NOSOCOMIAL NOSOCOMIAL INFECTIONSINFECTIONS

A hospital-acquired infection, also known as a HAI or in medical literature as a nosocomial infection, is an infection that develops in a patient during hospitalization. It is usually

defined as an infection that is identified at least forty-eight to seventy-two hours following

admission, so infections incubating, but not clinically apparent, at admission are excluded. With recent changes in health care delivery, the concept of “nosocomial infections” has sometimes been expanded to include other

“health care–associated infections.”

The most frequent types of infection are The most frequent types of infection are urinary-tract infection, surgical-wound infection, , surgical-wound infection, pneumonia, and bloodstream infection. These pneumonia, and bloodstream infection. These infections follow infections follow interventions necessary for  necessary for patient care, but which impair normal defenses.  patient care, but which impair normal defenses.  Nosocomial pneumonia occurs most frequently  occurs most frequently in in intensive-care-unit patients with  patients with endotracheal intubation on mechanical  on mechanical ventilation—the endotracheal tube bypasses ventilation—the endotracheal tube bypasses normal defenses of the upper airway. Finally, normal defenses of the upper airway. Finally, primary nosocomial bloodstream infection primary nosocomial bloodstream infection occurs virtually only with the use of indwelling occurs virtually only with the use of indwelling central vascular catheters, and correlates directly central vascular catheters, and correlates directly with the with the duration of  of catheterization..

In the United States, the Centers for Disease Control and Prevention estimated roughly 1.7 million hospital-associated infections, from all types of microorganisms, including bacteria, combined, cause or contribute to 99,000 deaths each year. In Europe, where hospital surveys have been conducted, the category of Gram-negative infections are estimated to account for two-thirds of the 25,000 deaths each year. Nosocomial infections can cause severe pneumonia and infections of the urinary tract, bloodstream and other parts of the body. Many types are difficult to attack with antibiotics, and antibiotic resistance is spreading to Gram-negative bacteria that can infect people outside the hospital.

Ventilator-associated pneumonia Staphylococcus aureus Methicillin resistant Staphylococcus aureus Candida albicans Pseudomonas aeruginosa Acinetobacter baumannii Stenotrophomonas maltophilia Clostridium difficile Tuberculosis Urinary tract infection Hospital-acquired pneumonia Gastroenteritis Vancomycin-resistant Enterococcus Legionnaires' disease

Known nosocomial infectionsKnown nosocomial infections

Spreading of MRSASpreading of MRSA

Patient with sepsis (bed-sore)Patient with sepsis (bed-sore)

Patient with sepsis (sugulations)Patient with sepsis (sugulations)

FurunculFuruncul

CarbunculCarbuncul

MastitisMastitis

Control and preventionControl and prevention

Prevention of nosocomial infections requires a Prevention of nosocomial infections requires a systematic, multidisciplinary approach. This is systematic, multidisciplinary approach. This is usually achieved under the leadership of an usually achieved under the leadership of an institutional institutional infection-control program. The  program. The principle activities of such a program include principle activities of such a program include surveillance, outbreak management, policy surveillance, outbreak management, policy development, expert advice, and education. An development, expert advice, and education. An optimal program may decrease the incidence optimal program may decrease the incidence of nosocomial infections by 30 to 50 percentof nosocomial infections by 30 to 50 percent ..

An effective infection-control program requires dedicated staff An effective infection-control program requires dedicated staff with appropriate training and sufficient resources. The number of with appropriate training and sufficient resources. The number of personnel is determined by the size and complexity of the personnel is determined by the size and complexity of the facility. Infection-control practitioners, usually from a nursing facility. Infection-control practitioners, usually from a nursing background, are responsible for program activity. In larger background, are responsible for program activity. In larger hospitals, program leadership is provided by a physician with hospitals, program leadership is provided by a physician with training in training in epidemiology and infection control. Smaller facilities  and infection control. Smaller facilities may obtain such expertise by contractual arrangement with may obtain such expertise by contractual arrangement with outside experts. Oversight of the infection-control program is outside experts. Oversight of the infection-control program is usually provided by a multidisciplinary infection-control usually provided by a multidisciplinary infection-control committee. The program director, however, should report committee. The program director, however, should report directly to senior hospital management to ensure optimal directly to senior hospital management to ensure optimal program effectiveness.program effectiveness.

