Transcript Community Health

Community health
Health services
Major services in hospital
1) Accident and emergency service - for the
initial
assessment and treatment of people who
develop
a sudden illness or who sustain an
accident
2) In-patient service - service for patients who
have
to be hospitalised
3) Specialist out-patient service - for treatment
of
mild cases, and for particular types of
diseases,
such as those of eyes, teeth, ears and
noses,
chests and lungs, of old people and
mental
illnesses.
Health services for children
1) Family health services
The Family Health Services operates Maternal and Child
Health Centres, providing a comprehensive health
programme for children up to five years old. Under this
scheme, the followings are provided
a) Immunisation programmes for infants and children.
b) Assessment of children at different ages to
detect
early developmental abnormalities, and
referring any
child to specialist care when necessary.
c) Health talks and counselling on child care offered
to
parents and expectant mothers.
d) Telephone service available to answer enquiries from
the
public.
2) Child Assessment Services
There are two Child Assessment Centres for children
from birth to 12 years old. They provide comprehensive
physical, psychological and social assessment as well as
therapy, parental counselling and referral for appropriate
placement of the child in the various institutions and
centres run by the government and voluntary agencies.
3) Dental Services
The School Dental Care Service provides regular dental
examinations, simple dental treatment and oral health
education to primary school children.
4) School Medical Services
The School Medical Service Scheme offers an economic
form of medical treatment service to all school children in
Primary 1 to Secondary 3 with the main objective of allowing
school children to have early detection, diagnosis of defects
and continued medical supervision.
Health services for the Physically and Mentally Handicapped
1) Prevention and early identification
Prevention of diseases, disabilities and accidents has an
important effect on reducing the rehabilitation services
required. The main aim is to prevent disability by
a) improving health education within the community,
b) establishing neonatal screening programmes
common
treatable congenital disorders,
c)
introducing
immunisation
programmes
controlling
common communicable diseases,
d) controlling usage of medicines hazardous to health,
e)
improving
environmental
living
conditions
prohibiting
usage of chemicals,
f) holding annual campaigns on road, industrial, home
and
recreational safety.
for
for
by
The comprehensive observation scheme by the Family
Health Centres for all infants between birth and the age of
five identifies children with risk of developing disabilities
and referred them for special attention. Observation of
children above the age of five is conducted in primary
schools by the Education Department. A combined
screening programme provides all Primary 1 population with
audiometric, vision and speech screening and identification
of children with learning difficulties.
2) Medical services
Medical services for the handicapped are available in
most hospitals, day centres, out-patient clinics and
infirmaries.
As for mental health services, the Castle Peak Hospital
and Kwai Chung Hospital provides facilities for
sophisticated treatment.
Psychiatric units are also available at the regional and
district hospitals. In parallel to these, psychiatric centres
provide a wide range of out-patient treatment, assessment,
counselling and after-care services on a regional basis.
3) Rehabilitation services
To enable the disabled to recover to the fullest extent
which their disabilities permit, special treatments are
provided, e.g.
a) Physiotherapy.
b) Occupational therapy.
c) Prosthetic-orthotic Services (this allows patients with
physical
disability to be fitted and supplied with various
prosthetic and
orthotic appliances designed to restore wholly
or partly their
bodily functions and /or appearance). Other
social,
rehabilitative services provide counselling, housing,
training,
day and residential care, transport, access,
sport
and recreation, and welfare grants for the disabled.
Health services for the old
Most hospitals include a Geriatrics Department
providing special treatment for the aged. There are
also special geriatrics department in some outpatient clinics and day hospitals. Besides, Community
Nursing Services provide continuing care to patients
discharged from hospitals and provides domiciliary
medical care and support for the elderly in their own
homes.
Food & water hygiene
Effect of various factors on bacterial growth
1) Temperature - With a rise in temperature, there is
a
steady increase in the growth rate of
bacteria,
reaching a maximum at the optimum
temperature.
Further increase in temperature,
however, leads to a
rapid drop in the growth rate due
to the denaturation
of enzymes. Low temperature also
slows down the
rate of bacterial growth.
2) Nutrient - Bacteria need food for growth.
Food
provides the energy for cellular activities and
the
material for forming cellular structures.
Food
availability is usually one of the most
important
factors affecting the growth of bacteria.
3) pH - Bacterial growth is also affected by the
pH
of the surrounding medium. Bacteria grow
best
at a particular pH, the optimum pH. The rate
of
growth drops rapidly as the pH deviates from
the
optimum value.
4) concentrated solution - When the bacteria
are
surrounded by hypertonic solutions, water will
be
drawn out of the cells by osmosis. As a result,
the
growth of bacteria may be slowed down. If
too
much water is lost, the bacteria may die
and
growth stops completely.
Principles of proper food handling
If food is handled by an infective person, the
contaminated food may cause infections. Persons who
handle food should always wash their hands first,
especially after visiting the toilet. In order to
prevent food from being contaminated by vectors of
diseases, such as flies and cockroaches, food should
be covered or wrapped, and stored under suitable
conditons.
Food Preservation
If fresh foods such as meat, fish, fruits and
vegetables are not preserved immediately after they
are harvested, they may become spoiled very quickly.
Food spoilage is due to the action of micro-organisms
which feed and multiply on food. Spoiled food usually
has an unpleasant smell and taste that makes it
unsuitable to eat. Furthermore, the pathogens it
contains are hazardous to health.
Food Preservation
(storing food under conditions that inhibit the
growth of microorganisms or killing them)

