Sepsis is a common complication after severe trauma (burns), shock, infection, and major surgical procedures, and is a syndrome of systemic inflammatory response with infectious factors. Sepsis can further develop into infectious shock and multi-organ dysfunction syndrome (MODS), which is a syndrome of simultaneous or sequential damage to more than two organs to failure (or sequential occurrence of multiple organ dysfunction not directly related to the original disease damage), with a high morbidity and mortality rate. The research on sepsis is progressing, but the incidence and mortality rates remain high, with some reports of 28% to 56%. Infections caused by non-common pathogens are special infections. The occurrence of sepsis in special infections is more difficult to treat than ordinary sepsis and has a higher morbidity and mortality rate. And there is a risk of causing occupational exposure and nosocomial outbreak of infection. 1.Definition 1.1 Definition of infection: The disease caused by the spread of disease and epidemic is said to be infectious. Modern medicine refers to the invasion of pathogens from diseased organisms to other organisms. 1.2 Definition of infection: Infection refers to the invasion of pathogens into the body and their multiplication in the body, resulting in different clinical manifestations. Many microorganisms are present in the skin, gastrointestinal tract and other parts of the human body, which coexist with humans, and they can cause infections only under certain specific conditions. These microorganisms that live in various parts of the human body are not pathogenic in a normal state. Infections occur when surgical procedures or trauma cause these microorganisms to translocate and enter otherwise sterile body cavities, or when local and systemic immunity is reduced. 1.3 Definition of special infections: Infections caused by non-ordinary pathogens are called special infections. Special infections can be divided into three categories: (1) general sterilization methods can not inactivate the pathogenic infection. For example, tetanus and gas gangrene, the pathogen can not be inactivated by ordinary sterilization methods, the infected organism can release toxins, causing strong systemic symptoms of toxicity. (2) Extensively drug-resistant pathogenic infections. For example, superbug infections that are resistant to various antibiotics. (3) Infection by pathogens that are combined with infectious diseases. 2 .Pathogenesis of sepsis The pathogenesis of sepsis is complex and involves many issues of infection, inflammation, immunity and tissue and organ damage. When bacteria invade the body, the body’s immune system is activated by bacterial exotoxins and endotoxins, which trigger the production and release of inflammatory cytokines such as tumor necrosis factor (TNF) and multiple interleukins (ILS), causing a systemic inflammatory response in the body as a way to control and eradicate the infection. However, once this process of systemic anti-inflammatory compensatory response is out of control, it causes extensive damage to vascular endothelial cells and other cells, which in turn causes tissue factor expression to initiate coagulation mechanisms, thrombomodulin depletion, and decreased levels of protein C activation, leading to microvascular thrombosis and tissue hypoxia, ultimately causing multi-organ insufficiency and death. Surgical infections mostly have clear causes, such as infection of the surgical area cavity, surgical incision infection, and open wound infection. They are usually easy to detect, but sometimes no foci of infection can be found and no bacteria can be cultured in the blood, while the signs and symptoms of systemic infection are obvious and difficult to explain. It has been demonstrated that endogenous intestinal bacterial translocation is often the cause of infection, and bacteria or bacterial toxins (mainly endotoxins of gram-negative bacteria) enter the portal vein, hematogenous dissemination, directly or through cytokine mediation, stimulating the release of more cytokines and mediators from hepatic sinusoidal endothelial cells, Kupffer cells, etc., further aggravating SIRS. bacteria can migrate through the intact intestinal canal to the peritoneal cavity, leading to peritonitis . Bacterial translocation is due to the weakened intestinal barrier function, which in turn increases intestinal mucosal permeability during acute critical illness due to hypoperfusion of the intestinal mucosa, and possible excess reperfusion injury, causing movement of bacteria and toxins in the intestinal canal through the mucosa to the microvasculature and lymphatic vessels of the intestinal wall. Therefore, the dysfunction of the intestinal tube itself is the primary cause of the weakened barrier. In the course of subsequent development, the infection and its accompanying SIRS and MODS become increasingly severe. Severe sepsis leading to severe SIRS becomes a prelude to MODS due to the release of large amounts of cytokines or mediators such as TNF-α, prostaglandin E2 (PGE2), and thromboxane A2 that can trigger infectious hypotension or shock, which leads to inadequate organ perfusion. In other acute critical illnesses that do not start with bacterial involvement, such as acute necrotizing pancreatitis, massive burns, and severe open injuries, bacterial infection originating from the gut is often inevitable if SIRS develops out of control. The pathogenesis of sepsis is approximately the same if the infection is caused by a non-common pathogen. However, due to the difference of pathogens, the treatment effect and prognosis can be very significantly different. 