Chlamydia Flashcards
what are the treatment options for urogenital CT infection in pregnancy?
- Azithromycin 1g stat, 500mg OD for next 2 days
- erythromycin 500mg BD for 14 days
- erythromycin 500mg QDS for 7 days
- amoxicillin 500mg TDS for 7 days
What serotypes of chlamydia cause urogenital infection?
Answer: Serotypes D-K
What serotypes of chlamydia cause LGV
serotypes L1, L2 and L3
L2b most commonly
Name three risk factors for developing a chlamydia urogenital infection
- age <25 years
- new sexual partner
- more than one sexual partner
What is the concordance rates in couples where one of the partners tests positive for chlamydia?
answer: 75%
Name three sites where chlamydia can be found
- urogenital
- pharyngeal
- rectal
- conjunctiva
What percentage of chlamydia infections can resolve spontaneously within 12 months from initial diagnosis?
answer: up to 50%
List the common symptoms that women can present with indicative of chlamydia urogenital infection
Symptoms include:-
- . unusual/ increase in vaginal discharge
- PCB +/- IMB
- dysuria
- symptoms associated with PID (lower pelvic pain, dyspareunia)
note .. the majority of CT infections are asymptomatic
What are the signs on examination suggestive of chlamydia urogenital infection in women
- mucopurulent cervicitis +/- contact bleeding
2. signs of PID - lower pelvic pain, CME on bimanual examination
What are the symptoms of urogenital chlamydia infection in men?
- urethral discharge
2. dysuria
what is the main sign in men associated with chlamydia infection
majority are asymptomatic but if symptoms present - clear/milky coloured urethral discharge
How do extra-genital chlamydial infections present specifically pharyngeal, rectal and conjunctival
- pharyngeal - usually asymptomatic
- rectal - usually asymptomatic, rectal discharge can be present
- conjunctiva - unilateral low grade irritation
List the complications of chlamydia infection in men and women
Women: 1. PID (endometritis/salpingitis) 2. tubal infertility 3. SARA (<1%) 4. peri-hepatitis (fitz hugh curtis)
men: 1. SARA, 2. epididymo-orchtitis
both: LGV (servers L1 - L3)
What are the symptoms associated with LGV?
- tenesmus (the feeling of needing to pass stool when your bowels are empty)
- rectal discharge usually bloody
- diarrhoea or altered bowel habit
note can be asymptomatic!
what is the window period for chlamydial testing
2 weeks
What percentage of women with untreated chlamydia can go on to develop PID?
up to 16% of women
A patient attends sexual health with symptoms of unusual vaginal discharge and IMB. How would you test for chlamydia?
Vulvo-vaginal NAAT CT/GC –> this can be self taken or by the clinician
studies suggest that self taken swabs are more sensitive than clinician taken
What is the investigation in men used to diagnose urogenital chlamydia?
first catch urine (FCU) - advise men to hold their urine for 1 hour prior to this test.
what is the sensitivity of a vulvo-vaginal NAAT CT/GC swab in women
96-98%
Does the sensitivity of extra-genital CT/GC testing increase or decrease compared to sensitivity of urogenital testing
decrease
Maria attends clinic for treatment of chlamydia from a self swab taken at her GP surgery (VVS). what other investigations would you want to complete during this consultation?
offer full STI screen including bloods for HIV, STS +/- hep B and C serology dependent upon risk factors
no evidence to swab extra-genital sites in CT infection in women
Maria is currently 12 weeks pregnant and CT positive, she has no drug allergies and is not on any other medication. How would you treat Maria?
- Azithromycin 1g stat, followed by 500mg OD for 2 days
- TOC at 6 weeks is indicated in pregnancy
- PN should be initiated at the time of the consultation
- no sex until her and partner have completed Rx and symptoms resolve
Maria is now 18 weeks pregnant. She attended for her TOC at 6 weeks post treatment as advised following treatment with Azithromycin (1g stat, 500mg OD 2 days). Her TOC has come back positive. She has NKDA and the pregnancy has otherwise been uneventful. She denies having had sex since the treatment. How would you manage Maria?
