Categorized into four modes of transmission.
(1) water and food transmission pathogens through the feces out of the body, contaminated water and food, susceptible people through the contaminated water and food infected. Bacterial dysentery, typhoid fever, cholera, viral hepatitis A and other diseases transmitted through this way.
(2) air droplet transmission of pathogens by the infectious agent through coughing, sneezing, talking about the discharge of secretions and droplets, so that susceptible people inhaled infected. Brain fever, scarlet fever, whooping cough, influenza, measles and other diseases, through this way of transmission.
(3) insect vector transmission pathogens in the insect body reproduction, complete its life cycle, through different ways of invasion of pathogens into the susceptible body. Mosquitoes, fleas, ticks, chiggers, flies and other insects are important vectors. For example, mosquitoes transmit malaria, filariasis, encephalitis B, ticks transmit fever, ticks transmit typhus, fleas transmit plague, and chiggers transmit scrub typhus. Because the pathogen in the insect body in a certain stage of the reproductive cycle can cause transmission, so it is called biological transmission. Pathogens are transmitted to susceptible individuals through mechanical carriage by flies, which is called mechanical transmission. Such as bacillary dysentery, typhoid fever, etc.
(4) contact transmission of direct contact and indirect contact with two modes of transmission. Such as skin anthrax, rabies and other direct contact and infected, hepatitis B injection infected, schistosomiasis, leptospirosis for contact with infected water infection, are direct contact transmission. A variety of intestinal infectious diseases transmitted through contaminated hands, so-called indirect transmission.
Susceptible population refers to the degree of susceptibility or immunity level of the population to a certain infectious disease pathogen.
An increase in the newborn population, the concentration of susceptible people or enter the infected area, the army's new recruits, easy to cause infectious disease epidemics.
Acquired immunization after the disease, hidden infection of the population, artificial immunization, all make the population less susceptible, less likely to infectious diseases or terminate their epidemics.
How can infectious diseases be prevented?
The three basic links for the epidemic of infectious diseases, based on a comprehensive epidemic prevention measures, the main preventive measures are as follows:
(a) Management of infectious sources --- 1
Category A infectious diseases
bubonic plague cholera
Category B infectious diseases
Contagious Atypical Pneumonia,
AIDS,
Viral Hepatitis,Polio. Highly Pathogenic Avian Influenza, Measles, Epidemic Hemorrhagic Fever, Rabies, Epidemic Encephalitis B, Dengue Fever, Anthrax, Bacterial and Amoebic Dysentery, Tuberculosis, Typhoid and Paratyphoid, Epidemic Cerebrospinal Meningitis, Whooping Cough, Diphtheria, Neonatal Tetanus, Scarlet Fever, Brucellosis, Gonorrhea, Syphilis, Leptospirosis, Schistosomiasis, Malaria.
Category C infectious diseases
Infectious influenza, mumps, rubella, acute hemorrhagic conjunctivitis, leprosy, epidemic and endemic spotted typhoid fever, black fever, filariasis, encapsulated disease, infectious diarrhoeal diseases other than cholera, bacterial and amoebic dysentery, typhoid fever and paratyphoid fever.
(i) Management of infectious agents - 2
Management and necessary treatment of carriers of pathogens. Especially for food production and marketing personnel, cooks, caregivers for regular carrier checks, timely detection, timely treatment and transfer of work.
(I) management of infectious agents --- 3
Contacts of infectious diseases, must be medical observation, observation, collective quarantine, immunization or drug prevention, if necessary.
(I) Management of infectious sources---4
Management and treatment of infected animals The source of animal infections, wild animals and domestic animals with economic value shall be isolated for treatment, slaughtered and disinfected if necessary, and wild animals without economic value shall be trapped and killed by mobilizing the masses.
(2) cut off the transmission
According to the different ways of transmission of infectious diseases, to take different measures to prevent epidemics.
Intestinal infectious diseases, bedside isolation, disinfection of vomit and diarrhea, strengthening dietary hygiene and personal hygiene, and good management of water and feces.
Respiratory infectious diseases, should make indoor ventilation, air flow, air disinfection, personal masks.
Insect-borne infectious diseases, there should be anti-insect equipment, and the use of drugs to kill, prevent and expel insects.
(C) protection of susceptible populations
Improve the resistance of the population, focused and planned preventive vaccination to improve the population-specific immunity.
Artificial automatic immunization is a planned vaccine, bacteriophage, toxoid vaccination of susceptible people, after vaccination immunity appeared in 1 - 4 weeks, lasted for several months to several years.
Artificial passive immunization is the urgent need to inject antivenom, gammaglobulin, placenta globulin, high-efficiency immunoglobulin. Immunity appears quickly after the injection and loses its effect after 1 to 2 months.
Control of common infectious diseases
Flu Mumps Varicella
Measles
Intestinal infectious diseases
Intestinal infectious diseases
Infectious diseases in which pathogens invade the intestinal tract through the mouth and can be discharged from the feces include cholera, bacillary dysentery, typhoid fever, paratyphoid fever, viral hepatitis, poliomyelitis and other infectious diarrhea, etc.
Patients and carriers of pathogens are the most important source of infection, and the feces of all patients with enteric infectious diseases contain a large number of pathogens. Pathogens with patients or carriers of fecal contamination of the environment, through water, food, hands, flies, cockroaches and other media from the mouth to cause infection. Morbidity accordingly to the higher temperatures of summer and fall are more.
Preventive measures:
1, timely detection of patients, to be isolated for treatment;
2, to strengthen the "three pipes and one extinction" work;
3, to carry out health education, cultivate good personal hygiene habits;
4, there are specific vaccination to be carried out. preventive vaccination, such as hepatitis A vaccine, polio vaccine.
Influenza
Influenza (ingluenza) referred to as influenza, is an acute respiratory infectious disease caused by influenza virus. Clinical characteristics of the acute onset of high fever, body aches, fatigue, or with mild respiratory symptoms. The disease has a short incubation period, is highly contagious and spreads rapidly. Influenza viruses are divided into three types: A, B and C. Influenza A poses the greatest threat. Due to the strong pathogenicity of influenza virus, easy to mutate, easy to cause outbreaks and epidemics.
(A) pathogens
Influenza virus belongs to the family of orthomyxoviruses, divided into A, B, C three types.
Influenza virus is not resistant to heat, acid and ether, and is sensitive to formaldehyde, ethanol and ultraviolet light.
(2) Epidemiology
1, the source of infection: mainly patients and hidden infected. Patients from the end of the incubation period to the onset of 5 days after the onset of the virus can be discharged from the nasal mucus, saliva, sputum and other secretions, the infectious period of about 1 week, to the beginning of the disease 2 ~ 3 days the most infectious.
2, transmission: the virus with coughing, sneezing, talking to the droplet transmission is mainly through the virus contaminated tea utensils, eating utensils, towels and other indirect transmission is also possible. The speed and breadth of transmission is related to population density.
3, the population susceptibility: the population is generally susceptible to infection of the same antigen type can be different degrees of immunity, type and type of no cross-immunity.
4. Epidemiological characteristics: sudden onset, rapid spread, high morbidity and short epidemiological process is the epidemiological characteristics of influenza. There is no obvious seasonality in the epidemic, and the winter and spring seasons are the most common. Pandemic is mainly caused by influenza A virus, when the influenza A virus appears new subtype, the population is generally susceptible to pandemic. Generally, a worldwide pandemic occurs every 10 to 15 years, and a minor pandemic every 2 to 3 years. Influenza B tends to be localized or disseminated, but can also be pandemic. Influenza C is usually only circulating.
(2) Epidemiology
(3) Clinical manifestations
The incubation period ranges from 1 to 3 days, with a minimum of several hours and a maximum of 4 days. Symptoms caused by various types of influenza viruses, although different in severity, but the basic performance is the same.
1, simple influenza acute onset of high fever, systemic symptoms are more serious, respiratory symptoms are lighter. Significant headache, body pain, fatigue, dry throat and loss of appetite. Some patients have nasal obstruction, runny nose and dry cough. Fever peaks in 1 to 2 days, and then subsides in 3 to 4 days, with other symptoms subsiding, but upper respiratory symptoms often last 1 to 2 weeks before gradually disappearing, and physical recovery is also slow.
Some of the mild cases, similar to other viral episodes, will be cured in 1 to 2 days, and are easy to be ignored.
