Disease

Infectious disease These disease can be transferred from one person to another or from one organism to another

Pathogens —> micro-organism that cause disease Eg virus, bacteria, fungi and protocist

Yes Direct contact Body fluid eg blood, semen Airborne Waterborne Food borne

COVID-19 AIDS/ HIV Flu/Influenza

Chronic disease These disease are not transferred between peoples or other organism

Genetic Environment Lifestyle

No

Cancer Cardiovascular disease eg CHD

Infect human lymphocytes Reproduce inside the lymphocytes Decrease the number of lymphocytes and antibodies It attacks a specific type of immune cells weakens the CD4 cells, which are helper T cell When HIV destroy the CD4 cells using their replication machinery to create new copies of the virus, it become harder for the body to fight off other infections Without treatment the infection might progress to an advanced disease stage called AIDS

On the surface of a T cell HIV binds to a CD4 receptor and one of the CCR5

The virus fuses with the host cell membrane and release RNA into the cell

The single stranded HIV RNA is converted into double stranded HIV DNA by the reverse transcriptase enzyme

After the HIV DNA Enters the cell nucleus the enzyme inegrase cuts the cells DNA and inserts the HIV DNA into it

The enzyme makes RNA copies of the DNA. HIV RNA is either inserted into new virus particles or processed and translated into HIV proteins

The long protein chains are cut into individual proteins by the enzyme HIV protease. A new virus is assembled with these proteins and HIV RNA.

The new virus particle is released from the host cell, taking with it part of the cell membrane and capable of infecting other cell

Semen Unprotected sex Injectors drug uses Blood transfusion and organ transplant - contact of blood and infected sexual fluid * virus cannot pass through undamaged skin Menstrual flow Vaginal secretion Pre ejaculatory fluid Breast milk

Small chemical molecules or compounds that are effective in treating inflection caus3d by bacteria Excessive amount of antibiotics is disposed out of the body Not stimulat3d or gain immunity

Don’t contain dead pathogen or weak pathogens or any toxins or special elements of pathogen Contain antibody formed in another organism Acquired immunity immediately Remain immune for a short time

1) harmless pathogens injected 2)antigens trigger an immune response it can take days for a lymphocytes making complementary antibodies to be activated 3) lymphocytes able to produce complementary antibodies multiples , antibodies released 4) the antibodies target the antigen and attach themselves to it in order to create memory cells The memory cells remain in the blood and will quickly respond to the antigen if it is encountered again in an infection by a live ‘pathogen’ As memory cells have been produced this immunity is long lasting

Animal testing and

Phase 1 Testing new drug on a small group of healthy individuals to find out the safe dosage or any side effect Phase 2 Testing on a small group of people with the disease Phase 3 Testing on a very large group of people FDA review Review and examine all the submitted data related to th drug or device and make the decision to approve or not Scale up to manufacturing Improve to commercial scale and validate process Post-marketing monitor & research FDA monitor all drug and device safety once product are available for use by the public

Age Gender Family history

Unhealthy diet Smoking High blood pressure High cholesterol Physical inactivity Overweight Excessive alcohol intake Stress