Bacterial STIs Flashcards
How long is the half life of azithromycin?
68 hours
What % of NGU is cause by M genitalium?
25%
What is the commonest cause of non STI PID?
Anaerobes-most commonly E coli
Often severe and in older women
Why should all PID regimens be effective against GC and CT?
Negative vulvovaginal tests don’t rule out upper reproductive tract infection
What is association between PID and anaerobes/BV?
Endometritis causes bleeding- which can provoke BS
Is metronidazole important in management of PID?
Abx regimes without metronidazole perform as well suggesting that anaerobes are less important in mild PID
Is test of cure required for Mycoplasma genitalium?
Yes - 5 weeks post treatment to ensure microbiological cure
Who do BASHH Recommend that we test for Mycoplasma genitalium?
Recommend: NGU PID Consider: Cervicitis Epidydimitis Proctitis
What is recommended to manage GC if penicillin allergy?
3rd generation cephalosporins (cefixime and ceftriaxone show negligible cross allergy)
Gentamycin 240 mg IM + azithromycin 2g
Spectinomycin 2g IM +azithromycin 2g
Azithromycin 2g alone (high resistance)
What is recommended treatment of recurrent/persistent NGU?
If treated with doxycycline regimen first line:
Recommended
Azithromycin 1g stat then 500 mg once daily for the next 2 days,
PLUS metronidazole 400mg twice daily for five days
Azithromycin should be started within 2 weeks of finishing doxycycline. This is not necessary if the person has tested Mgen-negative.
NB patients should be advised to abstain from sexual intercourse until 14 days after the start of treatment and until symptoms have resolved.
If treated with azithromycin regimen first line:
Recommended
Moxifloxacin 400mg once daily for 10 days, PLUS metronidazole 400mg twice daily for five days
Alternative
Doxycycline 100mg twice daily for 7 days, plus metronidazole 400mg twice daily for five days
What is the treatment for 1st episode NGU?
Doxycycline 100mg twice daily for 7 days
Alternatives
Azithromycin 1g stat then 500mg once daily for the next 2 days
or
Ofloxacin 200mg twice daily, or 400mg once daily, for 7 days
How long should patients abstain from sex if being treated for NGU?
14 days after the start of treatment, and until symptoms have resolved.
Why should patients abstain from sex for 14 days after start of treatment for NGU?
This is likely to reduce the risk of selecting/inducing macrolide resistance if exposed to Mgen or Neisseria gonorrhoeae which would make these infections more difficult to treat.
What is the commonest cause of NGU?
chlamydia 11-50% M gen- 6-50% Ureaplasma 11-26% TV 1-20% Adenovirus 2-4% HSV 2-3%
What are the STI causes of neonatal conjunctivitis?
CT
GC
Group B beta haemolytic strep
What is the management of neonatal ophthalmia neonatorum cause by CT
50 mg/kg erythromycin orally
4 doses in 24 h
14 day course
What is the risk of neonatal ophthalmia neonatorum if mother has untreated CT and what are complications?
30-50% risk of vertical transmission
67% bilateral conjunctivitis
Corneal scarring is RARE
What is the risk of neonatal ophthalmia neonatorum if mother has untreated GC and what are complications?
30-40% risk of vertical transmission
Can lead to ulceration, corneal scarring, blindness
What is the management of neonatal ophthalmia neonatorum cause by GC
25-50mg /kg of Ceftriaxone IM/IV
Is GC and CT neonatal ophthalmia neonatorum a notifiable disease?
No - not since 2010
What is the commonest cause of neonatal ophthalmia neonatorum in the UK?
Chlamydia
what i’ll is the recommended antibiotic regime for SARA?
standard course of antibiotics for whichever STI is identified?
morphology of chlamydia?
Gram negative ovoid
Morphology of M genitalium?
Flask shaped with narrow terminal rod
Morphology of haemophilia ducreyi?
Shoals of fish
Small gram negative coccobacillus in chains
(Microscopy low sensitivity- PCR most sensitive 95%)
Morphology of klebsiella granulomatosis?
donovanosis Donavon bodies deep purple Wrights/giemsa stain Closed safety pin appearance Shiny halo around bacteria Bipolar inclusions in bacteria Cant do PCR/culture- not available
Morphology of GC?
Gram negative diplococci
Incubation of LGV?
3-30 days
What constitutional symptoms are associated with LGV?
Fever, arthritis, aseptic meningitis, hepatitis, pneumonia
Erythema multiforme
Erythema nodosum
What is tertiary LGV?
