ASEPSIS AND INFECTIONS CONTROL
A lot of lives are lost every year due to the spreads of infections in hospitals.
Health care workers are therefore required to take steps to prevent the spreads of
these diseases within and outside the health facilities.
Definition: Asepsis is defined as the state of being free from disease-causing
contaminant (such as bacteria, viruses, fungi and parasites)
Infection control is simply defined as a discipline concerned with preventing
nosocomial infection (health associated infection), infection control can be
achieved by ensuring that all medical and surgical procedures are performed
using aseptic techniques.
Medical Asepsis is any procedure intended to limit the number, growth and
transmission of microorganisms
Surgical asepsis is any procedure /practices that destroy all micro-organisms
and their spores. JOSEPH LISTER is the founder of aseptic techniques.
Definition of terms
Sterilization: is the process of total destruction of microorganism and
their spores ( both pathogenic and non –pathogenic )
Disinfection: this is the process of destruction of most pathogenic
microbes (excluding bacterial spores) on inanimate object.
Antiseptics: these are substances that destroy or inhibit the growth of
microorganism on living tissue or reduce the possibility of infection.
Examples are Dettol, Savlon, iodine, hydrogen peroxide and etc.
Disinfectant: these are chemicals that destroy microorganism that are
found on non-living objects e.g. Izal, chlorine, formaldehyde
High level disinfection: this is destructions of all microbes, but spores
may survive if initially present in large numbers usually through the use
of drastic method such as the use of concentrated chemicals (e.g.
formaldehyde), very high temperature or intense radiation.
Decontamination: this is the process of removing foreign material such
as blood, body fluids or radioactive substances from the objects, tissue or
surfaces. It does not eliminate microbes completely, but it is a necessary
step before disinfection or sterilization. Its significance is to make
something safe for handling by health workers.
Principles of asepses in health care settings
I. Only sterile object should touch sterile object
II. Always hold sterile object above the waist
III. Avoid talking, coughing, sneezing or reading over sterile field or object
IV. All items brought in contact with broken skin or used to penetrate the
skin in order to inject substances into the body or normally enter sterile
cavities should be sterile
V. Used dry sterile forceps always
VI. Consider an object contaminated if you have any doubt as to its sterility
VII. Any sterile package that is tempered with (e.g., syringe are considered
contaminated) hence should not be used
Signs of localized infection
1. Localized swelling
2. Localized redness
3. Pain or tenderness with palpation or movement
4. Loss of function of body part affected
Signs of systemic infections
2. Increase pulse and respiratory rate if the fever is high
3. Malaise and loss of energy
4. Anorexia, nausea and vomiting
5. Enlargement and tenderness of lymph nodes that drain the area of i
Course of infections
1. Incubation period
The time between the initial contact with infectious agent and appearance
of first sign and symptoms
2. Prodromal stage: the time period from the onset of non-specific
symptoms to appearance of specific symptoms related to causative
3. Full stage : manifestation of specific signs and symptoms of infectious
agent refer to as acute stage
4. Convalescence: time period that the host takes to return to pre-illness
Method of sterilization and disinfection
1. Physical method: this includes
i. Use of steam: applying high temperature and high pressure to
destroy microorganism. Common example is autoclaving use to
sterilize metal instrument, gowns, mask etc
Disadvantage: plastics and rubber devices are damage by
autoclaving. It also requires light.
ii. Boiling water: this method is simple and inexpensive; just boil
items for at least 10minutes from the time the water start boiling.
Disadvantage: it is insufficient to destroy all microbes and it should
be use where there is no autoclave
iii. Dry heat: used for metal items. Heat with very high temperature for
specified time. Disadvantage: Not very common
iv. Radiation: used for drugs, foods, plastics and other heat sensitive
items. Disadvantage: posed risk to personnel
v. Chemical method: chemical solution is mostly used for disinfection
and decontamination. Examples are sodium hypochlorite (JIK),
alcohol, beta-dine etc. Disadvantage: it does not destroy all spores
and may cause corrosion on metal surfaces.
Universal precautions are guideline to ensure prevention of transmission of
blood borne diseases to and from health workers, the patient and the environm
ent. Thorough these guidelines, all equipments are disinfected before and after
use and are disposed of properly. The guidelines are as follows:
The use of protective barrier (glove, mask, Google, etc)
Hand washing using antiseptic solutions and water
Proper disposal and management of medical waste
Disinfection of instrument with 0.5% chlorine solution (common chlorine
solution used in Nigeria are JIK, parazone and hypo
Steps of universal precaution using chlorine solution
Step 1. Decontamination: completely immerse all soiled instruments into the
0.5% chlorine solution. Make sure instrument are open, tubes are flushed allow
to stand for 10minutes.
Step 2. Cleaning: thorough cleaning with detergent and brush, Make sure all
stains are removed.
Step 3. Rinsing in clean water
Step 4. High level disinfectant (HLD)
Boiling: boil washed instruments for 20minutes, start counting from when
water starts boiling. Remove for use or store.
Remove instruments from solution using HLD cheatle forceps
Rinse with boil water
Place instrument on HLD tray or in HLD container then allow to dry
Use of personal protective equipments
PPE are equipment used by health workers to protect them from contacting
infection from others/environment or spreading infection to others. They
Surgical and latex disposable gloves
Masks protects contact of infection that are airborne, droplet infection,
poisonous gasses etc eg TB exposure
Surgical gloves: protect the health worker from contact with body fluid (e.g.
blood, other body secretions) wound etc
Gown: also protect the worker and the patient e.g. during surgery or conduct of
delivery. Gown must be sterile
Apron: protect worker from contact with body fluids e.g. blood. Always
Boots: also worn by nurses, midwives and doctors especially in bloody areas eg
labour room, theatre, accidents and emergency ward
Goggle: worn over the eyes to protect it from splashes of body fluids e.g. blood,
amniotic fluid etc