Public health measures are preventive measures which are taken to check the spread of various infectious diseases. These measures should be taken to reduce the contact with infectious agents.
Some of these methods are:
(1) Maintenance of personal and public hygiene: It is one of the most important methods of preventing infectious diseases. This measure includes maintaining a clean body, consumption of healthy and nutritious food, drinking clean water, etc. Public hygienic includes proper disposal of waste material, excreta, periodic cleaning, and disinfection of water reservoirs.
(2) Isolation: To prevent the spread of air-borne diseases such as pneumonia, chicken pox, tuberculosis, etc., it is essential to keep the infected person in isolation to reduce the chances of spreading these diseases.
(3) Vaccination: Vaccination is the protection of the body from communicable diseases by administering some agent that mimics the microbe inside the body. It helps in providing passive immunizationto the body. Several vaccines are available against many diseases such as tetanus, polio, measles, mumps, etc.
(4) Vector Eradication: Various diseases such as malaria, filariasis, dengue, and chikungunya spread through vectors. Thus, these diseases can be prevented by providing a clean environment and by preventing the breeding of mosquitoes. This can be achieved by not allowing water to stagnate around residential areas. Also, measures like regular cleaning of coolers, use of mosquito nets and insecticides such as malathion in drains, ponds, etc. can be undertaken to ensure a healthy environment. Introducing Laxvivorous fish such as Gambusia in ponds also controls the breeding of mosquito larvae in stagnant water.
AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immunodeficiency virus (HIV).
It has the following modes of transmission:
(a) Unprotected sexual contact with an infected person.
(b) Transfusion of blood from a healthy to an infected person.
(c) Sharing infected needles and syringes.
(d) From an infected mother to a child through the placenta.
AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immunodeficiency virus (HIV) via sexual or blood-blood contact. After entering the human body, the HIV virus attacks and enters the macrophages. Inside the macrophages, the RNA of the virus replicates with the help of enzyme reverse transcriptase and gives rise to viral DNA. Then, this viral DNA incorporates into the host DNA and directs the synthesis of virus particles. At the same time, HIV enters helper T- lymphocytes. It replicates and produces viral progeny there. These newly formed progeny viruses get released into the blood, attacking other healthy helper T-lymphocytes in the body. As a result, the number of T-lymphocytes in the body of an infected person decreases progressively, thereby decreasing the immunity of a person.
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Normal cell |
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Cancerous cell |
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1. |
Normal cells show the property of contact inhibition. Therefore, when these cells come into contact with other cells, they stop dividing. |
1 |
Cancerous cells lack the property of contact inhibition. Therefore, they continue to divide, thereby forming a mass of cells or tumor. |
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2. |
They undergo differentiation after attaining a specific growth. |
2. |
They do not undergo differentiation. |
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3. |
These cells remain confined at a particular location. |
3 |
These cells do not remain confined at a particular location. They move into neighboring tissues and disturb its function. |
y B� �y0� ��� and T-lymphocytes.
4
It does not have a specific memory.
4
It is characterized by an immunological memory.
(b) Active and passive immunity
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Active immunity |
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Passive immunity |
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1. |
It is a type of acquired immunity in which the body produces its own antibodies against disease-causing antigens. |
1. |
It is a type of acquired immunity in which readymade antibodies are transferred from one individual to another. |
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2. |
It has a long lasting effect. |
2. |
It does not have long lasting effect. |
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3. |
It is slow. It takes time in producing antibodies and giving responses. |
3. |
It is fast. It provides immediate relief. |
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4. |
Injecting microbes through vaccination inside the body is an example of active immunity. |
4. |
Transfer of antibodies present in the mother’s milk to the infant is an example of passive immunity. |
The property of metastasis is exhibited by malignant tumors. It is the pathological process of spreading cancerous cells to the different parts of the body. These cells divide uncontrollably, forming a mass of cells called tumor. From the tumor, some cells get sloughed off and enter into the blood stream. From the blood stream, these cells reach distant parts of the body and therefore, initiate the formation of new tumors by dividing actively.
Alcohol and drugs have several adverse effects on the individual, his family, and the society.
A. Effects of alcohol:
Effects on the individual: Alcohol has an adverse effect on the body of an individual. When an individual consumes excess alcohol, it causes damage to the liver and the nervous system. As a result, other symptoms such as depression, fatigue, aggression, loss of weight and appetite may also be observed in the individual. Sometimes, extreme levels of alcohol consumption may also lead to heart failure, resulting coma and death. Also, it is advisable for pregnant women to avoid alcohol as it may inhibit normal growth of the baby.
Effects on the family: Consumption of excess alcohol by any family member can have devastating effects on the family. It leads to several domestic problems such as quarrels, frustrations, insecurity, etc.
Effects on the society:
(a) Rash behavior
(b) Malicious mischief and violence
(c) Deteriorating social network
(d) Loss of interest in social and other activities
B Effects of drugs: An individual who is addicted to drugs creates problems not only for himself but also for his family.
Effects on the individual: Drugs have an adverse effect on the central nervous system of an individual. This leads to the malfunctioning of several other organs of the body such as the kidney, liver, etc. The spread of HIV is most common in these individuals as they share common needles while injecting drugs in their body. Drugs have long-term side effects on both males and females. These side effects include increased aggressiveness, mood swings, and depression.
Effects on the family and society: A person addicted to drugs creates problems for his family and society. A person dependant on drugs becomes frustrated, irritated, and anti-social.
Yes, friends can influence one to take drugs and alcohol. A person can take the following steps for protecting himself/herself against drug abuse:
(a) Increase your will power to stay away from alcohol and drugs. One should not experiment with alcohol for curiosity and fun.
(b) Avoid the company of friends who take drugs.
(c) Seek help from parents and peers.
(d) Take proper knowledge and counseling about drug abuse. Devote your energy in other extra-curricular activities.
(e) Seek immediate professional and medical help from psychologists and psychiatrists if symptoms of depression and frustration become apparent.
Drug and alcohol consumption has an inherent addictive nature associated with euphoria and a temporary feeling of well-being. Repeated intake of drugs increases the tolerance level of the body’s receptors, leading to more consumption of drugs.
Many factors are responsible for motivating youngsters towards alcohol or drugs. Curiosity, need for adventure and excitement, experimentation are the initial causes of motivation. Some youngsters start consuming drugs and alcohol in order to overcome negative emotions (such as stress, pressure, depression, frustration) and to excel in various fields. Several mediums like television, internet, newspaper, movies etc. are also responsible for promoting the idea of alcohol to the younger generation. Amongst these factors, reasons such as unstable and unsupportive family structures and peer pressure can also lead an individual to be dependant on drugs and alcohol.
Preventive measures against addiction of alcohol and drugs:
(a) Parents should motivate and try to increase the will power of their child.
(b) Parents should educate their children about the ill-effects of alcohol. They should provide them with proper knowledge and counselling regarding the consequences of addiction to alcohol.
(c) It is the responsibility of the parent to discourage a child from experimenting with alcohol. Youngsters should be kept away from the company of friends who consume drugs.
(d) Children should be encouraged to devote their energy in other extra- curricular and recreational activities.
(e) Proper professional and medical help should be provided to a child if sudden symptoms of depression and frustration are observed.
Various advancements that have occurred in the field of biology have helped us gain a better understanding to fight against various infectious diseases. Biology has helped us study the life cycle of various parasites, pathogens, and vectors along with the modes of transmission of various diseases and the measures for controlling them. Vaccination programmes against several infectious diseases such as small pox, chicken pox, tuberculosis, etc. have helped eradicate these diseases. Biotechnology has helped in the preparation of newer and safer drugs and vaccines. Antibiotics have also played an important role in treating infectious diseases.
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Disease |
Causative organism |
Mode of transmission |
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a. |
Amoebiasis |
Entamoeba histolytica |
It is a vector-borne disease that spreads by the means of contaminated food and water. The vector involved in the transmission of this disease is the housefly. |
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b. |
Malaria |
Plasmodium sp. |
It is a vector-borne disease that spreads by the biting of the female Anopheles mosquito. |
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c. |
Ascariasis |
Ascaris lumbricoides |
It spreads via contaminated food and water. |
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d. |
Pneumonia |
Streptococcus pneumoniae |
It spreads by the sputum of an infected person. |
Water-borne diseases such as cholera, typhoid, hepatitis B, etc. spread ¬¬ by drinking contaminated water. These water-borne diseases can be prevented by ensuring proper disposal of sewage, excreta, periodic cleaning. Also, measures such as disinfecting community water reservoirs, boiling drinking water, etc. should be observed.
A ‘suitable gene’ refers to a specific DNA segment which can be injected into the cells of the host body to produce specific proteins. This protein kills the specific disease-causing organism in the host body and provides immunity.
(a) Primary lymphoid organs include the bone marrow and the thymus.
(b) Secondary lymphoid organs are the spleen, lymph nodes, tonsils, Peyer’s patches of small intestine, and appendix.
(a) MALT- Mucosa-Associated Lymphoid Tissue
(b) CMI- Cell-Mediated Immunity
(c) AIDS- Acquired Immuno Deficiency Syndrome
(d) NACO- National AIDS Control Organization
(e) HIV- Human Immuno Deficiency virus
(a) Innate and acquired immunity
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Innate immunity |
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Acquired immunity |
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1. |
It is a non−pathogen specific type of defense mechanism. |
1. |
It is a pathogen specific type of defense mechanism. |
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2. |
It is inherited from parents and protects the individual since birth. |
2. |
It is acquired after the birth of an individual. |
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3. |
It operates by providing barriers against the entry of foreign infectious agents. |
3. |
It operates by producing primary and secondary responses, which are mediated by B−lymphocytes and T-lymphocytes. |
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4 |
It does not have a specific memory. |
4 |
It is characterized by an immunological memory. |
(b) Active and passive immunity
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Active immunity |
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Passive immunity |
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1. |
It is a type of acquired immunity in which the body produces its own antibodies against disease-causing antigens. |
1. |
It is a type of acquired immunity in which readymade antibodies are transferred from one individual to another. |
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2. |
It has a long lasting effect. |
2. |
It does not have long lasting effect. |
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3. |
It is slow. It takes time in producing antibodies and giving responses. |
3. |
It is fast. It provides immediate relief. |
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4. |
Injecting microbes through vaccination inside the body is an example of active immunity. |
4. |
Transfer of antibodies present in the mother’s milk to the infant is an example of passive immunity. |
The life cycle of malarial parasite includes various steps:
CT- Computed Tomography; It uses X- rays to generate the 3- D image of internal organs.
MRI- Magnetic Resonance Imaging; It uses strong magnetic fields and non- ionizing radiations to detect the pathological changes in the living tissue correctly.
Both are used in the cancer detection.
Drugs like barbiturates, amphetamines, benzodiazepines and other similar drugs that are normally used as medicines to help those patients that are suffering with mental illness such as depression and insomnia. Morphine is a very effective sedative and painkiller and is very useful in patients who have undergone surgery. It is widely used in small doses to relieve pain and induce sleep in cases of serious injury, burns and fractures etc.
Misuse of plant metabolites fruits and seeds in amounts/ frequency more than prescribed for medicinal purposes can impair one’s physical, physiological or functional behaviour creating problem for the society and slowly leads to the eternal truth, i.e. death.
Cannabinoids are banned in sports, as athletes misuse these drugs to enhance their performance but these drugs obtained from cannabinoids contains, a serious negative effect on their health and in long term can hamper the normal functioning of organ system. Their other effects include red eyes, dry mouth, light headedness, increased appetite, delayed response etc. and if they are taken with alcohol then it lowers the level of sex hormone and produces death inducing effects too.
Secondary metabolism also known as specialised metabolism; is a term for pathways and metabolites; small molecule produced by metabolism process which are not required for the survival of the organism.
In case of plants, metabolites aid in the growth and development of plants. It also facilitates or make easier to the primary metabolism.
Curiosity is necessary for doing adventure, excitement and experimentation; they constitute common causes which motivate youngsters towards drugs and the alcohol use. The frequent use of drugs or alcohols encourage people to take them very frequently or even when these are not needed, or even their use becomes self-destructive.
