Encyclopedia of Family Medicine

Chapter 40 Prevention of Common Diseases (1)
Infectious Disease Prevention

Infectious diseases are diseases caused by pathogens that can be transmitted from person to person, from person to animal, or from animal to animal.Pathogens can be divided into two categories: microorganisms and parasites.Microbial pathogens include bacteria, viruses, mycoplasma, chlamydia, spirochetes, fungi, etc. Parasitic pathogens include protozoa, roundworms, hookworms, filarials, pinworms, schistosomes, tapeworms, etc.

There are various infectious diseases, which are generally divided into respiratory infectious diseases, intestinal infectious diseases, insect-borne infectious diseases, animal infectious diseases, parasitic diseases (helminth diseases and protozoal diseases) and so on.The common characteristics of infectious diseases are: each infectious disease has its own specific pathogen, which has a certain degree of infection and prevalence, some infectious diseases have a certain locality and seasonality, and many infectious diseases have immunity (that is, have no or very little reinfection after such an infectious disease).

1.Basic conditions for the spread of infectious diseases

The prevalence of any infectious disease must meet three interconnected conditions, namely the source of infection, the route of transmission and the susceptible population.

(1) Source of infection
The source of infection refers to humans and animals that carry pathogens in their bodies and can excrete them.Patients with various infectious diseases, pathogen carriers (that is, people who have no symptoms on the outside but can carry and excrete pathogens), infected animals (including livestock, poultry, wild mammals, birds and fish) are important source of infection.

(2) Transmission route
Transmission route means that after the pathogen is discharged from the source of infection, it invades other susceptible persons in a certain way, and the route through which it passes is called the transmission route.Transmission routes include airborne, waterborne, foodborne, contact transmission, insect-borne, soil-borne, etc.Every infectious disease has a certain route of transmission.

Airborne.All respiratory infections are airborne.With coughing, sneezing, shouting, etc., pathogens are sprayed into the air in a certain range around the source of infection along with mucus, and when people inhale, they can inhale droplets containing pathogens into their bodies.Airborne diseases have the following epidemic characteristics: wide spread, high incidence, continuous occurrence of patients, periodicity and seasonality, more children, and related to living conditions, especially crowded.

food spread.All intestinal infectious diseases, individual respiratory infectious diseases, and zoonotic infectious diseases can be transmitted through contaminated food.Some of the contaminated food has pathogenic factors in the food itself, and some are contaminated during storage, transportation, production, processing, and sales.The epidemiological characteristics of food-borne diseases are: patients all have a history of eating some kind of contaminated food, and the same food can cause collective disease. When the contaminated food is stopped or measures are taken, the outbreak will subside quickly; except for very few exceptions Generally, the duration is short and does not form a chronic epidemic.

Spread by water.Many intestinal infectious diseases, several zoonotic infectious diseases, and parasitic diseases can be transmitted through water.When people drink contaminated water or wash utensils, vegetables, fruits, bathing, swimming, labor, etc. in it.Pathogens in water can enter the body through the mouth or skin.Its epidemic characteristics are: the distribution of patients is consistent with the scope of water supply, and there is a history of drinking the same water source. If the water source is polluted once, it can cause disease outbreaks or epidemics. If the water source is frequently polluted, the patients can continue all year round. After that, the outbreak or epidemic can subside.

Contact spread.Diseases are transmitted through direct or indirect contact between humans and humans, and between humans and animals. Many intestinal infectious diseases, some respiratory infectious diseases, surface infectious diseases and some zoonotic diseases can be transmitted through this route.The epidemic characteristics of contact transmission are: generally sporadic onset, which can form transmission among families or co-residents, and there are many cases in areas with poor personal hygiene habits and poor sanitation conditions; the epidemic process is slow, and the onset can occur all year round without obvious Seasonal peak; strengthening the management of infection sources, strict disinfection system, and paying attention to personal hygiene can reduce transmission.

Vector transmission.Refers to certain diseases that are transmitted through mosquitoes, fleas, lice, ticks, mites, etc., biting and sucking blood or carried by machinery, such as malaria, forest encephalitis, plague, kala-azar and other infectious diseases.Its popular characteristics are: there is a certain regional distribution and seasonal distribution, and some diseases such as forest encephalitis have obvious occupational characteristics.

soil spread.Many intestinal parasitic diseases, as well as anthrax, tuberculosis, typhoid, tetanus, botulism, etc., can be transmitted through soil, because parasites must develop in the soil at a certain stage before they can cause infection, and germ spores such as Bacillus tetani are also present in the soil. long-term preservation in the soil.