Heating
– kill most microorganisms & their
spores by high temperature

Canning & Bottling
– sealing in cans to avoid
bacterial entry
– should work together
with sterilization
Food Preservation

Refrigeration (4°C)
– to decrease or stop the activities &
growth of microorganisms (NOT killing
them)
 Freezing (-20¢XC for deep freezer)
– stop the activities of micro-organisms
– NOT killing them
– they can resume activity when ice melts
Food Preservation

Pasteurization
– kill most microorganisms without changing the flavour of
milk
– 72°C for 15s and then quickly cooled (or 63°C for 30
minutes) & bottled

UHT (Ultra High Temperature) treatment
– common in killing bacteria in milk
– superheated to ~150°C for a few
seconds and then sealed
To show the effect of pasteurization on milk
1) Expose some fresh milk to air for one hour. Then pour 20
cm3 of the milk into each of three conical flasks
2) Flask 1 - Boil a flask of milk.
Flask 2 - Put milk in a water bath at 63°C for 30 minutes.
Flask 3 - Leave the flask of milk at room temperature.
3) Plug all three flasks with sterile cotton wool.
4) Transfer 1 cm3 of milk from each flask to an agar plate with
nutrient agar. Swirl the plate to spread the milk over the
agar surface.
5) Seal the agar plates with adhesive tape
6) Incubate the plates at 25°C for at least 48 hours.
7) Count the number of bacterial colonies in each plate.
Results:
Plate 1 - least bacterial colonies
Plate 2 - slightly more bacterial colonies
Plate 3 - most bacterial colonies
Explanation
Plate 1 - sterilization kills nearly all the bacteria
Plate 2 - pasteurization kills quite a number
of bacteria, but not as effective as sterilization
Plate 3 - it shows the number of bacteria present
in the untreated milk.
Food Preservation

Drying (Dehydration)
– micro-organism in the food become inactive and cannot
multiply if water is removed from food. Thus the food can
be stored for a long time without spoilage. This method can
be used to preserve meat, fish, fruits and vegetables.
Food can be dried in air, under the sun or by vacuum (in
which water evaporates from food under low pressure and
at temperature well below boiling point of water, e.g.
in making milk powder that does not change its flavour or
destroy vitamins)
Food Preservation
Osmotic preservation
by adding salt (e.g. for fish and meat such as ham)
or concentrated sugar solution (e.g. for jam
preparations)
to remove water from micro-organisms by
osmosis to kill them