SterilizationSterilization

Sterilization goes further than just sanitizing. Sterilization goes further than just sanitizing. It kills all microorganisms on equipment It kills all microorganisms on equipment and surfaces through exposure to and surfaces through exposure to chemicals, ionizing radiation, dry heat, or chemicals, ionizing radiation, dry heat, or steam under pressure.steam under pressure.

IsolationIsolation

Isolation precautions are designed to Isolation precautions are designed to prevent transmission of microorganisms prevent transmission of microorganisms by common routes in hospitals. Because by common routes in hospitals. Because agent and host factors are more difficult to agent and host factors are more difficult to control, interruption of transfer of control, interruption of transfer of microorganisms is directed primarily at microorganisms is directed primarily at transmission.transmission.

Handwashing and glovingHandwashing and gloving

Handwashing frequently is called the single most Handwashing frequently is called the single most important measure to reduce the risks of transmitting important measure to reduce the risks of transmitting skin microorganisms from one person to another or  from one person to another or from one site to another on the same patient. Washing from one site to another on the same patient. Washing hands as promptly and thoroughly as possible hands as promptly and thoroughly as possible between patient contacts and after contact with between patient contacts and after contact with blood, , body fluids, , secretions, excretions, and equipment or , excretions, and equipment or articles contaminated by them is an important articles contaminated by them is an important component of infection control and isolation component of infection control and isolation

precautions.precautions.  

The microbes comprising the The microbes comprising the resident flora resident flora 

Staphylococcus epidermidisStaphylococcus epidermidis, , S. hominisS. hominis, , and and MicroccocusMicroccocus, , Propionibacterium, Propionibacterium, Corynebacterium, DermobacteriumCorynebacterium, Dermobacterium, , and and PitosporumPitosporum spp., while in the  spp., while in the transitional could be found transitional could be found S. aureusS. aureus, , and and Klebsiella pneumoniaeKlebsiella pneumoniae, , and and Acinetobacter, Acinetobacter, EnterobacterEnterobacter and  and Candida Candida spp. spp. 

Surface sanitationSurface sanitation

Sanitizing surfaces is an often overlooked, yet Sanitizing surfaces is an often overlooked, yet crucial, component of breaking the cycle of crucial, component of breaking the cycle of infection in health care environments. Modern infection in health care environments. Modern sanitizing methods such as NAV-CO2 have sanitizing methods such as NAV-CO2 have been effective against gastroenteritis, MRSA, been effective against gastroenteritis, MRSA, and influenza agents. Use of hydrogen and influenza agents. Use of hydrogen peroxidevapor has been clinically proven to peroxidevapor has been clinically proven to reduce infection rates and risk of acquisition. reduce infection rates and risk of acquisition. 

Antimicrobial surfacesAntimicrobial surfaces

Touch surfaces commonly found in hospital rooms, Touch surfaces commonly found in hospital rooms, such as bed rails, call buttons, touch plates, chairs, such as bed rails, call buttons, touch plates, chairs, door handles, light switches, grab rails, intravenous door handles, light switches, grab rails, intravenous poles, dispensers (alcohol gel, paper towel, soap), poles, dispensers (alcohol gel, paper towel, soap), dressing trolleys, and counter and table tops are dressing trolleys, and counter and table tops are known to be contaminated known to be contaminated with with StaphylococcusStaphylococcus, MRSA (one of the most , MRSA (one of the most virulent strains of antibiotic-resistant bacteria) virulent strains of antibiotic-resistant bacteria) and vancomycin-resistant and vancomycin-resistant EnterococcusEnterococcus (VRE).  (VRE).