3.Treatment of special infection sepsis 3.1 Basic treatment: The basic treatment of sepsis includes traditional measures to strengthen the monitoring of vital organs such as heart, lungs and kidneys, rational and effective use of antibiotics, maintenance of hydrophobic mediators and acid-base balance, nutritional support and metabolic conditioning, etc. Various measures for adjustment of cytokines and mediators are also being studied and tried, mainly two methods of purification and antagonism. The antagonistic method is to give monoclonal antibodies to cytokines or soluble cytokine receptors and anti-cytokine receptor antibodies, and the current clinical application has shown initial results, but there are still many problems, such as how to use blood filtration technology, how to remove only pro-inflammatory factors, while appropriately retaining anti-inflammatory factors, and how to properly grasp the start and stop use For example, there is no mature experience on how to use hemofiltration technique, how to remove only pro-inflammatory factors and retain anti-inflammatory factors appropriately, and how to properly control the time of starting and stopping and the duration of treatment to achieve the best effect. All cytokine antagonists used in clinical practice are single-targeted antagonists that cannot stop the polar association (waterfall) effect of cytokines and are more effective when administered only before the onset of SIRS. The use of glutamine and recombinant growth hormone to protect and strengthen the intestinal mucosal barrier, and the use of Chinese herbal medicines such as hemiphilic acid and fish oil and ustekin to regulate the overly strong inflammatory response have achieved some clinical efficacy, but there are still many problems to be solved. 3.2 Pathogenic infections that cannot be inactivated by general sterilization methods: such as tetanus, gas gangrene and other sepsis treatment, on the one hand, requires the application of sensitive antibiotics for the pathogen, and for tetanus also requires the application of potent tetanus antitoxin, combined with basic treatment of sepsis, symptomatic application of sedative drugs for sustained muscle spasm caused by tetanus toxin, timely incision and drainage of gas gangrene. Anti-anaerobic bacterial treatment and hyperbaric chamber treatment. Wound dressings and necrotic tissues contaminated with pathogens from patients should be placed in plastic bags for airtight transfer and incineration. The patient’s bed linen, surgical towels, surgical instruments, etc. are treated by autoclaving methods. 3.3 Extensively drug-resistant pathogen infections: The widespread use of antibiotics has resulted in the production of extensively drug-resistant pathogens. For sepsis caused by extensively drug-resistant pathogens infection, the prognosis is very poor because there is no drug available for the pathogen. First of all, we should find and remove the lesions, such as abdominal, thoracic or soft tissue interstitial abscesses, contamination of deep vein placement, etc., and get rid of the source of infection as much as possible. The basic treatment of sepsis should be strengthened and the immune function of the patient should be regulated. Also very important is sterilization and isolation treatment. Because these pathogens are mainly contact transmitted, strict disinfection treatment is used for all treatments of patients to prevent the spread of these pathogens in the hospital. 3.4 Treatment of sepsis in combined infectious diseases: Infectious diseases are a class of diseases caused by various pathogens that can be transmitted from human to human, animal to animal or human to animal. At present, China’s statutory infectious diseases are divided into three categories A, B and C, with a total of 39 species. Patients are an important source of infection because of the presence of a large number of pathogens in their bodies, which can be transmitted through the respiratory tract, digestive tract and direct or indirect contact. Sepsis caused by infectious diseases and sepsis caused by common pathogenic bacteria have similar pathophysiological changes and are infectious. For these infectious diseases, it is necessary to understand their transmission routes and prevent