MGen Flashcards
Can you Gram stain MGen?
No. Lacks a cell wall.
Is MGen culture possible?
Yes but MGen is fastidious so typically requires weeks or months to culture
Where can MGen infect?
Genitourinary system
Rectal
Respiratory
(Throat carriage rare)
Prevalence in general population
1-2% (higher in women)
Prevalence peaks later than CT particularly men
Risk factors
Younger age
Non-white ethnicity
Smoking
Increasing no sexual partners
Transmission
Genital-genital
Penile-anal
Carriage in oropharynx uncommon, therefore contribution from oral sex likely to be very small
Risk per coital act unknown, likely to be smaller than CT
Clinical associations
NGU
PID
PCB
Cervicitis
Endometritis
Prevalence in NGU
15-25%
Prevalence in NCNGU
10-35%
Prevalence in persistent / recurrent NGU
40%
Risks in pregnancy
Pre-term birth
Miscarriage
Prevalence in PID
10-13%
Affect on fertility
Can cause epithelial cilia damage in human fallopian tube culture
Association with tubal factor infertility not yet demonstrated in studies
Is asymptomatic screening a good idea?
Majority of people infected with MGen in genital tract do not develop the disease
Current tx imperfect and a/w development of resistance
No evidence that screening aSx individuals of benefit (likely to do harm at population level)
Only current partners of MGen index Pt to be tested/offered epidemiological tx
Sx / Si men
Majority aSx
Urethral discharge
Dysuria
Penile irritation
Urethral discomfort
Urethritis (acute, persistent, recurrent)
Balanoposthitis (in one study)
Complications in men
SARA + EO (possible)
Prostatitis (data lacking)
SX/Si women
Majority aSx
Dysuria
PCB
Painful IMB
cervicitis
Lower abdo pain
Complications in females
PID
tubal factor infertility (uncertain association)
SARA
Pre term delivery
Who do you test for MGen?
Based on Sx:
NGU
PID
Consider:
- mucopurulent cervicitis, particularly PCB
- EO
- sexually acquired proctitis
Based on risk factors:
- current sexual partners of MGen infected
Window period for MGen
No data on incubation period
It is likely that sensitive tests will detect early infection
Management of uncomplicated urogenital infection (urethritis, cervicitis)
1.
7/7 doxycycline 100mg BD
then
Azithromycin 1 g then 500mg OD (3/7)
- Moxifloxacin 400 OD 10/7
(If macrolide resistant or treatment failure)
Management of complicated MGen (PID / EO)
Moxifloxacin 400mg OD 14/7
How long should patients avoid SI ?
14/7 after start of tx and until Sx resolved
Where azithromycin has been used this is especially important because of its long half life, and is likely to reduce the risk of selecting / inducing macrolide resistance if the patient is re-exposed to MGen.
who should have a TOC and when
Everyone
5/52
Partner notification
Current partner only (to reduce risk of re infection to index patient)
Partner should be given same Abx as index patient unless there is available resistance info to suggest otherwise.
Rate of MGen macrolide resistance in UK
40%
Azithromycin treatment failure and MGen sensitive to macrolides
Do not repeat azithromycin as resistance is likely to have developed on treatment
Role of doxycycline in MGen treatment
Doxycycline as mono therapy has poor efficacy and eradication rates are low (30-40%).
There is evidence that prior tx with doxycycline may improve tx success when given with, or followed by extended azithromycin regimen
(Doxy reduces organism load and hence the risk of pre-existing macrolide mutations being present).
Efficacy of moxifloxacin
Excellent efficacy in Europe
Increasing resistance in Asia-Pacific (where it’s use is greater)
Data shows more tx failures with 7/7 course than 10/7
How long after completed doxycycline can give azithromycin?
Within 2/52
- If longer repeat doxy
Counselling points when commencing moxifloxacin
Can cause tendon rupture
Stop if any pain
Which MGen treatments can increase QT interval
Azithromycin
Moxifloxacin
(Caution if already on medications that prolong QT)
What class of drugs is moxifloxacin
Fluroquinolone
Alternative MGen treatments (3rd line)
- Doxycycline 100mg BD 7/7 then pristinamycin* 1g PO QDS 10/7
- Pristinamycin* 1g PO QDS 10/7 (75% effective as mono tx)
- Doxycycline 100mg BD 14/7
- Minocycline 100mg PO BD 14/7
*not currently available in the UK and must be imported against a prescription (2-3 week lead time)
Management of MGen proctitis
Same as urogenital
Severe proctitis - 14/7 moxifloxacin can be considered
Treatment of uncomplicated MGen in pregnancy / BF
Azithromycin 3/7 course (1g, 500mg, 500mg)
Management of MGen in pregnancy with macrolide resistance or upper genital tract infection
Options are limited
Moxifloxacin is contraindicated in pregnancy and BF
