Human Health

 Lecture 6 Human Health

Nutrition

Malnutrition- Malnutrition refers to deficiencies, excesses, or imbalances in the intake of energy and nutrients.

• Overnutrition- overweight, obesity and diet-related noncommunicable diseases (such as heart disease, stroke, diabetes and some cancers).
• Undernutrition- Wasting(low weight for height), stunting(low height for age) and underweight(low weight for age)
• Micronutrient based malnutrition- which includes micronutrient deficiencies(a lack of important vitamins and minerals) or micronutrient excess. Micronutrients deficiency is also known as Hidden Hunger. 

Body mass index(BMI)- Body mass divided by the square of the body height(Kg/m²) 

• Wasting <18.5 Kg/m²
• Normal Weight < 25 Kg/m² 
• Obese > 30 Kg/m²

Overweight and obese individuals are at an increased risk for many diseases

Food Fortification- Process of adding micronutrients to food to combat micronutrients based malnutrition. 

Biofortification- Breeding crops to increase their nutritional value by use of selective breeding and genetic engineering. 

Golden Rice- Rice produced through genetic engineering(food fortification) to combat Vitamin A deficiency.

Anaemia- Condition in which the number of RBCs or their oxygen-carrying capacity is insufficient to meet physiologic needs bacuse of the deficiency of Iron, Folate, Vitamin B12 and vitamin A. 

For details on Vitamin(Click Here) 

Immunity

Ability of an organism to resist getting infected by certain diseases due to the presence of an immune system. Mainly of two types

1. Natural immunity- Antibody is generated by body itself

• Innate Immunity- Present from birth, the natural response to infection
• Acquired Immunity- The immunity that is obtained by vaccination or exposure to pathogens is called acquired immunity.

2. Passive Immunity- Antibody is injected in body from external source. 

Herd immunity- Also called herd effect, community immunity, population immunity and mass immunity is a form of indirect protection to contagious diseases. It occurs when a sufficient percentage of a population has become immune to an infection thereby reducing the likelihood of infection for individuals with low immunit by acting as a barrier in disease transmission. 

Immune disorder(Autoimmune disease)- Dysfunction of the immune system and abnormal immune response to normal condition.

Immunodeficiency(immunocompromisation)- State in which the immune system's ability to fight infectious diseases is compromised or entirely absent.

• Primary Immunodeficiency- Caused by inherited genetic mutations.
• Secondary/Acquired Immunodeficiency- Caused by something outside the body such as a virus or immune suppressing drugs.

Immunosuppression- Reduction of the efficacy of the immune system for body part transplantation and other purposes. 

Human Immunodeficiency Viruses(HIV)- Virus that infect humans and severely affect the immunity system. Over time, HIV results in development of Acquired Immunodeficiency Syndrome(AIDS). 

Diseases

Abnormal condition that adversely affects the structure or function of some part of an organism.

Diseases related Terminology

• Pathology- Study of disease
• Etiology- Study of cause of disease
• Acute Disease- Disease of a short term nature. 
• Chronic Disease- Disease that persists over time. 
• Acquired Disease- Began at some point during one's lifetime
• Congenital Disease- Disease that was already present at birth
• Genetic Disease- Disease caused by one or more genetic mutations. Genetic disease is often Congenital but sometimes Acquired disease. 
• Hereditary/Inherited Disease- Type of genetic disease caused by genetic mutations that are hereditary
• Iatrogenic Disease- Disease caused by medical intervention such as side effects of medicines
• Idiopathic Disease- Disease with unknown causescauses or sources. 
• Zoonotic Diseases- Infectious disease that has jumped from a non-human animal to humans.
• Neglected Tropical Diseases- Diverse group of tropical diseases that are common in low income developing regions and receive little or no attention on its scientific treatment. 
• Orphan disease- rare diseases for which drug manufacturing will not be profitable
• Orphan drugs- to treat orphan diseases. 
• Drug resistance- Reduction in the effectiveness of a medication such as an antimicrobial in treating a disease or condition. 
• Quality Adjusted Life Year(QALY)- Measure of disease burden on the quality and the quantity of life lived.
• Disability Adjusted Life Year(DALY)- Measure of overall disease burden expressed as the number of years lost due to ill-health, disability and early death.

Types of Diseases

Congenital Diseases

Hemophilia- Genetic disorder that impairs the body's ability to make blood clots. It is of two types

• Hemophilia A- low levels of clotting factor VIII
• Hemophilia B- low levels of clotting factor IX

The disease is associated with X chromosome. 

• Female(carrier)- X(Affected)X(Normal) 
• Female(Affected with hemophilia)- X(Affected)X(Affected) 
• Male(Affected with hemophilia)- X(Affected)Y

Colour Blindness- Colour Vision Deficiency(CVD) is the decreased ability to see color or differences in color. Colour blindness is mainly congenital disease but it can be acquired disease also. 

Colour blindness is also associated with X chromosome. 