Options:
- erythromycin 500mg QDS for 7 days
- erythromycin 500mg BD for 10-14 days
- amoxicillin 500mg TDS for 7 days
advise no sex for 7 days until her and partner completed Rx, TOC at 6 weeks, inform obstetrics
Which antibiotics used in the management of chlamydia are contra-indicated in pregnancy and breast-feeding?
doxycycline and ofloxacin
what is the first line treatment option for chlamydia infection
doxycycline 100mg BD for 7 days
James is a heterosexual, cis-gender male. he reports urethral discharge for the past 2 weeks and did an online STI screen that has come back positive for chlamydia. He tells you he last had sex 3 weeks ago, how would you manage the partner from 3 weeks ago?
advise them to ring an STI clinic and offer screening and treatment- doxycycline 100md bd 7 days
James was treated with azithromycin for urogenital CT, he has not had sex since the treatment and TOC has come back positive. He is allergic to doxycycline and erythromycin how would you treat him?
ofloxacin 200mg BD or 400mg OD for 7 days
no sex for 7 days until him and partner been treated, TOC at 6 weeks
what are the indications for CT TOC
pregnancy
rectal CT
peristent symptoms despite RX
when compliance is suspected to be low.
What percentage of patients who test positive for chlamydia can be co-infected with Mycoplasma genitalium?
from 3-15%
If someone is allergic to doxycycline and azithromycin what are the treatment options for CT?
- ofloxacin 200mg BD for 7 days or ofloxacin 400mg OD for 7 days
- ? might be allergic to macrolides though!
erythromycin 500mg BD for 10-14 days
What is the look back period for PN in:
a) symptomatic men
b) asymptomatic men and women
c) symptomatic women
a) symptomatic men - look back period for PN is 4 weeks
b) asymptomatic men and women, symptomatic women look back period is 6 months
what are potential complications for babies born to mothers infected with Chlamydia?
Opthalmia neonatrum and pneumonia
- opthalmia neonatrum commonly develops within 5-12 days post delivery and pneumonia in first 3 months following delivery
test using NAATs - conjunctiva or nasopharynx
how would you treat a neonate diagnosed with ophthalmia neonatrum or pneumonia due to chlamydia
erythromycin 50mg/kg/per day divided into four equal doses for 14 days
mum needs treatment and PN
Describe the microbiology of chlamydia trachomatis
C. Trachomatis is an intracellular obligate bacterial organism
how many biovars is chlamydia divided into
4 (LGV, trachoma, murine and swine)
can you name the biovar that causes urogenital chlamydia
trachoma
what divides the biovars of chlamydia into serovars
major outer protein membrane (MOMP)
SEROVARS D-K COMMONLY CAUSE UROGENITAL INFECTION
where does Chlamydia trachomatis get its energy from
host cell adenosine triphosphate
how long is the chlamydia life cycle
48-72 hours
what two structures appear during the chlamydial life cycle
elementary bodies followed by reticulate bodies
what is the most common cause of bacterial STI in the UK
genital chlamydia
what is the transmission rate of chlamydia following a single episode of UPSI
A - 5%
B-10%
c-20%
D - 50%
B - 10%
chlamydia can be responsible for which of the pregnancy complications listed below:
A - cardiac defects
B - pre-eclampsia
C- PROM
D- preterm birth
E- low birth weight
PROM, preterm birth, low birth weight
if chlamydia is present at the time of birth what complications can this cause for the neonate
30-50% will acquire chlamydial ophthalmia neonatrum
respiratory tract infection
light microscopy can be used to diagnose chlamydia trachomatis
True or false
false - can identify PMNL
what is the best type of test used to diagnose C.Trachomatis
A - light microscopy
B - cell culture
C- NAAT
D- EIA
E- DFA (direct fluorescent antibody)
C - NAAT (nucleic-acid amplification tests)
NAAT offers highest sensitivity and specificity (98-100%) over other tests.
light micro- can’t identify CT under microscopy
EIA, cell culture and DFA phased out as NAAT is now more sensitive and specific
what is more sensitive and specific - self taken vvs or clinician taken
self taken
what is the specificity of urogenital NAATs
98-100%
what is the sensitivity of urgoegnital NAATS
- vvs
- endocervival
-FPU
vvs- 96-98%
endocervical - 88-95%
urine 88->95%
note endocervical less sensitive than VVS
how do NAATs work
they work to amplify the DNA by PCR using either strand displacement or transcription mediated amplification, via cryptic plasmid or 23SrRNA
when should we test for LGV
in men and women who have proctitis
MSMs who are HIV positive patient with CT +ve at any site.
