The Tzanck smear stains for the presence of multinucleated giant cells that are formed as a result of fusion of cell membranes due to insertion of viral proteins into the membrane. Tzanck smear does not detect the presence of inclusion bodies, dead cells, herpes DNA, or cell envelope.

Adenoviruses are non-enveloped viruses with an icosahedral nucleocapsid. The capsid contains 12 pentons at each vertices with 12 fibers projecting from the vertices. The genome is a linear double stranded DNA with terminal protein. Viral attachment proteins are present in the fibers projecting from the vertices of the virions.

The additional characteristics of adenovirus include the following:

• The virions replicate in the nucleus
• Encode proteins to promote mRNA and DNA synthesis, including its own DNA polymerase
• Infects epithelial cells lining respiratory and enteric organs
• Virus can become latent in lymphoid tissue and can be reactivated by immunosuppression or infection with other agents
• Forms basophilic intranuclear inclusions within an infected epithelial cell

Last, they are commonly associated with respiratory diseases, adenoviral pneumonia, epidemic keratoconjunctivitis, and pharyngoconjunctival fever.

Rickettsia, chlamydia, prions, and viroids can be distinguished from viruses, but not by just one of the mentioned criteria. While all of these groups are obligate intracellular organisms, only the viruses are parasites with an absolute intracellular requirement, which also depend on the machinery of the host cell for replication. Prions are small infectious protein particles. Viroids are subviral infectious nucleic acids, which lack even the protein capsid found in viruses. Viruses may contain a genome of DNA or RNA, so the presence of an RNA genome is indicative of a virus, but the presence of a DNA genome is not.

Orchitis due to mumps has decreased significantly due to vaccination, but it is still a significant risk in unvaccinated individuals. Mumps-related orchitis can result in testicular failure later in life. None of the other microbial infections listed have an association with orchitis.

Epstein-Barr virus and cytomegalovirus elicit a large T-cell response, resulting in a mononucleosis-like syndrome. EBV infection is subclinical and milder in children than adolescents or adults. EBV initiates infection in the epithelial cells of the oropharynx and then spreads to the B lymphocytes in lymphatic tissue and blood. Classical lymphocytosis is associated with the activation and proliferation of suppressor T cells, and it leads to infectious mononucleosis. The atypical lymphocyte, also known as "Downey cells", increases in peripheral blood during the second week of infection. Major T-cell response causes swollen lymph glands, spleen, and liver. Fever, malaise, fatigue, pharyngitis, lymphadenopathy, and hepatosplenomegaly are the classical symptoms associated with infectious mononucleosis.

Cytomegalovirus is associated with heterophile-negative mononucleosis. Polyclonal B cell activation by EBV leads to production of heterophile antibodies, which can be detected by the end of first week of infection and last for several months.

Respiratory syncytial virus, varicella zoster virus, and influenza virus are not associated with infectious mononucleosis.

Individuals with hepatitis C have a much higher incidence of development of type II diabetes. This is thought to be due to increased levels of tumor necrosis factor (TNF)-alpha, which leads to insulin resistance. Gaucher's disease is a hereditary disorder of glucosylceramide accumulation that can affect the liver but is not caused by hepatitis C virus. Wasting syndrome is a general term for individuals who experience unintentional weight loss due to a disease such as cancer. Fabry disease is a rare liposomal storage disorder unrelated to any viral infection.

The influenza virus is a member of the orthomyxovirus group and is an enveloped ss-RNA virus. Lentiviruses are a group of retroviruses which include HIV-1. Parainfluenza virus and respiratory syncytial virus (RSV) belong to the paramyxovirus group.

Both the enterovirus group (which includes the poliovirus, coxsackieviruses, and echoviruses), and the Reoviridae, (which includes the reovirus, orbivirus, and rotavirus), have an RNA genome. The genomes of the enterovirus group are linear and single-stranded, whereas those of the Reoviridae are double-stranded and may be either linear or segmented.

The Picornaviridae family of viruses contains the enterovirus and the rhinoviruses, which have numerous properties in common with each other. Viruses of this family lack an envelope, and are icosahedral, with a diameter of 20nm. The genome is a single-strand RNA. The enteroviruses are stable to acid, while the rhinoviruses are acid-sensitive.

While HPV strains 31 and 33 have been associated with genital malignancies, more than 70% of cervical dysplasia is associated with HPV strains 16 and 18. Strains 6 and 11 are associated with genital warts, while 2 and 7 are associated with common warts.

Molluscum contagiosum is a form of poxvirus. Poxviruses are a family of enveloped group 1 double-stranded DNA viruses that includes molluscum contagiosum virus, smallpox virus, vaccinia virus, and monkeypox.