pathogen
Every infectious disease is caused by its specific pathogen, which can be microorganisms or parasites. Include viruses, bacteria, fungi or parasites.
transmissibility
Infectious diseases are the main difference between infectious diseases and other diseases. Infectious diseases mean that pathogens can spread to others through various channels. The infectious period is called the infectious period. The pathogen is excreted from the host and reaches the new susceptible population in a certain way, showing certain infectivity, which is related to the species, quantity, virulence and immune status of the susceptible population.
Epidemiological characteristics
1. Epidemiology is divided according to the intensity and breadth of the epidemic process of infectious diseases. Transmission: refers to the sporadic occurrence of infectious diseases in the population; Epidemic situation: refers to the incidence of an infectious disease in a certain area or unit in a certain period exceeding the incidence level in the same period of last year; Epidemic situation: refers to the rapid spread of an infectious disease in a short period of time, exceeding the general epidemic intensity; Outbreak: refers to the sudden appearance of a large number of patients with the same disease in a short time in a local area or unit.
2. Endemism refers to some infectious or parasitic diseases, and the intermediate host is often limited to a certain geographical range because of the changes of geographical conditions and temperature conditions. Such as insect-borne diseases and natural focus diseases.
3. seasonality refers to the incidence of infectious diseases, which increases seasonally in a year. This is related to the change of temperature and humidity.
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preventive measure
The way to control the effectiveness of infectious diseases lies in prevention and control, because the lack of any of the three basic conditions of infectious diseases: the source of infection, the route of transmission and the susceptible population can not cause the epidemic of infectious diseases, so the prevention of infectious diseases mainly focuses on these three aspects:
1. Control the source of infection: This is the most effective way to prevent infectious diseases.
For human-borne infectious diseases, patients or pathogen carriers should be properly placed in designated isolation locations in time, temporarily isolate people, actively carry out treatment and nursing, and carry out necessary disinfection treatment on infectious secretions, excreta and utensils to prevent the spread of pathogens.
However, if the source of infection is unknown, especially animals, it is not easy to get exact results because of the need for epidemiological causal inference and sufficient evidence of laboratory test results, especially in the case of sudden acute infectious diseases, it is even more difficult to locate the source of infection in a short time.
However, once the source of infection is determined, effective measures should be taken to control the source of infection in time to ensure that the source of infection will not continue to spread pathogens to susceptible people.
2. Cut off the route of transmission: For infectious diseases, insect-borne diseases and parasitic diseases transmitted through digestive tract, blood and body fluids, cutting off the route of transmission is the most direct prevention method.
The main way is to block, disinfect or cull the media.
For example, food or drinking water contaminated by pathogens should be discarded or disinfected, rooms or utensils contaminated by pathogens should be fully disinfected, disposable medical supplies should be disinfected or burned in time after use, and measures should be taken to prevent mosquitoes and insects in the season when insect-borne infectious diseases spread.
At the same time, it is also extremely necessary to intervene in health education for high-risk groups, such as advocating intravenous drug users to disinfect needles and educating people who will have high-risk sex on condom use.
At present, the methods to prevent influenza A (H7N9) virus are still paying attention to basic hygiene, washing hands frequently, wearing masks and eating cooked meat-although it is the same old tune, it is still the most effective way to cut off the transmission route.
3. Protecting susceptible people: Protecting susceptible people is also an important part of infectious disease prevention, and it is often a relatively easy prevention method.
For infectious diseases with preventive vaccines, it is the safest way to vaccinate susceptible people. Over the years, people have successfully conquered smallpox with highly effective vaccines, which proves the important role of protecting susceptible people in the prevention and treatment of infectious diseases.
Several main infectious diseases and their prevention
flu
Influenza is an acute respiratory infectious disease caused by influenza virus, and it is also a highly contagious and fast-spreading disease. It is mainly spread through droplets in the air, contact between people or contact with contaminated items.
Typical clinical symptoms are: sudden high fever, general pain, obvious fatigue and mild respiratory symptoms. Generally, autumn and winter are a high incidence period, resulting in serious complications and deaths. The disease is caused by influenza virus, which can be divided into three types: A, B and C. A virus often mutates its antigen, which is highly contagious, spreads quickly and is prone to widespread epidemic.
Type a H 1N 1 is a type a. The disease is self-limited, but in infants, the elderly and patients with cardiopulmonary diseases, it is easy to be complicated with serious complications such as pneumonia and lead to death.
Main preventive measures for influenza
First, early detection of influenza patients, early local isolation of patients, early treatment. During the epidemic, large-scale gatherings and collective activities should be reduced; Wear a mask when going to public places to avoid going in and out of crowded places.
Open the window regularly every day to keep the indoor air fresh.
Second, drug prevention: adamantane hydrochloride * has a certain effect on preventing influenza A, but it is ineffective on influenza B.
Therefore, it is necessary to determine the type of epidemic strains in the early stage of epidemic, so as to carry out drug prevention for unprotected people.
Vaccine prevention: Commonly used vaccines include attenuated vaccine and inactivated vaccine. Attenuated vaccine is sprayed through nasal cavity, and inactivated vaccine is sprayed through skin.
The same type of influenza can be prevented from six months to one year after vaccination. However, the strain of influenza virus often changes, so it is difficult to predict the type of virus prevalent this year, and we can only guess what type it may be. The vaccine strain is as close as possible to the epidemic strain.
tuberculosis
Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis, which can invade many organs, especially tuberculosis infection. Bacterial secretions are an important source of infection. People may not get sick after being infected with tuberculosis. When the resistance decreases or the cell-mediated reaction increases, it may cause clinical diseases. If it can be diagnosed in time and treated reasonably, most of them can be cured clinically.
Etiology and symptoms of pulmonary tuberculosis
Mycobacterium tuberculosis belongs to the genus Mycobacterium of Actinomyces and Mycobacteriaceae, and it is a virulent acid-resistant bacterium. Mainly divided into human, cattle, birds, rats and other types. Human-type bacteria are the main pathogens to human beings.
Tuberculosis patients generally have a close contact history with tuberculosis, and the onset can be urgent or slow, mostly with low fever (afternoon), night sweats, fatigue, anorexia, emaciation, and menstrual disorders in women. Respiratory symptoms include cough, expectoration, hemoptysis, chest pain, chest tightness or dyspnea.
Prevention of pulmonary tuberculosis
1. Control the source of infection
Timely detection and treatment.
2. Cut off the route of transmission
Pay attention to window ventilation and disinfection.
3. Protecting vulnerable groups
Inoculate BCG, pay attention to exercise and improve resistance.
epidemic parotitis
Mumps is called mumps for short, commonly known as mumps. It is popular all year round, especially in winter and spring. It is a common respiratory infectious disease among children and adolescents. It is an acute systemic infection caused by mumps virus, which is characterized by swelling and pain of parotid gland and sometimes involves other salivary glands. Common seizures include viral encephalitis, inflammation, pancreatitis and oophoritis. Mumps virus belongs to paramyxovirus family. The patient is the source of infection, and the main route of transmission is through direct contact, droplets and saliva inhalation.