Definition of occupational infection
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Transcript Definition of occupational infection
By : Dr ASLANI
OCCUPATIONAL MEDICINE SPECIALIST
Contents:
Definition of biologic agent
Types
Spreading
Definition of occupational infection
TB
HBV
HCV
HIV
Zoonoses
Controlling the risks
Definition of biologic agent:
Biological agents are living organisms or
products of living organisms.,
which may cause infection, allergy, toxicity
or otherwise create a hazard to human
health.’
Types:
They include:
bacteria
viruses
fungi (yeasts and moulds)
parasites
plants
Occupations and workplaces where people
may come into contact with biological
hazards
Medical staff, cleaning staff and laboratory
technicians in the medical profession;
Cleaning services
Agriculture, fishery, veterinary services,
BIOLOGICAL OCCUPATIONAL HAZARDS
infectious
allergic
toxic
Markku Seuri, FIOH, 2004
9
= occup. biohazards
SPREADING
by inhalation
by ingestion (from hand to mouth)
by sharps injuries
by blood or other body fluid contact
by bites
Work-related infection has been reported in the
literature as the third leading cause of occupational
disease.
Healthcare workers (HCWs) who are most often at
the frontline of outbreaks of emerging agents.
Definition of occupational infection
Work-related infectious disease is referred
to as disease that is caused or aggravated by
occupational exposure to biological agents
including bacteria, fungi, viruses and
parasites (helminths, protozoa) through
human, animal and/or environmental
contact.
Occupational infection can occur
following:
contact with infected persons, as in the case of
health care workers.
with infected animal or human tissue, secretions,
or excretions, as in laboratory workers.
with infected animals, as in agriculture.
………………………….
Occupational illness through contact with human
Type of
contact
Agents
Prevention
Percutaneous
inoculation
Hepatitis B, C
Gloves, needle stick
prevention
Air born transmission
TB, VZV,SARS, measles
Respiratory isolation,
air filtration(TB)
Respiratory droplet
SARS, rubella, influenza, mycoplasma, Respiratory isolation,
diphteria, etc
respiratory droplet
precautions
Fecal- oral
Shigella, vibrio, clostridium difficiel, E
coli, etc
Hand washing, gloves
Direct contact
HSV, VZV, SARS
Gloves, protective
clothing
TUBERCLOSIS
tuberculosis
مایکوباکتریوم توبرکلوزیز:عامل
Incubation Period :(+PPD)4-12W
The risk of development of clinical disease following
infection is higher in
-سوء تغذیه
-نقص ایمنی
-(ژنتیکHLA Bw15 )
- سن(کودکی و16-21 )سال
- کارسینوم، لنفوم، لوسمی،بیماری ها(سیلیکوزUpperGIدیابت،(
tuberculosis
HIGH RISK WORKS:
Staffs of
laboratories and necropsy rooms
health care settings (especially hospitals,
long-term care facilities, and dialysis centers)
substance abuse treatment centers
tuberculosis
Tubercle bacilli may be present in :
gastric fluid
cerebrospinal fluid
urine
sputum
tuberculosis
Transmition:
coughing
sneezing
talking by expelling small infectious droplets
that may remain suspended in the air for
several hours and then inhaled by susceptible
persons
tuberculosis
PPD>=5mm:
close contacts of
infectious patients
immunosuppressed
persons with known or suspected human
immunodeficiency infection (HIV)
tuberculosis
PPD>=10mm:
high-prevalence
(> 5%),
high-risk occupational groups (above)
high-risk groups such as
-immigrants from high prevalence areas
-alcoholics,
-intravenous drug users, and
-those with other disease states mentioned above
tuberculosis
PPD>=15mm:
persons
with no risk factors in areas of low
prevalence
tuberculosis
PPD:Neg
measles
Hodgkin
disease
sarcoidosis
immunosuppressive states
tuberculosis
Occupational candidates for periodic PPD
testing include
those having contact with suspected or known
infected patients,
persons working with potentially infected cattle
(veterinarians,……)
all others working in the higher-risk environments
mentioned above.