In addition to the above-mentioned common transmission routes, there are other forms of iatrogenic transmission, placental transmission, vertical transmission, and horizontal transmission.

(3) Susceptible population

The so-called susceptible population is the person whose body lacks immunity to a certain disease and is easily infected with the disease.When the proportion of these people in the population increases, the epidemic of infectious diseases may occur.Conversely, people who are resistant to a disease generally do not develop the disease, even during an epidemic.

2.Infectious Disease Prevention
In view of the three basic conditions for the prevalence of infectious diseases (source of infection, transmission route and susceptible population), the following measures can be taken to prevent infectious diseases.

(1) Control the source of infection
When a patient with an infectious disease or a suspected patient is found, it shall be reported to the relevant epidemic prevention department in a timely manner.According to the strength of contagion, the state divides infectious diseases into three categories and stipulates the corresponding reporting time.

There are two types of infectious diseases, namely plague and cholera.These diseases must be reported to the local health and epidemic prevention department within 6 hours in cities and 12 hours in rural areas with the fastest speed and communication method.

There are 22 kinds of B infectious diseases, including viral hepatitis, bacterial and amoebic dysentery, typhoid and paratyphoid fever, AIDS, gonorrhea, syphilis, polio, measles, pertussis, diphtheria, meningococcal meningitis, Scarlet fever, epidemic hemorrhagic fever, rabies, leptospirosis, brucellosis, anthrax, epidemic and endemic typhus, epidemic Japanese encephalitis, kala-azar, malaria, dengue fever.These diseases should be reported to the local health and epidemic prevention agencies within 12 hours in urban areas and within 24 hours in rural areas.

There are 14 infectious diseases in category C, which are tuberculosis, schistosomiasis, filariasis, hydatid disease, leprosy, influenza, mumps, rubella, neonatal tetanus, acute hemorrhagic conjunctivitis and cholera Infectious diarrheal diseases other than dysentery, typhoid and paratyphoid.These diseases should be reported to the local health and epidemic prevention agency within 24 hours.

Patients with infectious diseases must be isolated and treated in a timely manner.The methods of isolation include hospital isolation, home isolation, and temporary centralized local management.

Medical observation should be carried out for contacts of infectious diseases and pathogen carriers.All healthy people who have been in close contact with the source of infection are called contacts during the incubation period of the disease.Contacts may become sources of infection (pathogen carriers) but they are not equal to patients, so the measures taken for contacts are different from those of patients.Medical observation of contacts is called quarantine.The quarantine period is calculated from the date of last contact and is equivalent to the longest incubation period of the infectious disease.Animals that are sick or carrying pathogens are killed, burned, and buried in depth according to the harmfulness of the disease and the economic value of the animals.

(2) Cut off the transmission route
Eliminate pathogens in the surrounding environment and make the external environment healthy and harmless.Including general hygiene measures and disinfection, insecticidal measures.

(3) Protect susceptible populations

Improve the resistance and immunity of susceptible people to infectious diseases.In addition to strengthening physical exercise, reasonable nutrition, and paying attention to hygiene, the main task is to carry out vaccination work.

Cardiovascular disease prevention

There are many types of cardiovascular diseases, such as hypertension, coronary heart disease, pulmonary heart disease, and rheumatic heart disease.These diseases are often not manifested until middle-aged and old age, while pathological changes begin in adolescents.Therefore, prevention of cardiovascular disease should start with adolescents.If you develop non-smoking, pay attention to a balanced diet.Maintain a cheerful disposition, adhere to physical activities, avoid obesity and other lifestyles that are beneficial to cardiovascular health, and control various pathogenic factors.This kind of precautionary measures and prevention before getting sick is called primary prevention in medicine, also called primary prevention.As for middle-aged and elderly patients with existing cardiovascular disease, timely correcting bad habits and strengthening preventive measures can delay the development of the disease and avoid serious complications. This is called secondary prevention, that is, secondary prevention.Complications have occurred, through timely treatment, to prevent the deterioration of the disease, prolong the patient's life, for the tertiary prevention.

1. Prevention and health care of cardiovascular diseases in children and adolescents
(1) Pre-disease prevention

It mainly includes the following aspects:

life management.Life should be regular, and daily life should be regular.Adhere to go to bed early and get up early, take a lunch break of 1-2 hours; have three meals at regular intervals, and roughly quantify them, and keep exercising for a long time. From infants and young children, you should start sleeping with the window open in the warm season, and exercise outdoors for no less than 1 hour a day .

Diet management.Adhere to a good diet according to age needs.It is necessary to ensure that there is enough protein and vegetables every day, avoid eating too much fat, and try not to make children obese.

