Hospital infection refers to the infection that patients or staff get in the hospital and produce clinical symptoms. Because infection has a certain incubation period, nosocomial infection also includes patients who are infected in the hospital and get sick after discharge.
Second, the classification of hospital infection
According to the different sources of infection, hospital infection is divided into:
(1) Endogenous infection (autoinfection)
Refers to the infection caused by normal flora in immunocompromised patients. That is, the patient was a pathogen carrier before hospital infection, and when the body's resistance decreased, it caused its own infection.
(2) Exogenous infection
Refers to the infection caused by invasive flora brought by others in the environment. Including:
1 cross infection
Direct infection caused by hospitals or other people (patients, carriers, staff, visitors, nurses).
2. Environmental infection
Infection caused by environmental pollution (air, water, medical equipment and other articles). Such as postoperative incision infection caused by operating room and air pollution, hepatitis B epidemic caused by lax sterilization of syringes, etc.
Third, the common hospital infection
(1) pulmonary infection
Pulmonary infection often occurs in some chronic diseases that seriously affect patients' defense mechanism, such as cancer, leukemia, chronic obstructive pneumonia, or patients with tracheotomy and tracheal intubation. Judging pulmonary infection mainly depends on clinical manifestations, X-ray fluoroscopy or photos, and its incidence accounts for about 23.3% ~ 42% of nosocomial infection. Pulmonary infection is a great threat to critically ill patients, immunosuppressed patients and patients with weak immunity, and the mortality rate can reach 30%-50%.
(2) Urinary tract infection
The patient had no symptoms of urinary tract infection when he was admitted to hospital, but he had symptoms (fever, dysuria, etc. 24 hours after hospitalization, bacteria grow in urine culture, or although there are no symptoms, the number of white blood cells in urine sample is above 10 /ml, and the number of bacteria is above 105 /ml, which can be judged as urinary tract infection. According to Chinese statistics, the incidence of urinary tract infection accounts for about 20.8% ~ 3 1.7% of nosocomial infection.
66% ~ 86% of urinary tract infections are related to the use of urinary catheters.
(3) Wound infection
Wound infection includes surgical operation and wound infection in traumatic events. The judgment of wound infection mainly depends on whether there is inflammatory reaction or pus in the wound and nearby tissues, more specifically, bacterial culture. According to statistics, the incidence of wound infection accounts for about 25% of hospital infection.
(IV) Viral hepatitis
Viral hepatitis can spread not only among healthy people, but also among patients. Viral hepatitis can be divided into five types: A, B, C, D and E.
The sources of infection of hepatitis A and hepatitis E are patients and asymptomatic infected people, and they spread through the digestive tract. The patient excretes feces with virus, does not disinfect, pollutes water or food, and people make mistakes.
Fecal mouth infection is caused by eating boiled water or undercooked food.
The sources of infection of hepatitis B, hepatitis C and hepatitis D are patients and virus carriers. Viruses exist in blood and various body fluids. Infectious blood can be infected by slight damage to skin and mucous membrane, vertical transmission from mother to child, or close contact with blood products.
(5) Infection of skin and other parts.
During hospitalization, the patient developed skin or subcutaneous tissue suppuration, various dermatitis, bedsore infection, bacteremia, venous catheter and puncture site infection, endometrial infection, intra-abdominal infection and so on.
In-patients with tracheal intubation, repeated operation or prolonged operation time, indwelling catheterization, chemotherapy, radiotherapy and immunosuppressants, and elderly patients should be the key targets to prevent nosocomial infection.
Four, the inducing factors of hospital infection
(A) subjective factors
Medical staff have insufficient knowledge of hospital infection and its harm; Can not strictly implement aseptic technology and disinfection and isolation system; Hospital rules and regulations are not perfect, there is no sound pre-inspection and triage system in outpatient and emergency departments, and there is no sanitary disposal system in inpatient departments, which leads to the spread of infectious sources. In addition, the lack of monitoring of disinfection and sterilization effect can not effectively control the occurrence of hospital infection.
(B) objective factors
1. There are more and more invasive diagnosis and treatment methods.
According to statistics, 45% of hospital infections in the United States occur every year due to the use of medical devices. Such as endoscope, urinary catheter, arteriovenous catheter, tracheotomy, tracheal intubation, inhaler, organ transplantation, dental drill, blood collection needle, blood suction tube, monitor probe and other invasive diagnosis and treatment means, not only can introduce external microorganisms into the body, but also can destroy the body's defense barrier, making pathogens easily invade the body.
2. Use treatments that can suppress immunity.
Because of the need of treatment, the use of hormones or immunosuppressants, after receiving chemotherapy and radiotherapy, leads to the decline of patients' autoimmune function and becomes susceptible.