(D) Diagnosis and differential diagnosis
Diagnostic points:
1, epidemiological data: winter and spring in the same area, 1 ~ 2 days that a large number of patients with upper respiratory tract infections, or an epidemic in a certain area, should be used as a basis.
2, clinical manifestations: the onset of acute, fever, headache, body aches, fatigue and other symptoms of systemic toxicity, and respiratory performance is light. Combined with physical examination and X-ray photographs for diagnosis.
3, laboratory tests; white blood cell count is normal or decreased, classification is normal or relative lymphocytosis. If there is significant leukocytosis, it often indicates secondary bacterial infection.
In addition, pharyngeal gargle or cotton swabs within 3 days of onset of illness can be taken for viral nucleic acid testing and viral culture.
Differential diagnosis:
1, other viral respiratory infections: can be caused by rhinovirus, adenovirus, respiratory syncytial virus, parainfluenza virus, coronavirus and so on. It can be initially identified according to clinical features and epidemiologic data.
2, Mycoplasma pneumoniae: slow onset. A small amount of mucous sputum or hemosiderin sputum, moderate condition, good prognosis. Cold agglutination test and MG streptococcal agglutination test is elevated.
(E) treatment
1, general treatment: according to the respiratory isolation of patients for 1 week or until the disappearance of major symptoms. Bed rest, drink plenty of water, give fluids or semi-fluid diet, after eating to warm salt water or warm boiled water gargle, keep nasopharyngeal and oral hygiene.
2, symptomatic treatment: high fever and irritability can be given antipyretic sedative, discretionary use of APC, anakinra, luminal and so on. Those with significant high fever and severe vomiting should be given appropriate rehydration.
3, anti-inflammatory antiviral treatment: early medication has a certain effect, can inhibit viral proliferation, shorten the course of the disease. In addition to clearing heat and detoxification of Chinese medicine treatment, the effect is obvious.
(F) Prevention
1, management of infectious agents: patients isolated treatment for 1 week, or until 2 days after the fever subsides. Those who are not hospitalized should wear masks when going out. Unit epidemic should be collective quarantine, and to improve and strengthen the epidemic reporting system.
2, cut off the transmission path: open windows and ventilation, keep the indoor air fresh, available vinegar or peroxyacetic acid fumigation disinfection. Suspension of assembly and collective cultural and sports activities during the epidemic. To the public **** place should wear a mask. Do not visit the patient's home to reduce the chance of transmission. Food utensils, clothes, handkerchiefs and toys used by patients should be boiled and sterilized or exposed to sunlight for 2 hours.
3, health education: education students usually strengthen physical exercise, reasonable diet and rest, to enhance their ability to fight diseases, and develop good personal hygiene habits such as washing hands regularly, not facing others coughing and talking loudly.
(F) Prevention
4, influenza vaccination: in the case of the vaccine strain and the virus strain antigenic consistency, all have a definite preventive effect. Vaccination time: 1 to 2 months before the peak of the influenza epidemic, the recommended vaccination time is from September to November. Vaccination target: All those who want to reduce the possibility of influenza, no contraindications to vaccination, age 6 months or older can be vaccinated against influenza. Recommended Population
(1) People over 60 years of age;
(2) People with chronic diseases and those who are frail;
(3) Staff of healthcare organizations, especially frontline staff;
(4) Primary school students and kindergarten children.
People who are prohibited from receiving influenza vaccination: (1) people who are allergic to eggs or other ingredients in the vaccine; (2) people with Guillain-Barre syndrome; (3) pregnant women within 3 months of pregnancy; (4) people with acute febrile illness; (5) people with chronic illnesses in the period of exacerbation; (6) people with severe allergies; (7) children under 12 years of age who can't use inactivated whole-virus vaccine; (8) people whom doctors think are not fit for The vaccine is not suitable for those who are considered unsuitable for vaccination by the doctor.
Mumps
Mumps is a common respiratory infection among children and adolescents, caused by the mumps virus. It is characterized by fever and non-purulent swelling and pain in the parotid gland, and may invade various glandular tissues or the nervous system, as well as the liver, kidneys, heart, joints and other organs. The disease is most common in children, but can also be seen in adults.
