epidermiology and research presentation

1. DISEASE TANSMISSION AND
CONTROL
Presented by ;
TUMWINE AMBROSE-2023-08-19698
RUBAHIMBYA ROBERT
MUGALU ANISHA-2023-08-18607
NAKAWEESA GIDAH KULUSUMU-2023-08-18784
OWORI JOHN PAUL-2023-08-20542

2. Definition of a Disease
Is an abnormal condition that negatively affects the
structure or function of all or part of an organism,
and that is not immediately due to any external
injury.
Diseases are often known to be medical conditions
that are associated with specific signs and
symptoms.

3. Causes of Diseases
 Bacteria. These one-cell organisms are responsible for illnesses
such as strep throat, urinary tract infections and tuberculosis.
 Viruses. Even smaller than bacteria, viruses cause a multitude of
diseases ranging from the common cold to AIDS.
 Fungi. Many skin diseases, such as ringworm and athlete's foot,
are caused by fungi. Other types of fungi can infect your lungs or
nervous system.
 Parasites. Malaria is caused by a tiny parasite that is transmitted
by a mosquito bite. Other parasites may be transmitted to humans
from animal feces.

4. Predisposing factors of Disease Transmission
Predisposing factors also unknown as the risk factors
are characteristics, conditions or behavior that
increase the likelihood of getting a disease or an
infection.
And these may include the following;
 Poor environmental sanitation (water, air and soil
pollution)
 Poor personal hygiene
 Forced mass population displacement

5. Cont
 Addictions to substances and drugs (alcohol, smoking etc)
 Lack of vaccination
 Lack of health care facilities and resources
 Poor climatic and geographical factors
 Demographic factors (age and gender)
 Individual’s life style
 Poor nutrition
 Compromised/suppressed immunity
 Poor social-economic standards of living (poverty, poor
housing conditions)

6. Mode of disease transmission
 (contact, vector, vehicle)
 Contact transmission
– direct contact with infectious blood or body substances.
 droplet transmission
– infectious agent in large droplets (respiratory secretions /
splash / splatter).
 Airborne transmission
– infectious agent in aerosols and are inhaled.

7. Con’t
 Food-borne transmission
– consumption of contaminated food.
 Water-borne transmission
– consumption of contaminated water.
 Vector-borne transmission
– carried by a vector e.g. mosquito bites etc.

8. Airborne/Droplet Transmission
Droplets can carry viruses and
bacteria through the air which
can then be deposited onto
mucous membranes of the eye,
nose and mouth of a
susceptible person via
sneezing, coughing and talking.
e.g. whooping cough, rubella,
mumps, influenza,
meningococcal disease.

9. Contact Transmission
Direct contact
When blood or bodily substances from a person or
animal come in direct contact with another person
in such a way that it can enter their body.
e.g. Infected blood or other bodily fluid enters
another person’s system directly, via a wound or
via mucous membrane
e.g. Infected blood or other body fluid from an
animal, enters another person’s system via a
wound or via mucous membranes

10. Contact Transmission
Indirect contact
When germs from an infected host or other
source are passively transmitted to another
person e.g. via an inanimate object such as
surfaces, keyboards, mouse, telephone, utensils,
soiled linen, taps and sinks etc.

11. DISEASE TRANSMISSION CYCLE

12.  Infectious agents (pathogens)
Any microorganism that can cause a disease such as a
bacterium, virus, parasite, or fungus. Reasons that the
organism will cause an infection are virulence (ability to
multiply and grow), invasiveness (ability to enter tissue), and
pathogenicity (ability to cause disease).
 A reservoir
is any person, animal, arthropod, plant, soil or substance
(or combination of these) in which an infectious agent
normally lives and multiplies. The infectious agent depends
on the reservoir for survival, where it can reproduce itself in
such manner that it can be transmitted to a susceptible host.

13.  Portal of Exit
The place where the organism leaves the reservoir,
such as the respiratory tract (nose, mouth), intestinal
tract (rectum), urinary tract, or blood and other body
fluids
 Mode of transmission
Refers to how an infectious agent also called a
pathogen can be transmitted from one person, object
or animal to another e.g through contact, airborne,
water borne, food borne and vector borne.

