Papillomaviruses and Adenoviruses

Jumpstart 5/14 1.What type of virus causes warts? 2.What is an adenovirus?

Papillomaviruses Capable of causing lytic, chronic, latent, or transforming infections depending on the host cell Non-enveloped DNA Contains genetic material that is capable of promoting proliferation of certain cells –Can possibly promote cancer in some cases –These genes are referred to as “oncogenes”

Human Papillomaviruses-HPV Cutaneous HPV or Mucosal HPV Circular DNA Icosahedrol shape Enters through breaks in the skin Virus has genes for increasing cell proliferation (you get more cells) thus forming a wart

Pathogenesis Papillomaviruses infect and replicate in the squamous epithelium of skin (warts) and mucus membranes (genital, oral, conjunctival papillomas). Usually remains local and will seem to go away, but can recur.

Several types of HPV are associated with cancers –Example: HPV-16 and HPV-18 are associated with cervical papillomas and dysplasia

Epidemiology HPV can be transmitted by –Sexual contact –Direct contact through breaks in the skin or mucosal membranes (often times from fomites) –An infant passing through an infected birth canal Asymptomatic shedding may promote transmission

How common is it? Common warts Plantar warts HPV is by far the most prevalent STI in the world –At least 20 million in the U.S. (5 mil new cases per year) HPV is present in 99.7% of all cervical cancers

Clinical Syndromes Common warts Plantar Warts

1.Write 3 cause and effect relationships from the article. 2.What is the cause(s) of Dede’s condition? 3.Describe Dede’s life. 4.You are a member of Doctors Without Borders and are being sent to Indonesia to explain Dede’s condition to a group of local school children. Explain (in kids terms) Dede’s condition and treatment and how the children can prevent such a disease.

Clinical Syndromes Below shows a pap smear: left= normal cells, right= cells showing cervical dysplasia

Diagnosis Histologic appearance –Hyperplasia, cells may appear more rounded, excess keratin

Treatment, Prevention, Control Warts spontaneously regress, but it may take months or years –For cosmetic reasons or discomfort, doctors often treat warts with cryotherapy, electrocautery, or chemical means HPV vaccine has capsid-like particles to help prevent infection

1. Write 3 cause and effect relationships from the article. 2. What is the cause(s) of Dede’s condition? 3. Describe Dede’s life. 4. You are a member of Doctors Without Borders and are being sent to Indonesia to explain Dede’s condition to a group of local school children. Explain (in kids terms) Dede’s condition and treatment and how the children can prevent such a disease.

Adenoviruses First discovered in adenoid cell culture

Adenoviruses Linear DNA Non-enveloped Genes for DNA polymerase

Pathogenesis Typically infect cells lining the oropharynx, respiratory organs, GI tract, Conjunctiva, lymphoid tissue Spread by aerosol, close contact, or fecal- oral means. Fingers may spread the virus to the eyes

Epidemiology Resists drying, detergents, pH ranges, even chlorine Close interaction among people (like in a classroom) helps spread these viruses

Clinical Syndromes Primarily infect children Pharyngitis, conjunctivitis

Clinical Syndromes Cold-like symptoms Gastoenteritis (peyer’s patches)

Treatment, Prevention, Control No treatment for adenovirus infection No vaccines