The problem of nosocomial infection in health care settings dental profile

Nosocomial, or hospital, or nosocomial (Greek. Nosocomeo - to care for the sick) infection - a clinically recognizable disease of microbial origin that affects the patient as a result of hospitalization or outpatient visits to institutions, developed during his stay in a medical facility or after discharge and disease institution's staff as a result of professional activities.

Hospital-acquired infections (HAI) are becoming increasingly important public health problem worldwide. Burdening the main disease, they often pose a threat to the patient's life, extend the length of stay of patients in hospitals, causing significant economic damage. In economically developed countries, these infections are being reported in 5-10%. For example, in Germany the frequency of nosocomial infections among patients of various departments of hospitals ranges from 3.6-6.3%, in Spain - 3,9-9,9%, in the United States - 5,7-6,2%. In Russia, these figures are somewhat lower, at 1.2-1.6 per 1000 patients. These figures are explained by underreporting of cases of nosocomial diseases, as More is not adjusted accounting and registration of septic complications.

In hospitals in various fields are added specific micro-ecological conditions, the features of which determine the nature and possibilities of formation of hospital strains of pathogens, adapted to specific hospitals. Most susceptible to BIV surgical patients, including dental profile.

The incidence of nosocomial infections is dependent on several factors: the capacity of medical institutions (by volume held diagnostic and therapeutic invasive procedures); the number of personnel contact with a patient; the nature of the disease patients, their susceptibility to infection; use in therapy, immunosuppressive drugs (antibiotics, hormones, and chemotherapeutic agents, to radio waves, etc.).

The spread of nosocomial infections is associated with a complex of traditional factors: MICROECOLOGY hospital, the advent of highly virulent strains of hospital, the presence of sources of infection among patients and medical staff.

Height HAI is currently linked to two factors: 1) down immunobiological resistance of people and change of medical technologies; 2) to change the biological properties of microorganisms - pathogens of these diseases.

Epidemiology of nosocomial infections.

The main routes of transmission of nosocomial infections - airborne, air-dust, pin, tool, implantation. The source of infection are patients (patients and mikrobonositeli), medical staff, hospital environment. This is due to the fact that most of these infections agents usually have a high resistance to adverse environmental factors (antibiotics, disinfectants, UV irradiation) and their ability to exist and multiply in a minimum amount of nutrients (sinks, drug solutions preparations, ointments, saline). And this leads to the fact that the contamination of hands of personnel is not only in contact with the patient, but also when dealing with medical supplies and hospital equipment. In 40% of cases, the development of infections caused by gram-negative flora, due to the presence of these microorganisms on the hands of staff.

The etiology of nosocomial infections.

There are more than 100 species of microorganisms that can cause the spread of nosocomial infections. In the treatment of dental diseases can be transmitted pathogens of a number of infections, the most common of them are presented in Table 2 of the Annex.

HAI can be divided into two groups:

- "Traditional" infectious diseases caused by pathogens;

- Purulent-septic infections caused by opportunistic pathogens (ICG).

"Traditional" infections are usually a result of the introduction of pathogens in hospital bacteria carriers or persons who were in the incubation period (up to 15% of all nosocomial infections). The most serious problem for dental clinics are patients with hepatitis B, C, D, HIV, tuberculosis, diphtheria, etc.

Septic-purulent nosocomial infections caused by opportunistic pathogens (85% of all nosocomial infections). The upper respiratory tract, including the nose, oral cavity, nasopharynx and oropharynx, colonized with a wide range of gram-positive and gram-negative microflora, deprived of the cell wall of aerobic and anaerobic microorganisms. Composition of oral microflora is dynamic and varies depending on the age, hormonal background, diet, general health of the individual. Total of periodontal pockets can be allocated up to 300 different microbial species, and, up to 100 species may be obtained from a single site. It is known that 1 ml of saliva contains from 4 million to 5 billion microorganisms; 1 gram of the plaque contains 10-1000 billion organisms.

In dentistry, the problem of purulent-septic infection is highly relevant. In recent years there has been:

- A sharp increase in the number of patients with odontogenic inflammatory diseases;

- Osteomyelitis of the jaws began to acquire long-term and recurrent;

- Noted increased frequency of severe odontogenic inflammatory diseases of the spread of the process for a few anatomic regions, extensive destruction of bone tissue and the development of complications such as sepsis, mediastenit, septic shock, which are a major cause of disability and death from dental diseases and complications.

Of great importance is the prevention of complications and the generalization of the process flow in the presence of acute odontogenic infection. In this regard, it is necessary to develop a system of effective preventive measures to optimize the sanitary-epidemiological status of nosocomial environment dental clinics and maxillofacial hospitals at various stages - from the time of initial application to the clinic and from admission to patient discharge from the hospital. There are problems associated with the complexity of processing dental instruments contaminated with blood and colonization by microorganisms because of its complex configuration, the presence of retention points and locking fasteners. This causes difficulty in selecting a rational method of disinfection and sterilization of instruments.

ICG pathogens in health care settings dental profile are:

 Opportunistic aerobic microorganisms that live in the human oral (streptococci, Corynebacterium, Neisseria, pneumococci, Proteus, sartsiny, zalotisty and Staphylococcus epidermidis). The share of viridans streptococci accounted for about 35%. Opportunistic microorganisms (UTM) are always present on the skin and mucous membranes, and do not cause disease in a healthy person. They become pathogenic under certain conditions: the weakening of the body's defenses due to undergoing surgery, primary or concomitant diseases, inadequate antibiotic therapy, etc. Nosocomial infections are caused, as a rule, hospital strains with high virulence that are resistant to drugs, disinfectants, and features the ability to rapid colonization.