Short term effects of drugs/ alcohols are as follows:
Long term effects of drugs/ alcohols are as follows:
Dysentery, cholera and typhoid are more common in crowded settlements because these are infectious or communicable diseases that spreads from person to another person. Water gets contaminated with the excreta or faeces of infected people and spread the infection to other people.
Cannabinoids are obtained from the inflorescence of the plant Cannabis sativa commonly known as bhang; and Cannabis indica.
Marijuana, hashish, charas, ganja are some cannabinoids which are known as marihuana. These chemicals interact with cannabinoid receptors of the body that are mainly present in the brain. Cardiovascular system of the body gets affected adversely by taking these substances or drugs.In metropolitan cities life style of the human beings is responsible in the lowering of immunity and sensitivity to allergens. More polluted environment such as dust in the surroundings increases the chances of allergic reactions in children. Some symptoms of allergic reaction like sneezing, watery eyes, running nose and difficulty in breathing etc.
In metropolitan cities life style of the human beings is responsible in the lowering of immunity and sensitivity to allergens. More polluted environment such as dust in the surroundings increases the chances of allergic reactions in children. Some symptoms of allergic reaction like sneezing, watery eyes, running nose and difficulty in breathing etc.
The principle of vaccination is based on the property of immune system of memory cells.
In vaccination, a preparation of antigenic proteins or inactivated or live occurs but weakened pathogens are introduced into the body. The antigens generate or produces the primary immune response by producing antibodies along with memory B- cells and T- cells.
When the vaccinated person is attacked by the same pathogens again, the existing memory B- cells and T- cells recognize that antigen and overwhelm the invaders with massive production of lymphocytes and antibodies.
Hepatitis B vaccine is produced from yeast.
An abnormal and uncontrolled growth of cells that causes malignant growth and enlargement of tissues is termed as cancer. Genes called cellular oncogenes or proto-oncogenes present in normal cells when activated under certain conditions lead oncogenic transformation of the normal cells that leads to cancer. A cancer cell is different from the normal cell in following ways:
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Cancer cell |
Normal cell |
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Cancer cells divide in an uncontrolled manner. |
Normal cells divide in a controlled manner. |
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The cells do not show contact inhibition. |
The cells show contact inhibition. |
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Life span is indefinite. |
Life span is definite. |
People think that the city life is better than village life. However, there are so many advantages as well as disadvantages of urban life and rural life that are described below.
Advantages of Urban Life
The city life is more comfortable because there are lot of facilities in the city. There are many more opportunities for people to progress or enhance their lives and they have more opportunities for making money.
Children living in the city can get a good education in the town than the villages. When a person falls ill, there are good government and private hospital in the city to get treatment. There are large shopping complexes, malls, banks, office, cinemas, clubs, hospitals etc. in and around the city for recreations.
People in the city have better transport facilities than the villages. There is electricity, highway, communication, telecommunication, plumb facilities in the city. So, people can enjoy a comfortable and enjoyable life in the city.
Disadvantage of Urban life:
Although living in the city has many advantages but there are some disadvantages too. The cost of living is very high in the city. Goods are expensive, no fresh air and contaminated water is present. The environment is polluted with dust, smoke, garbage and gases from factories that leads to various health hazards.
Most of the people who live in the city are corrupted, so there are lots of crime happened in the city. Many thefts and murders often happens in the city. The city is always busy and noisy with the vehicles. There are a lot of vehicles and people in the road. The streets are dusty and unclean. So, it is hard to have a healthy or normal life in the city.
Advantages of Rural life:
The people of the village lives in unity and with the peace. The villagers earn money enough for living very hardly. So, they live in less competition with each other. They have more friends in the community than the people living in cities.
The village people always try to protect their traditional habits and culture. The village has clean air and the environment is very beautiful and has less noise and rush. So, the pollution is very less in the villages. The village do not have lot of vehicles. So, roads are less dangerous for driving or cycling. They can get fresh vegetables and fresh fruits because they almost grow everything instead of purchasing. The environment of the village is pleasant and silent; and it has scenic beauty.
Disadvantages of Rural life:
People living in rural area suffered with many problems due to specific food habits, work related posture or exposure to harmful radiations or substances, lack of physical exercise, mental stress etc. Some life style diseases are cancer, alcoholism, heart diseases etc. that are dangerous.
