Flashcards in Repro 6.1- STIs Deck (49):
What's the difference between a STI and a STD?
Sexually transmitted infection- includes both symptomatic and asymptomatic cases.
Sexually transmitted disease- includes only symptomatic cases.
What aspects of sexual behaviour affect risk of contracting an STI?
-age of first sexual intercourse
- number of sexual partners
- sexual orientation (eg syphillis more common in MSM)
- unsafe sexual activity
Why have STI's increased in prevelance over time?
- altered attitudes and behaviours surrounding sex
- more screening programs (so more are diagnosed)
- GUM clinics, so more will get diagnoses
- more awareness and education- people more likely to be concerned and therefore get tested
- increased density and mobility of populations (e.g. Holidays to Maga more common and social norm)
Why are STIs such a big deal?
- cause recurring and chronic infections (e.g. Herpes keeps coming back, increases risk of transmission)
- can cause complications- pain and symptoms, but also things like PID which can lead to infertility or ectopic pregnancy.
- some increase the risks of cancers (e.g. HPV and cervical cancer)
- transmission between mother and neonate is a problem
- disseminated diseases- as seen in syphillis which can affect the CVS/ neuro systems. Could potentially be fatal.
- stigma surrounding STI's
What's efforts do GUM clinics make to increase likelihood of people presenting to them?
- trained friendly staff who won't pass judgement
- confidentiality- even labs won't know your name, samples will be labelled with a number only
- contact tracing- helps prevent future transmission from people who may not know they are infected.
In general, how are STIs diagnosed?
Symptomatic cases present to healthcare.
Contact tracing helps to find those who don't know they are infected.
Screening programs (eg chlamydia) helps pick up cases.
History taking skills of HCW. Also being able to identify and ask about other symptoms which the patient may not realise are associated.
In general, how are STIs managed?
Specific treatment- eg antibiotics and topical creams
Prophylaxis when needed
Education about contraception and symptoms to prevent new cases.
Screening for other STIs once one is found as it's not uncommon for one person to have many.
What are the most common strains of HPV?
What do they cause?
HPV 6 and 11.
Benign painless warts on and around genitals which may resolve on their own.
Why is and important complication of HPV?
Increased risk of cervical cancer/ anogenital cancers.
This is the most common cancers found in females from 15-34
Which strains of HPV have associations with cancer?
Oncogenic strains 16 and 18.
How do you diagnose HPV?
Via a biopsy of the endocervix, and analysis of the genes.
Clinical examination, looking at the warts.
What is treatment for HPV?
If benign treatment often isn't needed as it will resolve.
Some will require topical creams.
Freezing of the wart/surgical excision is sometimes used.
What screening methods are there for HPV?
Cervical Pap smear
Colposcopy- involved a camera looking at the cervix for signs of abnormal cells.
What does the cervical Pap smear consist of?
Who has it?
Female gets some cells from her cervix scraped off and sent for biopsy. These are tested for any abnormalities (which most of the time aren't cancerous) or precancerous changes.
Females of 25+ are offered a smear every 3 years, until they are 50.
50-64 year olds get one every 5 years.
65+ won't need smear tests unless they've previously had abnormal cells found.
What is the HPV vaccine?
Gardasil- offered to girls aged 12-13. Given in 2 doses.
99% effective at preventing cases of HPV 6,11,16,18 in people not already infected.
Previously used cervarix- only effective against strains 16,18 (backlash because why use a vaccine which is only protective against 2 when there is a vaccine effective against 4)
What's the full name of the organism that causes chlamydia.
What are some facts about the organism?
It's an obligate intracellular bacteria, meaning you cNt culture it or gram stain it (doesn't have it's own cell wall)
Give common symptoms of chlamydia in
1) urethritis, epidymitis, postatitis, proctitis. Leads to swelling, pain, discharge.
2) most commonly asymptomatic. Can cause cervicitis, salpingitis, urethritis, perihepatitis can happen as a complication.
Can cause vaginal discharge, pain, dysuria.
Apart from the genital tracts, where else can you get chlamydia?
If in contact with the eyes you can get conjunctivitis.
If a neonate contracts the disease it can also cause pneumonia.
How do you diagnose chlamydia?
CANT DO STAINING OR CULTURE.
Option of endocervical and urethral swabs, but this is time consuming, quote invade ad esquire professional people.
First void urine- collect the first part of a urine sample, this should contain any bacterial cells. Then do NAAT on these.
For a neonate, take swabs of their conjunctiva.
What's the treatment for chlamydia?
Doxycycline- a short course. (Common method)
Azithromycin- one large single dose (ideal)
Erythromycin in neonates.
Give symptoms of the herpes simplex virus.
Forms recurring, painful ulcerations around the genitals.
Can cause fever
What type of herpes is genital herpes?
What other types are there?
Why can herpes cause relapsing infections?
Ability to remain dormant in the dorsal root ganglia, (as seen in herpes zoster virus).
How do you diagnose herpes?
Take swabs of the ulcers.
PCR the fluid collected to identify the genes.
How do you treat herpes.
Can give topical creams
Aciclovir can be used for severe primary infections.
Barrier contraception to prevent transmission.
Prophylaxis and antivirals on standby for recurrences.
Give som facts about the neisseria gonorrhoea bacteria.
Gram negative diplococcus.
Likes to multiply within wbc.
Looks and stains the same as neisseria meningitidis.
What symptoms do males get for gonorrhoea?
Urethritis, purulent discharge, epidydimitis, prostatitis.
In MSM- proctitis, pharyngitis
What symptoms do females wth gonorrhoea get?
Urethritis, endocervitis, can cause PID which can lead to infertility.
How do you diagnose gonorrhoea?
Swab from urethra/ cervix,
First void urine test, with NAAT. can test at the same time as chlamydia,
How do you treat gonorrhoea?
Previously, other antibiotics were used but now there is resistance.
You can also give azithromycin, as chlamydia is commonly present too, and it's thought to help the action of ceftriaxone
What's the name of the organism which causes syphillis?
Treponema pallidum- spirochaete.
Which group of people are most at risk of syphilis?
What's different about an infection with syphillis?
There are progressive stages,
What stages are there of a treponema pallidum infection (syphillis)
Primary- hard,painless lesions on the genitals. Known as chancre.
Secondary- fever, rash, lymphadenopathy, mucosal lesions in mouth. Occurs a couple of months later. Patients often doesn't make the link.
Latent period, no symptoms.
Tertiary- neurosyphillis (general paralysis of the insane) cardiovascular syphillis, local destruction,
How do we Diagnose of syphillis?
Can be grown or cultured.
Have to look at serology, use EIA Antibody test.
How do you treat syphillis?
Do a follow up test to ensure patient is cured
Give som features of a trichimonas vaginalis infection.
Caused by a flagellated protazoa.
Causes a frothy offensive discharge.
Vaginal inflammation and irritation.
How do you diagnose an infection with trichimonas infection
Do a wet vaginal preparation- a sample of discharge mounted between 2 slides.
How do you treat a trachimonas infection?
Metroniadazole. (Clive against anaerobes and PROTAZOA)
What is Vulvovaginal candidiasis?
Vaginal thrush, often caused by an overgrowing of candida which may be part of the normal GI/ genital flora.
What are risk factors for vaginal thrush?
- oral contraceptives
- antibiotics (deplete lactobacillus)
What are some features of vaginal thrush?
- itchy, curd like discharge.
Very characteristic. Can diagnose via sight and a good clinical history.
How do you diagnose vaginal thrush?
- do a high vaginal smear.
- could do a culture
- history and characteristic symptoms
How do you treat vaginal thrush?
Describe scabies and pubic lice?
General skin mites, which live in nad around pubic areas.
Known as 'crabs'
What causes bacterial vaginosis?
Overgrowth of normal flora, eg due to the use of antibiotics.
What are symptoms of bacterial vaginosis?
Characteristic fishy odour,
Burning during urination.
How do you diagnose bacterial vaginosis?
- KOH whiff test
-a vaginal pH over 5
- presence of clue cells (epithelial cells studded with gram variable coccobacilli.
- reduced numbers of lactobacilli