3. Development and popularization of a large number of antibiotics
The application of multiple antibiotics or concentrated use of a large number of antibiotics in the treatment process will lead to the imbalance of normal flora in patients and the increase of drug-resistant strains, thus prolonging the course of disease and increasing the chance of infection.
4. The number of susceptible patients increased.
With the progress of medical technology, some intractable diseases in the past can be cured or their survival time can be prolonged, so the hospitalization rate of chronic diseases, malignant diseases and elderly patients increases, and their resistance to infection is quite low.
5. Serious environmental pollution
There are many sources of infection in hospitals, so the environmental pollution is also serious. Among them, the most serious pollution is the infected ward, and the toilet pollution is also very serious. Every time the toilet is pumped, it may arouse a large number of microbial aerosols. Public goods in wards, such as pools, tubs, toilets, trolleys, mops and rags, are often polluted.
6. There are no necessary restrictions on visitors.
When the reasonable and necessary restrictions on visitors are relaxed, the possibility of visitors or caregivers bringing pathogens into the hospital increases.
Five, prevention and control of hospital infection
Although there are many reasons for hospital infection, nearly two-thirds of hospital infections can be prevented as long as management is strengthened and effective measures are taken.
(A) improve the hospital building and layout
Whether the hospital building layout is reasonable is very important to prevent hospital infection. Used in infectious wards, clean wards, operating rooms, intensive care units, observation rooms, visiting reception rooms, supply rooms, laundry rooms, kitchens, etc. From the point of view of preventing infection, in order to prevent the spread of bacteria and diseases, there should be special requirements on equipment and layout.
(2) Strictly implement the rules and regulations.
System is the basis for people to sum up experience, handle and check all work in long-term work practice. Including disinfection and isolation system, aseptic technology operating rules and visiting system. Isolation aims at limiting pollution to a minimum and is one of the most important measures to prevent hospital infection. Aseptic operating procedures are medical regulations that medical personnel must abide by, which run through all medical and nursing processes. Every medical staff should strictly implement the system, routine and implementation rules from the perspective of hospital infection and protecting patients' health, and advise patients and visitors to abide by them.
(3) Do a good job of disinfection and sterilization.
Disinfection and sterilization is an effective measure to control hospital infection.
(4) Strengthen the cleaning and hygiene work.
Cleaning and sanitation work includes wiping and removing dust and dirt, and preventing mosquitoes, flies, cockroaches and mice.
When cleaning and sanitation work, we must be careful not to raise dust and avoid the spread of pollution. Don't use brooms and dusters in the hospital. You'd better take mop head down and disinfect it. After pollution, the ward should be cleaned immediately. The sequence should start from the less polluted ward, gradually enter the more polluted area, and finally deal with the public activities of patients. The workplace of medical staff should also be cleaned.
(5) Adopt reasonable diagnosis and treatment methods.
The use of antibacterial drugs should be targeted, and the application of immunosuppressive therapy should take corresponding protective measures, such as treating chronic diseases to prevent self-infection, regularly checking the dynamics of white blood cells and providing drug prevention. For diagnosis and treatment projects that are easy to introduce microorganisms into the body, disinfection and sterilization should be done well and aseptic technical operation should be strictly carried out.
(6) Control the epidemic of infectious diseases in time.
Controlling the epidemic situation of infection mainly includes finding the source and route of infection and taking corresponding isolation and disinfection measures.
(seven) to carry out hospital infection monitoring.
The purpose of hospital infection monitoring is to obtain first-hand information through monitoring, analyze the causes of hospital infection, find weak links, provide basis for taking effective measures, and evaluate the effects of various measures through monitoring. The main contents of monitoring include: environmental pollution monitoring, sterilization effect monitoring, disinfection pollution monitoring and special ward monitoring (such as burn, urology ward, operating room, intensive care unit, etc.). ), strain drug resistance monitoring, cleaning and hygiene monitoring, infection source monitoring, rules and regulations implementation monitoring, etc. As a routine work, monitoring should be carried out regularly, at a fixed point and on a project-by-project basis. Infection records should be detailed and specific, and statistical analysis should be carried out on a regular basis with wards as units.
(eight) to improve the health and hygiene conditions of workers.
All hospital staff should have regular health check-ups, and report any discomfort or suspected infectious diseases immediately, so as to take corresponding measures, inject relevant vaccines as needed, and take passive immunization or drug prevention if necessary.
Medical staff should also do personal protection. First of all, they should prevent bacteria from infecting themselves or taking them out of the ward. The second is to prevent the spread of germs to indoor susceptible people. Personal protection mainly includes wearing personal protective equipment (clothes, hats, shoes, gloves, masks) and hand washing and disinfection.