STIs Flashcards
what is the most common bacterial STI
chlamydia
how many people with chlaymdia dont have symptoms
70-80% of women asymptomatic
50% of men asymptomatic
what type of bacteria is chlamydia
gram negative olbigate intracellular bacterium
cell wall lack peptigoglycan so cant be seen on gram stain
how is chlamydia transmitted
vaginal, oral or anal sex
which age group has the highest incidence of chlamydia
20-24 years
how many women with chlamydia develop PID
9%
what does PID increase the risk of
ectopic pregnancies x 10
tubal factor infertility 15-20%
what are the patterns of pathogenesis of chlamydia
Mucosal epithelial cells are primary target, replicates within vacuole in cytoplasm of host cell
Some can naturally clear their infection (good TH1 and gamma interferon response), some have abnormal host immune response which confers damage
what is the presentation of chlamydia in females
Post coital or intermenstrual bleeding
Lower abdominal pain
Dyspareunia
Mucopurulent cervicitis
what should dyspareunia and mucopurulent cervicitis in chlamydia make you worried about
upper pelvic infection/ inflammation
what do a lot of women think irregular bleeding is due to
poor pill taking
what is the presentation of chlamydia in males
Urethral discharge Dysuria Urethritis Epididymo-orchitis Proctitis (LGV) (inflammation of anus and lining of rectum)
what are the possible complications of
PID - ectopic pregnancy, tubular infertility
conjunctivitis
chronic pelvic pain
transmission to neonate: 17% conjunctivitis, 20% pneumonia
reiters syndrome
fitz hugh curtis syndrome (piano string adhesions between liver and diaphragm)
should you test women with vaginal discharge for chlamydia
no- not a good predictor of chlamydia more likely to be candida or BV
is reinfection with chlamydia common
yes
what is LGV
lymphogranuloma vereneum
serovar of chlamydia trachomatic
how is lGV spread
via unprotected anal sex
what are the symptoms of a LGV infection
rectal pain, discharge and bleeding
what is there a high risk of in LGV
concurrent STIs, 67% have HIV
how is chlamydia diagnosed
test 14 days following exposure
NAAT- females self taken vulvovaginal swab, males self taken first void urine
(combined test for chlamydia and gonorrhoea)
MSM - add rectal swab if has receptive anal intercourse (risk missing 1/4 of all infections if dont do this)
what is the treatment for chlamydia
1st line- Doxycycline 100mg BD x 1 week
2nd line- Azithromycin 1G stat followed by 500 mg daily for 2 days
what is mycoplasma genitalium associated with
non gonococcal urethritis and PID
what are the signs of someone carrying mycoplasma genitalium
asymptomatic carriage
what test for mycoplasma genitalium
NAAT test but in viral medium
what type of bacteria is gonorrhoea
gram -ve intracellular diplococcus
what are the primary sites of dipolococcus infection
mucous membranes of urethra, endocervix, rectum and pharynx
what is the incubation period of urethral gonorrhoea infection
2-5 days
which gender transmission is highets risk in gonorrhoea
from male to female
what is the presentation of gonorrhoea in males
asymptomatic = 10%
urethral discharge >80%
dysuria
pharyngeal/ rectal infections are mostly asymptomatic - do swab
what is the presentation of gonorrhoea in females
up to 50% asymptomatic
increased/ altered vaginal discharge (40%)
dysuria
pelvic pain (<5%)
pharyngeal and rectal infection usually asymptomatic
what are the possible complications of gonorrhoea
lower genital tract:
- bartholinitis
- tysonitis
- periurethrial abscess
- rectal abscess
- epididymitis
- urethral stricture
upper genital tract
- endometritis
- PID
- hydrosalpinx
- infertility
- ectopic pregnancy
- prostatitis
how is a diagnosis of gonorrhoea made
NAATS screening test
mciroscopy if symptomatic (urethral more sensitive than endocervical)
culture (in micro + or contact of GC)
(urethral more sensitive than endocervical) to get antibiotic sensitivities
what does gonorrhoea look like on microscopy
kidney shaped pairs in cells
what is the treatment for gonorrhoea
1st line- ceftriaxone 1g IM
2nd line- ceftixime 400 mg oral and azithromycin 2g oral
test of cure in all patients- swab sites that were infected
what are the difference between primary and non primary first infection genital herpes infection
Primary- never been exposed before, have no antibodies, big symptomatic episode
Non primary first episodes- have been exposed, have antibodies but this is first episode of symptoms
what is the incubation period for primary infection of genital herpes
3-6 days
what is the duration of a primary genital herpes infection
14-21 days
will be longer than any recurrent episodes
what are the symptoms of a primary herpes infection
Blistering and ulceration of the external genitalia
Pain
External dysuria
Vaginal or urethral discharge
Local lymphadenopathy
Fever and myalgia (prodrome)- flu like symptoms
which type of herpes is recurrent episodes more common in
HSV-2
Type 1 is better type to have, 1 attack every 12/18 months
