Nosocomial infectionNosocomial infection

Hospital acquired Hospital acquired infectionsinfections

Instructional Objectives:

At the end of the lecture the student would be able to:

1-Define Nosocomial infections.2 -Demonstrate the main clinical characteristics of

Nosocomial infections.3-Point out the occurrence of the disease.4-List the causative agents, mode of transmission, and incubation period of Nosocomial infections .

5-Define the control strategies of Nosocomial infections. 6-List the main preventive measures of Nosocomial infections.

An infection occurring to a An infection occurring to a patient in hospital or other patient in hospital or other health care facility in whom health care facility in whom it was not present or it was not present or incubating at the time of incubating at the time of admission or the residual admission or the residual of an infection acquired of an infection acquired during a previous during a previous admissionadmission. .

Descriptive epidemiologyDescriptive epidemiologyAgentAgent hosthost

EnvironmentEnvironment

Diagnostic procedures , medical or Diagnostic procedures , medical or surgical therapy ..it can cause.. surgical therapy ..it can cause.. infectioninfection

Potent Potent immunosuppressive ,chemotherapeutimmunosuppressive ,chemotherapeutic agents &antibiotics ic agents &antibiotics affect affect normal floranormal flora

Exposure to persons who are infected Exposure to persons who are infected or carriers can transmit inf. (health or carriers can transmit inf. (health workers or patients)workers or patients)

Infection rate Infection rate differ considerably differ considerably among hospitalsamong hospitals

• Referral hospitals generally have Referral hospitals generally have higher rate than community higher rate than community hospitals:hospitals:

(More complex patient mix &more (More complex patient mix &more aggressive modes of therapy used)aggressive modes of therapy used)

Prevention (general outbreaks)Prevention (general outbreaks)::• Investigation of reservoir &mode of Investigation of reservoir &mode of

transmission transmission • Appropriate use of diagnostic Appropriate use of diagnostic

procedures ,invasive devices &medical procedures ,invasive devices &medical therapy particularly therapy particularly antibioticsantibiotics

• Hospital environment may be modified Hospital environment may be modified • Strategies to proper use of isolation Strategies to proper use of isolation

materials hand washing ,&other effective materials hand washing ,&other effective approaches to prevent transmission .approaches to prevent transmission .

Main categories of Main categories of Nosocomial infectionNosocomial infection

11..Urinary Tract InfectionUrinary Tract Infection::IT accounts 1/3 of NIIT accounts 1/3 of NI80%80% of NUTIs caused by urinary of NUTIs caused by urinary

catheterscatheters

The typical UTIs prolongs hospital stayThe typical UTIs prolongs hospital stay The prevalence of bacteruria during a The prevalence of bacteruria during a

short term use of catheter is: short term use of catheter is: approximately approximately 15%15% compared with a compared with a prevalence of prevalence of 90%90% in along term use in along term use

Risk factor for bacteruria:Risk factor for bacteruria:Duration of catheterizationDuration of catheterizationMicro bacterial colonization of the Micro bacterial colonization of the

drainage bagdrainage bagNo antibiotic useNo antibiotic useFemale genderFemale genderDiabetes mellitusDiabetes mellitusAbnormal serum creatinineAbnormal serum creatinineErrors in catheter careErrors in catheter care

PreventionPreventiona. Prevention of catheterization by the a. Prevention of catheterization by the

use of alternative approachuse of alternative approachPatient trainingPatient trainingMedicationMedicationSurgerySurgeryUse of special clothes &bagsUse of special clothes &bagsIntermittent catheterizationIntermittent catheterizationUse of external collection &urinary Use of external collection &urinary

diversiondiversion

b. Prevention of bacteruria once b. Prevention of bacteruria once catheterizedcatheterized

recommended recommended minimizing the minimizing the durationduration

closed drainage systemclosed drainage system

Good hand washing after caring each patient Good hand washing after caring each patient is the single measure most is the single measure most ––likely to likely to prevent cross-transmission of urinary prevent cross-transmission of urinary pathogenspathogens

2.Lower respiratory infection (LRI) 2.Lower respiratory infection (LRI) &pneumonia&pneumonia

It accounts >13% of NIs It accounts >13% of NIs

CFR 20-50%CFR 20-50%

N pneumonia associated with an excess N pneumonia associated with an excess length of stay of >/one weeklength of stay of >/one week

Most of NLRI occur in ICU &surgery Most of NLRI occur in ICU &surgery recovery units recovery units

Predisposing factorsPredisposing factorsEndotracheal intubationsEndotracheal intubationsTracheostomyTracheostomy (lead to decrease LRT defense (lead to decrease LRT defense

mechanisms ..drying and direct rout of entry)mechanisms ..drying and direct rout of entry)VentilatorVentilatorContaminated aerosolsContaminated aerosolsOther contaminated equipmentOther contaminated equipmentChronic lung diseases Chronic lung diseases Advanced age Advanced age prior administration of antibioticsprior administration of antibioticsImmunosuppression. Immunosuppression.

PreventionPrevention • General hygienic measuresGeneral hygienic measures• Use of barrier isolation materialsUse of barrier isolation materials• Routine decontamination of Routine decontamination of

respiratory equipments respiratory equipments • Using gloves ,gowns &masksUsing gloves ,gowns &masks• Annual influenza immunization of pts Annual influenza immunization of pts

&hospital staff&hospital staff

3.Surgical wound infections 3.Surgical wound infections (SWIs)(SWIs)

• sWIs are now the 2sWIs are now the 2ndnd most common most common NI accounting for at least 17%NI accounting for at least 17%

• Infection rate variesInfection rate varies according to: according to:• operative siteoperative site• patient co morbidity patient co morbidity

Sources :Sources : Inoculation from ptInoculation from pt’’s residual floras residual flora Contaminated host tissues Contaminated host tissues Surgical team members hands at the time Surgical team members hands at the time

of surgeryof surgery

Airborne contamination at the time of Airborne contamination at the time of surgery surgery

Post operative drains or cathetersPost operative drains or catheters

PreventionPrevention::

Disinfection of the skin at the incision Disinfection of the skin at the incision sitesite

Appropriate use of preoperative Appropriate use of preoperative antibiotics when indicatedantibiotics when indicated

Perioperative antibiotics started Perioperative antibiotics started immediately before surgery &continued immediately before surgery &continued for up to 24 hrs after are effectivefor up to 24 hrs after are effective

4.Nosocomial Diarrhea4.Nosocomial Diarrhea::A common problemA common problemRisk factorsRisk factors1.1. Older age Older age 2.2. sever underlying disease sever underlying disease 3.3. Hospitalization of more than one Hospitalization of more than one

weekweek4.4. Long stay in the ICULong stay in the ICU5.5. Prior antibiotic treatment.Prior antibiotic treatment.

5.Blood stream infection (BSIs)5.Blood stream infection (BSIs)Account for 14% of NIsAccount for 14% of NIs

Source:Source: 1-1-IV catheters , intrinsic IV fluid IV catheters , intrinsic IV fluid

contamination ,multi dose parenteral IV contamination ,multi dose parenteral IV medicationsmedications

2-Contamination of antiseptics2-Contamination of antiseptics

3-Contamination of hands of health workers3-Contamination of hands of health workers

4-External colonization of the catheter 4-External colonization of the catheter