Food Preservation
Preservatives
– add some chemical to food to stop bacterial
growth or kill them, e.g. sodium nitrite
 Antioxidants - chemicals which stop oxidation and thus
prevent organisms from respiring. For instance, sulphur
dioxide is often used to preserve fruit juices and soft
drinks. It forms a reducing agent which kills microorganisms by removing oxygen.
Irradiation
The food processing industry is using ionizing radiation as
an alternative to chemical preservatives for certain foods.
Radiation kills microorganisms, parasitic worms and insect
pests, inhibits the growth of sprouts on potatoes and onions,
extends refrigerated shelf life, and delays ripening in some
fruits. For many foods, treatment with radiation does not
affect the flavour, texture, or colour of the food. The
nutrient quality of irradiated foods is equal to foods
processed by other commercial processing methods.
Irradiation never makes foods radioactive. It does, however,
create small chemical changes on certain food molecules,
producing unique radiolytic products. The long-term safety of
the consumption of such compounds is under investigation.
Irradiation
Many consumers react negatively to the use of
radiation on foods, associating radiation with cancer.
Some may confuse it with food contamination by
radioactive particles, such as that occurs in the
aftermath of a nuclear accident. For this reason, some
suggest using the term pico wave, believing consumers will
accept that term as readily as they did microwaves.
Irradiation reduces food wastage and can replace some
costly pesticides. Unfortunately, poor countries that have
many hungry people and little food for them lack
irradiation technology, and much of their food rots or is
eaten by insects.
Water purification
Why needed?
Water for domestic use is mainly supplied from
rivers, lakes or reservoirs which collect rain
water from large areas called catchment areas.
Waters from these sources contains particles of
different sizes, microbes and chemical substances.
The water has to be purified and treated before
it is supplied to homes for domestic use.
Steps
1) Screening - using metal grids at the place
where
water is taken from the reservoir to keep out
weeds
and large particles
2) Sedimentation - Water is pumped to the
sedimentation
tank where large particles will settle to
the bottom
3) Filtration - water is passed through filter beds of
sand
and gravel to remove suspended particles
4) Chlorination - chlorine is added to kill harmful bacteria.
5) Fluoridization - fluorine is added to water
to strengthen
the enamel of teeth to prevent tooth
decay
6) Storage - water is pumped up to water towers
for
storage from where water is delivered to our
homes
water
from
reservoir
pump
metal grids (screening)
sedimentation tank
water tower
sand
consumer
pump
chlorine added
gravel
filter bed
Disease patterns
Endemic (地方病)
An endemic disease is one that occurs regularly
in a certain region but clinically recognizable in only
a few.
Epidemic (疫症)
Epidemic diseases are infectious diseases which
occur in outbreaks when a large number of people
are affected at the same time, but later the
disease is brought under control.
Recent trend in modern societies
Shift from infectious diseases to chronic diseases (which
are more persistent, e.g. diabetes, tuberculosis and allergies,
degenerative conditions (such as heart and circulatory diseases,
strokes, arthritis), kidney failure, haemophilia and cancers) +
mental ill health.
Cause: Many infectious diseases (e.g. bubonic
plaque, malaria, small pox and measles) now under control
due
to
Understanding
of the nature of infection
Use of antibiotics and other drugs
Improvement in nutrition and personal health/ sanitation
Higher awareness of personal and community hygiene
due to health education
Device of more effective preventive measures such
as vaccines
On the other hand, people live longer and a great
proportion reach old age. It is in the elderly that
many chronic diseases show up.
Under long periods of continuous or intermittent
discomfort, sufferers of chronic diseases may
become much weakened and disabled. Medical and
nursing care has to be maintained for a long time.
Relation of major health problems of a modern industrialized
society to its physical and social environment
1) High concentrations of air pollutants in industrialised
city
cause more acute cardiac and respiratory disorders
2) More common contact with chemical agents, some of which