(I) Pathogenesis
Mumps virus belongs to the family Paramyxoviridae,
The virus is cold-resistant, and has considerable resistance to low temperatures. It is sensitive to ultraviolet light and general disinfectants. It is only alive for half a minute under strong ultraviolet light, and is inactivated by contact with formaldehyde solution, 30% Lysol, 75% ethanol, etc. for 2 to 5 minutes. The virus has only one serotype. In nature, man is the only host of the virus.
(II) Epidemiology
1. Sources of infection Early patients and hidden infections. The virus exists in the patient's saliva for a long time, and the virus can be isolated from the patient's saliva from 6 days before to 9 days after the parotid swelling, so it is highly contagious within these two weeks. After infection with the mumps virus, there is no mumps manifestations, but there are other organs such as the brain or testes and other symptoms, the saliva and urine can also detect the virus. In a pandemic, about 30-40% of patients have only subclinical infection of the upper respiratory tract, which is an important source of infection.
2, the transmission of the virus in saliva through droplet transmission (saliva and contaminated clothing can also be infected) and its infectious power is weaker than measles, chickenpox. Pregnant women infected with the disease can be transmitted through the placenta to the fetus, resulting in fetal deformity or death, and the incidence of miscarriage is also increased.
(2) Epidemiology
3, susceptibility Universal susceptibility, its susceptibility with the increase of age and decline. 90% of cases occur in 1 ~ 15 years of age, especially 5 ~ 9 years of age of the children. 1 year old infants can be in the body of the mother's immunity, and seldom get sick. In adults, 80% have had either dominant or recessive infection. There is no gender difference in pediatric patients, with more males than females developing the disease after puberty. There is persistent immunity after illness.
4. Epidemiologic features The disease can occur throughout the year, but mainly in winter and spring. It can be epidemic or disseminated. In the children's collective institutions, troops and poor sanitation in crowded crowds are prone to cause outbreaks of epidemic. The epidemiological pattern is that as the source of infection accumulates and the number of susceptible persons increases, the epidemiological cycle is formed, and the duration of epidemics can fluctuate between 2 and 7 months. In unvaccinated areas, there is a tendency for epidemics to occur every 7 to 8 years.
(3) Clinical manifestations
The incubation period is 8 to 30 days, with an average of 18 days. The onset of the disease is mostly acute, with no prodromal symptoms. There are fever, chills, headache, sore throat, poor appetite, nausea, vomiting, generalized pain, etc. For a few hours, parotid gland swelling and pain, gradually obvious, body temperature up to 39 ℃ or more, adult patients are generally more serious. Parotid gland swelling is most characteristic. Generally centered on the earlobe, developing forward, backward and downward, shaped like a pear, with unclear edges; the local skin is tense, shiny but not red, tough and elastic to touch, with light tenderness; stimulation of salivary secretion during speech and chewing (especially when eating an acidic diet) leads to intensification of the pain; usually, one side of the parotid gland involves the opposite side one to four days after the swelling, and the bilateral swelling accounts for about 75% of the cases. The submaxillary or sublingual glands may also be involved. There may be redness and swelling at the opening of the parotid duct in the early stage, and there is no purulent secretion from the opening when the parotid gland is squeezed. Most of the swelling of parotid gland reaches its peak in 1~3 days, and gradually subsides and returns to normal in 4~5 days. The whole process takes about 10 to 14 days.
Laboratory tests
1. Blood picture The white blood cell count is normal or slightly low, with a relative increase in lymphocytes in the later stages. The white blood cell count may increase when there are complications.
2, serum and urine amylase measurement Serum amylase is mildly and moderately increased in 90% of patients, which helps in diagnosis.
3, serologic examination Complement binding and hemagglutination inhibition test early and recovery double serum determination of complement binding and hemagglutination inhibition antibody, there is a significant increase in the diagnosis can be confirmed (potency 4 times or more). Foreign countries use enzyme-linked immunosorbent assay and indirect fluorescence immunoassay for IgM antibody, which can be used for early diagnosis.
4, virus isolation Early patients can be isolated in saliva, urine, blood, cerebrospinal fluid.
(4) Diagnosis and differential diagnosis
Based on the epidemiology and history of exposure, and the characteristics of typical acute attacks of parotid swelling and pain, diagnosis is not difficult.
For cases without parotid swelling and pain or reoccurring cases and atypical suspected cases, the definitive diagnosis depends on serologic and viral methods.
Differential diagnosis
1, suppurative parotitis, often one-sided, localized redness, swelling and tenderness is obvious, the mass is limited, late fluctuating feeling, parotid ducts are red and swollen and pus can be squeezed out of the mouth. The secretion smear and culture can find pyogenic bacteria. The total number of leukocytes and neutrophils are obviously increased in the blood picture.
2, neck and pre-auricular lymphadenitis enlargement is not centered on the earlobe, confined to the neck or pre-auricular region, for the nucleus is hard, clear margins, tenderness is obvious, superficial can be active. Inflammation of tissues associated with lymph nodes in the neck or preauricular region, such as pharyngitis and ear sores, may be found. The total number of white blood cells and neutrophils are markedly increased.
(E) Treatment
There is no specific treatment for mumps, and general antibiotics and sulfa drugs are ineffective. Interferon can be tried, which has an effect on the virus. A combination of Chinese and Western medicine is often used to treat the symptoms.
1, general care Isolation of patients to bed rest until the parotid swelling completely subsided. Pay attention to oral hygiene, diet to liquid or soft food is appropriate, avoid acidic food, ensure fluid intake.
2. Symptomatic treatment is suitable for dispersing the wind and relieving symptoms, clearing away heat and removing toxins. Use 60 to 90 grams of Panax quinquefolium decoction or silver fins with 15 grams of water decoction; local external application of Zijinzhuang or Qingdai San with vinegar, external application of the local, several times a day; or with thin Gongying, Metatarsalgia, Narcissus root, amaranth, etc. Pounding external, can reduce the local distension and pain. If necessary, take painkillers, aspirin and other antipyretic and analgesic drugs.
(F) Prevention
1, management of infectious sources Early isolation of patients until the parotid swelling subsides completely. In collective children's institutions, troops and other contacts should be retained for testing for 3 weeks, and suspects should be immediately and temporarily isolated.
2, cut off the transmission pathway: open windows and ventilation, keep the indoor air fresh, use peroxyacetic acid or chlorine disinfectant to disinfect the polluted places. During the epidemic period, the suspension of assembly and collective cultural and sports activities. Patients used eating utensils, clothing, handkerchiefs, toys, etc. should be boiled and disinfected or sun exposure. Educate students to develop good personal hygiene habits such as washing hands frequently and not coughing or talking loudly in front of others.
3, automatic immunization: with glandular parotitis live attenuated vaccine or measles, mumps and rubella triple vaccine.
4, drug prevention Use 30 grams of Panax quinquefolium or 9 grams of honeysuckle decoction, 1 dose per day for 6 days.
Chickenpox
Chickenpox is an acute respiratory infectious disease caused by varicella zoster virus.
Chickenpox is a primary infection, most commonly seen in children,
clinically characterized by mild and systemic symptoms and the appearance of rapidly progressing blotches, papules, herpes with crusts on the skin and mucous membranes in batches.
(I) Pathogenesis
The virus belongs to the herpesvirus family and is spherical in shape, with a diameter of 150-200 nm, with a double-stranded DNA in the center and a 20-octahedral capsid outside, which is covered by a lipoprotein envelope containing complement-binding antigens, and contains no hemagglutinin or hemolysin.
The virus has only one serotype and is a unique host.
The virus is heat intolerant, does not survive in scabs, and is easily inactivated by disinfectants. However, it can survive in herpes fluid at -65°C for up to 8 years.
(2) epidemiology
1, the source of infection chickenpox patients as the main source of infection, since chickenpox rash 1 ~ 2 days before the rash to the rash is dry and crusted, are infectious. Susceptible children in contact with patients with herpes zoster, can also occur chickenpox, but rare.
2, the way of transmission mainly through droplets and direct contact transmission. In close proximity, a short period of time can also be transmitted indirectly through healthy people.
3, susceptible people Universal susceptibility. However, the most pre-school children. 6 months of infants due to maternal antibodies, the incidence of less, chickenpox during pregnancy can infect the fetus. After the disease to obtain lasting immunity, but can occur herpes zoster.
4, epidemic characteristics can occur throughout the year, winter and spring are common. The disease is highly contagious, susceptible to contact with the patient about 90% morbidity, so kindergartens, elementary school and other children's collective institutions are prone to cause epidemics.
