Science Answer the questions.[Bio-3M]

Malaria: Malaria is caused by a protozoan parasite Plasmodium. This disease spreads through the bite of an insect vector–the female Anopheles mosquito which feeds on human blood. Male Anopheles mosquito feeds upon plant juice. Main symptoms of malaria include headache, nausea, muscular pain and high fever.

Malarial attack consists of three stages:

1. Cold stage, feeling of extreme cold and shivers.
2. Hot stage, high fever, faster respiration and heart beat.
3. Sweating stage, due to profuse sweating, temperature of the body goes down to normal.

AIDS: AIDS stands for Acquired Immuno Deficiency Syndrome. It is a fatal disease. The disease of AIDS is caused by retrovirus (a RNA virus) known as Human Immunodeficiency Virus (HIV). AIDS virus attacks white blood cells (WBCs) or lymphocytes of human beings and weakens the human body’s immunity or self-defence mechanism.

Some important symptoms of AIDS are: Swollen lymph nodes, regular fever, sweating at night and weight loss. Its virus also cause severe damage to brain and may lead to loss of memory, ability to speak and of clear thinking.

Tuberculosis: T.B. is an infectious disease which is communicated from one person to another directly or indirectly. It is caused by the bacterium called Mycobacterium tuberculosis. T.B. can affect all parts of the body such as lungs, lymph glands, bones, intestine etc. The incubation period of T.B. includes a few weeks to a few years. The patient of tuberculosis feels sick and weak. There is a loss of appetite and weight. Typical fever pattern and night sweats are also common.

Polio: Poliomyelitis or polio is a disease of the nervous system caused by one of the smallest known virus, called polio virus. The virus enters the body through the food and water and reaches the intestine and from there it enters the CNS or central nervous system via blood stream and lymphatic systems. Children between the age of 6 months to 3 years are most prone to polio infection. Polio is transmitted among children by the faeco-oral route and through the direct contact, dirty hands, contaminated food or milk and flies. The early symptoms of the polio disease are sore throat and headache.

Pulse Polio Programme: Pulse polio immunization programme forms the largest single day public health project. Pulse means a dose of a substance (here polio vaccine) especially when applied for a short period of time. It was conducted for the first time in 1995. The program uses oral polio vaccine or OPV. As per the National Immunization Schedule (NIS), a dose of 3 drops is given orally to the child, i.e. one dose each at 1.5, 2.5 and 3.5 month’s age. Finally a booster dose is given at the age of 1.5 years. After oral administration, virus particles in the vaccine begin to live in the intestine of the human body and multiply. It leads to production of protective molecules in the intestine and the blood.

Principle of Treatment: There are two ways to treat an infectious disease. One is to reduce the effects of the disease and the other way is to kill the cause of the disease. For the first requirement, we can provide treatments that will reduce the symptoms. The symptoms are usually a result of inflammation. For example, we can take medicines that bring down fever, reduce pain or loose motions. We can take bed rest so that we can converse our energy. However such a kind of symptom-directed treatment by itself is inadequate. Since it will not make the pathogen go away, so the disease will not be cured. For that we have to kill the microbe itself.

Organ Specific Manifestation: These are the diseases caused in the same organ or organ system as the point of entry of the microbe. E.g. Tuberculosis which enters through the nose and affects the lungs. (Both are organs of the respiratory system)

Tissue Specific Manifestation: These are the diseases caused in a different organ as the point of entry. E.g. Japanese Encephalitis which enters through the blood but affects the brain.

Casual organisms of the following diseases:

1. Tuberculosis: Mycobacterium tuberculosis.

2. Kala-azar: Leishmania (protozoa).

3. Malaria: Plasmodium.

4. Measles: Virus.

5. Athlete's foot: Fungi.

6. Cholera: Vibrio Cholerae.

Colds are caused by viruses. When people take them unnecessarily, antibiotics become less effective because bacteria build up a resistance to them. That's why your doctor won't prescribe an antibiotic if you have a common cold. Common cold is caused by a virus and virus do not have a fixed biochemical pathways that is why antibiotics and not able to get into their way.

