chapter 13

• The treatment for dengue are bed rest ,drink plenty of fluids to prevent dehydration ,paracetamol for high fever.
• There are two types of dengue ,the first one is Dengue Fever Virus and then the Dengue Haemorrhagic Fever
• The sign and symptoms for Dengue Fever Virus are red rash ,fever and vomiting while for Dengue Haemorrhagic Fever the symptoms are red dots ,severe bleeding from nose and gums and also abdomical pain .
• The prevention of dengue which is

  Social factor

  -increase literacy level

  -increase public education through advertisement

  -more inspection on mosquito breeding site .

  economical factor

  -fogging

  -fine by government

  -add more funds in programs that killed mosquito

  biological factor

  -use netting for windows gaps

  -wear bright colours with long sleeve shirt

  -cover container with lids
• The causative agent of dengue is Dengue Fever Virus (DENV) and the vector is the infected female Aedes aegypti mosquito .It is a arbovirus because it is a vector-borne virus .
• Malaria

  -causative agent :Plasmodium (it is a protoctist )

  Plasmodium vivax ,ovule ,malariae ,falciparum

  -vector :infected female Anopheles mosquito

  -it is a arbovirus as it is a vector-borne disease .
• Malaria transmission


  1. Mosquito takes blood meal from uninfected person

  2. Mosquito injects saliva containing anticoagulant

  3. Sporozoites released into uninfected person

  4. Sporozoites diffuse into liver cells

  5. Sporozoites undergo multiple fission in liver cells

  6. Merozoites produced and released into bloodstream

  7. Merozoites infect red blood cells

  8. Merozoites undergo multiple fission in red blood cells

  9. Red blood cells burst releasing merozoites and toxins

  10. Some merozoites differentiate into gametocytes
• Malaria transmission in mosquito


  1. Mosquito takes blood meal from infected person

  2. Gametocytes fuse to form zygote in mosquito gut

  3. Cyst forms on outside of mosquito gut

  4. Sporozoites form through multiple fission in cyst

  5. Sporozoites migrate to mosquito salivary gland
• The symptoms of malaria

  -periodic chill and fever

  -jaundice

  -anaemia
• The treatment of antimalarial drugs are chloroquine and prophylatics .
• Five ways to prevent malaria :

  -increase education about malaria

  -prevent stagnant water

  -increase funding on health care and program to kill mosquito

  -insecticide DDT

  -increase literacy level
• Cholera

  -causative agent : Vibrio Cholerae ( a small ,comma-shaped bacterium with distinctive flagellum )

  -It is transmitted by water and food
• Transmission of Cholera


  1. Vibrio Cholerae moves to small intestine

  2. Vibrio Cholerae multiplies by binary fission

  3. Vibrio Cholerae releases neuraminidase enzyme and extoxin choleragen

  4. Neuraminidase enzyme alters surface protein on epidermal cell to accept choleragen toxin

  5. Choleragen toxin stimulates epithelial cell to secrete chloride ion to small intestine lumen

  6. Sodium ion flows out to lumen to maintain electrical neutrality

  7. Water flows from cell to lumen following water potential gradient

  8. Prevents normal absorption of salt and water

  9. Dehydration of cell causes inflammation of small intestine

  10. Causes vomiting and severe water diarrhea
• The signs and symptoms of cholera

  -severe watery diarrhea

  -nausea and vomiting

  -dehydration
• The treatment of cholera

  -Oral dehydration treatment (to replace lost of fluids and electrolytes )

  it is because it contain sodium ,potassium ,chloride.

  -antibiotic

  reduce duration of cholera symptoms

  -zinc

  play a role in immune system to shorten the duration of diarrhea
• Tuberculosis

  -causative agent : mycobacterium tuberculosis

  it is a air-borne disease

  it is a fungus- like rod shape bacteria

  often affect lungs
• Mode of transmission :

  -bacteria enter and travel into the lungs

  -It is collected in the alveolus

  -The alveolar macrophages will engulf and destroy the bacteria by forming a granuloma.

  -However mycobacterium tuberculosis resist the destruction of microphage

  -When the immune system starts to weak ,the myocardium tuberculosis will escape from granuloma and replicate ,causing symptoms of active tuberculosis

  -the active tuberculosis will then flow into the blood vessel .
• sign and symptoms of tuberculosis :

  -persistent cough

  -clubbing finger

  -shortness of breath
• Treatment of tuberculosis

  -antibiotics (streptomycin )

  -use DOT therapy (Directly Observe Therapy )
• prevention of tuberculosis .

  -provide BCG vaccine to new birth ,to ensure herd immunity

  -isolation

  -contract tracing
• Reasons why tuberculosis increase

  -infected migrant

  -poor housing condition

  -drug resistant
• Vector is the organism that transmits disease from an infected person to an uninfected person .
• kill bacteria ->antibiotics

  kill virus -> antiviral

  kill fungi->antifungal disease
• Lymphatic system is the system consists of lymphatic vessel .lymphatic duct ,lymphatic node and other lymphoid organs which involve in body defense system .
• Role of lymphatic vessel are return the remainder of body fluid into the blood circulatory system and transport lymphocytes in immunity .
• Immunity is the capacity to recognise the invasion of foreign materials and to mobilise cell and products to destroy the foreign material .
• The antigen is a organic molecule which is naturally proteins ,glycoprotein and large polypeptide molecule .
• The antibody comprise by four polypeptide chain which is two heavy and two light chain link by disulphide bond .
• The components of lymphatic system are lymphatic vessel ,lymph ,lymphoid organ .
• The lymph are clear and colourless, it does not have proteins and erythrocytes .It flow slowly .
• The lymphatic vessel :

  lymphatic capillary

  -slow

  lymphatic duct

  -have valve (can flow in one direction )

  -two main lymphatic ducts are right lymphatic ducts and thoracic duct
• Lymphoid organ

  -spleen (filter blood)

  -tonsil (filter food and air)

  -thymus gland (a site where lymphocytes is divide and mature to T cell ,T cell will then migrate to blood, lymph,spleen and lymph node .
• The classes of antibody are IgM,IgA,IgG,IgD,IgE .
• IgM

  -It is a pentamer

  -large size

  -function : involved in first immunity response

  -helps in agglutination and complement activation
• IgA

  -A gred ,small amount of antibody in blood

  -a dimer

  -produce many by cell in the mucous membrane

  -function:to prevent attachment of pathogen on the epithelial cell on tract for example respiratory tract ,urinary trach ,reproductive ,digestive .and also prevent invasion of pathogen into the tissue

  -mostly found in body secretion ,mucus such as is tears ,saliva ,breast milk (colostrum )which will prevent baby from gastrointestinal infection.
• IgG

  -monomer

  -circulating in blood

  -small (can cross the wall of blood vessel to lymph )

  (can cross to placenta ,IgG from maternal blood will be transfer to the baby foetal blood .As this baby will get natural passive immunity from the mother .)

  -function : involve in secondary immune response

  -complement activation