Diseases and Pathogens
Concept: Vectors and Deficiency Diseases
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.
Vitamins and related 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 and related 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.
