A SLIGHT SUMMARY OF THE HUMAN PAPILLOMA VIRUS
- 1. HUMAN PAPILLOMAHUMAN PAPILLOMA VIRUSVIRUS (HPV)(HPV) SAM DICKSON ASEHSAM DICKSON ASEH SELENKEH NISSISHALOMSELENKEH NISSISHALOM
- 2. HUMAN PAPILLOMA VIRUSHUMAN PAPILLOMA VIRUS • HPV is the virus that causes warts.HPV is the virus that causes warts. • Nonenveloped virus with icosahedralNonenveloped virus with icosahedral nucleocapsid and circularnucleocapsid and circular double-stranded DNAdouble-stranded DNA • More than 100 different kinds, 30-some ofMore than 100 different kinds, 30-some of this cause genital HPV.this cause genital HPV. • Spread by sexual contact or from mother toSpread by sexual contact or from mother to baby.baby. • Genital warts appear 6 weeks to 8 monthsGenital warts appear 6 weeks to 8 months after contact with an HPV infected person.after contact with an HPV infected person.
- 4. HPVHPV • The most common sexually transmittedThe most common sexually transmitted disease worldwide.disease worldwide. • Certain types of HPV are linked withCertain types of HPV are linked with cervical cancer.cervical cancer. • Divided into 2 subcategories: GenitalDivided into 2 subcategories: Genital Warts and Cervical Dysplasia.Warts and Cervical Dysplasia. • Most people do not know they have it.Most people do not know they have it. • There are high risk and low risk types of it.There are high risk and low risk types of it.
- 5. HISTORYHISTORY • The papillomaviruses are part of theThe papillomaviruses are part of the PAPOVAVIRIDAE family of DNA tumorPAPOVAVIRIDAE family of DNA tumor viruses.viruses. • First discovered in the early 40’s.First discovered in the early 40’s. • Gained notoriety in the early 80’s when itGained notoriety in the early 80’s when it was discovered that some types of HPVwas discovered that some types of HPV caused cervical cancer.caused cervical cancer.
- 7. MECHANISM OF INFECTIONMECHANISM OF INFECTION • All PV exhibit extreme specificity forAll PV exhibit extreme specificity for infection on epithelial cells.infection on epithelial cells. • The infection normally results inThe infection normally results in hyperproliferation of the host cell and mayhyperproliferation of the host cell and may lead to transformation.lead to transformation.
- 8. GENITAL WARTSGENITAL WARTS • Sometimes called condylomataSometimes called condylomata acuminata.acuminata. • Are soft, moist or flesh colored, andAre soft, moist or flesh colored, and appear in the genital area within weeks orappear in the genital area within weeks or months after infection.months after infection. • Sometimes appear in clusters and areSometimes appear in clusters and are either raised or flat, small or large.either raised or flat, small or large. • Women: appear in the vulva, cervix,Women: appear in the vulva, cervix, vagina and anus.vagina and anus. • Men: Can appear on the scrotum or penis.Men: Can appear on the scrotum or penis.
- 9. HPV TYPESHPV TYPES • Numbered in order of discovery.Numbered in order of discovery. • 30 HPV types primarily infect the squamous epithelium30 HPV types primarily infect the squamous epithelium of the lower anogenital tracts of both males and females.of the lower anogenital tracts of both males and females. • HPV types 6, 11, 42, 43, or 44 present as papillaryHPV types 6, 11, 42, 43, or 44 present as papillary condylomas, may also present as flat lesions that may orcondylomas, may also present as flat lesions that may or may not be visible to the unaided eye are part of themay not be visible to the unaided eye are part of the “low-risk” HPV types.“low-risk” HPV types. • Types 16, 18, 31, 33, 35, 45, 51, 52, and 56 areTypes 16, 18, 31, 33, 35, 45, 51, 52, and 56 are considered “high-risk” types because they have beenconsidered “high-risk” types because they have been found in cervical and other lower genital tract cancers.found in cervical and other lower genital tract cancers.
- 10. HOW HPV CAUSES CANCERHOW HPV CAUSES CANCER • HPV DNA integrates into the host genome.HPV DNA integrates into the host genome. • The proteins E6 and E7 are produced from the resultant DNA.The proteins E6 and E7 are produced from the resultant DNA. • E6 binds and degrades p53 (a tumor suppressor gene).E6 binds and degrades p53 (a tumor suppressor gene). • If the DNA is altered, the cell keeps replicating. The mutation rate ofIf the DNA is altered, the cell keeps replicating. The mutation rate of the cell increases.the cell increases. • E7 binds and degrades retinoblastoma (another tumor suppressorE7 binds and degrades retinoblastoma (another tumor suppressor gene).gene). • Retinoblastoma normally keeps the cell from growing too fast orRetinoblastoma normally keeps the cell from growing too fast or responding to growth stimulators. This inhibitory factor is now lost.responding to growth stimulators. This inhibitory factor is now lost. • without these two mechanisms to slow down cell growth andwithout these two mechanisms to slow down cell growth and prevent mutation. . .prevent mutation. . . • Malignant Transformation Occurs.Malignant Transformation Occurs.
- 11. HPV TREATMENTHPV TREATMENT • Genital warts can be treatedGenital warts can be treated by a doctor and by differentby a doctor and by different methods.methods. • Podofilox gel:Podofilox gel: A patient-A patient- applied treatment for externalapplied treatment for external genital warts.genital warts. • Imiquimod cream:Imiquimod cream: AA patient-applied treatment.patient-applied treatment. • Chemical treatments (includingChemical treatments (including trichloracetic acid andtrichloracetic acid and podophyllin), which must bepodophyllin), which must be applied by a trained healthapplied by a trained health care provider to destroy warts.care provider to destroy warts. • Cryotherapy:Cryotherapy: Uses liquidUses liquid nitrogen to freeze off the warts.nitrogen to freeze off the warts. • Laser therapy:Laser therapy: Uses a laserUses a laser beam or intense lights tobeam or intense lights to destroy the warts.destroy the warts. • Electrosurgery:Electrosurgery: Uses andUses and electric current to burn off theelectric current to burn off the warts.warts. • Surgery:Surgery: Can cut away theCan cut away the wart in one office visit .wart in one office visit . • Interferon:Interferon: an antiviral drug,an antiviral drug, which can be injected directlywhich can be injected directly into warts.into warts.
- 12. HPV VACCINEHPV VACCINE • Vaccine is commonly called GardasilVaccine is commonly called Gardasil • It is given in 3 separate injections over theIt is given in 3 separate injections over the course of 6 months.course of 6 months. • It protects against four types of HPVIt protects against four types of HPV – two that cause 70 percent of all cervicaltwo that cause 70 percent of all cervical cancercancer – two that cause 90 percent of all genital warts.two that cause 90 percent of all genital warts.
- 13. CURECURE • There is currently no cure for humanThere is currently no cure for human papillomavirus.papillomavirus. • Once an individual is infected, he or sheOnce an individual is infected, he or she carries the virus for life even if genitalcarries the virus for life even if genital warts are removed.warts are removed. • If left untreated, some genital warts mayIf left untreated, some genital warts may regress on their own.regress on their own.
- 15. SOURCESSOURCES • http://cinvestav.mx/genetica/MyFiles/Papillhttp://cinvestav.mx/genetica/MyFiles/Papill omavirus/PAPepi.htmlomavirus/PAPepi.html • http://www.life.umd.edu/classroom/bsci42http://www.life.umd.edu/classroom/bsci42 4/BSCI223WebSiteFiles/LectureList.htm#4/BSCI223WebSiteFiles/LectureList.htm# LecureListLecureList • WWW.STDSERVICES.ON.NET/STD/WAWWW.STDSERVICES.ON.NET/STD/WA RTSRTS • Review of medical microbiologyReview of medical microbiology