Leptospirosis
Introduction
Introduction to leptospirosis Leptospirosis (leptospirosis) is an acute systemic infectious disease caused by various types of pathogenic Leptospira (Leptospira). It is a natural epidemic. Diseases, rodents and pigs are the two main sources of infection. The clinical features are rapid onset, early high fever, body aches, weakness, conjunctival hyperemia, gastrocnemius tenderness, superficial lymphadenopathy and other symptoms of hemoptysis; middle stage may be associated with pulmonary hemorrhage, diffuse pulmonary hemorrhage, myocarditis, hemolysis Anemia, jaundice, generalized bleeding tendency, nephritis, meningitis, respiratory failure, heart failure and other target organ damage manifestations; recovery of most cases in the late stage, a few cases may appear after fever, ocular uveitis and occlusion of cerebral artery occlusion A post-onset associated with allergic reactions following infection. Diffuse pulmonary hemorrhage, myocarditis, hemolytic anemia, and liver and kidney failure are common causes of death. basic knowledge Sickness ratio: 0.001%-0.002% Susceptible people: no special people Mode of transmission: indirect contact propagation Complications: myocarditis, hemolytic anemia, anterior uveitis, encephalopathy
Cause
Cause of leptospirosis
Trauma factor (45%)
The hook body passes through the normal or damaged skin of the human body, and can also enter the human body through the mucous membrane. It quickly reaches the whole body from the lymphatic system and blood, and bacteremia occurs. Then it enters various organs, tissues, cells, and even invades the subarachnoid space. This kind of penetrating power may be related to the special, flexible spiral motion of the house and other tissues, and also has a certain relationship with the hyaluronidase component in the bacteria.
Virus infection (35%)
After the hook body invades the human body and causes infection, due to the different nature of the human body and the hook type and its toxic substances, the result of the interaction may be manifested as leptospirosis of different clinical types. In general, the virulence of the jaundice type is stronger. Infections such as autumn type, Australian type, and canine type are more likely to cause heavier clinical manifestations such as jaundice or hemorrhage; and cold and typhoid type, seven-day heat type, especially Pogner type and other weaker infections. , often cause leptospirosis, but the virulence of the jaundice type is more toxic, and there may be mild jaundice. Conversely, infections such as influenza typhoid can cause a certain degree of jaundice or bleeding. This may be related to the original immune status of the human body.
Pathogenesis
The hook body passes through the normal or damaged skin of the human body, and can also enter the human body through the mucous membrane. It quickly reaches the whole body from the lymphatic system and blood, and bacteremia occurs. Then it enters various organs, tissues, cells, and even invades the subarachnoid space. In the house and other tissues, this penetrating power may be related to its special, flexible spiral motion, and it also has a certain relationship with the hyaluronidase component in the bacteria. In the early stage of bacteremia, clinical symptoms of infection and poisoning, systemic capillaries Acute, severe functional changes in organs such as the lungs, liver, kidneys, heart, and central nervous system. Leptospirosis is a generalized disease of the whole body. In the early stage, it is mainly a change in the toxic microvascular function of the infection, which is characterized by a slight change in pathological morphology. The functional changes are more significant. The invasiveness of the leptospira may invade the cells by its adherent cell action or its toxic products, causing changes in cell ultrastructure, such as mitochondrial swelling, emptying, disappearance of the condyle, increased lysosomes; microvascular congestion, even See microvascular wall damage, capillary oozing or fibrin oozing, as the disease progresses, the hook and its poison into one It causes functional and morphological damage of organs such as lung, liver, kidney, heart, striated muscle, lymph nodes, central nervous system, etc., and causes organ damage such as pulmonary hemorrhage, jaundice, renal failure, encephalitis, etc. The human body's response is different, the performance of leptospirosis is complex and diverse, and the degree of severity is different. Clinically, some organ lesions are dominant, and different types appear. Leptospirosis tissue morphology damage is generally mild. After treatment, it can be Complete recovery, no scars, after the hook body invades the human body, the neutrophils in the blood first