Cangworm disease

Introduction to tsutsugamushi Ascariasis is also known as the jungle type typhus, or red worm disease. The main cause of the disease is an acute fever infected by the bite of aphid larvae with rickettsia. In general, mice are the most common host of aphids. The incubation period of tsutsugamushi disease is about 9 to 12 days. The main clinical symptoms are: the formation of a special painless cavernous eschar in the cheek; high fever (39 °C or even 40.5 °C); local lymph gland inflammation and swelling; 4-5 days from the onset of the disease, the trunk first appears red rash and then spread to the limbs and face, about 9-10 days of disease will fade; often accompanied by headache, sweating, conjunctival congestion, coma, terminal heart failure, shock And other symptoms. is the vector of the disease. In China, it has been proven that it can spread dozens of cockroaches in the field and use it as the main medium of transmission of red fiber. live in the warm and wet jungle green field, the bank of the lakeside, these areas of the rodent sneak, larvae larvae infected with mites in the oriental body of the rat body fluid, the pathogens in the larvae reproduction, sputum, childish Insects, adults and eggs are passed on to the second generation of larvae. The larvae then bite the rats and dye them, so that they circulate and form a natural foci. Therefore, cockroaches are not only the vector of the disease, but also the original storage of the tsutsugamushi oriental body. Host. People are infected by being bitten by larvae entering the woodland. The larvae are parasitic only, and the rest of the life is self-employed. At the end of the year, only the body fluids of humans and animals are sucked once, but since the pathogens can pass the larvae through the eggs, the mites are transmitted after the infection. Second generation larvae. basic knowledge The proportion of illness: 0.0005%-0.0007% Susceptible people: no specific population Mode of infection: contact spread Complications: edema

The cause of tsutsugamushi disease

Cause of disease

1. Source of infection

Rats are the main source of infection. In the south of China, the yellow-haired rat and the brown rat are the main ones, while in the north, the black-lined mouse and the squirrel are the main ones. The murine is asymptomatic after infection, but the pathogen can exist for a long time in its internal organs and is therefore the main storage host of the disease. In addition, rabbits, pigs, poultry, birds, etc. can also be infected or carry sputum, so it can also be the source of infection and storage host. It is only an accidental phenomenon that a person is bitten. Although the pathogen appears in the blood after being infected, it is of little significance as a source of infection.

2, the route of transmission

is the vector of the disease. In China, it has been proven that it can spread dozens of cockroaches in the field and use it as the main medium of transmission of red fiber. live in the warm and wet jungle green field, the bank of the lakeside, these areas of the rodent sneak, larvae larvae infected with mites in the oriental body of the rat body fluid, the pathogens in the larvae reproduction, sputum, childish Insects, adults and eggs are passed on to the second generation of larvae. The larvae then bite the rats and dye them, so that they circulate and form a natural foci. Therefore, cockroaches are not only the vector of the disease, but also the original storage of the tsutsugamushi oriental body. Host. People are infected by being bitten by larvae entering the woodland. The larvae are parasitic only, and the rest of the life is self-employed. At the end of the year, only the body fluids of humans and animals are sucked once, but since the pathogens can pass the larvae through the eggs, the mites are transmitted after the infection. Second generation larvae.

3, crowd susceptibility

People are generally susceptible to this disease. Those who work in the field, have more exposure to jungle weeds, and young adults have a higher incidence due to more exposure opportunities. After the disease, the immunization against the same strain of pathogen can be obtained, and the immunity to the different strains can only be maintained for several months, so the infection can be re-infected.