Pay attention to hygiene to avoid infection.Pay attention to environmental hygiene, food hygiene and personal hygiene.Take a bath 1-3 times a week, pay attention to indoor cleanliness and fresh air, especially in the cold season, it is best to ventilate once a day.Moderate room temperature, prevent too cold or too hot.Avoid taking children to crowded places such as theaters and markets.

Vaccination.Doing a good job in planned immunization according to the regulations and carrying out various preventive vaccinations systematically can reduce many infectious diseases.

(2) Post-ill health care

Common cardiovascular diseases in children include congenital heart disease, myocarditis, rheumatic heart disease, Kawasaki disease, and endocardial fibroelastosis.Some adult cardiovascular diseases also often originate in childhood, such as essential hypertension, Takayasu arteritis, and even a few coronary heart diseases.The health care of the above-mentioned children should pay attention to the following aspects:

Timely and accurate diagnosis and treatment.In children, some mild discomfort is often ignored, and parents should be vigilant about the early manifestations of cardiovascular disease, such as pale complexion, lack of activity, fatigue, chest tightness, shortness of breath (prolonged breath), palpitation, dizziness, etc. In the above situation, you should go to the hospital for examination in time.In addition to general physical examinations for these diseases, special cardiac examinations, such as electrocardiogram, echocardiography, cardiac X-ray examination, and further professional examinations, such as color Doppler, cardiac catheterization, cardiac Angiography, etc.To strive to get the correct diagnosis and treatment as soon as possible as soon as possible.During the recovery period, you should also go to the hospital for regular re-examination, and you must not go on and off.

Prevention of complications and recurrence.When children with congenital heart disease and rheumatic heart disease are infected with bacteria, they are prone to infective endocarditis, and children with rheumatic heart disease are prone to rheumatic activity and recurrence when they are infected with streptococcus.Therefore, preventing infection is of great significance to their smooth recovery.In addition to insisting on treatment (surgery or medicine), pay attention to hygiene, avoid contact with people infected with bacteria or viruses, avoid going to crowded places, and isolate your family members when they are sick.

enough rest.The purpose is to reduce the load on the heart.Due to the lively nature of children, rest can only be implemented by taking effective measures, not only by parental orders.In addition to bed rest, the parent's embrace is also very important for the rest of infants and young children, and children should be prevented from crying. Children aged 3 to 5 are the most active and refuse to be held. Rest is the most difficult to grasp. Remaining quiet, such as telling stories, listening to recordings or radio, paper cutting, making flowers, building blocks, puzzles, etc.; more persuasion and education should be given to school-age children so that they can understand the importance of rest and bed rest, such as telling them "to If you want to get better quickly, you have to rest well”, and try to guide their hobbies, such as learning to draw, learn to play chess, read mini-books or pictorials, practice writing, learn simple foreign languages, review their homework, etc. Pursue some aspirations, be happy and quiet, so as to achieve the dual purpose of recuperation and learning.

Schedule your life.We must insist on getting up early and going to bed early, not watching TV until late at night and sleeping late the next morning.After 8 o'clock every night, you should prepare for bed, such as brushing your teeth, washing your feet, etc., get up at 1 or 2 o'clock in the morning to wash your face, try to take a nap for [-] to [-] hours after lunch, and take a short walk outdoors before breakfast after your condition improves. In the future, when the sun is good in the morning, you can wear warm clothes and go to the balcony or the courtyard to rest for a short time, and you can use this opportunity to ventilate the room.The diet should be flexibly arranged according to the condition of the child and the doctor's advice.

2.Prevention of coronary heart disease

The blood vessels that supply the heart are called coronary arteries, which have two branches.When atherosclerosis occurs in the coronary arteries, the lumen of the arteries is narrowed, reducing blood flow to the heart, causing myocardial hypoxia, and various symptoms, which are called coronary atherosclerotic heart disease.

The most important cause of arteriosclerosis is the disorder of lipid metabolism.Our food contains a certain amount of fat. After digestion and absorption, some of these fats are decomposed and converted into energy for consumption, and some excess fat is stored in the body.The existence of subcutaneous fat can make people fat, and the existence of fat in the arterial wall can make the arteries harden.The main lipid component that constitutes arteriosclerosis is called cholesterol.When the blood cholesterol rises, the cholesterol can invade the arterial wall, deposit and accumulate under the intima, and gradually form a plaque.This kind of plaque is uneven, grayish yellow in appearance, and looks like dry rice porridge, so it is called atherosclerosis in medicine.If the plaque continues to develop, coupled with the fibrosis of the arterial wall, the arterial lumen becomes narrower. When the stenosis exceeds half of the original inner diameter of the lumen, the arterial blood flow can be significantly reduced, causing ischemia in the organ being supplied by blood. .This situation occurs in the coronary arteries, which leads to myocardial ischemia, and angina pectoris or other symptoms will appear clinically.Ulceration, hemorrhage, calcification, and local thrombosis can also occur in advanced atherosclerotic plaques, so that the arteries are completely blocked, and the organs supplied by blood are necrotic due to interruption of blood flow.If it occurs in the coronary arteries, it will cause myocardial infarction, and if it occurs in the cerebral arteries, it will cause stroke.