Anorectal syndrome
Direct infection from AI
Proctitis
Anal discharge with bleeding, rectal pain, tenesmus, fever
Chronic–> fistula, abscesses, strictures, scarring
(saxophone penis)
Management of LGV?
Doxycycline 100mg po bd 21 days
or
Erythromycin 500mg ads 21 days
PN for LGV?
30 days from symptom onset
Or 3/12 of asymptomatic (like CT)
Epidemiological treatment
Should be examined and tested for chlamydial infection and receive presumptive treatment with 21 days of doxycycline 100 mg twice daily or alternative regimen for the same duration
Does LGV require follow up
Patients should be followed up until symptoms resolve.
Routine TOC not necessary if recommended regimen has been completed.
If TOC is required it should be performed 2 weeks after completion of therapy.
Is routine LGV typing of symptomatic and asymptomatic Chlamydia infection at any site recommended?
Only in HIV-positive MSM
What are associations between LGV and HIV?
There is a strong association between LGV infection and established or incident HIV infection and with incident hepatitis C infection.
Who should be offered 3 monthly STI screen including HIV?
UAI with partner of unknown or serodiscord-
ant HIV status over last 12 months
> 10 sexual partners, over last 12 months
Drug use (methamphetamine, inhaled nitrites) during sex over last six months
Drug use (GBL, ketamine, other NPSs during sex over last six months)
Multiple or anonymous partners since last tested
Any unprotected sexual contact (oral, genital or anal) with a new partner since last tested
Which infections tend to cause proctitis in MSM?
STIs - transmitted rectally through receptive anal intercourse or fomites (fingers, sex toys or other objects carrying these pathogens) or through oro-anal intercourse.
Which infections tend to cause enterocolitis in MSM?
Enteric pathogens, which are statutorily notifiable, tend to cause enterocolitis, although symptoms may overlap with those caused by STIs and there may be dual pathologies.
Acquisition of enteric pathogens may be linked to travel or occur in outbreaks related to food in addition to person-to-person trans- mission (e.g. for norovirus)
However, there is increasing evidence that a range of enteric infections may be transmitted during sex between men
What are the causes of sexually transmitted proctitis?
Neisseria gonorrhoeae Chlamydia trachomatis Genotypes D-K Genotypes L1-3 (LGV) Treponema pallidum Herpes simplex virus
What are causes of sexually transmitted enteric infections?
Shigella spp VTEC (verotoxin-producing Escherichia coli) Campylobacter spp. Salmonella spp. Entamoeba histolytica Cryptosporidium spp. Cytomegalovirus Giardia duodenalis Microsporidium spp. Hepatitis A
What are the symptoms of sexually transmitted enteric infections?
diarrhoea and/or dysentery
abdominal pain
What would be indicative of proctitis on microscopy?
> 10 PMNL per high power field
What is treatment for proctitis?
Empirical therapy, in symptomatic men with proctitis in whom the rectal chlamydial status is unknown, should include LGV (which also effectively treats syphilitic proctitis) and gonorrhoea treatment
Which infections causing proctitis are notifiable?
Infectious bloody diarrhoea as a clinical syndrome is a notifiable infection and should be notified to the Local Authority Proper Officer
Which part of the bowel do enteric infections usually affect?
Typically affect the large bowel (the colon) and less commonly, the small bowel.
Enteric infections are characterised by sudden onset of diarrhoea, with or without vomiting and are usually transient disorders due to enteric infection with viruses, bacteria or protozoa.
Other symptoms include blood and/or mucous in the faeces (dysentery), and fever or malaise.
For ix of sexually transmitted enteric infections, when is microbiology recommended?
Microbiology examination of stool is recommended in all cases and is essential when the patient:
- needs antibiotics.
- is systemically unwell.
- needs hospital admission.
- has blood, mucous or pus in stool.
- has diarrhoea after foreign travel.
- is immunosuppressed
What can be used to treat diarrhoea in sexually transmitted enteric infection?
Antidiarrhoeal (or antimotility) drugs such as loper- amide are contraindicated for the management of infectious diarrhoea
What can be used to treat diarrhoea in sexually transmitted enteric infection?
Antidiarrhoeal (or antimotility) drugs such as loper- amide are contraindicated for the management of infectious diarrhoea
When might empirical treatment be recommended in sexually transmitted enteric infection?
Guided by microbiology advice based upon most likely aetiology, empirical rx may be considered when:
• The patient is pyrexial (temperature >38C)
• The stools are bloody
• Diarrhoea lasts more than seven days
• Co-morbidities (frailty, inflammatory bowel
disease, immunocompromised state, e.g. advanced HIV infection, immunosuppressive agents, etc.) are present
Advice on preventing spread of sexually transmitted enteric infection?