A prolonged bout of diarrhea or vomiting can cause the body to lose more fluid than it can take in. The result is dehydration, which occurs when your body doesn't have the fluid it needs to function properly. Severe dehydration can cause your kidneys to shut down. Though some types of diarrhea, such as those due to other medical conditions, are unavoidable, infectious diarrhea can be prevented. The most important way to avoid diarrhea is to avoid coming into contact with infectious agents that can cause it. This means that good hand washing and hygiene are very important.

Infection of HIV is found to have multiple dimensional effects. In case of HIV infection, the virus goes to immune system and ultimately damages its function. Thus many symptoms of HIV-AIDS infection are due to the fact that patients body no longer fight off many minor infections that he/she faces everyday.

Antibiotics are effective against bacteria but not against viruses. Antibiotics block specific pathways found in bacteria. Viruses do not have their own metabolic pathways, therefore, in order to reproduce us to use the metabolic pathways of the cells they infect.

Our immune system is activated in response to infection. Multicellular animals have dedicated cells or tissues to deal with the threat of infection. Some of these responses happen immediately so that an infecting agent can be quickly contained. Other responses are slower but are more tailored to the infecting agent. Collectively, these protections are known as the immune system. The human immune system is essential for our survival in a world full of potentially dangerous microbes, and serious impairment of even one arm of this system can predispose to severe, even life-threatening, infections.

The provisions made by local authorities was to allocate funds and guide investments, encourage research, develop human resources through training and other capacity-building efforts, promote water quality monitoring, provide guidelines for various programmes and ensure the implementation of the water supply programmes.

There are many provisions provided by local authorities for solid waste management. These are followings:

1. Sweeping.
2. Collection.
3. Vermi-composting.
4. Recycling system.
5. Transportation system.
6. Power generation.
7. Dumping.

The immune system protects the body against disease or other potentially damaging foreign bodies. When functioning properly, the immune system identifies and attacks a variety of threats, including viruses, bacteria and parasites, while distinguishing them from the body's own healthy tissue.

An antigenic substance prepared from the causative agent of a disease or a synthetic substitute, used to provide immunity against one or several diseases. Immunization is done through various techniques, most commonly vaccination. Vaccines against microorganisms that cause diseases can prepare the body's immune system, thus helping to fight or prevent an infection.

There are two ways to treat an infectious disease. One is to reduce the effects of the disease and the other way is to kill the cause of the disease. For example, we can take the medicines that bring down the fever, reduce pain or loose motions. We can take bed rest so that we can converse our energy. This exercise will enable us to focus on the healing. However it will not make the pathogen to go away, so the disease will not be cured. For that we have to kill the microbe.

The two consequences that a person has to face while dealing with an infectious diseases are that the body organs and functions are damaged and need a lot of care for the recovery. The second thing is that the person becomes prone to further infections and diseases and have low immunity.

Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an agent (known as the immunogen). The most important elements of the immune system that are improved by immunization are the T cells, B cells, and the antibodies B cells produce.

1. Physical inactivity: It is one of the main reasons for many diseases

2. Raised cholesterol: It leads to blocked heart and arteries. It causes damage to cardiac and nervous system

3. Unhealthy diet: Unhealthy diet leads to malnutrition and excess of nutrition. It damages the body parts and bodily functions

4. Raised blood glucose: It leads to diabetes and a person has to rely on medicine throughout life.

“Prevention of disease is more desirable than its treatment” The three strategies that can be adopted for the prevention of infectious diseases, Maintenance of hygiene and precautions to ward of diseases Proper nutrition to cope with the loss incurred by disease Intake of medicine and proper treatment to stop the disease for ever.

Prevention is better than cure as a disease always cause some damage to the body, loss of working days, besides expenditure on medication. The important precautions for preventing occurrence of diseases include.

• Hygienic environment.
• Personal hygiene.
• Proper nutrition.
• Clean food.
• Clean water.
• Regular exercise
• Adequate relaxation.

Everybody should also be aware of diseases and their mode of spreading (epidemic). A regular medical checkup is also earnestly required to stay healthy.

There are many types of health problems that can possibly arise after disaster such as victims of disaster might suffer from lack of nourishment due to inadequate food. The immediate health problems after disaster includes suffering of trapped people, people may suffer from fractures, burns and asthma due to dust particles arising from buildings. Contaminated water can also cause other health issues.

The right answer is Diarrhoea: Diarrhea, also spelled diarrhoea, is the condition of having at least three loose or liquid bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss.

