Infectious fever 1, respiratory viral infections This group of diseases accounts for 70%-80% of acute respiratory diseases. It is caused by rhinovirus, influenza virus, parainfluenza virus, adenovirus, respiratory syncytial virus, ECHO virus, coxsackievirus, etc.; its clinical features have a variety of manifestations, most of the symptoms of upper respiratory tract infection are mild while the symptoms of bronchitis and pneumonia are heavy. The diagnosis is mainly based on clinical manifestations, white blood cell count and X-ray examination and response to antibiotic treatment. In recent years, due to the progress of diagnostic technology, immunofluorescence and enzyme-linked immunosorbent assay (ELISA) rapid diagnostic methods can be used to determine the pathogen. Commonly there are influenza; common cold; adenopharyngeal conjunctival fever; herpetic pharyngitis; fine bronchitis; pneumonia, etc., which must be distinguished from respiratory bacterial infections. 2.Hemorrhagic fever with renal syndrome (HFRS) Main basis: ①Epidemiological data except Xinjiang, Tibet, Qinghai Taiwan Province and autonomous regions, other provinces and cities have been reported. Highly disseminated with obvious seasonality. Most areas (wild rodent type) have a pandemic peak in October-December, and some areas have a small epidemic in May-July brown house mouse type onset ≥ peak in March-May. History of direct or indirect contact with rodents and their excreta; ② clinical features, with fever hemorrhage, renal damage three main symptoms and five stages of the passage (fever, hypotensive shock, oliguria, polyuria, recovery X) ③ increased white blood cell count can have a leukemia-like reaction, 1 to 2 d after the disease appears anomalous lymphocytes (≥ 7%), thrombocytopenia proteinuria and short-term acute increase, if there are membranous material can be clearly diagnosed ④ Positive HFRS antibody IgM1:20, used for early diagnosis 1-2d after disease, positive rate of 4-5d is 89%-98%. Double serum HFRS antibody IgG with more than 4-fold increase in recovery period than early stage can also confirm the diagnosis. 3. Infectious mononucleosis caused by EBV, can be disseminated throughout the year, seen in adolescents characterized by fever, pharyngitis, enlarged lymph nodes behind the neck enlarged liver and spleen. White blood cell count is normal or slightly low, monocytes are elevated and accompanied by heterogeneous lymphocytes (>10%) positive eosinophilic agglutination test 1:64 and positive anti-EBV IgM, which can be clearly diagnosed. 4. Epidemic B encephalitis is strictly seasonal, with the majority of cases concentrated in July, August and September. The predominance of children under 10 years of age, with a higher incidence in adults and the elderly in recent years, may be related to the widespread vaccination of children. It is characterized by rapid onset, high fever and impaired consciousness, convulsions, signs of meningeal irritation, and abnormal cerebrospinal fluid. In combination with the epidemic season, the diagnosis is generally easy, and atypical cases rely on cerebrospinal fluid examination, epidemic B encephalitis-specific antibodies, and epidemic B encephalitis virus antigen testing for diagnosis. 5, acute viral hepatitis A, hepatitis E in the yellow value of the first, can appear chills and fever, accompanied by symptoms of upper respiratory tract infection, similar to influenza easy to misdiagnose. But characterized by obvious gastrointestinal symptoms and weakness, such as lack of appetite nausea. Vomiting, aversion to oil abdominal distension. Pain in the liver area, yellow urine liver function is clearly abnormal to help distinguish. 6, typhus Mild epidemic typhus and endemic typhus must be distinguished from other febrile diseases. The main manifestations are rapid onset, retention type high fever, severe headache, rash after 3-5 d. OX agglutination test, Fei test positive or recovery period antibody titer than the early titer increased by more than 4 times can confirm the diagnosis. 7 Acute focal bacterial infections Common features of these diseases are high fever, chills or chills with locoregional symptoms 1) Acute renal meningitis: common in female patients in their reproductive years, with back pain, frequent urination and painful urination such as urine examination with pus, can establish the diagnosis, the etiological diagnosis is pending confirmation of bacterial culture severe symptoms, attention should be paid to differentiate from perirenal cellulitis, perirenal ten timely B-type ultrasound or CT If necessary, diagnostic aspiration of the renal area should be performed. If necessary, diagnostic aspiration of the renal area can clarify the diagnosis. (2) Acute biliary tract infection with biliary colic: If it is not obvious, but there is obvious pressure pain in the gallbladder area on physical examination can help to diagnose. 3) Bacterial liver abscess. 