Pathophysiology

The pathogen invades the human body from the bite, first propagates in the local tissue of the bite, causing local damage, and then enters the bloodstream through the lymphatic system, forming the tsutsugamushi disease, and the pathogen in the bloodstream is infiltrating the vascular endothelial cell nucleus. And phagocytic cells grow and multiply, producing toxin cathodes for deep toxic symptoms and multiple organ lesions. The pathogenicity of Orientia tsutsugamushi to the human body is affected by the pathogen itself and the two methods of the body. The former mainly refers to the difference of the invading pathogen strain (the virulence of different strains), while the latter is mainly the reactivity of the organism. Patients with poor non-specific and specific immune response are more severe). The basic principle of the disease changes to systemic small vasculitis, inflammation around the blood and phagocytic proliferation. The local skin that is bitten is first congested, edema, forms a small papule, and becomes a small blisters. The central blisters are necrotic and hemorrhagic, forming a round or elliptical black suede called an eschar. The sputum can be found to be ulcerated. The lymph nodes near the eschar or ulcer are swollen and can be accompanied by swollen lymph nodes. The internal organs are generally congested, and the liver and spleen are swollen due to hyperemia and phagocytic hyperplasia, and focal or diffuse myocarditis, hemorrhagic pneumonia, interstitial nephritis and lymphocytic meningitis may occur.

Ascaria prevention

1. Elimination of infectious source rodent control is the main measure, patients do not have to be isolated, and contacts are not quarantined.

2, cut off the route of transmission to improve environmental sanitation, in addition to weeds, eliminate the breeding ground. For field operations, insecticides can be sprayed to eliminate cockroaches.

3, personal protection in the popular season to avoid sitting, lying, drying clothes on the grass. In the wild area of the popular area, in order to prevent bites, the sleeves and the trousers should be tightened, and the repellent such as 5% phthalic acid can be applied to the exposed skin. There is currently no practical use of tsutsugamushi vaccine.

Ascariasis complications Complications edema

The local skin that is bitten is first congested, edema, forms a small papule, and becomes a small blisters. The central blisters are necrotic and hemorrhagic, forming a round or elliptical black suede called an eschar. The sputum can be found to be ulcerated. The lymph nodes near the eschar or ulcer are swollen and can be accompanied by swollen lymph nodes. The internal organs are generally congested, and the liver and spleen are swollen due to hyperemia and phagocytic hyperplasia, and focal or diffuse myocarditis, hemorrhagic pneumonia, interstitial nephritis and lymphocytic meningitis may occur.

Symptoms of tsutsugamushi Common symptoms Lymph node swelling, chest pain, cold war, conjunctival congestion

The incubation period is 4-21d, usually 10-14d. The onset of rapid onset, body temperature rises rapidly, can reach 39-40 in 1-2d, mostly relaxation heat type, occasionally chills or chills, often accompanied by headache, body aches, loss of appetite and other symptoms. Signs may have facial and neck and chest flushing, conjunctival hyperemia, eschar or ulcerated lymph nodes, rash, hepatosplenomegaly and so on. After the second week of the disease, the condition is often aggravated, and the manifestations of the nervous system may have nervous apathy, hearing, convulsions, even convulsions or coma, and may have meningeal irritation; the circulatory system may have fast heart rate, weak heart sound, heart rate disorder, etc. Myocarditis manifestations; respiratory system can have cough, shortness of breath, chest pain, two lungs and other pneumonia. A few can have a wide range of bleeding. After the third week, the patient's body temperature gradually decreased to normal, the symptoms were alleviated to disappear, and gradually recovered. However, if effective pathogen treatment is not obtained in time, some patients die seriously. The virulence of the oriental strains of the tsutsugamushi disease in the north and south of China is different from that of the southern summer type tsutsugamushi, while the northern autumn and winter type is lighter.

The incubation period is 6 to 18 days with an average of 10 days. Acute onset, chills, high fever, headache, conjunctival congestion, and a red pimples appear in any part of the body. The papules are enlarged, and the central necrosis is crusting and is anxious. With the maturity of the eschar, the patient has sudden headache, fever and chills, and there are blisters on the top of the body. After a few days, it is dry and has no symptoms of black eschar. On the fifth day of fever, dark red macules and maculopapular rash appeared in the body. The trunk usually showed a moderate enlargement of the whole body lymph nodes within a few days, especially in the lymph nodes of the primary lesion drainage area. The liver and spleen are also swollen and tender. Unlike other rickettsial diseases, the disease is progressively elevated in fever, with relatively slow pulse and easy to develop pneumonia. In the next few days, these symptoms are more aggravated, and the body temperature is also increased, which is more due to the large variation of the rickettsial antigen of tsutsugamushi disease. This disease is often prone to recurrence.