are
disease-causing. For instance, a person‘s
occupation
may expose him or her to special chemicals
hazardous to
health.
3) Living habits like overeating, particularly of fatty foods,
and
habits like cigarette smoking and drinking alcohol,
all
contribute to many chronic diseases associated with
the
heart and respiratory tract.
4 )
Manual work has been largely replaced by machines.
This
together with public and private transport has given
many
people a life-style in which exercises has very
little
part. Lack of exercises has now been recognised as a
health
risk and possibly lead to certain chronic diseases.
Some vaccination programs
When antigens of pathogenic microorganisms are artificially
introduced into the human body, the immune system is stimulated so
that the body becomes immune to subsequent infections by the
living pathogens. Such technique is called immunization or
vaccination. One vaccination schedule for children in Hong Kong is as
shown below:
Age
Immunisation recommended
Newborn
B.C.G.卡介苗
Polio小兒痳痺Type I
Hepatitis & B Vaccine - First dose
1 month
Hepatitis Vaccine - Second dose
2-4 months
Triple vaccine (diphtheria, tetanus &
whooping cough) - first dose
Polio trivalent - first dose
Age
Immunisation recommended
3-5
Triple vaccine (diphtheria, tetanus &
months whooping cough) - second dose
Hepatitis B vaccine - third dose
4-6
Triple vaccine (diphtheria, tetanus &
months whooping cough) - third dose
Polio trivalent - second dose
1 year
MMR vaccine (measles, mumps & rubella)
1O year Triple vaccine (diphtheria, tetanus &
whooping cough) - booster dose
Polio trivalent - booster dose
Age
Primary 1
Primary school
children
Immunisation Recommended
Combined vaccine (diphtheria &
tetanus) - booster dose
Polio trivalent - booster dose
B.C. G. (after tuberculosis testing)
Combined vaccine (Diphtheria &
tetanus) - booster dose
Polio trivalent - booster dose
Primary 6 (girls) Rubella vaccine
Primary 6
These vaccinations effectively wiped out or controlled a large no.
of diseases in children (e.g. small pox, measles, polio & tuberculosis)
Role of immunization in controlling infectious
diseases induces resistance to
Immunization, applied artificially,
specific infection. It is valuable not only in the protection
of the individual but also to prevent the spread of certain
infections, mainly those that spread directly from one
person to another, e.g. poliomyelitis, measles or smallpox.
When a significant proportion (usually more than 60%) of
the population is immunized, protection of unimmunized is
also achieved through a decrease in exposure to the
infectious agent. This is because successful transmission
from an infected person to a susceptible person is much
more difficult. The small numbers of vulnerable individuals
are, as it were, protected by being scattered among people
who are incapable of catching the infection and passing it on.
This is how immunization controls infection.
Sexually Transmitted Diseases (STD)
STDs refer to infections which can be spread from one
person to another through sexual contact. They can also be
transmitted from an infected mother to her child when it
is still in the uterus or when it passes out through the
vagina at birth.
Examples of common serious STDs are:
1) Syphilis梅毒- caused by bacteria
skin rashes caused
by syphilis
2) gonorrhoea淋病 - caused by bacteria and
3) AIDS (Acquired Immune Deficiency Syndrome)愛滋病caused by the HIV virus
Means of transmission
Since HIV cannot survive outside the human body, AIDS
can be contracted only through
a) blood (e.g. sharing of contaminated syringes for
injecting drugs) and
b) other body fluids (e.g. semen, vaginal secretion), e.g.
due to casual sex (both homosexual and heterosexual)
c) Breast milk.
Saliva, tear, urine, sweat and sputum may contain a very
small amount of HIV, but this amount is not known to
cause infection.
Preventive measures against the spread of STDs
1) Avoid sex outside marriage, although the use
of condoms may reduce the chance of infection
2) Avoid contact with contaminated blood, e.g.
wounds
should be covered up,
contaminated
syringe should not be used and
contaminated
materials should be handled
properly.
3) Early check-up and treatment of diseases in
a social hygiene clinic
4) Sex education for adults and school children
to
help them understand the risks of casual
sex,
the early symptoms of diseases, and where
they
can obtain information, advice and
treatment.