Nosocomial Infections

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Nosocomial infections also known as hospital acquired infections are infections not present and without evidence of incubation at the time of admission to a healthcare setting.[1] They become evident 48 hours after admission or 48 hours after patient is discharged.

Definition of nosocomial infections[edit | edit source]

  • NI - not an infection contracted by health care personnel in the course of their profession - professional infection.
  • Basic feature of NI - hospital strains have higher resistance to antimicrobials and disinfection.
  • Cause of higher morbidity and mortality.

Classification of nosocomial infections[edit | edit source]

By agent:

  • Exogenous - the agent is introduced into the organism from outside;
  • endogenous - own infectious agent from the colonized site into another system, into a wound, into serosal cavities (Blood, during surgery, invasive procedures, immunosuppressive treatment); the etiologic agent is the microflora present in the body, which is normally non-pathogenic.

According to the epidemiological point of view:

  • non-specific - reflect the epidemiological situation in the catchment area of the health facility or are an indicator of the hygiene level of the facility;
  • specific - a consequence of diagnostic and therapeutic procedures, their occurrence can be influenced by asepsis, sterilization, disinfection, hygiene-epidemiological regime.

According to the affected system:

  • respiratory;
  • catheter - from the bloodstream;
  • urinary tract infections;
  • gastrointestinal;
  • wound infections;
  • genital tract;

Process of spreading nosocomial infections[edit | edit source]

  • Existence of a source of the causative agent - Transmission of the causative agent by NI - Presence of a susceptible individual - Transmission of the causative agent by NI - Presence of a susceptible individual.

Source - Nosocomial agent[edit | edit source]

  • Patient - his own microflora, another patient (his microflora is in saliva, on hands, in air, dust, tools, etc.).
  • Health care worker - does not appreciate his own disease.
  • Visitor - least serious source, control of visitors.

Forms of nosocomial infections[edit | edit source]

  • Manifest - less dangerous, easily diagnosed and treatable.
  • Carriage - carriers harbor and excrete infectious agents without obvious signs of disease.

Nosocomial transmission[edit | edit source]

  • Direct transmission:
    • presence of a source of infection and a susceptible individual;
    • contact (e.g., kissing/sexual contact);
    • essentially transmission by the hands of health care personnel;
    • in newborns - eye infection (direct contact with the mucous membrane of the vagina);
    • droplet infection;
    • alimentary route - preparation of milk food in the neonatal unit.
  • Indirect transmission depends on:
    • the ability of the microorganism to survive outside the host body;
    • the existence of a suitable medium in which the aetiological agent multiplies and with the help of which the infection is transmitted.

Most common bacterial agents of nosocomial infections[edit | edit source]

Mechanism of bacterial resistance[edit | edit source]

  • ATBs have been used for more than 50 years.
  • ATBs are a substantial part of all drug costs.
  • Adequate application of ATBs - economics and spread of resistance.
  • Emergence of resistance - most in ICU and ARO settings - multiple ATB applications.

Most important microorganisms: gram-positive bacteria[edit | edit source]

  • MRSA - methicillin-resistant Staphylococcus aureus.
  • MRCNS - methicillin-resistant coagulase-negative staphylococcus aureus.
  • VISA - Staphylococcus aureus with reduced susceptibility to vancomycin.
  • PRSP - Streptococcus pneumoniae resistant to PNC.
  • VRE - vancomycin-resistant enterococci.
  • Enterococci with high resistance to aminoglycosides.

Most important microorganisms: gram-negative bacteria[edit | edit source]

Resistant strains of MRSA[edit | edit source]

  • Identified in 1961.
  • In the US, incidence increased from 2.4% in 1975 to 30-60% after 1990.
  • Scandinavia - still 1% in 1990.
  • Spain and France - more than 30%.
  • 1990 in Central Europe - prevalence from 1.7% to 8.7%'.
  • England - from 3% in 1989 to 34% in 1998.
  • Measures - isolation and compliance with a hygiene and epidemiological regime, including hand washing.

MRSA resistance in the Czech Republic[edit | edit source]

  • Exact figures are not available;
  • 70 hospitals have investigated invasive isolates under the EARSS (European Antimicrobial Resistance Surveillance System) project;
  • MRSA incidence - 3.8% in 2000 increased to 8.8% in 2004.

Resistance is caused by[edit | edit source]

  • The production of bacterial enzymes that disrupt or modify the structure of the ATB;
  • Alteration of the bacterial wall - reduction of its permeability;
  • modification of the target sites of ATBs;
  • increased excretion of ATB from bacterial cells to prevent its intracellular accumulation.