Hepatitis B Virus (HBV)
Individuals at occupational risk
Hepatitis B vaccination is recommended for the
following groups who are considered at increased
risk:
healthcare workers
laboratory staff
other occupational risk groups:
-morticians and embalmers
-prison service staff.
The prevalence of HBV infection among health care
personnel was 10 times higher than the general population
Blood contains the highest titers of virus in infected
individuals
with lower levels in various other body fluids,
cerebrospinal,
synovial,
pleural,
peritoneal,
Pericardial,
amniotic fluids,
semen and vaginal secretions.
Viral titers in
urine,
feces,
tears
Saliva
are low enough that these are not felt to be routes of
transmission
The risk for transmission of HBV through
needlestick injuries is approximately 30%.
HBV can remain viable for at least 1 month on dried
surfaces at room temperature.
-This poses additional opportunities to acquire
occupational HBV infections when individuals with
open cuts
or
abraded skin or mucous membranes contact
contaminated surfaces
Prescreening serologic testing
The current recommendations
check for surface antibodies 4 weeks to 6 months
following the primary series.
If the person tests negative for antibodies,
--- three additional doses (for a total of six doses) will
induce antibodies in 30–50% of nonresponders.
Those who do not develop
antibodies after six total doses
should consider changing positions
at work not involving blood or blood
products.
Hepatitis C Virus (HCV)
Occupational Exposure
It has been well-documented that transmission
of hepatitis C in a health care situation can occur.
The current estimate for transmission of HCV
following a needlestick injury from a positive
carrier of HCV is approximately 1.8%.
Transmission following mucous membrane
exposure is rare.
Following exposures to known
HCV-positive blood or blood
products
HCV RNA testing is often
considered 2–4 weeks after
exposure
Following exposures to Unknown
Source
HCV Ab testing is often considered
6–8 weeks after exposure
Human Immunodeficiency
Virus (HIV)
HIV transmission
occurs via blood and sexual contact.
Fortunately, occupationally acquired
infection has been a relatively
infrequent (albeit serious)
occurrence.
body fluids considered higher risk for HIV
transmission
Blood
semen and vaginal secretions
cerebrospinal
synovial
pleural
peritoneal
pericardial
amniotic fluids
The established rate of transmission
following a positive HIV exposure from a
needlestick injury
is approximately 0.3%,
making it approximately 10-fold less
transmissible as HCV
and 100-fold less transmissible as HBV.
postexposure TEST
Baseline testing for preexisting
infection at the time of the exposure
follow-up testing at 6 weeks and 3 and
6 months.
zoonoses
Zoonoses are defined as any disease and/or
infection that is naturally transmissible from
vertebrate animals to humans.
Occupations involving contact with infected
animals and/or their infected secretions or tissues
or contact can result in workrelated zoonotic
disease.
Zoonoses(occupation at risk)
veterinary medicine
farm workers
zoo keepers
meat processing plant workers and butchers
leather industries
pet shop workers
zoonoses
Zoonoses involve different types of agents:
bacteria (eg, salmonellosis and
campylobacteriosis),
parasites (eg, cysticercosis/taeniasis),
Rickettsia (eg, Q-fever),
viruses (eg,rabies and avian influenza),
Controlling the risks
eliminating risks:
eg by substituting a hazardous biological agent
with something less/non-hazardous:
eg using a non-toxigenic strain of a biological
agent when carrying out laboratory quality control
(QC) tests;
Controlling the risks
Engineering controls such as improvement of
- ventilation,
-partial isolation of the contamination source,
-installationof negative pressure and separate
ventilation and airconditioning system (e.g. in
medical wards for infectiousdiseases)
-the use of ultraviolet lamps can help contain the
spreadof contaminants.
Controlling the risks
If the contact with biological hazards cannot be
prevented,
the employees must use personal protective equipment
and adhere strictly to the practice of personal
hygiene.
Controlling the risks