Viruses cause many viral diseases in man, animals and plants. These viral diseases are discussed here completely with their symptoms and methods to control or cure.
Viral Diseases in Animals (Humans)
The animal’s viral diseases are caused by many types of viruses.
- Diseases by Rhinovirus (Virus of Nose and Throat)
- Diseases by Paramyxovirus
- Disease by Pox virus
- Diseases by Arbovirus (Arthropod born viruses)
- Disease by Retrovirus (Tumor viruses)
- Diseases by Rhabdovirus (Virus of Saliva)
- Disease by Polio Virus
- Disease by Herpes virus
1. Viral Diseases by Rhinovirus
It is the infection of upper part of respiratory tract, caused by rhinovirus.
Symptoms: Pain in throat and chest congestion, flue, cough and sometimes fever.
Control: Immunization is the method of control; due to various strains it is difficult.
It is the infection of lower part of respiratory tract. This disease is caused by a virus called myxovirus influenza.
Symptoms: Pain in throat, headache, pain in arms and back fever, pneumonia may occur.
Control: Use of Antibiotics, Contact with patient should be avoided, sudden change in temperature should be avoided and Immunization.
2. Viral Diseases by Paramyxovirus
It is a contagious disease. Mumps is widely distributed, and therefore, It is not a fatal disease. About 60% of the adults are immune to it. It is a disease in which salivary glands are infected by virus.
Symptoms: Salivary glands become swollen due to infection, Pain in the jaws muscles, headach, indigestion and fever.
It is a common disease of children and adults. It occurs all over the world. This disease develops immunity in its victims.
Symptoms: In this disease, small reddish pustules are developed on skin. Other symptoms are pain and fever.
Control: Use of antibiotics in the effective treatment of these disease and vaccination.
3. Disease by Pox Virus
Small pox is caused by pox virus. It is a DNA enveloped virus. Small pox is an ancient disease. It occurred in China as an epidemic in 12th century B.C. Small pox was common disease of the world before early twentieth century.
Symptoms: Raised vesicles are formed on the body. These vesicles are fluid – filled. Later these vesicles changes into pustules. These pustules later forms pitted scars. These scars are called pocks.
Control: In 1950, Immunization or vaccination of small pox started. This immunization and other control measures have decreased this disease. It is still present in third world countries. Many people are affected with this disease in these countries.
4. Viral Diseases by Arbovirus
(Yellow Fever, Encephalitis and Dengue)
These are the viral diseases called arboviruses. These viral diseases are arthophode-borne i.e. they live in body of insects and other arthropods, from their body these ruses are transferred into man’s body and cause disease.
The virus of yellow fever is transferred from the body of Culex mosquitoes. These viruses attack liver, kidneys, blood capillaries. Fever and jaundice are main symptoms, so the disease is called yellow fever.
Encephalitis and Dengue diseases are also dangerous diseases, caused by viruses. These viruses are transferred into the body of man from Aedes mosquitoes. They damage liver, blood vessels and nervous system. Due to these diseases death may occur.
- Use of antibiotics.
- Eradication of mosquitoes which are involved in the spreading of disease.
5. Diseases by Retrovirus:
The retroviruses are RNA tumor viruses, cause rumor formation in many animals. The most common virus of this group is HIV, which causes AIDS (acquired immune deficiency syndrome) in human beings. It was discovered in 1985.
Symptoms: Immune system of body is destroyed other diseases like pneumonia may attack the body. Blood is infected, also causes skin cancer.
Control: Blood should be tested before donation, Chemotherapy and radiotherapy.
6. Diseases by Rhabdovirus: (Saliva virus)
Rhabdovirus causes Rabies disease. It was discovered in the 19th century by Louis Pasteur. This disease is also called hydrophobia. Usually it is found in dogs and foxes. The viruses are transferred into the body of man by biting the mad dog. The virus is present in the salvia of animal.
Symptoms: In this disease nervous system is affected. Salivary glands are infected, Pain in the muscles. The patient feels fearness by seeing water and becomes mad, so the disease is called Hydrophobia.
Control: Vaccination is the control of disease.
7. Disease by Polio Virus
Poliomyelitis is caused by polio virus. It is present all over the world. It occurs mostly in childhood. The age of infection varies with social and economic factors. The polio virus is the smallest know virus. It contains RNA in spherical Capsid.
Symptoms: Indigestion, fever, pain in muscles, stiffness of back muscles and legs become paralysed.
Control: Vaccination of Babies and use of Antibiotics.
8. Diseases by Herpes virus
It is caused by Herpes virus. Herpes Simples is a DNA virus. It is naturally occurring disease of mankind.
Symptoms: It forms vascular lesions in the epithelial layers of the ectodermal tissues. This disease occurs in the mouth, on the lips and at other skin sites.
Viruses attack many important plants and cause diseases in them, so the crop is badly damaged and yield is greatly reduced. Some plants are tobacco, tomato, sugar cane, wheat, corn, rice and beet etc.
Tobacco mosaic virus disease is very common. The virus is called TMV (Tobacco mosaic virus). In this disease white, yellow, green spots are produced on leaves. It looks like a mosaic. The disease in plants spreads in two ways:
1. Horizontal transmission:
In this infection the plant is infected from source through insects or injured pans.
2. Vertical transmission:
In this infection the plants get virus form parent plant by inheritance.
Control of Viral Diseases:
There is no proper control of viral diseases of plants, but some methods are as follows:
The best control is use of resistant varieties, i.e. Strong and healthy verities. Clean and free of disease seeds should be used for cultivation of crop.