What is Virus ?

A virus is a biological agent that reproduces inside the cells of living hosts. When infected by a virus, a host cell is forced to produce thousands of identical copies of the original virus at an extraordinary rate. Unlike most living things, viruses do not have cells that divide; new viruses are assembled in the infected host cell. But unlike still simpler infectious agents, viruses contain genes, which gives them the ability to mutate and evolve. Over 5,000 species of viruses have been discovered

Viruses spread in many ways Some viruses of animals, including humans, are spread by exposure to infected bodily fluids. Viruses such as influenza are spread through the air by droplets of moisture when people cough or sneeze. Viruses such as norovirus are transmitted by the faecal–oral route, which involves the contamination of hands, food and water. Rotavirus is often spread by direct contact with infected children. The human immunodeficiency virus, HIV, is transmitted by bodily fluids transferred during sex. Others, such as the Dengue virus, are spread by blood-sucking insects.

Types of Viruses

  • The virus can be classified on the basis of the type of host and genetic material.
  • The viruses which infect and live inside the animal cell including man are called animal viruses.
  • Viruses which infect bacterial cells are known as bacteriophage or bacteria eaters.

virus Affected Disease

  • Viral Infections.
  • Bird Flu.
  • Chickenpox.
  • Common Cold.
  • Cytomegalovirus (CMV) Infection.
  • Dengue.
  • Ebola Virus and Marburg Virus Infections.

Different Types of Viruses

Diseases can be defined as a disorder, infections or malfunction of the cells, tissues, organs and different parts of our body. If these diseases are left unrecognized or not diagnosed on time, results to the death of an individual.

There are many diseases, which varies in modes of transmission, diagnosis, symptoms and treatments. There are two types of diseases.

Infectious diseases: These are the diseases, which are caused by pathogenic organisms like: bacteria, viruses, fungi, protozoa, etc. They are spreading disease and can be infected by eating, touching, drinking or by breathing something that contains germs. These diseases can also spread when we come in contact with someone who has been infected.

Non-infectious diseases: These are the diseases, which are neither caused by any pathogenic organisms, nor by spreading from an infected person. These diseases are generally caused by genetical disorder, environmental factors or by deficiencies in nutrition.

Viruses are non living strands of genetic material, which are coated with a protein coat. They are non motile and cannot reproduce by their own, hence they are considered non living.
AIDS stands for “Acquired immune deficiency syndrome”. It is a viral infection, which is caused by HIV-human influenza virus.
AIDS is the final stage of HIV infection. A person  suffering with AIDS has a very weak immune system and the ability to fight against infection is very low.
  • Modes of transmission:
           a. By unprotected sexual intercourse.
           b. Contact with an infected blood.
           c. Breastfeeding  and
           d. Injecting drugs.
  • Symptoms: Diarrhea, fatigue, fever, loss of appetite, weight loss, dry cough, shortness of breath, night sweats, difficulty in concentrating, numbness, etc.
  • Diagnosis: The diagnosis for aids includes some preliminary tests like blood test and urine test. Other test like ELISA, PCR, RIP and western blotting is also used to diagnosis HIV.
  • Treatment: The most effective treatment for HIV is highly active anti retro-viral therapy.
  • Precautions: Avoid sharing personal items, such as tooth-brush, intravenous needles, syringes, cotton, drugs, razors, etc. As it may be contaminated with blood, semen, or vaginal fluids and by having safe sex.

It is a viral infection, which is caused by a polio-virus that attacks and infects the nerve cells of the brain and spinal cord, which results in severe injuries and paralysis.

  • Modes of transmission: It is a viral infection, caused by polio-virus and it is transmitted both by orally and fecal routes. Polio-virus lives in the throat and intestinal tract of a human body.
  • Symptoms: fever, headache, nausea and vomiting. These patients develop a higher fever and severe headache with stiffness of the neck and the back.
  • Diagnosis: Viral isolation and other fluid tests like: blood test, throat secretion and cerebrospinal fluid.
  • Treatment: Bed rest, close monitoring of respiratory and cardiovascular functioning, respiratory therapy may be needed, depending on the severity of patients.
  • Precautions: This disease can be controlled by immunization the infants with polio vaccine.
 It is an acute, highly contagious viral disease caused by measles virus. It is an infection to the respiratory system.
  • Modes of transmission: It is an air-borne disease and spreading disease. It can be spread by eating, touching, drinking or breathing something that contains this virus.
  • Symptoms: Runny nose, dry cough, swollen eyelids with sensitivity to light, sneezing, fever, grayish-white spots found usually in the mouth, cheeks and throat.
  • Diagnosis: Blood test.
  • Treatment: It can be easily cured by proper and supportive care taken at home.
  • Precautions: This disease can be controlled by vaccinating the infants with the vaccination active and passive immunization.