increase, there are different degrees of phagocytosis activity, there is a weak inflammatory reaction, but no obvious leukocyte infiltration, no pus, mononuclear Macrophage hyperplasia, obvious ability to phagocytosis, inguinal and other superficial lymph nodes, about 1 week after the onset of leptospirosis, specific antibodies began to appear in the blood, and the antibody titer gradually increased with the course of the disease, after the onset of the disease It can reach a peak in about 1 month, and the titer of antibody is sometimes as high as 1:10000. When IgM first appears and the titer increases gradually, the hooks in the blood circulation begin to decrease. And disappeared. After that, the hooks rarely appear in the blood circulation. When the antibodies in the serum appear and the hooks disappear, the hooks in the kidneys are not affected by specific antibodies in the blood, and can survive and multiply in the kidneys. Often excreted with the urine, the germinal center and medulla are rapidly enlarged and the paracortical area is relatively decreased in the swollen lymph nodes after infection with the leptospira, and the plasma cells are increased in a large amount, showing obvious bone marrow-dependent lymphocytes (B cells). Proliferative response occurs in the immune response. When the hook body disappears from the blood, a specific immune response may occur, and the patient may develop fever, eye and nervous system complications, and other clinical manifestations related to hypersensitivity reaction. It has been proposed that the leptin toxin, the hook body adhesion, the leptin poisoning threshold, the organ hook content and other factors are theories that triggered the disease, but they have not been fully confirmed.
After the hook body invades the human body and causes infection, due to the different nature of the human body and the hook type and its toxic substances, the result of the interaction may be manifested as leptospirosis of different clinical types. In general, the virulence of the jaundice type is stronger. Infections such as autumn type, Australian type, and canine type are more likely to cause heavier clinical manifestations such as jaundice or hemorrhage; and cold and typhoid type, seven-day heat type, especially Pogner type and other weaker infections. , often cause leptospirosis, but the virulence of the jaundice type is more toxic, and there may be mild jaundice. Conversely, infections such as influenza typhoid can cause a certain degree of jaundice or bleeding. This may be related to the original immune status of the human body.
Different types of leptospirosis lesions are very different, and the degree of tissue damage in different cases of homologous leptospirosis is also significantly different. Compared with the pathological morphology of lung diffuse hemorrhage and jaundice hemorrhage, the main damage of these two types Organs and their basic pathological changes are inconsistent, but they also have common basic pathological changes.
Prevention
Leptospirosis prevention
It is the key to controlling the outbreak of leptospirosis and reducing the incidence of morbidity due to the implementation of mass comprehensive prevention measures in response to local conditions.
1. Eliminate and manage the source of infection
1 Eliminate the source of infection: fight against rodents and prevent diseases, kill rodents and protect the masses. The rodents are the main storage hosts for leptospirosis. In some areas, the prevalence of rats is as high as 48.7%. Therefore, it is necessary to take drugs and equipment according to local conditions. Anti-rat measures such as ecology (burrowing, filling holes, filling holes) to control the number and density of rodents.
2 Management of infectious sources: combined with "two tubes" (tube water, tube dung), "five changes" (improved wells, toilets, livestock pens, stoves, environment), carry out the accumulation of pigs, so that the animal urine and feces do not flow directly into the vicinity Gully, pond, river, paddy field, prevent rainwater scouring, no need for fresh pig manure, use after composting and fermenting, strengthen the prevention and treatment of leptospirosis and quarantine work of exotic pigs, and use veterinary leptotomy vaccine in conditional areas. Vaccination is given to pigs, especially young animals, from April to May each year.
2. Cut off the transmission route, eliminate the infectious factors, the ponds, the water rafts, the muddy fields in the mountainous areas, the cold paddy fields are the places where rats often move, and they are often the main source of leptospirosis, which should be combined with the construction of farmland water conservancy to transform the above-mentioned nature. The source of the epidemic.