Three diseases caused by Bacteria are:

1. Tuberculosis(T.B.).
2. Cholera.
3. Typhoid.

Three diseases caused by Virus are:

1. Influenza.
2. Jaundice.
3. AIDS.

Infectious diseases are illnesses that are contagious, meaning they can be spread from one person to another. Infectious diseases are caused by microorganisms, called pathogens, or what we commonly refer to as germs. Viral and bacterial infections are the most common causes of infectious disease. However, fungi and one-celled organisms called protozoa can also be responsible. Flu or influenza Non infectious diseases are illness that are non contagious and cannot spread through contact. Example is Allergy and blood pressure.

The person having AIDS lose the power of fighting any infection. The disease of AIDS is caused by retrovirus (a RNA virus) known as Human Immunodeficiency Virus (HIV).

AIDS disease spreads among human beings in the following ways:

1. The AIDS usually spreads through unprotected sexual contacts with an infected person carrying AIDS virus.
2. It also spreads through the transfusion of blood contaminated with an AIDS virus.
3. It also spreads through the use of infected needles for injections.
4. An AIDS infected mother can transmit the virus to her child during pregnancy or during birth.

The Advisory Committee on Immunization Practices (ACIP) recommends that all children receive their first dose of Hepatitis B vaccine at birth and complete the vaccine series by age 6–18 months. Older children and adolescents who did not previously receive the Hepatitis B vaccine should also be vaccinated. It may be due to lethargic attitude or ignorance of the parents that children did not get the vaccination.

Stagnant water (of pools, ponds) in the locality is the habitat of larvae of many types of mosquitoes and they are the vector of a disease, called malaria.

Doctor confirms malaria if the patients have following symptoms:

Headache, nausea, muscular pain and high fever. Doctor also checks the presence of malarial parasite in the human body by blood test.

For the culture, a small sample of your blood, stool, urine or bone marrow is placed on a special medium that encourages the growth of bacteria. The culture is checked under a microscope for the presence of typhoid bacteria. A bone marrow culture often is the most sensitive test for S. typhi.

Antibiotics: They block biochemical pathways of bacteria such as synthesis of cell wall and proteins. Therefore bacteria die due to antibiotic action.

There are many disease that are mostly internal and non-infectious. For example, High blood pressure can be caused by excessive weight and lack of exercise. Lack of exercise and excessive add more cholesterol and makes the pressure of blood high. It leads to high blood pressure and causes problem in heart.

Important viral diseases of human beings are:

1. Influenza: Influenza is commonly called flu. It is caused by an influenza virus (Myxovirus influenza). There exist three types of influenza viruses-A, B and C. A and B types of influenza viruses are important because these are responsible for causing of disease epidemics throughout the world. The inhaled virus attacks the epithelial cells in the mucous membrane of nose, throat and upper respiratory tract. Influenza is spread mainly from person to person contact and by droplet infection via sneezing, coughing and talking.

2. Jaundice: Jaundice or hepatitis is the disease of liver. Since liver is a very important organ in the body, so its inflammation due to jaundice affects digestion adversely. Jaundice is caused by viral infection. The types of hepatitis are: Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis D, Hepatitis E or Hepatitis G. Except for type B which is a DNA virus, all the other are RNA viruses. Hepatitis is spread mostly by food and water contaminated with hepatitis virus.

3. AIDS: AIDS stands for Acquired Immuno Deficiency Syndrome. It is a fatal disease. The disease of AIDS is caused by retrovirus (a RNA virus) known as Human Immunodeficiency Virus (HIV). AIDS virus attacks white blood cells (WBCs) or lymphocytes of human beings and weakens the human body's immunity or self-defencemechanism. AIDS becomes prone to many other infections or diseases.

4. Polio: Poliomyelitis or polio is a disease of the nervous system caused by one of the smallest known virus, called polio virus. The virus enters the body through the food and water and reaches the intestine and from there it enters the CNS or central nervous system via blood stream and lymphatic systems. Children between the age of 6 months to 3 years are most prone to polio infection. Polio is transmitted among children by the faeco-oral route and through the direct contact, dirty hands, contaminated food or milk and flies.

Methods of prevention of Malaria:

1. Wire-gauze should be used on doors and windows of houses to prevent entry of mosquitoes.
2. One should sleep under mosquito nets.
3. Insect-repellents should be used to prevent mosquito-bite.
4. Mosquito larvae can be killed by sprinkling kerosene oil on large-sized water bodies.

