With the increasing improvement of organ transplantation technology, allogeneic kidney transplantation has become one of the most important means of treating end-stage renal failure. According to a nationwide survey on the physical and mental health status of transplant recipients, the current status of health management in transplant centers and social rehabilitation support groups launched in July 2011, a total of 392 organ transplant recipients were surveyed in a one-on-one study on the physical and mental health status of patients after kidney/liver transplantation, including 151 liver transplants (38.52%) and 241 kidney transplants ( 61.48%). For post-transplantation treatment and daily life, the most important concern of the recipients was post-transplantation complications accounting for 29.1%, of which the most mentioned was infection, accounting for 9.4% of the total. For kidney transplantation, due to the long-term use of immunosuppressive drugs, the immunity of patients can be reduced, and various infections can easily occur after surgery, and infection is not only a serious complication after kidney transplantation, but also the main cause of death of kidney transplant recipients. 70% of patients have at least one infection within one year after surgery, which directly affects the long-term survival of people and kidneys. Therefore, how to prevent and treat post-transplantation kidney infection has very important clinical significance.
First, the time of infection after kidney transplantation and its infection site
Post-operative renal transplant recipients are in a long-term immunosuppressed state due to the application of immunosuppressive drugs, which reduces the body’s resistance to exogenous infection factors and increases the chance of opportunistic infections significantly. The timing of infection after kidney transplantation has a certain pattern: infection occurs in the first month of kidney transplantation mostly in the following cases.
① the transplant recipient already had an infection before receiving the organ transplant and it persisted until after the transplant;
② Immunosuppression aggravates the existing infection;
(iii) Infection of the vascular suture due to contamination of the donor organ by pathogens;
(iv) Nosocomial infection due to various catheters left in place.
Infections occurring within the second to sixth months after transplantation are mostly caused by viruses with immunomodulatory functions such as herpes simplex virus and cytomegalovirus, especially viral pneumonia, which in our experience is more serious 4-6 months after renal transplantation. The common causes of viral pneumonia are.
(1) Virus in the transplanted kidney of the kidney donor.
(2) Transmission through blood transfusion in patients requiring blood transfusion for reasons such as trauma and blood loss.
(3) Viral infestation from other causes after discharge from the hospital.
(4) Infections occurring more than 6 months after renal transplantation are mostly community infections, as most of the transplanted organs are good and the infections are mostly respiratory infections due to respiratory viruses and pneumococci.
Among the 10 cases of infections occurring more than 6 months in our hospital, the longest infection occurred 11 years after renal transplantation with pulmonary infection, and there were also patients with infections occurring after 3 and 6 years. Therefore, it can be seen that infection can occur at any time in patients after renal transplantation. The sites of infection after kidney transplantation are mostly respiratory system, urinary system, oral cavity, etc., among which lung infection takes the first place.
Second, the pathogens of post-renal transplantation infection
The pathogens of post-transplantation infection include bacteria, viruses, fungi, protozoa and mixed infections. The criteria for distinguishing infections are.
(1) Bacterial infection: temperature greater than 38℃, duration of more than 24 hours, and other causes of fever can be excluded, effective treatment with antibiotics, positive culture of blood, sputum and urine.
(2) Cytomegalovirus infection: temperature ≥38℃, duration of more than 72 hours, cough, chest tightness, cyanosis or dyspnea, chest X-ray with interstitial pneumonia, abnormal liver and kidney function (excluding infectious hepatitis and drug-related liver damage).
(3) Fungal infection: the infection caused by fungal invasion of skin and its appendages is superficial fungal infection, if further invasion of organs and tissues form foci of infection, then it is systemic or systemic fungal infection. Of course, tuberculosis, Pneumocystis carinii, flagellates, herpes simplex virus, influenza virus, herpes zoster virus and hepatitis B virus are not uncommon after kidney transplantation.