Regarding the treatment of infected water, in areas where conditions permit, the land will be drained and harvested one week before harvesting the rice fields without affecting agricultural production. Combined with the specific conditions of agricultural time and water quality, there are plans and purposes. A variety of chemical fertilizers and pesticides are applied in the area. In some areas, 15 kg of lime nitrogen is applied per acre per season. The application time is better in 7 to 10 days before transplanting every year. In recent years, the prevalence of leptospirosis has been significantly reduced, and fertilizers are widely used. , changing the environmental conditions for the survival of the hook body in vitro, may have a certain relationship, children in the epidemic area of the disease, the popular season, do not fish in the pond, ditch, swimming, play, in the popular pit of the disease, the work of the sewer Workers and pig farms, slaughterhouse workers should wear rubber boots and rubber gloves to protect the skin from hooks.
3. Preliminary experience of drug prevention at home and abroad. In the epidemic areas of leptospirosis, during the epidemic season, oral doxycycline 0.2g/week for susceptible people, the effect is good, and it is simple and easy, especially in the prevention of uninoculated vaccines. The district acts as an emergency preventive measure when an outbreak occurs.
4. Enhance the body's resistance and protect susceptible populations. According to the main epidemic strains in the region, phenol-inactivated leptospirillum vaccines are prepared. At present, many chemical-integrated media without serum or other proteins are used in China or without rabbit serum. A semi-integrated medium with a small amount of albumin, cheese or human placenta tissue fluid. The vaccine has a trivalent price (eg, jaundice hemorrhagic type, autumn type, other local plant type), and 5 price (jaundice type, canine type, cold typhoid type) , Pomona type, autumn type or Australian type), the trivalent vaccine is mostly common bacterin (about 200 million / ml), can also be made into concentrated bacterin (about 600 million / ml) The 5-valent vaccine can also be made into two kinds of ordinary and concentrated, and the human body can produce immunity against the same type of hook, which is maintained for about 1 year.
(1) Inoculation target: In key epidemic areas, in addition to contraindications, injections should be carried out. In general epidemic areas, mainly in the lower paddy fields or in wet areas, especially in harvesting, transplanting, flood control, flooding and reclamation. Personnel in the wasteland, cadres and workers who participate in supporting agriculture when they are busy, livestock breeders, slaughters, sewers and mine workers, and rural children should be vaccinated.
(2) Inoculation time: The first month of the lepidosis epidemic season is completed, usually at the end of April or early May.
(3) Inoculation dose: 1ml subcutaneous injection of the first time, the second time, subcutaneous injection of 2ml at intervals of 7 to 10 days, children halved by the amount of adults, but must be injected twice, and then injected twice a year, the same dose.
Complication
Leptospirosis complications Complications Myocarditis hemolytic anemia anterior uveitis encephalopathy
Complications include diffuse hemorrhage of the lungs, myocarditis, hemolytic anemia, and renal failure.
Symptom
Symptoms of leptospirosis common symptoms jaundice bleeding tends to urinary meninges irritation symptoms relaxation heat convulsions chills fatigue hemoptysis irritability
symptom
The incubation period is 2 to 28 days, usually about 10 days.
1. Early stage of leptospirosis, usually within 3 days after onset, has the following main symptoms and signs.
(1) Fever: Most patients have acute onset, accompanied by chills and chills. A few patients may have weakness, fatigue, and fever in the first or two days before fever. Some patients have relaxation heat, body temperature is 39 °C up and down, heat The process is about 7 days, and it can reach 10 days. The pulse rate is often increased.
(2) headache, body pain: headache is sometimes very prominent, until the recovery period still complains of dizziness, headache, body muscle soreness, some patients have neck, knees, thighs, even chest, abdomen, back muscles are painful.
(3) general malaise: especially the leg is soft, sometimes it is difficult to move or can not stand and get out of bed.
(4) Conjunctival hyperemia: appeared in the early stage of the disease, and then rapidly increased. The severe conjunctiva was completely congested except for the cornea. The entire conjunctiva was red or pink. The small blood vessels were interwoven into a fine mesh, sometimes with subconjunctival hemorrhage. But without secretions, pain or photophobia, congestion persists after heat withdrawal.
(5) Gastrocnemius pain, tenderness: It can appear on the first day of onset. The lighter only feels the calf swelling, the mild pain of the pressure, and the severe calf pain is as sharp as a knife cut, can not walk, light pressure is pain, even refuse press.
