Stages of Infection

Health 8

1. Third Quarter Health EPIDEMIOLOGY

2. DISEASE An abnormal condition affecting the body of an organism Often construed to be a medical condition associated with specific signs and symptoms May be caused by factors originally from an external source such as infectious diseases or internal dysfunctions such as autoimmune diseases Any condition that causes pain, dysfunction, distress, social problems, or death to the person affected

3. DISEASE Physical injuries or disabilities are not classified as disease There can be several causes for disease, including infection by a pathogen, genetics (as in many cancers or deficiencies), noninfectious environmental causes, or inappropriate immune responses

4. INFECTION The successful colonization of a host by a microorganism Can lead to disease, which causes signs and symptoms resulting in a deviation from the normal structure or functioning of the host Microorganisms that can cause disease are known as pathogens

5. SIGNS vs. SYMPTOMS Signs are objective and measurable , and can be directly observed by a clinician. Vital signs, which are used to measure the body’s basic functions , include: Body temperature (normally 37 °C [98.6 °F ]) Heart rate (normally 60–100 beats per minute ) B reathing rate (normally 12–18 breaths per minute ) B lood pressure (normally between 90/60 and 120/80 mm Hg )

6. SIGNS vs. SYMPTOMS Symptoms of disease are subjective . They are felt or experienced by the patient, but cannot be clinically confirmed or objectively measured. Examples of symptoms include nausea, loss of appetite, and pain . Such symptoms are important to consider when diagnosing disease, but they are subject to memory bias and are difficult to measure precisely . Some clinicians attempt to quantify symptoms by asking patients to assign a numerical value to their symptoms.

7. SYNDROME A specific group of signs and symptoms characteristic of a particular disease Many syndromes are named using a nomenclature based on signs and symptoms or the location of the disease

8. OTHER RELATED TERMINOLOGIES Morbidity - the number of cases of a disease M ortality - the number of deaths due to a disease Communicable - capable of being spread from person to person through either direct or indirect mechanisms Non-communicable infectious disease - not spread from one person to another (e.g. tetanus) Non-infectious diseases - not caused by pathogens (e.g. Down syndrome)

9. OTHER RELATED TERMINOLOGIES Iatrogenic diseases - diseases that are contracted as the result of a medical procedure are known as Zoonotic diseases - not transmitted between humans directly but can be transmitted from animals to humans

10. Third Quarter Health STAGES OF INFECTION

11. INCUBATION STAGE

12. INCUBATION STAGE The onset of contagious disease wherein the virus multiplies until it affects the body’s defenses The period when infection and the first signs and symptoms associated with a disease appear

13. INCUBATION STAGE During this stage, a sick person may actually spread the disease-causing microorganisms without knowing because this is symptom-less stage where microbes can multiply inside the body and also spread to other people The length of this period is dependent on the kind of microorganism that invades the person and his/her immune system For example, the incubation period of chickenpox is 14-16 days and COVID-19 for 5-14 days

14. PRODORMAL STAGE

15. PRODORMAL STAGE During this stage, although the person does not feel weak, sick, or may not appear sick, the virus has become stronger than the body’s defenses The illness may be spread to other people This is a short stage of disease development where a person begins to feel that they are getting sick

16. PRODORMAL STAGE The signs and symptoms during this stage typically result from activation of the immune system, such as fever, pain, soreness, swelling, or inflammation.

17. ILLNESS STAGE

18. ILLNESS STAGE The illness has developed In case of flu, fever, aches, and pains, and other symptoms are present This is the stage where a person feels the typical signs and symptoms associated with the disease

19. ILLNESS STAGE This is also the stage where the person can most easily transmit a communicable disease to another person The peak of illness intensity is known as acme point

20. DECLINE STAGE

21. DECLINE STAGE This is the stage of disease development where the immune system begins to bring microbial replication under control which leads to the lessening of the signs and symptoms associated with the disease Damaged tissues begin to repair, and pathogen numbers decrease

22. CONVALESCENCE STAGE

23. CONVALESCENCE STAGE This is the final stage of the disease process where the microbial replication is fully stopped and the person returns to the pre-illness stage Although depending on the disease, the person may not proceed to this stage and may die from their disease or be disabled

24. The progression of an infectious disease can be divided into five periods, which are related to the number of pathogen particles (red) and the severity of signs and symptoms (blue).

25. REFERENCES: https://courses.lumenlearning.com/microbiology/chapter/characteristics-of-infectious-disease/#:~:text=The%20five%20periods%20of%20disease,into%20the%20host%20(patient).