Prevention of infection after renal transplantation
Kidney transplant patients are a high-risk group for opportunistic infections. Although these conditionally pathogenic bacteria, cannot cause disease in normal people, they can cause disease in immunocompromised people. Also you are more likely to get pathogens from others. Also, during kidney transplantation, patients are at risk of contracting pathogens from blood transfusions and donors. However, this does not happen very often because donors have to undergo special tests before they can donate. After a kidney transplant, your immune system is partially “shut down” by the drugs and the risk of infection is much higher, so you have to do everything possible to avoid it: stay away from patients and avoid contact with children (especially those with runny noses), and wash your hands more often every day. Let’s face it: infections are everywhere, and most people get them once or twice a year. However, kidney transplant recipients are different from the general population because you have special characteristics. Viral infections are more likely to occur after a kidney transplant. Viruses have a simpler structure than bacteria, and instead of surviving in the air for as long as bacteria do, they can only multiply inside cells and enter your body through the blood or other body fluids to cause an infection. Sometimes, after a virus causes an infection, it does not disappear, but enters certain parts of the body and begins to lie dormant (rest, inactive) or lurk, waiting for the right time (such as when your immune system is suppressed) to come back to life. There are many ways your doctor will check you for viral infections. Spring and fall are the seasons when the flu is prevalent. For post-transplant patients, influenza is a common respiratory illness. The influenza virus can be spread by the virus released when the patient coughs or sneezes or by touching objects that the patient has touched. Therefore, it is essential to wash your hands frequently during a flu epidemic. The illness caused by influenza can be mild or severe, and can cause serious complications in the elderly and in people who are immunosuppressed. Influenza viruses evade the immune system by constantly mutating, so a person can be infected with influenza viruses throughout his or her life.
CMV virus (or cytomegalovirus as we often call it) infection is one of the common infections within six months after kidney transplantation and is also the most aggressive! This virus can be transmitted through intimate contact and can cause serious illness in people at high risk of infection, the most common and serious being cytomegalovirus pneumonia. In order to prevent infection, please pay attention to the following points in your daily life.
①Regular follow-up and review of cyclosporine, tacrolimus and primaquine blood levels and immune function to avoid immune oversuppression;
②Regular postoperative oral administration of Vansevier (valganciclovir) 0.9 g once daily for 6 months can effectively prevent the occurrence of CVM infection;
③It is best not to go to public places and crowded places to avoid increasing the chance of infection, and remember to wear a mask when going out;
④Prevent trauma, even small wounds should be taken seriously and treated promptly to avoid spreading the infection;
⑤ Do not keep poultry or pets;
(6) Pay attention to the hygiene and shelf life of food, avoid eating unhygienic and expired food;
(7) It is best not to share household items such as toothbrushes and razors with others;
⑧ Avoid contact with patients, pay attention to hygiene, and develop good living and hygiene habits;
⑨ pay attention to warmth, cold and warm alternately to increase and decrease clothing, prevent colds, prohibit smoking and alcohol;
⑩The living environment should be frequently wiped with disinfectant solution, morning and evening room ultraviolet disinfection.
Fourth, the treatment of infection after kidney transplantation
Before the pathogen is clear, the general use of antibiotic ladder treatment, that is, antibacterial drugs + antiviral drugs + antifungal drugs combined, the patient as early as possible to do pathogenesis, serological examination (virus eight). Once the pathogen is identified as bacteria, drug sensitivity test should be done according to the identified bacteria, and then take sensitive antibiotics according to the results of the drug sensitivity test; if the pathogen is detected as a virus, the corresponding effective antiviral drugs should be used, such as cytomegalovirus infection should be treated with anti-cytomegalovirus strong effect of Vancive, the incidence of CMV disease treated with Vancive is 2.2% (the incidence of CMV in historical control is 20%) Herpes simplex virus infection should be treated with acyclovir, a strong anti-herpes virus drug. Our hospital found 18 cases of herpes simplex virus and 9 cases of cytomegalovirus among 27 virus-induced infections, suggesting that these two virus-induced infections are more common and are key to prevention and treatment. Because of the strong effect of vancomycin on both herpes simplex virus and cytomegalovirus, vancomycin is commonly used in our hospital. Because CMV can induce rejection and damage a variety of target organs, the mortality rate is high and requires high clinical attention.