(6) lymphadenopathy: generally appear on the 2nd day after the onset of the disease, more common in the inguinal lymph nodes, followed by the axillary lymph nodes, usually large soybeans or broad beans, such as large eggs, large surface, soft, there are It is tender, but there is no redness and no pus.
In addition, other symptoms and signs may appear in the early stage of the disease, such as sore throat, cough, pharyngeal congestion, tonsil enlargement, small bleeding points in the pharyngeal mucosa, nausea, vomiting, diarrhea and other symptoms in the digestive tract. Hemolytic anemia, toxic psychotic symptoms or toxic myocardial symptoms may occur.
The symptoms and signs of early leptospirosis described above are early manifestations common to each of the following major clinical types.
2. The mid-term symptoms are obvious, mainly the manifestations of injury of various organs, generally 3 to 10 days after onset, according to the common clinical types, respectively.
(1) Leptospirosis type: formerly known as "cold typhoid type", the clinical manifestation of this type is the continuation of symptoms and signs of early leptospirosis, no obvious symptoms of organ damage, and light weight of leptospirosis The natural process is generally 5 to 10 days, with an average of about 7 days. The body temperature of the light body of the hook is often below 38.5 °C, the signs are not obvious, and there is basically no bleeding tendency (individuals may have nosebleeds), such as the general "cold" Symptom group, some heavier patients, have obvious bleeding tendency, may have skin blemishes, ecchymosis, conjunctival hemorrhage, occasional venous bleeding, and some serious patients, formerly known as gastrointestinal shock patients, have varying degrees Gastrointestinal symptoms, such as nausea, vomiting, diarrhea, urgency and weight, diarrhea, usually less than 10 times a day, mainly with loose stools or watery stools, a small number of mucus, but no pus, no stench, not much, a few solutions Asphalt-like or black stools may be accompanied by hypotension or severe shock, while the typical signs of leptospirosis are less obvious.
(2) Pulmonary hemorrhage type: In addition to the initial symptoms of leptospirosis, there may be several different blood stasis or hemoptysis. Chest X-ray films often show different degrees, different ranges of bleeding points, small pieces or large pieces of fused shadows. According to the depth and breadth of chest X-ray hemorrhage lesions, especially the presence or absence of acute respiratory and circulatory dysfunction, clinically can be divided into common lung hemorrhage type and diffuse hemorrhagic type of lung, a few pulmonary hemorrhage type have blood stasis, hemoptysis Compared with the obvious pulmonary X-ray hemorrhage, but no obvious acute respiration, circulatory dysfunction, it is actually an intermediate transition type, but it is generally considered as a pre-treatment of diffuse hemorrhage in the clinic.
1 common pulmonary hemorrhage type: the clinical manifestations are similar to the disease of the disease, only with varying degrees of blood stasis or hemoptysis, chest signs are not obvious, chest X-ray film only mild (point or striated increase) lesions , no longer develop, but if the treatment is not appropriate, especially after the occurrence of the Ya-Her reaction, it can be quickly converted into a diffuse type of lung.
2 diffuse hemorrhagic type of the lung: formerly known as "pulmonary hemorrhage type", pulmonary hemorrhage hypoxia, asphyxia is a characteristic of this type, patients with diffuse hemorrhage of the lungs accompanied by progressive breathing, cardiac circulatory failure and other hypoxia, asphyxia performance Although the hemoptysis is little or not hemoptysis, the prognosis is very serious. Because the lung damage of leptospirosis can be a progressive, extensive intrapulmonary hemorrhage, not necessarily all of a large number of hemoptysis, so "diffuse hemorrhage The name should be more appropriate than the "pulmonary hemorrhage type".
Diffuse pulmonary hemorrhage is a common cause of death caused by jaundice-type leptospirosis in recent years. It is clinically rapid and rapid development, but it is still abruptly deteriorated on the basis of gradual changes. This type has not been injected in recent years. Adolescents, pregnant women or other susceptible people with body bacterin, 2 to 5 days after the illness, the patient did not rest well or continue to participate in strong physical labor, no effective antibiotics before the treatment, emotional over-stress after the illness, etc. This type can be divided into three phases:
A. Aura: The patient is pale, individual short-term flushing, palpitation, irritability gradually increases, breathing, heart rate increases progressively, the lungs gradually appear breathing tone thickening, followed by dry voice or limited wet voice, sometimes Hematemesis or hemoptysis, X-ray chest film showed increased lung lines, scattered spots or small pieces of fusion.