 Anaerobic microflora (obligate and facultative anaerobes that live in the mouth).

According to studies carried out in St. Petersburg in 2003, the most commonly extracted teeth from the wells and of intraoral incisions in patients with purulent-inflammatory diseases of the maxillofacial area sown α-hemolytic streptococci and fungi Candida.

Sources of infection.

Distinguish between endogenous and exogenous infection. When endogenous infection activates the endogenous flora of the mouth, nose and throat of the patient. Dental procedures may facilitate the introduction of microbial flora in deep-lying tissue and therefore lead to the spread of infection, especially in patients with reduced immune reactivity.

According to studies carried out in St. Petersburg in the Department of Maxillofacial Surgery General Hospital, 19% of patients coming from the mouth, the front of the nose, tonsils and the posterior pharyngeal wall produces large amounts of UTM, which later can cause purulent inflammatory complications, reform and superinfection. Attention is drawn to a large number of patients carrying S.aureus (36%), of which 10% were carriers of strains resistant to 5 or more antimicrobials. The data obtained suggest an endogenous infection with abscesses and phlegmon facial area caused by obligate and facultative anaerobes. In the study of purulent wounds in these patients 10% were allocated obligate anaerobic microorganisms, in 3% of cases - facultative anaerobes. When exogenous source of infection are infected patients department / office (infected with pathogenic and TPC) and medical personnel (patients and carriers).

The possibility of cross-contamination in the outpatient reception at the dentist is, first of all, to the omnipresence of dental disease, which affects almost the entire population of the country.

Structure dedicated opportunistic and pathogenic microflora in patients from the mouth, nose, and throat (St. Petersburg, 2003):

Candida albicans - 7%

Enterobacter ssp. - 5%

Escherichia coli - 6%

Neisseria ssp.- 8%

Staphylococcus aureus - 36%

Staphylococcus epidermidis - 13%

Streptococcus viridans, alpha-hem. - 5%

Other (Citrobacter sp., Corynebacterium, Haemophilus influenzae, Prevotella, Proteus mirabilis, Pseudomonas sp., Staphylococcus saprophyticus, Streptococcus pneumoniae) - 20%.

It should be noted that the profession of dentist is associated with surgical operations, during which a high risk of occupational exposure. Infectious diseases have always been a threat to dentists who have regular contact with the blood and saliva of patients. Dentist daily basis to advise and treat patients with inflammatory processes - or periodontal mucosa caused in most cases, highly virulent pathogens. It is important to remember that most dental patients as a source of infection are passive, ie not sneeze, do not cough, and therefore do not emit active microbes in the environment. Transmission of them occurs at a doctor's intervention on the epidemiological chain.

Laboratory diagnosis of nosocomial infections

The main method of diagnosis - Microbiology. Indication of hospital strains is an urgent task. The main criteria (markers) Gospitalnaya isolates used to study their sensitivity to antibiotics, disinfectants, UV irradiation. These features are encoded on plasmid level. Molecular weight R-resistance plasmids Plasmids from 50 to 120 Mg (megadalton). Hospital strains under favorable conditions it is easy (a few passages) exchange R-plasmids between themselves and community-acquired strains. Hospital strains that are linked bacillicarriers (patients or medical staff) have, as a rule, persistent characteristics - antilysozyme, antiinterferonovoy activity and so forth.

Ways and factors of transmission of nosocomial infections in Stomatology

In the dental practice may be different ways of transmission. One of the main ways - contact transmission, which can be caused by direct or indirect contact.

In dental offices and clinics Department of Maxillofacial Surgery pin mode of transmission occurs through the hands of health care worker and the tools he works with, especially when you operate in the mouth.

Airborne route of infection is due to work drills, especially when invasive surgery in the oral cavity. The microorganisms of the oral cavity with sprayed as an aerosol and fall on your face and hands, the mucosa of the nasopharynx and the eye doctor, and also apply to objects and surfaces in the dental office as an aerosol. During operation of the turbine dentist and his assistants are constantly exposed to the aerosol forming highly contaminated with microorganisms from the oral cavity of the patient. To prevent the spread of germs rich aerosols in the modern medical office equipment needed suctions that capture aerosols with microbes in their place of education. However, their effectiveness is greatly reduced in the absence or the imperfection of the filter, so that the exhaust air pollution leads to significant contamination of all the items and equipment in the office of oral microflora of patients.

The highest level of total microbial contamination observed in the offices of the therapeutic and prosthetic dentistry, and the lowest - in surgical dentistry. This is due to the fact that in the past, anti-epidemic regime was always strict enough and in the dental surgeons are not used high-speed drill and a turbine.

Transmission factors may come all the surrounding objects and surfaces (light switches, lamps actually handle when setting up lighting, surface drills, etc.). The level of protection and treatment in the exam room and dressing must be close to the level of sterility in the surgical operating room.

Factors of infection are:

 neobezzarazhennye items - towels public, spittoon, sink faucets and handles for hand washing, instrument trays;

 medical and auxiliary apparatus, such as Amalgamator orthopedic anvil and hammer, the storage box prostheses lacquer X-ray (in particular clamps for the X-ray film);

 any additional equipment used during treatment, for example, an ultrasonic device for the removal of tartar or a lamp for light-curing materials, handles and levers adjust lighting lamps, and last but not least, the telephone.

Transmission of infection from patient to patient occurs when medical intervention on the epidemiological chain: