Viroid

On the last article about viruses always says about viroids that is resulted from viruses. After the viruses contaminated the plant and other hospes, viruses that create a viroid that causes the hospes will suffer from viruses.

Viroids are extremely small infections particles that are thus far known to cause diseases only in higher plants, including the potato, tomato, and chrysanthemum. They consist solely of RNA and are about 1/1000 the size of the smallest known virus. Viroids can cause stunting of overall plant growth, distortions of leaf shape, discoloration of leaves, or even death of the entire plant.

Viroids can be transmitted between plant generations through both pollen and ovules. They can also be transmitted from an infected to a noninfected plant by farm implements. Their mode of reproduction in host cells, however, has not yet been determined, nor has any protein been found in host cells that could be associated with a particular viroid. It is thought that viroids represent segment of normal cellular RNA that somehow have become transmissible, disrupting the host’s metabolism.

Herpes Simplex

There are two kind and different strains of herpes simplex viruses, herpes simplex virus type 1 (HSV-1) and herpes simplex virus 2 (HSV-2), the description of those virus simplex as follows:

Herpes simplex virus type 1 (HSV-1) is usually associated with infections of the lips, mouth, and face. It is the most common herpes simplex virus and is usually acquired in childhood. HSV-1 often causes lesions inside the mouth such as cold sores (fever blisters) and is transmitted by contact with infected saliva. By adulthood, up to 90% of individuals will have antibodies to HSV-1.

Herpes simplex virus 2 (HSV-2) is sexually transmitted. Symptoms include genital ulcers or sores. In addition to oral and genital lesions, the virus can also lead to complications such as meningoencephalitis (infection of the lining of the brain and the brain itself) or cause infection of the eye -- in particular the conjunctiva, and cornea. However, some people have HSV-2but do not display symptoms. Up to 30% of U.S. adults have antibodies against HSV-2. Cross-infection of type 1 and 2 viruses may occur from oral-genital contact.

A finger infection, called herpetic whit low, is another form of herpes infection. It usually affects health care providers who are exposures to oral secretions during procedures. Sometimes, young children contract the disease.

A herpes virus can infect the fetus and cause congenital abnormalities. It may also be transmitted to a newborn during vaginal delivery in mothers infected with herpes viruses, particularly if the mother has active infection at the time. However, the virus may be transmitted even in the absence of symptoms or visible lesions.