• Female(carrier)- X(Affected)X(Normal) 
• Female(Affected with colour blindness)- X(Affected)X(Affected) 
• Male(Affected with colour blindness)- X(Affected)Y

Sickle Cell Anemia- Associated with Chromosome 11(Autosome) 

Infectious Diseases(Non Contagious) 

Polio- Infectious disease caused by the poliovirus(RNA viruses). It spread through fecal oral transmission because of poor hygiene. 

Three types of wild poliovirus

• Wild Poliovirus Type 1(WPV1)- still exist in Afghanistan and Pakistan
• Wild Poliovirus Type 2(WPV2)- fully eradicated
• Wild Poliovirus Type 3(WPV3)- fully eradicated

Polio vaccines

1. Oral Polio Vaccine(OPV)- Live weakened form of poliovirus are used in OPV. It is given orally as a birth dose for institutional deliveries. 
2. Injectable Polio Vaccine(IPV)- Inactive form of poliovirus are used in IPV. It is given through injection. 

Vaccine Derived Polio- Vaccine derived poliovirus is a strain of poliovirus mutated from the strain originally contained in the oral polio vaccine(OPV). 

 

Tuberculosis(TB)- Airborne infectious disease caused by Mycobacterium tuberculosis bacteria that mainly affects the lungs, but can also affect other parts of the body.

• Multidrug Resistant Tuberculosis(MDR-TB)- Bacteria that do not respond to the first line TB drugs. MDR-TB is curable by using second line drugs. 
• Extensively Drug Resistant TB(XDR-TB)- Serious form of MDR-TB caused by bacteria that do not respond to the second line TB drugs, often leaving patients without any further treatment options.

Program to combat TB in India

• Nikshay Poshan Yojna- Launched by Ministry of Health and Family Welfare in 2018 to combat TB issue in India by providing Direct Benefit Transfer(DBT) of Rs 500 per month for nutritional needs.
• Saksham Project- Project by Tata Institute of Social Sciences(TISS) to provide psycho social counselling to DR-TB patients.

Hepatitis- Hepatitis is a liver inflammation disease. It can be infectious(viral hepatitis) as well as non infectious(toxic and Alcoholic hepatitis). 

Viral Hepatitis- 

There are five main strains of the hepatitis virus that are A, B, C, D, and E. Each one is with different modes of transmission and most common one are hepatitis B and C. 

Mode of Transmission- 

• Hepatitis A and E- Contaminated food and water
• Hepatitis B and C- Contact with infected blood and other bodily fluid
• Hepatitis D(only occur in person already affected by Hepatitis B)- Contact with infected blood 

Vaccine

• Hepatitis A, B and D- Vaccine available
• Hepatitis C and E- No Vaccine available

Pneumonia- Lung infections caused by bacteria, viruses, fungi and parasites. 

Influenza(Flu)- Infectious disease caused by influenza viruses. 

4 types of influenza virus-

1. Type A- Primarily infects bird and mammal. The combination of the antigenic viral proteins haemagglutinin(H1-H16) and neuraminidase(N1-N11) in the viral envelope defines the subtypes of Type A influenza                                                               Swine flu- H1N1, Avian Influenza(Bird flu)- H5N1, H5N6, H5N8, H7N9
2. Type B- Primarily infects human
3. Type C- Primarily infects human
4. Type D- Primarily infects cattle and pig

Non Infectious Diseases

Diabetes- Endocrine diseases resulting in high blood sugar levels. 

Blood sugar – (Peptide Hormone- Insulin) → Energy

Reason for Diabetes 

• Pancreas not producing enough insulin(Type 1 diabetes- autoimmune disorder in which body's immune system mistakenly attacks and destroys the insulin producing cells in the pancreas. Usually develop in young age. Insulin injection is used in Type 1 diabetes) 
• Ineffectiveness of insulin(Type 2 diabetes- Usually develop in mature age. Diabetes medication is used to treat Type 2 diabetes)

Gestational Diabetes- Diabetes that consists of high blood glucose during pregnancy and is associated with complications for both mother and child. Usually disappears after pregnancy but affected women and their children are at increased risk of developing type 2 diabetes later in life.

Cancer- Abnormal and uncontrolled cells division that destroy the body tissue. Some major treatment methods of cancer are as follows

• Chemotherapy- Use of chemicals to treat cancer.
• Immunotherapy- Boosting the natural defenses system of body
• Radiation Therapy- Use of high energy rays to eliminate the cancer cells and surgery to remove the affected tissue.
• CAR-T Cell Therapy- Engineering of a patient's immune system(T cells) to attack cancer cells.

Taking blood out → Extracting T cell → Genetic modification of T cell(CAR-T cell) → multiplication of CAR-T cells → Injecting CAR-T cells in human body

One Health Approach

The rise of zoonotic diseases underline the interdependence of human, animal health and ecological change. One health approach monitors the infectious diseases in entire ecosystem including human, animal and environment. 

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