Type 2 usually have 4-6 attacks per year
what are recurrent episodes of HSV like
usually unilateral, small blisters and ulcers
minimal systemic symptoms, resolves within 5-7 days
often overlooked/misdiagnosed as “thrush“ (mild, localised anogenital tingling, burning or soreness)
what should you think when there is brojen skin/ ulceration of genitals
herpes
test for herpes
Swab base of ulcer for HSV PCR
treatment for herpes
oral antiviral Treatment (Aciclovir 400mg TDS x 5/7)
Consider topical Lidocaine 5% ointment if very painful
Saline bathing
Analgesia
which type of herpes virus has more viral shedding
HSV 2
-more recurrent and severe
when is viral shedding in herpes more frequent
in first year of infection
More in individuals with frequent recurrences
Reduced by suppressive therapy
when do you give suppressive therapy for herpes
more than 6 episodes per year
what is the suppressive treatment for herpes
Acyclovir 400mg BD taken for 4 months. When stop will have a breakthrough episode then should tract recurrences. Can be on acyclovir for years, reduces transmission
what needs to be done in herpes in pregnancy
if first episode in 3rd trimester then do serology to see if primary or secondary
50% risk of transmission if primary HSV. 50% type 1 50% type 2
70% can have localised CNS or disseminated disease
Disseminated hsv more common in preterm infants and exclusively in women following primary infection. Transplacental antibodies do not prevent HSV spreading to brain of neonate
Better if not primary as mum will have antibodies which can transfer to baby
what is the most common viral STI in the uk
HPV
what is the lifetime risk of acquiring HPV
80%
most people’s immune system deals with it:
10% probably harbour detectable infection
1% develop anogenital warts
what are the low risk types of HPV
6,11,42,43,44
what are the high risk forms of HPV
16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68
what types of HPV are currently covered by the vaccine
6, 11, 16, 18
what does HPV 6 and 11 cause
anogenital warts
what does HPV 1 and 2 cause
palmoplantar warts
what does HPV types 16 and 18 cause
cellular dysplasia- cervical, anal, penile, vulva and oropharyngeal cancer
who do most people get HPV from
asymptomatic partner
what is the incubation period of HPV
3 weeks to 9 months
what is common in HPV transmission
transmission of more than 1 type of HPV
what are the different progression of HPV infection
Spontaneous clearance of warts 20-34%
Clearance with treatment 60%
Persistence despite treatment 20%
treatment needed in vast majority
what do anogenital warts look like
Cauliflower lesions, keratinized lesions
Can be planar or pedunculated
Can be perianal, can present anywhere in anogenital region, don’t have to have had anal sex
what is the treatment for HPV
Podophyllotoxin (Warticon)
Cytotoxic
Not licensed for extra genital warts (but widely used)
Imiquimod (Aldara)
immune modifier
1st line for Anogenital warts
Cryotherapy
Electrocautery
what organisms causes syphilis
treponema pallidum (shirochete)
how is syphilis transmitted
Sexual contact
Trans-placental/during birth
Blood transfusions
Non-sexual contact – healthcare workers
classified as congenital or aquired
what are the stages of early infectious syphilis
primary
secondary
early latent
what are the stages of late non infectious syphilis
late latent
tertiary
when does syphilis become late non infectious
after two years infected
what is the incubation period of primary syphilis
9-90 (mean 21 days)
where do chancres occur
at site of inoculation
Sites are Genital=90% Extra-Genital=10%
what are the symptoms of primary syphilis
painless chancre
no tender local lymphadenopathy
what is the incubation period of secondary syphilis
6 weeks to 6 months
what are the signs of secondary syphilis
Skin (macular, follicular or pustular rash on palms + soles)
Lesions of mucous membranes
Generalized Lymphadenopathy
Patchy Alopecia
Condylomata Lata (most highly infectious lesion in syphilis, exudes a serum teeming with treponemes)
known as the great imitator
how do you diagnose syphilis
Demonstration of Treponema Pallidum (from lesions or infected lymph nodes) Techniques Dark Field Microscopy PCR (polymerase chain reaction)
Serological Testing
Detects antibody to pathogenic treponemes
what are the serological tests for syphilis
ELISA/EIA (Enzyme Immunoassay- IgM and IgG) SCREENING TEST
if +ve:
VDRL test/ RPR (activity- non specific)
TPPA test (specific)
what is the treatment for early syphilis
2.4 MU Benzathine penicillin x 1
what is the treatment for late syphilis
2.4 MU Benzathine penicillin x 3
how do you follow up syphilis treatment
serologically
Until RPR is negative or serofast
Titres should decrease fourfold by 3-6 months in early syphilis.
There is serological relapse/reinfection if titres increase by fourfold.
Profuse mucopurulent discharge form penis and painful urination are more commonly symptoms of what
gonorrhoea
what age do girls and boys get HPV vaccine
11-13
