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level: Level 3

Questions and Answers List

HUMAN PAPILLOMA VIRUS

level questions: Level 3

QuestionAnswer
with multiple serotypes of close to 140, where infected persons are asymptomatic, although mild symptoms presents as genital warts, the commonest STD in human is?HUMAN PAPILLOMA VIRUS. persistent anogenital infection is strongly associated with invasive carcinoma of cervix, vulva, penis and anus
of the 13 high risk HPV serotypes, some are likely inducers of malignant squamous cell transformation. they include:16, 18, 31, 33, 35, 39, 45, 59
HPV produce epithelial tumors of the skin and mucous membranes. current classification correlates with 3 clinical categories which are:1) anogenital or mucosal (latent, subclinical, clinical) 2) nongenital cutaneous 3) epidermodysplasia verruciformis
the etiology of HPV is such that?definitive cuase of anogenital warts. capsid lacks envelope making it resistant to treatment. no serotype of HPV due to lack of vitro culture methods. typing is based on genotype via melecular hybridization.
None enveloped virus of icosahedral symmetry with 72 capsomers that surround a genome containing doouble stranded DNA of apprx 8000 base pairs. these genome are divided into 3 functional regions:1) (E) region: codes for 6 non structural genes associated with cellular transformation 2) (L) region: 2 structural protiens: L1 and L2 that form the capsid 3) (C) noncoding long control region: regulates replication and gene function
production of viral particles CAN ONLY OCCUR IN HIGHLY DIFFERENTIATED KARATINOCYTES. The process of virus replication alters the character of the epidermis resulting in cutaneous or mucosal warts, it penetrates the basal layer and eventually is released at the surface; the modes of replication are?STABLE replication of episomal genomes in BASAL CELLs RUNAWAY/VEGITATIVE replication in DIFFERENTIATED CELLS to generate progeny virus. note: viral genes are not activated until infected karatinocyte leaves basal layer.
an individual with plantar warts can spread the virus walking barefoot.this is because?HPV virus can survive for many months and at low temperature without host.
viral multiplication os confined to the nucleous thus high degree of nuclear atypia in infected cells. the characteristic feature of productive papillomavirus is:KOILOCYTOSIS: perinuclear clearing(halo) and shrunken/pyknotic(raisinoid) nucleus.
HPV alone does not cause malignant transformation of infected tissues, co factors include:tobacco use, UV radiation, pregnancy, folate deficiency and immune suppression. people on immunosuppressive drugs and HIV infection are susceptible to HPV.
risk factors of HPV1) sexual activity 2) tobacooc smoking 3) oral contraceptive 4) chewing indian betel quid 5) UV and X-ray
virtually all cases of cervical cancer are caused byHPV, which also causes Anal cancer 90%, vulvar cancer 40%, vaginal cancer 40%, oropharyngeal cancer 12%, oral cancer 3%
globally HPV is the most common STD, where as in some devloping countries cervical cancer is the leading cause of cancer mortality amonsgt women., the second cause of cancer mortality amongst women is?cervical cancer. HPV is #8 cancer amongst women in the west. type 16 HPV is always associated with cervical cancer
clinical presentation of HPV is associated with cauliflower like warts (anogenital warts) others includenon anogenital mucous disease: oral wars nongenital cutanous HPV: common cutaneous warts epidermodysplasia verruciformis: autosomal recesssive familial trait
lab diagnosis of HPVDNA: hybrid cpature II and PCR acetic acid test tissue biopsy histologic findings
hpv screeningpap smear: high risk, sexualy active 1/yr, low risk 1/3 yrs
HPV treatment options1)immune repsonse modifiers: Imiquimod and interferon alfa : used for external anogenital warts and condylomate acuminate 2)cytotoxic agents: podofilox, podophyllin, 5-fu. or chempdestructive/karatolytic agents: salicylic acid, trichloroacetic acid(TCA) bichloroacetic acid(BCA) are the only agents recommended for nongenital cutaneous warts.
HPV can be treated wit drugs such as immune response modifiers and cytotoxic agents as well as chomodestructive/ karatolytic agents. other treatment options for HPVsurgical ablation and surgery
HPV complications includemeningitis, encephalitis and meningeoenciphalitis, cervical ca. STD complications in pregnancy.