The clinical manifestations of CHD are varied and include angina, arrhythmia, myocardial infarction, and sudden death.Although some patients have no subjective discomfort, the electrocardiogram shows ischemia at rest or after exercise, which is called recessive coronary heart disease.Several different symptoms can often appear in one patient.

(1) Risk factors for coronary heart disease

Coronary atherosclerosis is caused by a variety of factors acting on different links, and these factors are called predisposing factors or risk factors.They include:
age. It is more common in middle-aged and elderly people over 40 years old, and progresses faster after 49 years old, but young adults can also suffer from the disease.

gender.It is more common in men, with a male to female ratio of about 2:1.Women are more common after menopause.

Profession.Those who engage in less physical activity, intense mental activity, and frequent work with a sense of urgency are more likely to suffer from this disease.

diet.People who often eat higher calories and have more animal fat, cholesterol, sugar and salt are susceptible to this disease.

Dyslipidemia, elevated cholesterol, triglycerides, low-density lipoprotein (beta lipoprotein), or very low-density lipoprotein (pre-beta lipoprotein) due to excess intake of fats and sugars or metabolic disorders, while high-density lipoproteins Decreased lipoprotein (alpha lipoprotein) is prone to disease.

High blood pressure.60% to 70% of patients with coronary heart disease have hypertension, and the prevalence of coronary atherosclerosis in hypertensive patients is 4 times higher than that in normotensive patients, and the increase of systolic and diastolic blood pressure is important.

smoking.Smoking increases the morbidity and mortality of coronary heart pain by 2 to 6 times, and it is directly proportional to the number of cigarettes smoked per day.

obesity.Obese people who exceed the standard weight are prone to this disease, especially those who gain weight rapidly.

genetic.If there are people in the family who suffer from the disease at a younger age, the chances of their close relatives to get the disease can be 5 times that of families without this situation. Familial hyperlipidemia is often a factor that makes these family members susceptible to the disease.

diabetes.Diabetics are twice as likely to develop diabetes as non-diabetics.Those with reduced sugar content (hidden diabetes) are quite common in coronary heart disease patients.

People with type A personality who are impatient, aggressive and competitive, concentrate on work but don't relax, and force themselves to strive for achievement are prone to this disease.

Among the above factors, high cholesterol, high blood pressure, and smoking are considered to be the three main risk factors for coronary heart disease.

(2) Prevention of coronary heart disease

For the risk factors of coronary heart disease, preventive measures should include the following aspects.

Appropriate physical labor and physical activity.The amount of physical activity should be determined according to the original physical condition and physical activity habits, as well as the functional state of the heart, with the principle of not increasing the burden on the heart too much and not causing discomfort.In addition, it is necessary to proceed step by step, and it is not advisable to forcefully do strenuous activities.In fact, the most important aspect of physical activity is not the intensity of the activity, but the persistence of the activity.Medical experts especially recommend walking as a form of exercise that people of all ages, occupations and genders can adhere to and maintain for a lifetime.In addition to the benefits of general physical activity, walking can also provide peace of mind.It is not like jogging that has the risk of injuring knees, ankles or feet, because joggers have to bear 3 to 4 times their body weight, and people over the age of 40 are more likely to be injured.When walking, the whole foot is on the ground, and only bears 1 to 1 times the body weight, so there is no worry about excessive weight.Walking should persist for 5 hour a day, which can be done in batches.

Of course, everyone can also choose to do exercises, Tai Chi, dance and other activities according to their own hobbies, but pay attention to perseverance.

For patients with chronic coronary heart disease, who have general symptoms of angina pectoris and changes in the electrocardiogram of myocardial ischemia, appropriate physical exercise can reduce the risk factors for coronary heart disease, and also help the recovery of heart function and general physical strength.However, the exercise method and intensity need to be jointly controlled by the patient and the doctor, neither conservative nor excessively aggressive.

Anyone who has one of the following conditions should not exercise: frequent moderate to severe angina pectoris, ventricular arrhythmia.Heart failure, recent pulmonary embolism and cerebral embolism or limb arteriovenous embolism, etc.

(End of this chapter)