical forms of frustration:
- Conditions for the occurrence of intraventricular defects
The electrophysiological mechanisms involved in aberrant conduct were discussed in detail in Chapter 4, based on data from a review published earlier . Consideration of these mechanisms and some additional options is necessary here only for the completeness of the clinical data. Defects in intraventricular conduction, dependent on tachycardia or a short cycle
- Resources Needed for Child Care
Resources needed to support child care principles and practices include human resources, such as knowledge and health, and economic and organizational resources (Box 7) (12). These resources directly influence the practice of care, and therefore the growth and development of children. They also have an indirect effect, for example, facilitating access to sufficient food,
- Principles of resource mobilization in the event of crises under anesthesia
Principles of resource mobilization in crisis situations
- How many different poisons are needed to cure cancer?
It is known that some cancer cells may experience insensitivity to individual cytostatics or, during treatment, they may develop resistance (resistance, resistance) to them. Resistance can develop for several reasons: a change in the structure of cell enzymes or metabolic pathways in it, a modification of the assimilation and elimination of poison, etc. This type is especially dangerous.
- Help mothers need for successful breastfeeding
Practical advice A woman who has given birth for the first time may not know exactly how to put the baby on her breast. And the baby, although it is able to suck, sometimes does not gag its chest to a sufficient extent. Both mother and child need help learning this. Putting a baby on her chest is very simple for a mother who knows how to do this - however, she should know this. If the child takes the wrong
- Sources of information needed to assess the quality of care
When we discuss quality issues in domestic health care that are not resolved from year to year, we always try to find an analogue abroad and use the experience of reforming the health systems of economically developed countries. The U.S. healthcare system is often used as an example. There is a "rational grain" in this. There is a saying that if
- The need to feed the baby. Help breastfeeding accessories
There are several solutions to this problem. ^ Feeding from a drinker or cup with a lid is the simplest, but requires patience. If desired, this ability can be mastered by any mother. A more convenient option is a soft spoon, which has as a handle a bottle where the food is poured. In a spoon made of soft silicone, food enters in a dosed manner when a person feeding a baby