4) Subdiaphragmatic abscess: usually complicated after abdominal surgery or with purulent abdominal infection, acute appendicitis X duodenal ulcer perforated gallbladder or splenectomy. When chills, high fever and increased leukocytes are present and no other foci of infection are found, the disease should be thought of as being more common on the right side, with significant pulsating pain in the upper abdomen on the affected side, aggravated by deep breathing or inversion, and pressure percussion pain and local skin edema in the lower chest. On auscultation, the respiratory sound is weakened or disappeared; X-ray examination reveals rising and restricted activity of the affected septum, reactive pleurisy, etc.; timely examination by ultrasound, CT or MRI can clarify the diagnosis at an early stage. (5) Intra-abdominal abscesses may be located in the subdiaphragmatic paracolic colon, around the appendix, retroperitoneum and other parts of the body to form an encapsulated abscess. 8 Sepsis Diagnosis is facilitated in the presence of a primary focus of infection with signs of systemic sepsis and multiple migrating abscesses. One should be alert to the fact that the primary foci of infection can be very mild or have healed. Therefore, when encountering an acute high fever of unknown origin, accompanied by chills or chills and sweats, with heavy symptoms of systemic toxicity, increased white blood cells and nuclear left shift in the blood without parasites found, without special symptoms and signs, the disease should be considered to do blood cultures in time to find foci of infection and migratory lesions (lung, skin, etc.) The causative organisms are Staphylococcus aureus as the most common, followed by Escherichia coli and other intestinal gram-negative bacilli. In recent years, there has been an increase in fungal causes and rare pathogenic organisms have been encountered. (1) Staphylococcus aureus sepsis: there is a high probability of primary skin infection (e.g. extrusion of sores incising immature abscesses), followed by symptoms of toxemia and migratory lesions of the rash, to consider this disease. The diagnosis is more difficult if no foci of infection are found or if symptoms of damage to a particular organ are predominant. Timely blood culture and bone marrow culture can clarify the diagnosis Previously, it was thought that positive coagulase was the basis for determining the pathogenicity of Staphylococcus, and positive blood culture of Staphylococcus epidermidis (coagulase negative) was mostly contaminated. In recent years, it has been reported that the organism can cause nosocomial infections (e.g., wound infections, intubation infections, and sepsis) in immunodeficient individuals. The conditions for consideration of this disease are: blood culture must be positive for more than 2 times; isolated Staphylococcus epidermidis with similar biotype and antibiotic type; clinical symptoms improve after treatment with appropriate antibiotics (2) E. coli sepsis: common in liver and biliary tract, genitourinary tract, gastrointestinal tract infections cirrhosis, after abdominal surgery, after urethral surgery (including catheterization) characterized by bimodal fever, hyperthermia with relatively slow pulse, early onset of shock (about l/4-1/2 patients) and long duration Most leukocytes are elevated, a few may be normal or reduced (but neutrophils are high). Migratory lesions are rare (3) anaerobic sepsis: the main causative organism is Bacteroides fragilis followed by Streptococcus anaerobicus P. aeruginosa. Anaerobic bacteria are often mixed with aerobic bacteria. Characterized by a high incidence of jaundice (10%-40%) may be related to its endotoxin direct damage to the liver, and/or the hemolytic effect of P. aeruginosa a toxin; local or migratory lesions with gas formation (significant with P. aeruginosa); secretions have a special putrid odor; cause septic thrombophlebitis and abdominal, pulmonary thoracic, brain, endocardial Bone and joint abscesses; may have hemolytic anemia and renal failure. (4) fungal sepsis: commonly have Candida albicans (most of) Aspergillus, Trichoderma, etc.. Generally occur in the process of long-term use of corticosteroids or broad-spectrum antibiotics in the late stage of the original serious disease. Bed manifestations are less severe than bacterial sepsis. No fever or low fever is often masked by the symptoms of the original disease progresses more slowly. Blood culture can detect pathogenic fungi, pharyngeal swab sputum, feces, urine and other cultures can be obtained the same fungal growth (5) rare sepsis: such as Moraxella sepsis is common in immunodeficient children under 6 years of age, the key to diagnosis is the identification of Moraxella. Inactive bacillus sepsis is most common in the elderly and infants especially diabetic, cancer patients are most susceptible to nosocomial infections, the source of infection is mainly respirator intravenous cannula and the hands of health care workers. Purple bacillus sepsis, the causative agent is gram-negative bacillus is the only bacillus that produces purple pigment, can enter the body through skin breaks, gastrointestinal tract respiratory tract, local lymphadenitis, cellulitis can develop rapidly into sepsis, can be accompanied by migratory abscess, the main rely on bacteriological examination to confirm the diagnosis