B. Extreme period: If the patient is not treated promptly and effectively, the patient in the aura period will have extremely pale or grayish complexion, lip cyanosis, palpitation, rapid increase in irritability, rapid increase in heart rate, and weakened first heart sound within a few hours. In the case of galloping horses, the lungs are covered with wet squeaks, and the hemoptysis is significantly increased or continuous. A few patients may not have hemoptysis. The X-ray chest radiographs have extensive patchy shadows or large fusions.
C. dying period: If the patient still fails to control the disease in a timely and effective manner in the near future, the condition may be more serious within 1 to 3 hours or a little longer, the performance is extremely irritating, confusion, even coma, throat snoring, breathing Irregular or significantly slow, high in sputum; then the nose and mouth are not condensed bloody foam liquid, heartbeat slows down, and finally the heartbeat stops, the evolution of the above three periods, short hours, 12 to 24 hours, sometimes The third phase can not be completely separated. Occasionally, the patient who initiated the disease will have diffuse hemorrhagic lungs within 24 hours of onset. After a few hours, the patient will die due to the rescue. In the case of hemorrhagic jaundice, lung diffuse can occur. Bleeding, mostly in the jaundice bleeding orgasm, is generally not as dangerous as the development of no jaundice type, the cause is unknown.
(3) Hemorrhagic type of jaundice: This type is formerly known as external ear disease. It has become rare in China in recent years. The early stage is mainly symptomatic group of leptospirosis. However, during the course of 4 to 8 days, progressive jaundice, hemorrhage and renal function occur when body temperature begins to decline. Damage, some serious cases may be due to uremia, major bleeding or death due to hepatic encephalopathy; in some cases, when the jaundice appears, the symptoms of systemic poisoning gradually reduce, and enter the recovery period in a short period of time.
1 Astragalus and liver damage: Most cases have jaundice 4 to 8 days after the onset, and a few cases appear 2 days after the onset. The jaundice gradually deepens, reaching a peak in the course of 10 days, and the liver is mild to moderately swollen. Pain accompanied by pain in the liver area, some patients have mild swelling of the spleen, jaundice varies in depth, gradually reduced after 7 to 10 days, but bilirubin can also reach 400 ~ 600mol / L or higher, may be associated with skin itching Relatively slow veins, intractable hiccups, in general, most of the deep jaundice with obvious bleeding and renal failure, poor prognosis, liver failure in the 1950s reported about 10% to 20% of the deaths of this type, depth Patients with jaundice, if there is no serious change in liver function, and no obvious bleeding or kidney damage, the prognosis is better.
2 bleeding: common nosebleeds, skin, mucous membrane spots, ecchymosis, purpura, hemoptysis, hematuria, vaginal bleeding; hematemesis, especially gastrointestinal bleeding often caused by shock and death, a small number of patients can have diffuse hemorrhage or severe Adrenal hemorrhage shock and death.
3 Kidney damage: jaundice patients with hemorrhagic type almost all with renal damage, and this is an important cause of death, accounting for 60% to 70% of deaths, but kidney damage is different, lighter only a small amount of urine protein, Microscopic hematuria, a small amount of white blood cells, casts, etc., can appear in the late symptomatic group of leptospirosis, the course of disease tends to be normal within 10 days, and severe renal insufficiency occurs, mostly in the peak of jaundice, showing less urinary The urine color is dark yellow, the amount of protein in the urine is large, there is tube type, microscopic or gross hematuria, or no urine occurs, often lasting 4 to 8 days, sometimes up to 10 days, non-protein nitrogen, urea nitrogen in the blood, The increase of creatinine also peaks in the disease period about 10 days, and then gradually declines. Sometimes the renal insufficiency can occur as early as the jaundice bleeding, and it becomes more and more serious with the deepening of jaundice, and acidosis, uremia and even coma can occur.