(C) Clinical manifestations
Incubation period of 14 to 16 days (10 to 24 days)
1, prodromal period Infants and young children often have no prodromal symptoms. Elderly children or adults may have fever and headache, general malaise, nausea and upper respiratory symptoms, and the rash appears after 1 to 2 days.
(3) Clinical manifestations
2. Rash period The rash appears at the same time as the fever or 1~2 days later, and the rash has the following characteristics:
(1) It is first seen on the trunk and head, and then extends to the whole body. The rash develops rapidly, starting as a red blotchy rash, turning into papules within a few hours, and then forming herpes, the skin feels scratchy when herpes, and then drying and forming scabs, this process sometimes takes only 6-8 hours, if there is no infection, the scabs will fall off after 1-2 weeks, and usually leave no scar.
(2) The rash is often ellipsoidal, 3 to 5 mm, surrounded by a red halo, herpes superficial easy to break. The blister fluid is transparent at the beginning, then turbid, secondary infection may be purulent, scabbing time is prolonged and may leave a scar.
(3) The rash is centripetally distributed, the trunk is the most, followed by the head and face and proximal extremities. The number varies from a few to thousands.
(4) The rash appeared in batches, and blotches, papules, herpes, and crusts could be seen in the same area at the same time.
(4) Diagnosis
1. Epidemiology For preschool children with mild fever and respiratory symptoms in winter and spring, attention should be paid to a careful examination, and ask for a history of contact with chickenpox patients.
2, clinical manifestations according to the characteristics of the rash, centripetal distribution, appeared in batches, a variety of rash type at the same time, the appearance of mucous membrane rash, systemic symptoms are mild or absent, can mostly establish the diagnosis.
3, laboratory tests
(1) blood total white blood cell count is normal or slightly increased.
(2) Virus isolation Cell culture of herpes fluid taken within 3 days of the onset of the disease has a high positive rate of virus isolation.
(3) Serum antibodies can be measured by methods such as the complement binding test.
(E) treatment
1, general treatment and symptomatic treatment
Respiratory isolation, bed rest, strengthen the care, to prevent the herpes rashes broken infection. Rash has broken out can be coated with gentian violet or neomycin ointment. Secondary infection should be early selection of sensitive antibiotics. Itchy people can be given glycerine lotion and antihistamine drugs. Hormones are generally prohibited, when combined with serious complications, under the premise of applying effective antibiotics, discretionary use. Those who have used hormones before the disease should reduce or stop using them as soon as possible.
2, antiviral therapy
Interferon, 100,000 to 200,000 μ / day, for 3 to 5 days; other such as adenosine, acyclic guanosine can also be used.
(F) Prevention
1, management of infectious sources: isolation of patients until all rashes are crusted, contacts in the collective children's institutions should be retained for testing for 3 weeks, and suspects should be immediately and temporarily isolated.
2, cut off the transmission pathway: open windows and ventilation, keep the indoor air fresh, use peroxyacetic acid or chlorine disinfectant to disinfect the polluted places. During the epidemic period, the suspension of assembly and collective cultural and sports activities. Patients used eating utensils, clothing, handkerchiefs, toys, etc. should be boiled and disinfected or sun exposure. Educate students to develop good personal hygiene habits such as washing hands frequently and not coughing or talking loudly in front of others.
3, chickenpox vaccination: with chickenpox live attenuated vaccine, vaccination object: children over 1 year old.
Measles
Measles is an acute respiratory infectious disease caused by measles virus.
Clinical features are fever, runny nose, cough, ocular conjunctivitis, oral mucous membrane spots and generalized skin maculopapular rash.
(I) Pathogenesis
Measles virus is a paramyxovirus.
The virus is not strong external resistance, easy to be inactivated by ultraviolet light and general disinfectants; cold-resistant and not heat-resistant, 4 ℃ can survive for 5 months, -15 ℃ survival of 5 years; and 20 ~ 37 ℃ only survive for 2 hours, 56 ℃ for 30 minutes to be destroyed.
(2) Epidemiology
1, the source of infection: patients as the only source of infection. It is generally believed that 5 days before and after the rash are infectious. The disease is highly contagious, more than 90% of susceptible people can get sick after direct contact
2, the transmission pathway: the patient coughs, sneezes, the virus is discharged with the droplets, and directly reaches the respiratory tract of susceptible people or the conjunctiva of the eye and cause infection. Indirect transmission is rare.