Suppression of nosocomial infections[edit | edit source]

  • Knowledge of all data and information on the emergence and spread of NN is a prerequisite;
  • Data collection is integrated into the "Surveillance" programme;
  • Decree 195/2005 Coll. - lists infectious diseases for which isolation in inpatient facilities is ordered and treatment is mandatory;
  • Act on the Protection of Public Health and on Amendments to Certain Related Acts - 258/2000 Coll., last amended - Act No. 274/2003 Coll.

Repressive measures[edit | edit source]

  • Tasks:
    • eradication of an outbreak of an already established disease;
    • reporting of an outbreak of NI;
    • treatment of a patient with NI, isolation;
    • barrier nursing care;
    • search for contacts and source of infection;
    • disinfection - in the outbreak area;
    • increasing the immunity of susceptible patients;
    • control of the measures ordered, including thorough documentation.

Nosocomial urinary tract infections[edit | edit source]

  • Account for 30-40% of UTIs;
  • 60-90% - association with indwelling urinary catheter;
  • 10% - urological-endoscopic intervention;
  • Less costly NI, but prolonged hospitalization increases cost of treatment.

Prevention[edit | edit source]

  • Always use a sterile catheter;
  • thorough disinfection of the periurethral area;
  • hand disinfection, use of sterile gloves;
  • catheter fixation - prevention of movement in the urethra.

Surgical site infection[edit | edit source]

  • Third most common NI - 14-20% CDC:
    • superficial IMCHV;
    • deep incisional IMCHV;
    • Organ/space IMCHV.

Clinical picture of IMCHV[edit | edit source]

  • Redness,
  • serous secretions;
  • purulent secretion from a small area of the wound;
  • purulent secretion from the whole wound area, eventually its disintegration - dehiscence.

Prevention in the preoperative period[edit | edit source]

  • The shortest possible hospitalization before surgery;
  • Thorough bath and shower;
  • for elective procedures, overtreat other infections;
  • attention to shaving the surgical site;
  • antibiotic prophylaxis.

Intraoperative prophylaxis[edit | edit source]

  • Principles of asepsis and barrier nursing techniques;
  • use of protective equipment by theatre staff;
  • disposable drapes;
  • disinfection of the surgical field site with proper exposure to disinfectant;
  • precise surgical technique;
  • minimizing the number of staff in the operating room;
  • efficient ventilation and air conditioning in the operating room.

Postoperative interventions[edit | edit source]

  • Cover the incision with a sterile dressing for 24-48 hours;
  • principles of asepsis during dressings;
  • Educate family and patient about proper wound care and symptoms of wound infection.

Respiratory tract - pneumonia[edit | edit source]

  • 10-20% of all nosocomial infections;
  • incidence in ICUs can be as high as 65% with mortality rate above 25%;
  • prolong hospitalization;
  • persons at risk are over 70 years of age.

Specific risk factors[edit | edit source]

General principles of prevention[edit | edit source]

  • maintaining proper personal hygiene and hand washing
  • sterilisation of hospital equipment
  • providing clean and sanitary environment
  • existence of infection control team
  • regular, close observation of high-risk units .e.g intensive care
  • development of policies on areas such as isolation, disinfection and antibiotic usage

Links[edit | edit source]

Sources[edit | edit source]

  • KOLEKTIV AUTORŮ,. Základy ošetřování nemocných. 1. vydání. Praha : Karolinum, 2005. 145 s. ISBN 80-246-0845-6.
  • MIKŠOVÁ, Z, et al. Kapitoly z ošetřovatelské péče I.. 2. vydání. Praha : Grada, 2006. 248 s. ISBN 80-247-1442-6.
  • MIKŠOVÁ, Z, et al. Kapitoly z ošetřovatelské péče II.. 2. vydání. Praha : Grada, 2006. 171 s. ISBN 80-247-1443-4.
  • RICHARDS, A a S EDWARDS. Repetitorium pro zdravotní sestry. 1. vydání. Praha : Grada, 2004. 376 s. ISBN 80-247-0932-5.
  • ROZSYPALOVÁ, M a A ŠAFRÁNKOVÁ. Ošetřovatelství I., II.. 1. vydání. Praha : Informatorium, 2002. 239 s. ISBN 80-86073-97-1.
  • WORKMAN, B a C., L. BENNETT. Klíčové dovednosti sester. 1. vydání. Praha : Grada, 2006. 259 s. ISBN 80-247-1714-X.
  • MANDAL, BK. Lecture Notes : Infectious Diseases. 6th edition. Wiley-Blackwell, 2004. 280 pp. ISBN 978-1-4051-0820-1.

References[edit | edit source]

  1. Ayesha Mirza, MD Assistant Professor, Pediatric Infectious Diseases, University of Florida College of Medicine Jacksonville- Hospital-acquired infections. January 5th 2012 (