Transmissible diseases and non-transmissible diseases

• (a) distinguish between signs of a disease, e.g. rash, high temperature, which can be seen or measured, and symptoms, e.g. pain, which can only be described by the patient

• (b) distinguish between transmissible and non-transmissible diseases

• (c) state the chief signs and symptoms for each of the following transmissible diseases; influenza;severe acute respiratory syndrome(SARS) and dengue fever

• (d) state the chief signs and symptoms for each of the following non-transmissible diseases: colon cancer, coronary hear disease and diabetes

• (e) list general disease prevention measures such as personal hygiene, healthy lifestyle and regular medical check-ups

• (f) state that genes determine many of the characteristics that are passed on from parents to offspring, e.g. physical appearance, personality

• (g) state that some diseases are hereditary by nature, i.e. passed through the parents’ genes, e.g. thalassemia and sickle cell anaemia

1. Introduction

• How does our body parts protect ourselves from getting diseases?

• Mucus traps dust and germs in the air that we breathe in

• Tears contain an antiseptic liquid that kills germs

• Glands in the skin make an antiseptic oil that kills many germs

1. Introduction

• How does our body parts protect ourselves from getting diseases?

• Acid in the stomach kills germs in your food

• Blood clots stop the germs from getting in

• Skin forms a barrier to germs

(a) distinguish between signs of a disease, e.g. rash, high temperature, which can be seen or measured, and

symptoms, e.g. pain, which can only be described by the patient

• Signs of a disease

• Rash

• A high temperature

• Runny nose

• Watery nose

• High blood pressure

• Some symptoms of diseases

• Pain in joints

• Loss of appetite

• Stiffness in neck

• Headache

• Diseases can be broadly classified as

• 1) Transmissible

• 2) non-transmissible

1. Transmissible disease

• Transmissible diseases are diseases that are transmitted among people by

• disease-causing microorganisms

or

pathogens.

• Transmissible Diseases and their Main signs and

symptoms

Transmissible disease Main signs and symptoms

Influenza ( or flu ) Starts with headache, chills, cough

Severe acute respiratory syndrome ( SARS )

Starts with a fever higher than 38.0o C

Followed by cough, and difficulties in breathing, chills, headache, muscular aches, sore throat and diarrhoea

Transmissible disease Main signs and symptoms

Dengue fever Starts with a sudden high fever up to 40.5oC, severe headache, pain behind the eyes, severe joint pains, muscular pains and muscular aches

• Types of pathogens

• And

• Transmissible disease caused

Types of pathogens

Transmissible disease caused

Viruses Influenza, rubella( German measles), AIDS

Bacteria Tuberculosis, typhoid fever, cholera

Protists African sleeping sickness, malaria, amoebic dysentery

Fungi Athlete’s foot, thrush

virus

bacteria

protists

fungi

Spreading of Transmissible Diseases

• Transmissible diseases can be transmitted or spread by

• People ( those infected with transmissble diseases)

• Animals (e.g mosquitoes)

• Non-living things ( such as contaminated food, water and air)

• Pathogens are commonly spread through coughing, sneezing or using common objects such as infected needles.

3. Non-transmissible diseases

• Non-transmissible diseases are generally diseases that are not caused by pathogens and cannot be spread among people.

• Non-transmissible diseases are also known as non-infectious or non-communicable diseases.

Non-transmissible disease

Main signs and symptoms

Colon cancer No symptoms in early stages

Bleeding of gut wall, anaemia, traces of blood in faeces, diarrhoea or constipation

Coronary heart disease

Chest pain and shortness of breath in early stages

Heaviness, tightness, pain, burning, pressure or squeezing, usually behind the breastbone, arms, neck, jaws

Non-transmissible disease

Main signs and symptoms

Diabetes Loss of weight, excess urine production, weakness, extreme hunger and thirst

• General disease prevention measures:

• Practising personal hygiene

• Leading a healthy lifestyle

• Having regular medical check-ups

• Personal hygiene includes:

1) washing your hands before meals, after going to the toilet and before handling food or drinks

• 2) taking regular baths or showers especially in hot weather or after sweating

• 3) cooking food properly, covering it to keep flies away and eating it before it turns bad

• 4) boiling water before drinking it during any outbreak of transmissible diseases

Leading a healthy lifestyle

• There are two types of white blood cells in our immune system to defend our bodies against diseases.

• One type of white blood cells ‘eats’ and destroys pathogens.

• One type of white blood cells makes antibodies that kill pathogens.

Having regular medical check-ups

• To detect visible signs of diseases, a doctor

• Looks out for rashes, watery eyes and running nose

• Looks out for signs of diseases on the skin, tongue, hair and fingernails

• Use a thermometer to measure the body temperature

5. Hereditary and Diseases

• The passing of characteristics from parents to their offspring is called heredity.

• Chromosomes are found inside the nucleus of every cell in the human body.

• Each chromosome is composed of an extremely long thread of a compound called deoxyribonucleic acid or DNA. The DNA molecule looks like a spiral staircase with pairs of bases forming the steps on the spiral staircase.

• A gene is made up of a short length of DNA. Different genes are made up of different lengths of DNA with different bases

• Each gene contains instructions that determine the characteristics to be passed on from parents to their offspring.

• The offspring can inherit physical characteristics such as hair, eye and skin colour from the parents

• Some examples of inherited diseases are shown in the table below.

Inherited diseases Sign and symptoms

Sickle cell

anaemia

- Sickle-shaped red blood cells-Pale skin-Low count of healthy red blood cells (anaemia)-Breathing difficulties

Inherited diseases Possible effects

Sickle cell

anaemia

- Poor physical development

- Heart problems

- Fatigue

- Pneumonia

- Damaged abdomen

- Kidney failure

Inherited diseases Sign and symptoms

Thalassemia -Severe anaemia

-Pale skin

-Shortness of breath

- Abdominal swelling

Inherited diseases Possible effects

Thalassemia - Enlarged spleen

- Bone deformities

- Fatigue

- Viral infections

- Death before or shortly after birth

Thalassemia red blood cells

Thalassemia patient

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