(4) Renal failure type: simple renal failure type leptospirosis is extremely rare, a small amount of proteinuria occurs in the acute phase of leptospirosis, red blood cells, white blood cells or casts are common phenomena, such as proteinuria, hematuria and cast type Very obvious, and there is azotemia, but no jaundice, it is called renal failure type of leptospirosis, can appear oliguria, no urine, uremia, acidosis, coma and other clinical manifestations.
Patients with oliguria or anuria often occur in the first week of the disease, mostly after shock, and the duration varies from 10 days or longer in the elderly, and only 1 to 2 days in the short period. The prognosis is good. Most patients recover through oliguria, polyuria and recovery, leaving no residual damage. A few critically ill patients have oliguria, no urinary phase can be complicated with pulmonary edema, hyperkalemia, high phosphorus and low calcium. Symptoms, etc., may be due to hyperkalemia, uremia, acidosis, coma to death, in the polyuria period can be complicated by hypokalemia, lung and urinary tract infections.
(5) Meningoencephalitis type: Generally, after several days of onset of leptospirosis, meningeal irritation symptoms, such as severe headache, irritability, lethargy, unconsciousness, convulsions, convulsions and other symptoms of encephalitis, severe coma, convulsions, Acute cerebral edema, cerebral palsy and respiratory failure, cerebrospinal fluid examination pressure increased, protein increased, white blood cell count is generally within 0.5 × 109 / L, lymphocytes, sugar normal or slightly reduced, chloride more normal, cerebrospinal fluid separation The positive rate of the leptospira is higher, and the meningitis group is mainly called meningitis. The disease is mild and the prognosis is good. The encephalitis or meningoencephalitis is the main group, called encephalitis or meningeal brain. Inflammatory type, the general condition is heavier and the prognosis is poor.
In the development of leptospirosis, sometimes the above types can not be completely divided, and the main symptoms of each type can be transformed or coexisted at the same time. For example, diffuse hemorrhage of the lung or symptoms of meningitis can also occur in other types.
3. Late
For the recovery period or the late onset period, usually after 10 days of onset, most patients gradually disappear after heat retreat and tend to heal. A few patients have fever for about several days to three months or longer. During the time, symptoms can reappear, which is called after-onset. The more common ones are the following.
(1) Post-fever: After the acute fever is treated or naturally decreased, the fever reappears, generally more than 1 to 5 days after the normal temperature drop, most of them are around 38 °C, but whether or not treated with penicillin, it can be 1 ~3 days of fever, about half of patients with peripheral blood may have eosinophils, sometimes accompanied by meningitis, iridocyclitis, sputum fever, etc., can also occur in the continuous treatment of penicillin, with penicillin dose, The course of treatment has little to do.
Very few patients, after the onset of 18 days, after the fever, the third fever, 3 to 5 days of natural regression, post-heat is mainly related to the body's delayed hypersensitivity reaction, but it may also be a short-term recurrence.
(2) After-eye symptoms: The after-eye condition is common in the northern part of China. The disease is rare in the south, which is mainly related to the epidemic flora. The northern part is mainly populated by the Pomona group, but the jaundice bleeding group can also cause eye. The onset of symptoms is more than 1 week to 1 month after the acute phase of fever. It can be manifested as scleral inflammation, retrobulbar optic neuritis, vitreous opacity, uveitis, etc., but uveitis is common.
1 iris ciliary inflammation: manifested as visual impairment, eye pain, photophobia, tearing, etc., examination can be seen ciliary body congestion, pupil diminution, slow response or disappearance of light, aqueous humor, post-iris adhesion, ciliary tenderness , vitreous turbid and so on.
2 choroiditis: mainly due to visual impairment, sometimes can feel black spots floating in front of the eyes, or visual center dark spots, examination can be found retinal vein filling, retinal edema and exudate, optic disc congestion and blurred boundaries, vitreous opacity.
3 uveitis: both iridocyclitis and choroiditis, most of the disease is heavier, long delay, vision often have serious obstacles, can be reduced to below 0.1, the pupil is not easy to expand, the vitreous opacity is also heavy, thus It is quite difficult to check the fundus.