(2) Epidemiology
3, susceptible people Those who have not suffered from measles and have not been vaccinated against measles are susceptible. There is a long-lasting immunity after the disease. Usually 6 months to 5 years old children have the highest incidence, and infants under 6 months of age have maternal immunity and rarely develop the disease. Effective immunity can be obtained after vaccination with live measles vaccine, but the antibody level can decrease year by year, so the disease can still develop if exposed to infectious sources again. There is a tendency for the age of onset to increase after widespread vaccination.
4. Epidemiological features The disease is mostly circulating at present, but if the source of infection enters the area where the susceptible people are concentrated, then it can lead to outbreaks of epidemics. Epidemics mostly occur in winter and spring.
(3) Clinical manifestations
The incubation period is 10 to 14 days. Severe infection or blood transfusion infection can be as short as 6 days; passive immunization or vaccination, can be as long as 3 to 4 weeks.
The typical course of the disease is divided into three stages.
(3) Clinical manifestations --- 1. Prodromal stage
Also known as the prodromal stage of the rash, which lasts for 2 to 4 days, the main manifestations of the disease are inflammation of the upper respiratory tract, acute onset of fever, coughing, sneezing, sneezing, photophobia and tearing, conjunctival congestion, and swelling of the eyelids. The cough worsens day by day. Infants may be accompanied by vomiting and diarrhea. Onset of disease 2-3 days on the buccal mucosa opposite the first molar teeth appeared pinpoint size, fine salt grain-like grayish white spots, slightly elevated, surrounded by red halo known as measles mucous membrane spots (Koplik's spots); this sign has an early diagnostic value. They are small at the beginning, and then spread to the whole buccal mucosa and the gums of the lips. Most of the mucous membrane spots disappear completely 1 to 2 days after the appearance of the rash. A congested red line (stimson's line) is seen on the lower facial border.
(3) Clinical manifestations-- 2. Rash period
The rash begins around the 4th day of illness and usually lasts for 3 to 5 days. Rash first started behind the ear hairline, gradually to the forehead, face and neck, trunk and limbs, to be hands and feet when the heart of the rash, it is "out of Qi" or "out of penetration". Rash at the beginning of sparse reddish papules, diameter 2 - 4mm, gradually increase the rash, fusion of ovoid or irregular, between the rash can be seen in normal skin, the rash out of penetration after the turn to dark brown.
In this period, the systemic toxicity is aggravated, the body temperature is as high as 40 ℃, mental depression, lethargy, sometimes delirium and convulsions. Facial swelling, skin diagnosis, eye secretions increase, even adhesion eyelids are not easy to open, flow of thick mucus, the face of the above performance is known as the face of measles. Redness and swelling of tongue papillae, swelling and pain in pharynx, aggravation of cough, hoarseness, shortness of breath, chest X-ray, more extensive pulmonary infiltrate lesions of varying degrees of severity are seen. Lung signs are mostly negative, except for fine wet rhonchi in the lungs of patients with severe disease. The liver and spleen may be enlarged, and infants and young children are prone to diarrhea with loose watery stools and a few pus cells in fecal examination.
(3) Clinical manifestations -- 3, recovery
After the rash is complete, the symptoms of intoxication are obviously relieved, and the body temperature decreases, falling to normal in about 1 to 2 days. Mental appetite improved, respiratory tract inflammation rapidly reduced, the rash according to the order of rash subsides and retains bran-like fine flakes and light brown pigmentation, to drive dry more, 1 ~ 2 weeks to retreat net. If there is no complication of the typical measles throughout 10 to 14 days.
(D) Diagnosis
1, epidemiology susceptible (not out of measles, also not automatic immunization), in the 3 ~ 4 weeks before the disease has a history of contact with measles patients.
2, clinical manifestations Where there is fever, inflammation of the upper respiratory tract, conjunctival congestion, tearing and other symptoms should be suspected of measles, such as oral examination of measles mucous membrane spots, the basic diagnosis can be confirmed. If there is a typical rash, after the rash remains pigmentation, other symptoms accordingly reduced, the diagnosis is more clear.
(4) Diagnosis
3. Laboratory tests are only used to confirm the diagnosis of atypical and difficult cases or the first cases in areas where there has been no measles for a long time.
