Week 6.0 - Genital Infections Flashcards
What is a STD?
-Symptomatic cases only
Papillomaviruses cause…
…genital warts (genital cancers)
Chlamydia trachimatis causes…
…chlamydia, urethritis and lymphogranuloma venerem
Herpes simplex causes…
…genital herpes
Neisseriae gonorrhoeae causes..
…gonorrhea
Treponema pallidum causes…
…syphilis
Name some specific at risk groups of STI
- Young people
- Certain ethnic groups
- Low socio-economic status groups
- Certain aspects of sexual behavior
What are the possible reasons for increased incidence of STIs?
- Increased transmission (changing sexual/social behaviour and increasing population density)
- Increased GUM attendence
- Improved diagnostic methods
What is an STI?
-Symptomatic and asymptomatic infections transmitted by sexual activity
Give 3 complications of STIs
- Pelvic inflammatory disease
- Infertility
- Reproductive tract cancers
- Disseminated infections
- Transmission to fetus/neonate
Under what circumstances are STIs generally diagnosed?
- Patient presents with genital problems/lesions
- Clinician notes non-genital clinical features suggestive of STI
- Screening/contact tracing of asymptomatic infections
Discuss the general management of STIs
- Short course/single dose of antibiotics
- Screening for co-infections (empiric treatment?)
- Contact tracing
- Sexual health education/advice on contraception
What is the most common viral STI?
-Human papillomavirus
What type of virus is humanpapilloma virus?
-DNA virus
Which serotypes of HPV are the most common in causing genital warts?
-6 and 11
How does HPV present?
-Benign painless verrucous epithelia or mucosal outgrowths on the penis, vulva, vagina, urethra, cervix or perianal skin
Which serotypes of HPV are high risk for cervical or anogenital cancer?
-16 and 18
How is HPV a carcinogen?
- Expresses E6 and E7 proteins that inhibit p53 and pRB respectively, both of which are involved in cellular proliferation
- p53 is a TSG which suspends the cell cycle to trigger DNA repair mechanisms or mediates apoptosis in response to DNA damage
- pRB is an oncogene that prevents movement past the restriction point until the cell is ready for proliferation
How is HPV diagnosed?
-Clinical diagnosis or biopsy and genome analysis
What is the treatment for HPV?
- None-spontaneous resolution (1-2 years)
- Topical podophyllin, cryotherapy
Does HPV currently have a screening programme?
-It is screened for if indicatied in cervical smears
What serotypes does the HPV vaccine gardasil protect against and who gets it?
- 6,11,16 and 18
- Girls aged 12-13
What type of bacterium is chlamydia trachomatis?
-Obligate intracellular gram-negative bacteria
What significance to diagnosis does the fact that c.trachomais is an obligate intracellular bacteria have?
-Requires special medium to culture
How can chlamydia present in males?
-Utheritis, discharge, epididymitis, prostatitis, proctitis
How can chlamydia present in females?
-Urethritis, discharge, cervicitis, salpingitis, PID, proctitis, perihepatitis (fitzhugh-curtis syndrome)