Surveillance Of Health Care associated infections

Surveillance Of Nosocomial infections


Health care associated or hospital-acquired infection (HAI) (nosocomial infections) can be defined as:

Infection acquired during hospitalization; not present or incubating at the time of admission to hospital (i.e. occurs at least 48 hours after admission).

Determinants adding to increase the incidence of infection transmission at healthcare facilities

•Patients are generally less immune.
•Patients may have infections.
•Patients undergo invasive procedures.
•Healthcare providers may transmit infections to clients and to themselves.


Other general factors:

  • Overcrowding with limited physical space
  • Staff shortages.
  • Poor infrastructure.
 Modes of Nosocomial Infection Transmission

Modes of Nosocomial Infection Transmission

Disease-Transmission Cycle
(The Chain of Infection )


Chain of infection

Chain of infection


The infectious factor is the microorganism that can produce disease or illness.


The pathogen can be Colonization or Infection

•the colonization is the presence of microorganisms at body sites) without presence of symptoms or clinical manifestations of illness or infection.

•Colonization can be considered a form of vehicle and is a potential method of transmission.

•Developing an infection after contact with microorganisms depends upon the interaction between the contaminating organisms and the host.

•Not all individuals who are colonized will produce disease. actually, those who have grown from colonization to disease may represent only the “tip of the iceberg” of persons carrying a particular pathogen.

Smallest infective portion of a microorganism

•It is the critical number of microorganisms present on or in a tissue that when exceeded; it is very likely that the tissue will become infected.
•It varies by the microorganism and point of entry or invasion.
•Many causative agents of Hospital-acquired infections have a relatively high minimal infective dose e.g. For Klebsiella, Serratia spp. so other Enterobacteriaceae it is more than 100,000 microorganisms .
•Some causative factors, though, need very fewer particles to infect, such as hepatitis B virus (less than 10 viral particles).

Surveillance is the continuous, methodical compilation, review, analysis, and distribution of data considering a health-related matter for use in public health activity in order to decrease morbidity and death and to promote health.


• Design urgent procedure for cases of public health concern;

• Measure the burden of a disease (or other health-related event),

• Monitor trends in the burden of a disease (or other health-related event), including the detection of epidemics (outbreaks) and pandemics;

• Guide the planning, implementation, and evaluation of plans to limit and manage illness, damage, or adverse vulnerability;

• Prioritize the allocation of wellness sources;

• Present a source for epidemiological investigation.


Surveillance of Nosocomial infection work as an advanced alert system for approaching is a key function of the Infection Prevention & Control team.

•Steps of surveillance

• Assess the population served by the facility so that interventions can be directed at those complications of greatest value given available resources.

• Select the outcome (surgical site infection) or process (prophylactic antibiotics )for monitoring.

• Define all data elements and assure criteria definitions are valid, accurate, and reproducible.

• Collect the surveillance data.

• Calculate and analyze monitoring rates.

• Report and distribute surveillance information.


Aim of Surveillance

•Work as an initial notification practice for approaching public health emergencies.

•Document the influence of interference, or follow a progression towards designated objects.

•Monitor and explain the epidemiology of wellness obstacles, to allow preferences to be set.


Major types of HAI

Major types of HAI




Join our mailing list to receive our weekly updates