14. • Portal of enter
The opening where an infectious disease enters the host’s body
such as mucus membranes, open wounds, or tubes inserted in
body cavities like urinary catheters or feeding tubes.
 Susceptible host
The person who is at risk for developing an infection from the
disease. Several factors make a person more susceptible to
disease including age (young people and elderly people generally
are more at risk), underlying chronic diseases such as diabetes or
asthma, conditions that weaken the immune system like HIV,
certain types of medications, invasive devices like feeding tubes,
and malnutrition.

15. Disease Control and Prevention
This can be defined as a programme
directed towards reducing disease
incidence (new infections); reducing
disease prevalence (infection in the
community at any given point in time) or
completely eradicating the disease.

16. Triad cont..
 To understand the pattern, we need to consider the agent that
causes disease, people they infect (hosts) and surrounding
(environment)
 The people are affected by environment e.g they may live in
wet climate with many mosquitoes.
 People can also affect the environment by draining swamps,
stagnant water, slashing bushes
 Similarly, the environment can affect the agent e.g altitude
and temperature for malaria
 When the balance between the 3 are fairly constant, the
disease is endemic

17. Disease Prevention
 Wash your hands. This is especially important before and
after preparing food, before eating, and after using the toilet.
 Get vaccinated. Vaccination can drastically reduce your
chances of contracting many diseases.
 Stay home when ill. Don't go to work if you are vomiting,
have diarrhea or have a fever.
 Prepare food safely. Keep counters and other kitchen
surfaces clean when preparing meals. Cook foods to the
proper temperature, using a food thermometer to check for
doneness.

18.  Also promptly refrigerate leftovers — don't let cooked foods
remain at room temperature for long periods of time.
 Practice safe sex. Always use condoms if you or your partner
has a history of sexually transmitted infections or high-risk
behavior.
 Don't share personal items. Use your own toothbrush, comb
and razor. Avoid sharing drinking glasses or dining utensils.
 Travel wisely. If you're traveling out of the country, talk to your
doctor about any special vaccinations — such as yellow fever,
cholera, hepatitis A or B, or typhoid fever — you may need.

19. WAYS / GENERAL PRINCIPLES OF DISEASE
CONTROL
1.Attacking the source
 Early diagnosis; by screening hence early treatment
 Notifications; infectious diseases should be reported to the local
health authority
 Epidemiological notification; investigation are done to identify the
source of infection and factors influencing its spread.
 Isolation; separate the infected people from those who are not yet
infected
 Treatment; cases and carrier to kill the infectious agents
 Quarantine; limitation of movement of

20. 2.Interrupting the route of transmission
Environmental hygiene eg water treatment
Personal and food hygiene
Vector control eg control of pets and other
animals
Disinfection and sterilization procedures

21. 3.Protecting susceptible host
Immunization
Chemoprophylaxis

22. Levels of disease prevention
1. Primordial prevention
 This is where activities or efforts are directed towards preventing risk factors from
happening
 eg maintaining a healthy weight and discouraging children from adapting harmful lifestyles.
2. Primary prevention
 This involves the preventive measures that prevent the onset of the disease.
 It aims to reduce the incidence of the disease.
 Thus the interventions are applied before there is any evidence of disease or injury. It
involves activities directed to prevent the effects of the risk factors.
 Primary prevention can be achieved through health promotion and specific protection.

23. Primary prevention cont...
Health promotion measures
 Health education
 Environmental modification
 Good personal hygiene
 Nutrition interventions
Specific preventive measures
 Immunisation
 Chemoprophylaxis

24. 3. Secondary prevention
 This is the identification of people who have already developed the disease at
an early stage when the disease can be treated and controlled. This includes:-
 Adequate treatment of cases,
 Mass treatment
 Regular examinations and screening to detect disease in its earliest stages

25. 4. Tertiary prevention
 It is used when the disease has advanced beyond its early stages.
 It is defined as all measures available to reduce or limit impairment,
disability and promote patient’s adjustments to irreversible conditions.
 Thus it refers to interventions designed to arrest the progress of an
established disease and to control its negative