Examine
Examination of leptospirosis
1. Routine examination of the total number of white blood cells and neutrophils slightly increased or normal, jaundice bleeding type often increased, total white blood cells > 20 × 109 / L or < 4 × 109 / L are rare, erythrocyte sedimentation rate continues to increase, jaundice bleeding type More significantly, early urine can have a small amount of protein, red, white blood cells and casts, which occur in about 70% of patients.
2. Pathogen examination
(1) Direct inspection of the hook body:
1 dark field microscopy: the hook body is not easy to color, and the unstained specimen hook body is usually difficult to see under the light microscope. With the dark field microscope, the shape and movement pattern of the typical characteristics of the hook body can be clearly seen. Examination of body fluids or hooks in tissues can provide a quick diagnosis, but it is not easy to check because the concentration of the hooks in the blood or tissues is too low ( 2 × 104 strips / ml), especially for human nature. Infection, on the other hand, due to the inexperience of the tester, it is easy to mistake other components such as fibrin as a hook, which is generally not suitable for promotion at the grassroots level, but is suitable for the examination of experimentally infected animals.
2 staining direct microscopic examination: silver plating method, complex red methylene blue staining method and Giemsa staining method.
(2) Separation and culture of the leptospira: In the early stage of leptospirosis, in the peripheral blood and cerebrospinal fluid within 1 week of the onset of leptospirosis, a considerable number of hooks appeared, so in this period, blood was inoculated into Koshof containing rabbit serum (Korthof). Or Fletcher (Fletcher) semi-solid medium, can grow slowly, generally more than 1 week, the positive rate is 30% to 50%, if you have used penicillin drugs, the medium can be added penicillinase, such as Fluorouracil (5-FU) can be added to the medium to selectively inhibit or kill the bacteria, and the culture is purified, but the proliferation of the leptospira can be slightly inhibited, and the urine culture can be positive in the late stage of the disease.
(3) Animal vaccination: Infant guinea pigs or golden hamsters are usually inoculated intraperitoneally, and are generally not used for routine application.
3. Serological tests After 1 week of onset, specific antibodies appear in the blood and can be determined by serological tests.
(1) Microscopic agglutination test (MAT): The microscopic agglutination test is referred to as the coagulation test. This test uses a live standard strain as an antigen, mixed with suspected patient serum, and observed under a microscope, if specific antibodies are present. , you can see the phenomenon of agglutination, a serum titer reached or exceeded 1 / 400, or early, late two serum comparison, a four-fold increase is diagnostic, this method is currently the most widely used leptin serology method First, it can be used to diagnose patients, and standard antisera can also be used for identification of hook strains.
(2) Enzyme-linked immunosorbent assay: domestic report using this method to detect leptospirosis serum-specific antibodies compared with the coagulation test, its sensitivity and specificity are higher than the commonly used coagulation test, but still can not be used Early diagnosis.
(3) Indirect red blood cell agglutination test: This method extracts an antigen component from the leptospira cells and adsorbs it on the surface of human O type red blood cells to sensitize red blood cells. If the same antibody is present, red blood cell agglutination occurs. Therefore, it is called indirect red blood cell agglutination test. This test has specificity and no group formation specificity. It is earlier than the positive coagulation test, easy to operate, and does not require special equipment conditions. It is suitable for grassroots promotion and application.
(4) Indirect erythrocyte lysis test: It is often used as a diagnostic method for leptospirosis in foreign countries. When fresh sheep red blood cells are sensitized with leptospirosis antigen, they are hemolyzed when mixed with serum containing antibodies in the presence of complement, and their sensitivity is higher. The indirect red blood cell agglutination test was high.
(5) Indirect fluorescent antibody method: This method is to first make the standard leptospirosis strain into a smear, and then drop the serum of the suspected patient on the sterilized slide, and wash it. If the patient has antibodies in the serum, the antigen and antibody are combined. Then, an anti-human globulin fluorescent antibody is combined with the complex to generate fluorescence, which is positive, and the method is non-specific.
(6) Complement binding test.