(1) Viral nucleic acid test or viral culture: take gargle or nasal and pharyngeal swabs from early patients.
(2) serological examination: using enzyme-linked immunosorbent assay or immunofluorescence technique to detect the patient's serum anti-measles IgM; hemagglutination inhibition test, neutralization test, complement binding test to detect the measles antibody IgG, acute and recovery serum showed a 4-fold increase, are of diagnostic value.
Differential diagnosis
1, rubella (rubella): most common in young children, toxic symptoms and respiratory inflammation is light, the onset of 1 ~ 2 days of rash, for the small sparse reddish maculopapular rash, 1 ~ 2 days to retreat rash, no hyperpigmentation and desquamation. Swelling of lymph nodes behind the ear, occiput and neck are its distinctive features.
2, infantile rash (exanthema subitum, roseda infantum): most common in infants and young children within 2 years of age, sudden onset of high fever, upper respiratory symptoms are mild, the child's spirit is good, the fever lasts 3 to 5 days suddenly recede, the fever recedes when or after the rash, no hyperpigmentation, and not desquamated, is the characteristics of this disease.
Differential diagnosis
3, scarlet fever: prodromal fever, sore throat, the onset of a rash within 1 to 2 days, the rash is the size of a pinhead, red blotchy patchy rash or corn grain rash, the skin is congested between the rashes, the skin is diffusely flushed, the pressure of the receding color, flaking and peeling of the skin when the rash recedes, and the total number of leukocytes and neutrophils is significantly elevated.
4, enteroviral infections: Coxsackie virus and echovirus infections often occur rash. Mostly seen in summer and fall, before the rash fever, cough, diarrhea, occasionally see mucous membrane spots, often accompanied by generalized lymph node swelling, rash pattern varies, can be repeated, the rash does not flake, no hyperpigmentation.
(E) Treatment
1. General treatment and care:
(1) Respiratory isolation Patients should be isolated and treated at home until 5 days after the rash. Patients with complications should be hospitalized for isolation and treatment, and the isolation period should be extended for 5 days.
(2) Maintain indoor warmth and air circulation, give easy-to-digest and nutritious fluid or semi-liquid diet, with sufficient water; keep the skin and eyes, nose, mouth and ears clean, wash the face with warm water and gargle with saline; protect the eyes with antibiotic eye ointment or ophthalmic solution to prevent secondary infection.
(E) Treatment
2, symptomatic treatment High fever can be used in small doses of antipyretics, but the body temperature should not fall below 39 ℃, or moderate sedation to prevent convulsions. Avoid the use of strong antipyretic and ice water, alcohol and other baths, so as not to affect the penetration of the rash. Irritability or convulsions should be given compound chlorpromazine, luminal, valium, etc., cough heavy phlegm, can take cough expectorant drugs.
3, complications treatment: pneumonia, laryngitis and so on.
(F) prevention
1, the management of infectious sources: the patient should be closely isolated, the contact isolation and quarantine for 3 weeks; during the epidemic period, nurseries, kindergartens and other children's institutions should be suspended to pick up and receive susceptible children into the house.
2, cut off the transmission path: pay attention to the ventilation of the sick room, make full use of daylight or ultraviolet irradiation; health care workers should wash their hands after leaving the sick room to change their clothes or stay in the air for 20 minutes before contacting susceptible people.
(F) Prevention
3, the protection of susceptible people:
(1) automatic immunization: the application of live measles vaccine is the most effective and fundamental way to prevent measles. According to the immunization procedure for young children over 8 months of age who have not suffered from measles, measles vaccine, 1.5 years old and 6 weeks of age re-vaccination. Because the incubation period after vaccination is shorter than the incubation period of natural infection (3 to 11 days, mostly 5 to 8 days), susceptible persons can still prevent the occurrence of measles by receiving live vaccine 2 days after contacting the patient, and the preventive effect will be reduced if the vaccine is administered 2 days after contacting the patient, but it can alleviate the symptoms and reduce the complications.
(2) passive immunization: weak, sick, young susceptible children with a history of close contact should use passive immunization. Intramuscular injection of gammaglobulin 0.1-0.2ml/kg, placenta globulin 0.5-1.0ml/kg, 5 days after exposure to the injection can prevent the onset of the disease, 6-9 days within the injection can reduce the symptoms of the immunization is valid for 3 weeks.