In the next few days, these symptoms are even worse, and the body temperature is also increased. If not treated, it can be trapped in stupor or meningeal encephalitis. Cardiac dysfunction, including mild ECG changes such as once atrioventricular block, T wave inversion. The rash appeared on the first weekend and was a faint reddish rash of rash, first seen in the trunk and then on the limbs.

At the end of the first week of the examination, the systemic lymph nodes were swollen, and the spleen was sometimes affected by the liver. Although interstitial pneumonia is seen in the chest radiograph, there is often no change in lung examination. Patients with myocarditis may hear galloping, bad heart sounds, and systolic murmurs. Untreated cases can be found in different signs of cranial nerve loss, such as deafness and difficulty in swallowing, but in addition to deafness may last for several months, 87 cases (unimmunized) of the colonic typhus in Vietnam. Soldiers have symptoms of fever and headache, 46% have eschar, and 35% have rash. 85% of patients with generalized lymphadenopathy. Many people are misdiagnosed as infectious mononucleosis, and it is not the same as laboratory tests for early leukopenia. Later, it increases to normal levels. Coagulation disorders also occur, but only occasional disseminated intravascular coagulation syndrome occurs. Increased liver enzymes reflect liver cell damage. Proteinuria is common. The heat history of untreated cases is about 2 weeks, followed by the recovery period, which lasts for 4 to 6 weeks. Due to a large number of rickettsial antigens of tsutsugamushi. This disease is often prone to recurrence.

Locust disease check

Laboratory examination: laboratory tests for early leukopenia, and later increased to normal levels of coagulopathy, but the occurrence of disseminated intravascular coagulation syndrome is only occasional. Increased liver enzymes reflect liver cell damage. Proteinuria is common.

Other ancillary examinations: Pathological tsutsugamushi Oriental primordial invasion of endothelial cells causes vasculitis. The serious lesions of untreated cases are mainly myocarditis, meningoencephalitis and pneumonia. Coagulopathy is also present, but not as severe as RMSF and typhus. Papular lesions occur at the bite, and ulceration is accompanied by localized and followed by systemic lymphadenopathy.

Diagnosis and identification of tsutsugamushi disease

General diagnosis : Diagnosis is difficult due to different clinical manifestations. According to eschar and rash, rickettsial disease should be thought of, but less than half of the patients have this syndrome and eschar and rash can also suggest other rickettsia infections, such as typhus and typhus. The jungle typhus epidemic area and whether the patient has traveled or worked in such an infected area is an important epidemiological information. Cases suspected of being plague typhus should be treated with tetracycline or chloramphenicol. After taking the medicine, the fever should be given within 48 hours. The disease is characterized by primary lesions at the bite. On the 5th day of the fever, there is a rash on the whole body and it is easy to resolve. The course of disease was about 2 weeks, and the agglutination reaction of Proteus OX-K strain was positive at the 2nd weekend. Indirect immunofluorescence detects specific antibodies and allows for diagnosis. Specific serological tests revealed a significant increase in IFA (>4 fold) from duplicate serum samples separated by 2 weeks. Proteus OX-K antigen test is simple and easy, and the cost is low, so it is often used in infected areas. Approximately 50% of cases reach diagnostic titer. According to Malaya, the sensitivity and specificity of the two trials are about equal, but both are applied at the same time, and the practical value is greater. The tsutsugamushi oriental corpuscle can be isolated by inoculating the patient's blood into the abdominal cavity of the mouse. Rickettsia can be detected from mouse tissues.

Differential diagnosis : should be differentiated from other typhus typhoid according to its specific clinical location and serological response, it should not be difficult to identify.

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