Diseases and Pathogens
Vectors and Deficiency Diseases for class 5 Science
The organisms such as mosquitoes, ticks, etc., are the vectors of many diseases. They help in the spread of disease. On the other hand deficiency diseases are those that occur due to a lack of any particular nutrient in the body. In this concept, the students will know how vitamin and mineral deficiency in the body causes different diseases.
After reading the concept, students will be able to:
- Discuss the disease causing organisms and the vectors.
- Explain the relation between climate and vector-borne diseases.
- Demonstrate why prevention of vector-borne diseases is important.
- Remember diseases spread by Aedes mosquito.
- Recite the name of the vector of malaria disease.
- Summarise the vitamin deficiency diseases.
- Answer- which vitamin is responsible for night blindness?
- Understand the sources of vitamins and minerals.
- Describe kwashiorkor disease.
Each concept is explained to class 5 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.
Download the worksheets and check your answers with the worksheet solutions for the concept Vectors and Deficiency Diseases provided in PDF format.
Vector:
- A living organism that transfers disease-causing organisms (i.e., pathogens) from infected persons to healthy persons is called a vector.
- The vectors carry pathogens that multiply in or on their bodies. These pathogens are then transferred to healthy persons when the vectors bite them.
Examples:Vectors are generally insects like mosquitoes, houseflies, ticks etc.
Vector-Borne Diseases:
- The diseases caused by vectors are called vector-borne diseases.
- The prevalence of vector-borne diseases depends on the climate and weather of a place.
Examples:Malaria, dengue, yellow fever, encephalitis, etc.
Examples:In the rainy season, mosquitoes get favourable breeding grounds due to the accumulation of rainwater.
So, in the rainy season, people suffer from different mosquito-borne diseases.
Some Common Vector-Borne Diseases:
| S. No. | Vector | Name of the Disease |
| a) | Aedes mosquito | Chikungunya, Dengue, Yellow fever |
| b) | Anopheles mosquito | Malaria |
| c) | Black flies | Liver blindness |
| d) | Fleas | Plague |
| e) | Lice | Typhus |
| f) | Ticks | Lyme disease |
| g) | Tsetse Fly | Sleeping sickness |
Prevention of Vector-Borne Diseases:
We should take the following precautions to prevent the spread of vector-borne diseases—
- Use of insect repellents on clothes and skin.
- Regular tick checks on dogs, cats, cattle, and mice.
- Use of nets while sleeping to protect against mosquito bites.
- Washing and drying clothes after an outdoor visit.
- Removing leaf litters and woodpiles from the surroundings so that they do not become breeding grounds for insects.
- Preventing water to accumulate in the surroundings.
- Using disinfectants to control the spread of infections.
- Development of vaccines for protection against disease-causing pathogens.
Deficiency Diseases:
Diseases that are caused by the lack of essential nutrients, especially vitamins and minerals, in one’s diet over a prolonged time are called deficiency diseases.
Vitamin Deficiency Diseases:
Vitamins are nutrients required in small quantities in our diet for the growth and development of our body.
1. Vitamin A
| Sources | Carrots, spinach, milk, egg, liver, fish and yellow fruits like papaya, mango. |
| Functions | Required for normal vision, reproduction, growth and healthy immune system of an individual. |
| Deficiency disease | Night blindness |
2. Vitamin B
Vitamin B is of different types, such as Vitamin B1, B2, B12 etc. The deficiency diseases depend on the type of Vitamin B a person lacks.
| Sources | Egg, meat, chicken, red meat, milk and cheese |
| Functions | Vitamin B ensures that the body's cells are functioning properly. They help convert food into energy and form new blood cells. |
| Deficiency disease |
|
3. Vitamin C
| Sources | Citrus fruits such as oranges, lemons, strawberries, pepper, etc. |
| Functions | Vitamin C is necessary for the growth, development and repair of all body cells and tissues. It also maintains our body’s immunity and protect us from catching infections frequently. |
| Deficiency disease | Scurvy, a disease that is characterised by bleeding gums and skin spots.
|
4. Vitamin D
| Sources | Fatty fish, dairy products, cereals, beef liver, cheese, egg yolks, etc. |
| Functions | Vitamin D plays an important role in calcium absorption, immune function, and protecting bones and muscles. It can be produced by our body when our skin is exposed to sunlight. |
| Deficiency disease | Rickets, which is characterised by weakening of bones, especially near the joints.
|
5. Vitamin K
| Sources | Green leafy vegetables, fish, liver, meat, eggs. |
| Functions | Vitamin K is essential for blood coagulation.. |
| Deficiency disease | The deficiency of Vitamin K causes delayed blood clotting. |
Mineral Deficiency Diseases:
Minerals are nutrients that are required by our body in specific amounts to carry out the different body functions.
1. Iodine
| Sources | Salt and seafood. |
| Functions | Iodine is the most important element required for brain development. It is responsible for the production of hormones from the thyroid gland, which play a vital role in the metabolism of the body. |
| Deficiency disease | Goitre |
2. Iron
| Sources | Red meat, spinach, poultry, etc. |
| Functions | Iron helps in the formation of haemoglobin, a red pigment that plays a vital role in the transport of oxygen in our body. |
| Deficiency disease | Anaemia is a condition in which blood cannot carry the required oxygen to tissues, which sometimes results in death if not detected timely. |
Prevention of Deficiency Diseases:
The following ways can prevent the deficiency diseases—
- Eating a balanced diet with the right amounts of carbohydrates, proteins, fats, vitamins and minerals.
- Avoid overcooked or undercooked food.
- Avoid storing cut fruits and vegetables.
- Including fermented food and sprouts in the diet.
New Words
Fermented Food: Food prepared by controlled microbial growth which is good for health such as cheese, salami, yogurt, etc.
Blood Coagulation: The process by which blood thickens to form a blood clot. It prevents further blood loss during an injury.
Haemoglobin: The red pigment found in blood that helps in transporting oxygen to the tissues.
Hormones: Some chemical substances that are secreted by specific glands and travel to different parts of the body to regulate the functions of organs.
Did You Know?
- The deficiency of protein in the diet causes the disease Kwashiorkor. It is a severe form of malnutrition that occurs in children aged 5-7 years. The disease is characterised by swelling under the skin due to excess body fluids.
- Marasmus is another protein-deficiency disease that generally occurs in children below 5-7 years. This disease is mainly characterised by loss of muscle mass and fat. Children with this condition tend to be underweight.
