The epidemic process is characterized by infectious diseases. In this case, epidemic foci are formed. What is the meaning of this concept? Read more in the article below.
There are several definitions of an epidemic focus. V. D. Belyakov believes that this term denotes a territory where, within certain spatio-temporal boundaries, infection of people with infectious pathogens is possible.
Modern interpretation
The modern characteristic understands it as a manifestation of the epidemic process by asymptomatic and manifest forms of diseases, which includes the following components:
- sick or sick being assessed for the spread of an infectious agent;
- he althy people who are assessed in terms of the likelihood of infection;
- environment, which is assessed in terms of the risk of human infection.
Characteristicepidemic focus
There are two concepts that characterize such a hearth, namely, its boundaries and the duration of existence.
The definition of boundaries is made by the characteristics of the process of transmission of a certain infectious disease and the specific features of the environment in which the source of infection is located.
The duration of existence is set based on the period of residence of the source and the time of the maximum incubation stage of a particular infection. The epidemiological focus after recovery or departure of the patient retains its characteristic value throughout the maximum incubation period, since new infected may appear.
Examination of outbreaks
The method of examining epidemic foci is a specific set of methods designed to study the causes of the emergence and spread of infectious diseases in a given place. This means that the purpose of the epidemiological study of the focus is to determine the source of the infectious agent, factors and routes of its transmission, as well as contacts.
Techniques for conducting an epidemiological survey
There are the following techniques for examining epidemic foci.
1. Determining the source of infection:
- questioning a patient (creating a hypothesis about the source, factors and routes of transmission, time of possible infection);
- documentation study (what was the focus before the outbreak);
- laboratory examination of the infected person and persons who come into contact with him during the periodinfections;
- epidemic surveillance.
2. Identification of transmission factors and pathways:
- documentation research;
- sanitary analysis of the outbreak;
- laboratory analysis.
3. Definition of contact persons who have been exposed to the likelihood of infection:
- lab tests;
- poll of contact persons.
Then an act or a map of the focus examination is drawn up.
When is an epidemiological survey ineffective?
Ineffective (or ineffective) examination of an epidemic focus of infection under the following circumstances:
- for a single case of illness (excluding exotic infections);
- presence of carriage in this nosoform, especially when it dominates in frequency relative to overt infectious forms;
- probability of communication in different places (shops, transport, etc.);
- probability of infection at a great distance from the localization of the infectious source (for example, contamination of the product at the enterprise - home infection).
The work of an epidemiologist
The epidemiologist starts work even before visiting the epidemic focus. It consists in the fact that documents are being studied in the anti-epidemic institution that characterize the epidemic situation in this focus. The specialist also prepares the laboratory for future sampling from the patient, contact persons, suspected sourcestransmission.
Then the activity of the epidemiologist is carried out directly in the outbreak. An epidemiological examination begins with a questioning of the patient (if he is not in the infectious diseases hospital), as well as persons in contact with him.
The survey is conducted to collect such information that would enable the epidemiologist to put forward a hypothesis about the infectious source, factors and routes of transmission, that is, the causes of the outbreak. For this, the epidemiologist first of all establishes the time period (framework) of the alleged infection. To determine the period of infection, you need to know the exact date of onset of the disease of the person who formed such a focus. The infection time corresponds to the time between the minimum and maximum incubation periods. After that, the patient's places of stay are established.
Preventive measures play a big role - conducting preventive therapy, teaching patients and contact persons hygiene skills and a he althy lifestyle.
Instrumental and laboratory studies in the focus are needed to clarify and confirm the clinical diagnosis, determine the factors and sources of infectious transmission, evaluate the effectiveness of therapy, sanitation, etc. In the outbreak, observation is carried out throughout the time of its existence.
Events in the epidemic focus
There are the following activities:
- Registration. Patients and persons suspected of having an infectious disease are placed on a special record in a sanitary and epidemiological institution, in connection with whichthe dynamics of the arrival of infected people is transmitted to the headquarters of the SPK (sanitary and anti-epidemic commission) at least twice a day, and with quarantine infections - generally every two hours.
- Hospitalization and isolation of the infected. Active identification of patients with manifest forms of infection, carriers (clinical examination, questioning, microbiological and other laboratory tests). Quarantine and observational measures in the outbreak. Timely hospitalization of a patient with an infection is a cardinal measure that prevents the spread of the disease. What else are anti-epidemic measures in an epidemic focus?
- Stronger general sanitary measures (regarding sewage removal, water supply, nutrition). Final and current disinfection. There may be sanitization, deratization and pest control. In the room in which the infectious patient stayed before admission to the hospital, current disinfection is carried out. After his hospitalization - the final one, especially carefully in those places where the injured persons are temporarily accommodated (in dugouts, tents). In case of intestinal infections, from the time the patient was identified, disinfection and disinsection treatment of toilets should be systematically carried out. If it is parasitic typhus, along with the disinfection of the premises, sanitization of contact persons who live with the infected is done. Deratization works are carried out in natural foci.
- Emergency prophylaxis (passive immunization, phago-, chemo-, antibiotic prophylaxis). Vaccination of people according to epidemic indications.
- Epidemiological survey. Its purpose is to determine the source of infection and methods of transmission of the pathogen, the number of people who communicated, the volume of laboratory analysis and indications for antibiotic prophylaxis or the use of immunopreparations.
- Stronger sanitary and epidemiological surveillance: additional surveys of water sources and food stocks are being conducted.
- He alth outreach to improve people's sanitation.
The article examined the features of the epidemic focus.