occupational exposure of health care workers and cross-infection among hospital patients. Among them, tuberculosis and AIDS infected patients are mostly combined with immunocompromised, and are more prone to sepsis under the blow of surgery, trauma, etc. For these sepsis it is necessary to apply anti-tuberculosis therapy, antiretroviral therapy and immunomodulatory therapy on top of the treatment of common sepsis treatment. One of the recent advances in the treatment of surgical infections is to take a broader view of infection and to meet the challenge of infection by improving the condition of the body. For example, “immunomodulation” is used to reduce susceptibility to infection, “metabolic modulation” is used, such as the use of cyclooxygenase inhibitors to reduce fever and inflammation and inhibit catabolism, and growth hormone is used to promote protein synthesis and enhance the body’s defense against infection. The development of minimally invasive technology has also added new tools to anti-infection treatment. Endoscopic placement of nasobiliary ducts, endoscopic sphincter of Oddi dissection, percutaneous transhepatic bile duct placement or stent placement can provide immediate relief of obstructive biliary tract infections, allowing the patient to survive and be in a better position to undergo decisive surgical treatment. Ultrasound or CT-guided puncture and drainage of deep septic lesions, such as subdiaphragmatic abscesses, can save the patient from surgery. Treatment with highly effective antiretroviral drugs for HIV-infected patients can control HIV replication and gradually rebuild the immune function of patients, and many HIV-infected patients can reach the same age of life as normal people. The Shanghai Public Health Clinical Center has operated on more than 300 HIV-infected patients in the past 3 years, and the perioperative sepsis rate is about 40% and the morbidity and mortality rate is about 2%. The morbidity and mortality rates have been significantly lower than those reported in the past. 4. Prevention of special infections Nosocomial infections can be transmitted by air, contact between patients and medical sources, and the sites of infection are most commonly surgical wounds, respiratory tract and urinary system. Some common precautions to minimize the chance of HIV (and other pathogens transmitted through blood and body fluids) infecting health care workers include: (1) Apply routine protection (e.g., gloves and/or goggles) when in contact with blood or body fluids. (2) Washing hands and other exposed skin parts of the body immediately after contact with blood or body fluids. (3) Take extra care and place instruments properly when using and touching sharp objects. If clinical staff are inadvertently exposed to HIV-containing blood or body fluids in the course of their work (e.g., stabbed by a blood drawing needle), prompt precautions can reduce the rate of infection, and initial topical cleansing treatments and medication prophylaxis should be completed within a few hours. In more severe cases, 2 or even 3 antiretroviral drugs are recommended. If the patient’s HIV infection status is unknown, it is recommended that prophylaxis be started at the same time as testing is done and that antiretroviral drugs be applied for 4 consecutive weeks to almost completely block HIV infection. Surgeons and all other health care workers are at high risk for hepatitis B virus infection and should receive hepatitis B vaccination. The use of hepatitis B virus immunoglobulin in post-exposure prophylaxis can protect 75% of this population from infection. Aseptic practice in surgery is the most important aspect of preventing all kinds of infections. The operation should be performed with minimal tissue damage and timely removal of necrotic tissue, blood clots and exudates. The proficiency of the operator is also critical. Improved surgical approach and proficiency are beneficial for surgical infection control, such as careful manipulation, meticulous separation, removal of foreign bodies, hematomas and lifeless tissues, and drainage of oozing blood, exudate and pus. Attention should also be paid to various aspects of the perioperative period, such as measures to optimize the operating room environment such as filtered air, laminar flow system devices, and reduction of operating room visitors; handling of surgical instruments and dressings; routine hand washing and gloving; preoperative patient bathing, skin preparation and treatment of the operating field; improvement of skin preparation methods; and improvement of the nutritional status and organismal conditions of patients. By popularizing the basic knowledge of prevention and control of special infections among medical and nursing staff, understanding the latest advances in the prevention and control of special infections, and standardizing sterilization and isolation treatment procedures, it is possible to reduce or prevent nosocomial special infections.