Advise on hygiene
• Advise to avoid return to work until 48 h after last episode of diarrhoea
• For patients who work as food handlers or with people vulnerable to infections, return to work should be guided by local public health authorities
Advice on sexual practices to prevent spread of sexually transmitted enteric infection?
Wash hands, genitals and perianal skin before and after sexual activities such as intercourse, rimming, fingering or handling used condoms and sex toys.
If possible, showering is advised as bacteria like Shigella may be present on other skin surfaces.
- Use condoms for anal sex and latex gloves for digital penetration or fisting. Dental dams or a condom cut into a square to make a barrier for rimming.
- Avoid sharing sex toys or douching equipment.
- Avoid recommencing sexual contact until seven days after the last episode of diarrhoea.
Treatment of recurrent persistent NSU?
If had doxycycline first line:
Azithromycin 1 g stat then 500 mg once daily for the next 2 days
+ metronidazole 400mg twice daily for five days
Azithromycin should be given < 2 weeks of finishing doxycycline. (not necessary if the person has tested Mgen-negative.)
NO SEX 14 days after the start of treatment and until symptoms have resolved.
If had azithromycin as first line-
Moxifloxacin 400mg od 10 days
+ metronidazole 400mg bd five days
Alternative
Doxycycline 100mg twice daily for 7 days, plus metronidazole 400mg twice daily for five day
What are the growth requirements for GC?
35-37 degrees
PH 6.5-7.5
Atmosphere containing 5-7% Co2
Selective and enriched culture medium eg Thayer martin/modified New york city- supplemented with iron, essential AA, glucose and antimicrobials
Risk of transmission of GC men to women after 1 episode of sex?
60- 80%
Decreased by 40% with condoms
Risk of transmission of GC women to men after 1 episode of sex?
20%
Decreased by 75% with condoms
Risk of transmission of GC vertical?
Up to 30%
Spontaneous clearance of GC in pharynx?
100% at 12 weeks
How many men with GC have urethral discharge?
80%
How many men with GC are asymptomatic?
10%
How many women with GC have vaginal discharge?
50%
How many women with GC are asymptomatic?
50%
Urinary symptoms for GC urethral infection?
Dysuria but not frequency
Urinary symptoms for CT urethral infection?
Dysuria but not frequency
How many women with GC present with power abdominal pain?
25%
Does GC cause IMB or HMB?
Rarely
Infectious causes of proctocolitis?
Hepatitis A
Campylobacter
Salmonella
Cryptosporidium
Treatment of crytosporidium?
Protozoa
Fluids
No proven effective method
Paromycin, azithromycin and other abx- variable success
Example of a drug that should not be used with azithromycin?
Colchicine
Macrolide increases toxicity with colchicine
What is the incubation period for Donavonosis?
50 days
What is the incubation period for LGV?
3-30 days
What is the incubation period for primary sphilis?
9-90 days
What is the incubation period for Chancroid?
4-7 days
What is the incubation period for HSV?
3-14 days
Which STI causes gangrenous phagedenic ulceration
chancroid
Which STI causes complication rectal stricture
LGV
Which STI is associated with neoplastic changes?
Donavonosis
Which STI is caused by an RNA picornavirus?
Hepatitis A
Which STI is caused by a lentivirus?
HIV1
Which type of virus causes EBV?
DNA
Describe the type of virus causing HSV 1 or 2
neurotropic virus with a central DNA core
Describe the type of virus - CMV
largest DNA herpes virus
Risk factors for rectal LGV?
20-30 yo Sex workers MSM (anal sex, fisting, enemas/sex toys) STIs Social deprivation
Tropical/subtropical (Africa, SE Asia, caribbean)
Epidemic MSM UK, america, W Europe
PPV for chlamydia NAAT
If PPV >90% no need for confirmatory testing
(NB if prevalence increases so does PPV
If prevalence decreases, NPV increases)
Can PCR be taken from oral lesions for STS?
YES PCR can be used on oral or other lesions where commensal treponemes may also be present
( microscopy is not suitable for examining oral lesions due to the presence of commensal treponemes)
Treatment of steptococcus group A
Amoxicillin (on penicillin V)
Axithromycin (or clindamycin)
Treatment of steptococcus group B
Benzylpenicillin
GC culture medium/transport?
Transport bia amies/stuart or a CO2 producing medium
Transport kept at 4 degrees