If a person is hypersensitive to some substances that are present in the air, he may be allergic to it. Mast cells release some chemicals like histamine and serotonin, in response to these substance this results in the allergic reaction.
Precaution taken to prevent such reaction is to avoid the allergens responsible for particular allergy.
For an organ transplantation, it is an advantage to have an identical twin because the organ will have same surface markers and therefore, the recipient’s immune system will not identify it as foreign element and also will not react against it. In case of different surface markers, the immune system starts producing reaction and kills the foreign tissue or rejects it.
Life style diseases which are caused by the specific food habits, work related posture or exposure to harmful radiations or substances, lack of physical exercise, mental stress etc. E.g. cancer, alcoholism, heart disease etc.
RNA mutates faster than the DNA because DNA is more stable and also has better repair mechanisms that correct the changes in base pairs as soon as it is introduced.
The reasons why adolescents and youngsters starts consumption of drugs are as follows:
The following measures can be taken to avoid drug abuses that are as follows:
If a person is addicted to alcohol than It would leads to some behavioural changes and also physical changes in that person. Alcohol drinks are costly and most of the drinkers because of their selfish habits, deprive or beats their children and other members of the family for the basic needs. The drinking of alcohol is invariably associated with social crimes and dissolution of moral and culture inhibitions. Violence and other corrupt practices in the community are often happens directly or indirectly due to the consumption of alcohol.
Measures that should be taken to overcome the above mentioned problems are as follows:
if such help is provided to the affected persons with the sufficient efforts and their will power, the patient could completely cured and can live normal and healthy life.
Early detection of cancer is essential. The methods of cancer detection and diagnosis are as follows:
Common approaches for treatment of cancer
Harmful effects of drugs like LSD, barbiturates are as follows:
Harmful effects of drugs like LSD, barbiturates are as follows:
Pulse Polio is an immunization campaign established by the Government of India in 1995-96 to eradicate poliomyelitis (polio) in India by vaccination all children under the age of five years orally against polio virus.
This project deals with the efficient ways to fight with poliomyelitis through holding the large scale immunization programme, co- operating with various international institutions, state governments and the Non- Governmental Organizations too. In 1995, by following the polio eradication initiates of World Health Organization (1988), India launched huge Pulse Polio Immunization program along with the Universal Immunization Program which aimed at their 100% coverage.
Having mate on unprecedented progress in polio eradication, India is now gearing up to be declared polio free by 2014 by guarding itself against the import of polio virus from neighbouring countries and by boosting routine immunization.
Oral Polio Vaccine
Oral Polio Vaccine (OPV) is a live- attenuated vaccine that is produced by the passage of the virus through the non- human cells at a sub- physiological temperature that produces spontaneous mutations in their viral genome.
OPV also proved to be superior in administration, elimination the need for sterile syringes and making the vaccine more suitable for mass vaccination campaigns. OPV also provides long lasting immunity than the Salk vaccine.
One dose of OPV produces immunity to all three poliovirus serotypes in approximately 50% of recipients. India is yet to eradicate polio because inspite of many initiatives taken by government, few cases has reported.
The last reported cases of polio in India was in West Bengal and Gujrat on 13 January 2011. Earlier this year, the WHO (World Health Organization) had removed India from the list of polio- endemic countries. If no fresh case is reported till 2014, this country will be declared as polio free.
July 30 in year 2013, a nine month old boy from Navi Mumbai has been found positive for vaccine- Derived Polio- virus (VDPV) type 2 and he was on ventilator at Bj Wadia Hospital in Parel east. This is the fourth such case that have been recorded in the country that year.
In India the main stage in the eradication of polio had been the refusal of polio vaccine by certain communities on account of illiteracy and misinformation.
Recombinant vaccines are made up of a small circular DNA (plasmid) that has very tiny piece of pathogen DNA incorporated in it to produce one or two specific proteins of the pathogen.
This recombinant DNA is introduced in to the bacteria or yeast cells, where it can use cell’s machinery to produce polypeptides of the pathogen. These are used as vaccine to trigger a range of immune responses. Vaccine produced by using this approach allow large scale production, e.g.
Advantages:
