STI's Flashcards
What is the primary mode of transmission of STI’s ?
Human-human transmission (sexual intercourse)
Go over the general principles of STI’s
- Immunity is rare
- Reinfection is common
- Co-infections are common - STI ppathogens move together e.g. chlamydia and gonorrhoea
- Vaccines have been difficult to develop
What are the typical organisms which colonise the vaginal flora
Lactobacillus spp. predominate and are protective e.g L.crispatus and L. jensenii.
Other organisms:
- +/- Group B beta-haemolytic Streptococcus
- +/- Candida spp. (small numbers)
- +/-Strep “viridans” group
What is the normal pH of the vagina and why?
- ACID pH is Normal (4 to 4.5)
- This is because the Lactobacillus spp. produce Lactic acid +/- hydrogen peroxide
What is the most common cause of candida infections ?
Candida albicans
What percentage of females are colonised with small numbers of Candida albicans?
30%
List the predisposing factors to a candida infection
- Recent antibiotic therapy
- High oestrogen levels (pregnancy, certain types of contraceptives)
- Poorly controlled diabetes
- Immunocompromised patients
Describe the presentation of a candida infection
- Intensely itchy white vaginal discharge (cottage cheese appearance)
- +/- occasionally pain on intercourse or urination
How is a candida infeciton diagnosed?
- 1st line = clinical diagnosis
- 2nd line = high vaginal swab for culture if the diagnosis if uncertain, or women who have severe or recurrent symptoms, or if there is treatment failure
What is the treatment for a candida infection?
- Oral Fluconazole AND
- Clotrimazole cream daily or Clotrimazole pessary + clotrimazole cream daily
What is shown in this pic
Candida balanitis - this is inflammation of the glans of the penis +/- the foreskin.
What are the signs/symptoms of candida balanitis ?
- A red, inflamed ‘spotty’ rash on the head and shaft of the penis or under the foreskin
- Itching or burning in the affected area
- A white, clumpy or yellowish discharge from the affected skin or from under the foreskin
What is the most common cause of candida balanitis ?
Non-specific dermatitis +/- candida albcians infection
What is the treatment of candida balanitis ?
Topical hydrocortisone + clotrimazole cream
What is the causative organism of gonorrhoea ?
Neisseria gonorrhoeae
Describe the microscopic appearance of gonorrhoea
Gram -ve intracellular dipplococci - Look like “2 kidney beans facing each other”
Note also a fastidious organism so doesnt survive outside ideal growth conditions
What part of the body does gonorrhoea infect?
The urethra, rectum, throat & eyes (♂&♀) endocervix (♀) (same as chlamydia)
What is the incubation period of gonorrhoea infections ?
2-5 days
Describe the presentation of gonorrhoea
Men:
- Urethral infection - purluent discharge and dysuria, asymptomatic (<10%).
- Rectal & pharyngeal infections - usually asymptomatic; may cause anal discharge (purulent) or perianal/anal pain (proctitis), pruritus, bleeding, tenesmus.
Women:
- Endocervical infection - frequently asymptomatic (up to 50%); may get increased or altered vaginal discharge, +/- sometimes lower abdominal/pelvic pain, intermenstrual bleeding or menorrhagia.
- Urethral infection - cause of dysuria (10-15%) without frequency.
- Rectal and pharyngeal infections - usually asymptomatic.
What are the potential complications of gonorrhoea infection?
What is shown in the pic and what infection can cause these complications
Bartholinitis (right) and tysonitis (left)
What is the treatment of gonorrhoea ?
- 1st line = IM ceftriaxone + oral azithromycin
- 2nd line = Oral cefixime + azithromycin
Why is azithromycin given in the treatment of gonorrhoea ?
Because there is often co-infection with chlamydia
Due to the high antibiotic resistance of gonorrhoea what is required following treatment ?
Test of cure to be sure patient is cured
What is the most common sexually trasmitted infection ?
Chlamydia
What parts of the body can chlamydia infect?
The urethra, rectum, throat & eyes (♂&♀) endocervix (♀) (same as gonorrhoea)
What is the causative organism of chlamydia ?
Chlamydia trachomatis
What is the microscopic appearance of chlamydia trachomatis ?
Obligate intracellular bacteria with biphasic life cycle - does not gram stain
What are the 3 serological groupings of chlamydia trachomatis and the pathologies they cause?
- Serovars A-C = Trachoma (eye infection) (NOT an STI)
- Serovars D-K = Genital infection
- Serovars L1-L3 = Lymphogranuloma venereum
Who does Lymphogranuloma venereum (chlamydia trachomatis L1-3) mainly affect and how does it present?
- MSM (often HIV+) - it can cause proctitis ==> screening rectum important in MSM
- Presents with rectal pain, discharge and bleeding
What complications can LGV chlamydia result in ?
- Ulcers
- Abscesses
- Strictures
- Fistulae
What are the clinical features of chlamydia ?
In men:
- Anterior urethritis
- Dysuria
- Watery discharge
- Ascending infection can lead to Epididymo-orchitis
- Proctitis (LGV) - MSM
In women:
- Post coital or intermenstrual bleeding
- Lower abdominal pain
- Dyspareunia
- Mucopurulent cervicitis (from endocervix) – it is yellow or green, if this is present then worry about PID
- Watery vaginal discharge
- Ascending infection can lead to salpingitis
What are the clinical features of rectal chlamydia (not talking about LGV chlamydia here)
- 70% asymptomatic
- Milder than gonorrhoea
- Anal discomfort/itch, discharge
- Associated symptoms
What is the key thing to remember about the presentation of chlamydia ?
Many patients are asymptomatic - famles 70%, males 50%
What are the complications of chlamydia infection which can develop?
- PID (CT accounts for 50% of cases) ==> Tubal damage (infertility, ectopic pregnancy)
- Chronic pelvic pain
- Transmission to the neonate (17% conjunctivitis, 20% pneumonia)
- Adult conjunctivitis
- Sexually acquired reactive arthritis (SARA) /Reiter’s syndrome (commoner in men). – hence in a young man with joint pain its important to take a sexual history
- Fitz-Hugh-Curtis Syndrome (Perihepatitis) – piano string adhesions involving the liver capsule
What is reiters syndrome
- It is a reactive arthritis which can affect the joints & tendons, cause urinary symptoms & affect the eyes.
- It primary affects the joints and tendons causing pain & joint swelling
- It occurs in men primarily, often within 4 weeks of an infection typically an STI such as chlamydia
What is the treatment of chlamydia ?
- 1st line = Doxycycline (7 days)
- 2nd line = Azithromycin (2 days)
What are the symptoms of epididymo-orchitis ?
- scrotal pain (usually unilateral), and swelling
- +/- symptoms of UTI (dysuria, urgency, frequency) or urethritis (dysuria or urethral discharge)
What investigations and management is given for epididmyo-orchitis ?
Send MSSU, gonorrhoea & chlamydia tests.
- If STI likely (35 or new partner in last 3mth) give doxycycline
- If UTI likely (>35 and no new partner) give ofloxacin or ciprofloxacin
What is the treatment of chlamydia in pregnancy ?
1st line = azithromycin or erythromycin
Test of cure at 3 weeks after end of treatment + rescreen in 3rd trimester
What is the treatment of LGV ?
3 weeks of doxycyline
How is chlamydia and gonorrhoea diagnosed ?
- 1st line = Combined NAATs or PCR - tests for both organisms
- 2nd line = a culture & microscopy should be taken for all those +ve for gonorrhoea before prescribing antibiotics (due to resitance, done on male urethral and female endocervical swabs, not HVS)
How should the sample of the combined NAATs or PCR for diagnosing chlamydia and gonorrhoea be taken ?
- Male patients – first pass urine sample (N.B. not MSSU)
- Female patients – HVS or vulvo-vaginal swab (VVS), which can be self-taken by patient or clinician-taken endocervical swab (if patient is having speculum examination)
- Rectal and throat swabs, if sexual activity indicates i.e. MSM, or oral/anal carried out
- Eye swabs (for babies and adults if symptoms suggest)
What is prostatitis
This is inflammation of the prostate gland
What are the 3 classifications of prostatits ?
- Acute bacterial prostatitis
- Chronic bacterial prostatitis
- Chronic prostatitis/ chronic pelvic pain syndrome (CPPS)
What are the symptoms of acute bacterial prostatitis ?
Symptoms of UTI but may have lower abdo pain/back/perianal/penile pain & a tender prostate on exammination
What is the cause of acute bacterial prostatitis ?
- It is a rare complication of UTIs in men most commonly caused by E.coli
- In patients < 35 or those with a new sexual partner in the last 3 months check for STI (chlmaydia/gonorrhoea)
How is acute bacterial prostatitis diagnosed ?
Clinical signs + MSSU for culture & sensitivity +/- First pass urine for chlamydia/gonorrhoea test if indicated
What is the treatment of acute bacterial prostatitis ?
and explain the choice of antibiotics
- 1st line = ciprofloxacin or ofloxacin
- 2nd line = trimethoprim if patient is at high risk of C.diff
Gent and quinolones e.g. ofloxacin and ciprofloxacin are best for penetrating the prostate
What are the symptoms and treatment of asymptomatic prostatitis ?
- Asymptomatic - detected by chance e.g. when assessing infertility or checking for prostate cancer
- Doesnt usually require treatment
What are the symptoms, treatment and diagnosis of chronic bacterial prostatitis ?
Same as acute (classified as chronic when it lasts longer or equal to 3 months)
What are the symptoms of CPPS ?
- It is the most common type of prostatitis and can go on for a long time
- Causes pelvic pain without evidence of UTI - lasting > 3 months
- Pain can be present in the perineum, testicles, tip of penis, pubic or bladder area.
- Urinary symptoms may also be present
What is CP/CPPS caused by ?
Uknown - thought to be linked to stress/anxiety
How is a diagnosis of CP/CPPS reached ?
By ruling out other diagnoses e.g. BPH, overactive bladder, cancer, bacterial prostatitis
What is the treatment of CP/CPPS?
Includes physio, alpha-blockers and sometimes antibiotics (dont really need to know)
What is the causative organism of syphallis ?
Treponema pallidium
How is syphillis transmitted ?
- Sexual contact
- Trans-placental/during birth
- Blood transfusions
- Non-sexual contact – healthcare workers
Note - it is very infectious and can be transmitted during the primary up until the end of the early latent stage
What is the microscopic appearance of treponema pallidum?
Spirochete - does not gram stain
Why does the diagnosis of syphillis rely on PCR test (reference labs) or on serological (blood) tests to detect antibodies?
Because it cannot be grown in artificial culture media
What are the 4 stages of syphillis infections ?
- Primary
- Secondary
- Latent
- Tertiary (late)
Describe the primary stage of syphillis infection
- Occurs between 10-90 days (mean is 21) after exposure
- Painless ulceration develops at the site of inoculation (chancre)
- Non-tender local lymphadenopathy
- Chancre heals without treatment within 2-3 weeks
Describe the secondary stage of syphillis infection
4-10weeks after the appearance of the primary lesion (chancre often still present so look for it)
Large numbers of bacteria is circulating within the blood at this point producing multiple manifestations at different sites:
- Skin (macular, follicular or pustular rash on palms + soles)
- Ulceration of mucous membranes - found in the mouth & on the genitalia described as ‘snail track ulcers’
- Generalized Lymphadenopathy
- Patchy Alopecia
- Condylomata Lata (most highly infectious lesion in syphilis, exudes a serum teeming with treponemes)
Describe the latent stage of syphillis infection
- No symptoms during (early latent is < 2yrs after secondary syphillis and late latent is > 2yrs)
- Symptoms can recurr during this stage and some patients may self-cure or be treated coincidentally
Describe the tertiary (late) stage of syphillis infection
- Generally involves the skin & bone
- Characteristic lesion, the gumma which can occur anywhere on the skin but usually at sites of trauma
- Cardiovascular & neurovascular complications arise many years after intital stages of syphillis
How is syphillis diagnosed in tayside ?
1st line = Combined IgM & IgG screening test (ELISA test)
if negative no additional tests done, if positive then additional tests done:
- A reagin test (VDRL or RPR test) - to look for evidence of tissue damage, these are positive in active, untreated infection
- A test for T.pallidum specific IgM antibodies
- A test for T.pallidum specific IgG antibodies (e.g. TPPA and TPHA tests)
What is the gold standard test for diagnosing primary or secondary syphillis which is not done in tayside ?
Dark ground microscopy
What other methods are sometimes used for diagnosis of syphillis but not used in tayside ?
- Microscopy (dark ground microscopy) - can be used to diagnose primary or secondary by obtaining exudate from chancre
- PCR - swabs taken from chancre (again useful for primary or secondary)
What is the treatment of syphillis ?
- 1st line = penicillin G
- 2nd line = doxycycline (if pen allergic)
What is the cause of genital herpes infections ?
HSV-1 and HSV-2 (more commonly HSV-2)
Alongside genital herpes what can infection of HSV-1 also cause ?
‘Cold sores’
Who is genital herpes more common in ?
Females
What is the HSV virus and how is it spread ?
- It is an eveloped virus containing double-stranded DNA
- It is transmitted by close contact with someone sheading the virus via either genital to genital or orophrangeal to genital contact
Describe the pathogenesis of genital herpes infection
- Primary infection occurs - this may be asymptomatic
- Virus replicates - in the dermis & epidermis
- Virus enters nerve endings causing inflammation ==> equisitly painful, multiple small vesicles formed
- Virus migrates to sacral root ganlgion & hides from immue system (likely remains there for life)
- Virus can reactivate causing recurrent genital herpes attacks
- Intermittent virus sheading may occur in the absence of symptoms
What is the incubation period and then the duration of primary infection of genital herpes ?
- Incubation period = 3-6 days
- Primary infection duration = 14-21 days
What are the symptoms of primary genital herpes infections ?
Often asymptomatic (also note patient will have no antibodies at this time) but symptoms can include:
- Blistering and ulceration of the external genitalia
- Pain
- External dysuria
- Vaginal or urethral discharge
- Local lymphadenopathy
- Fever and myalgia (prodrome - often an early symptom)
What are the symptoms of recurrent genital herpes episodes ?
- More common with HSV-2
- Often overlooked/misdiagnosed as “thrush“ (mild, localised anogenital tingling, burning or soreness)
- Usually unilateral, small blisters and ulcers
- Minimal systemic symptoms, resolves within 5-7 days
How is genital herpes diagnosed ?
1st line = Deroof ulcer/blister & swab base of it for HSV PCR
What is the treatment of genital herpes ?
1st line = oral aciclovir + pain relief:
- Topical lidocaine ointment (may help if episode is very painful & can make them more comfortable and help in passing urine)
- Saline bathing may help (salty warm water)
- Analgesics
Which of viruses which cause genital herpes is more problematic and what sometimes may need to be done?
- HSV-2 because it has a much higher viral shedding ==> more contangious and more likely to cause recurrent episodes
- If patient has recurrent attacks ≥ 6 per year then suppresive daily aciclovir therapy may be used
What needs to be done if someone presents with possible primary infection of genital herpes during pregnancy ?
- Need to determine if it is a primary infection or not as if it is then the baby can be infected and will need referral to O&G for review of their birth plan
- Will need to do specific serology tests to determine if antibodies present because if not then its a primary infection (know because of HSV PCR confirming it is genital herpes but no antibodies on serology)
- In 1st and 2nd trimester there is no increased risk of misscariage or the baby developing developmental problems
- In 3rd trimester there is a high risk of passing the virus onto the child ==> may need C-section to help reduce risk of transmission + aciclovir for the last 4 weeks of there pregnancy (if recurrent attack then aciclovir taken from week 36 until birth)
What is the most common viral STI in the UK ?
HPV
There are hundereds of HPV genotypes, what are the important ones to remember and what are they associated with ?
6&11 and 16&18 are the ones to remember
- 6&11 are associated with causing genital warts (>90%)
- 16&18 infection are associated with significantly increasing the risk of cervical cancer, the also increase the risk of penile cancer
- 16 is also associated with increasing risk of oropharyngeal cancers
What percentage of the population are exposed to HPV viruses and how
- 80% of the population are exposed but only 1% develop anogenital warts
- Likely exposure is due to contact with an asymptomatic partner
What is the incubation period for the development of HPV genital wart symptoms ?
3-9months
What are the symptoms of genital warts ?
The warts are usually painless, but can be itchy and inflammed
What is the treatment of HPV genital warts ?
- 1st line = Podophyllotoxin (warticon) or Imiquimod (aldara)
What does the HPV vaccination protect against and what is it called
Called Gardasil it protects against 6,11,16&18
Who is eligable for HPV vaccination?
- Girls AND boys aged 11-13
- MSM upto age 45
What is bacterial vaginosis and what causes it
- It is a disorder charactersied by an offensive vaginal discharge
- It is caused by the normal vaginal flora being replaced by Gardnerella vaginalis
What are the clinical features of BV ?
- Vaginal discharge - greyish white, may contain bubbles
- Odor - fishy smelling
- Vaginal pH raised (>5/4.5)
- Approx 50% of women are asymptomatic
- Not usually associated with soreness or itching
How is a diagnosis of BV made ?
In general 3 of the following should be present:
- Characteristic homogenous, greyish white vaginal discharge
- The amine test showing raised vaginal pH >4.5-5
- A fishy odor produced on adding 10% potassium hydroperoxide to the discharge ‘whiff test’
- The presence of clue cells on wet mount microscopic exammination
Describe the appearance of clue cells
They are vaginal squamous epithelial cells covered with anaerobic gram variable cocobacilli (gardnerella vaginalis)
What is the treatment of BV ?
- 1st line = oral metronidazole
- 2nd line = clindamycin vaginal cream
What is trichomonas vaginalis and what does it cause?
It is a single celled parasite (has a fleggella)
Which is transmitted by sexual contact and causes:
- Vaginal discharge (frothy yellowish), cervix may have small haemorrhagic ares ‘strawberry cervix’ & irritation in females
- Males are usually asymptomatic but may have discharge, irritation or increased urinary frequency
How is trichamonas vaginalis diagnosed ?
HVS for microscopy (PCR test also available, but not used in Tayside, so no good test for males)
What is the treatment of trichamonas vaginalis ?
1st line = oral metronidazole
How are pubic lice transmitted and how do they present ?
- Transmitted by genital skin contact
- Cause itching in pubic area
What is the treatment of pubic lice ?
1st line = Malathion lotion
Q1.The most common bacterial STI is:
a) Genital Warts
b) Gonorrhoea
c) Chlamydia
d) Herpes
C
Q2.Profuse mucopurulent discharge from the penis and painful urination are more commonly symptoms of:
a) Herpes
b) HPV
c) Syphilis
d) Gonorrhoea
D
Q3.A chancre develops during which stage of syphilis.
a) Primary
b) Latent
c) Tertiary
d) Secondary
A
Q4.Which of these infections can lead to pelvic inflammatory disease in women.
a) Syphilis
b) HPV
c) Chlamydia
d) HIV
C
Q5.This STI is known as the “great imitator” because its symptoms resemble those of other infections.
a) HIV
b) Syphilis
c) HPV
d) Gonorrhoea
B
Q6.The vaccine for HPV is currently recommended in (HIV negative) females of which age:
a) 11-13
b) 40+
c) 9 - 26
d) 25 - 35
A - now males too
Q7.Viral shedding is higher with which type of Genital Herpes simplex virus
a) Type 1
b) Type 2
B