All of the above methods use specific antigens to measure specific antibodies in patients. As for the application of specific antibodies to determine in vivo antigens as an early rapid diagnosis of diseases, considerable progress has been made in recent years, especially for monoclonal preparation techniques. The application makes it possible to diagnose a small number of leptospirosis in early leptospirosis. With the development and application of molecular biology, the leptin DNA probe has been successfully prepared, and the early diagnosis of polymerase chain reaction has been successfully established. Leptospirosis, but these methods are used in clinical practice and need to be further improved and improved.
4. X-ray of the lungs: mildly visible reticular shadows of lung texture, or disordered lung texture, or significant lung texture thickening, often reaching the outermost edge of the lung field, extensive range of lesions, moderate lung image Small dots or small snowflakes, low density, blurred borders, some lesions can be fused into a sheet-like shadow of 1.5 to 2 cm in size, usually scattered, or confined to a certain area, severely in the above-mentioned point or snow On the basis of a small piece of shadow, there is a large fusion, which can occupy one or more leaves of the lung, most of which are unilateral or bilateral, mostly in the middle and lower lung fields, and the lung tip is less affected. The image is a large cloud-like density. The shadow, but there are still transparent areas formed by residual bubbles, which are different from the uniform negative image of general pneumonia.
The above lung images are seen in about 40% of patients with mild "heptospirosis", and in about 80% of patients with moderate and severe diffuse pulmonary hemorrhage, but there are also a few cases (such as the aforementioned intermediate type). X-ray changes in the lungs are not consistent with the clinical condition. The initial or mild changes in the X-ray of the lungs, if not treated promptly, can be rapidly developed into a wide-ranging, severe massive or whole-lung image of the lungs. After X-ray images are treated, most of them are completely absorbed within 5 to 10 days, and within 4 days or up to 3 weeks.
Diagnosis
Diagnosis and diagnosis of leptospirosis
The clinical manifestations of this disease are very complicated, so early diagnosis is difficult, easy to miss diagnosis, misdiagnosis, clinical diagnosis requires positive pathogen or serological test results, and these specific tests often take time, so in order to make a diagnosis, it is necessary Combined with epidemiological characteristics, early clinical features and laboratory tests, comprehensive analysis and identification with other diseases.
(1) The fever should be differentiated from other acute febrile diseases: typhoid fever, influenza, sensation, malaria, acute schistosomiasis, ascariasis, pneumonia, epidemic hemorrhagic fever, sepsis, etc., in addition to relying on clinical features, epidemiology The history of the disease, proteinuria and azotemia often provide important clues for differential diagnosis.
(2) Astragalus should be differentiated from jaundice hepatitis. Hepatitis is characterized by loss of appetite and other gastrointestinal symptoms. There is no ocular membrane hyperemia and gastrocnemius tenderness. The white blood cell count is normal or reduced. Liver function ALT and AST are abnormal, and CPK is not increased. Epidemiological history and serological tests can be identified.
(3) Patients with leptospirosis with nephritis and no jaundice need to be differentiated from nephritis. Leptospirosis has an acute infectious hot onset process, with conjunctival hyperemia, obvious myalgia, normal blood pressure, and no edema.
(4) Myalgia should be differentiated from acute rheumatic fever. The pain of acute rheumatic fever is more than the joint pain of the migratory joint, while the myalgia of leptospirosis is based on the gastrocnemius.
(5) Hemorrhage or hemoptysis can be differentiated from upper gastrointestinal bleeding, hematuria, leukemia, thrombocytopenia and aplastic anemia. It can be differentiated from hemorrhagic diseases by means of peripheral blood and bone marrow examination, GI examination, etc. Identification with tuberculosis, bronchiectasis, tumors, etc., by lung X-ray or CT examination.
(6) meningoencephalitis meningoencephalitis type leptospirosis and epidemic encephalitis B are popular in summer and autumn, no history of contact with water, no body aches, gastrocnemius tenderness, conjunctival hyperemia and lymphadenopathy, etc. Type of encephalitis is dangerous, convulsions, coma and other brain symptoms are more obvious than leptospirosis, urine routine, liver function is more normal.