General ways of preventing infection are:

Public hygiene is one basic key to the prevention of infectious diseases.

In the method of prevention of diseases, following practices are adopted:

• To avoid exposure to air-borne microbes, adopt living conditions that are not overcrowded.
• To prevent exposure to water-borne microbes, safe drinking water should be provided.
• To avoid vector-borne infections, we can provide clean environment as it would not allow mosquito breeding.

Vaccines help a body’s immune system prepare in advance to fight infectious illnesses and potentially deadly diseases caused by infectious agents or their by-products. Vaccines work on the principle of immunization. During vaccination, when the immune system first encounters an infectious microbe, it responds against it and then remembers it specifically. So the next time that particular microbe, or its close relatives enter the body, the immune system responds with greater vigour. This eliminates the infection even more quickly than the first occurrence of the disease.

There are many possible areas, organs and tissues within our body where microbes may reside. However the severity of disease symptoms depends on the number of microbes in the body. For example, if the number of microbes is very small, then the symptoms of disease will be minor or unnoticed. However, if the numbers are large, the disease can be severe enough to be life-risking.

Radha might have contracted the disease through sexual contact and blood transfusion. Other infections can affect the eyes, the organs of the digestive system, the kidneys, the lungs, and the brain. Some people develop rare kinds of cancers of the skin or immune system.

Immunization: It is the development of resistance against a pathogen. It is carried out through vaccination. Principle of vaccination. Vaccination introduces a harmless antigen of a pathogen into the body. Our immune system develops some antibodies and memory lymphocytes against the pathogen. When the actual pathogen happens to enter the body, the immune system recognises its antigen through memory cells. The memory cells induce large scale synthesis of cytotoxic and antibody producing lymphocytes to eliminate the pathogen.

The difference between acute and chronic when used for diseases is that acute means extremely severe pain, brief and dangerous disease whereas chronic refers to a medical condition that lasts over a long period. Chronic also means something always present and recurring or something habitual.

Few diseases caused by bacteria are:

1. Tuberculosis(T.B.): T.B. is an infectious disease which is communicated from one person to another directly or indirectly. It is caused by the bacterium called Mycobacterium tuberculosis. T.B. can affect all parts of the body such as lungs, lymph glands, bones, intestine etc.

2. Cholera: Cholera is an acutely infectious, fatal disease and is more common during overcrowded fairs, festivals and after floods. Cholera is caused by the bacterium Vibrio Cholerae. It is transmitted by flies, contaminated water and food.

3. Typhoid: Typhoid is most common communicable disease in India. Typhoid fever is common in humans of the age 1to 15 years age group. Typhoid is caused by a rod-shaped and motile bacterium, called Salmonella typhiwhich is commonly found in the intestine of human beings. Human infection is direct.

4. Diarrhoea: Diarrhoea is an abnormally frequent discharge of semisolid or fluid faeces. The diarrhoea spreads through infection by contaminated food, water, drinks, hands, clothes, etc. The causative agents of diarrhoea are mainly bacteria such as Escherichia coli, Clostridium botulinum, Shigella dysentiriae, Campylobacter jejuri and Salmonella.

Diarrhoea is an abnormally frequent discharge of semisolid or fluid faeces. It spreads through infection by contaminated food, water, drinks, hands, clothes, bed sheets and utensils.

Symptoms of Diarrhoea:

• Decreased appetite, nausea, vomiting and abdominal cramps.
• There may be blood and mucus in the stools.

Prevention:

• Eatables should be covered to prevent their contamination.
• Fruits and vegetable should be properly washed before use.
• Stale food should not be consumed.

Control:

• Complete bed rest should be ensured till the illness is fully controlled.
• For treating diarrhoea anti-microbial drugs and anti-diarrhoea agents should be used.

Infectious diseases are transmitted from person to person by direct or indirect contact. Certain types of viruses, bacteria, parasites, and fungi can all cause infectious disease. Malaria, measles, and respiratory illnesses are examples of infectious diseases.

An infectious agent is something that infiltrates another living thing, like you. When an infectious agent hitches a ride, you have officially become an infected host.

There are four main classes of infectious agents:

1. Bacteria.
2. Viruses.
3. Fungi.
4. Parasites.