Lecture 29: Urethritis and Cervicitis Flashcards
Define Urethritis
Urethritis is an inflammation of urethra, and is not the same as a urinary tract infection (UTI). Criteria vary in different centres.
- Urethritis is defined as that condition occurring in symptomatic males with >5 PMNL (peripheral blood monocytes and polymorphonuclear leukocytes) per HPF (high-power field) on microscopy of a urethral smear.
Symptoms are of an anterior urethritis, i.e. discharge/dysuria
Describe the physiological discharges in males
Littre’s glands
- Urethral glands
- Produce a colloid secretion containing glycosaminoglycans (protect against urine)
- Protects the epithelium against urine.
What are the causes of vaginal discharge? (5)
-
Physiological
- Cyclical variation
- Cervical mucus
-
Cervicitis:
- Endocervical infection (and inflammation involving TZ)
- Mucoprulent cervicitis e.g. gonorrhoea, or chlamydia
- “Strawberry cervix” (colpitis macularis: inflammatory punctate haemorrhage) due to trichomonas
- Other
- Endocervical infection (and inflammation involving TZ)
-
Genital candidiasis
- (inflammation of vagina)
- Bacterial vaginosis (BVAB)
- Others include atrophic vaginitis (and post-partum); desquamative inflammatory vaginitis; ‘cytolytic vaginitis’; foreign body such as retained tampon
Describe the characteristics of Chlamydia
Introduction
Chlamydia is a hallmark of the _serially monogamou_s rather than promiscuous
- Most common bacterial STI in NZ
- Rarely fatal. Commonly asymptomatic
Characteristics
Obligate intracellular bacterium (‘energy parasite’) with complex biphasic lifecycle (cycle 24-48 hours)
- Deficient in endogenous ATP production
- Can’t grow on artificial media
Outer membrane similar to that of other gram-negative bacteria
Serovars (distinct variation within a species of bacteria of different individuals, classified based on surface antigens) include:
- A, B, Ba, C cause endemic trachoma
- _D-K cause genitourinary disease (_infect squamocolumnar cells)
- L1, L2, L3 cause lymphogranuloma venereum (LGV) (infect lymphatic tissue)
Describe the Pathophysiology of Chlamydia
Initial infection is mild and self-limited
Antibodies against major outer membrane protein (MOMP) can neutralize organisms.
- Latent infection is induced
S_hort term serovar-specific immunity_ develops
Recurrent infection produces severe inflammation (resulting in tissue damage and scarring)
- Due to exaggerated host CMI response
- Cross-reacting heat shock protein aggravated by persisting intracellular chlamydia antigen (chlamydial heat shock protein 60 (Chsp60))
Describe how you would diganose Chlamydia
Diagnostic Advances: NAAT (Nucleic Acid Amplification Testing)
- NAAT is DNA amplification (nucleic acid amplification).
- NAAT has _increased sensitivity over EI_A, which detect < log 1 organisms per sample (NAAT > Culture > EIA).
- Enzyme immunoassay (EIA) detects log 5-7
- Culture detects log 1-2
- Obviates most of the problems with false positives. PPV and NPV better than other tests
- Fewer storage and handling problems compared swabs for culture. Can be automated.
Diagnosis of CT (Chlamydia)
- NAAT> Culture > EIA
- Modern NAATs are similar in sensitivity & specificity
- (SDA, PCR, TMA)
- Can be performed on self-collected samples, which remain stable at room temperature for many days, thus opening up the situation for novel screening strategies
- Rapid tests allowing point of care (PoC) testing are also well advanced
How do you take specimen sample in chlamydia?
Specimen Collection and Transport
- In males, first-void urine (FVU) in both symptomatic and asymptomatic men
- In females, vulvovaginalal swab for NAAT; speculum examination is still recommended in symptomatic female patients
How would you treat Uncomplicated Chylmydial infection?
Uncomplicated/Complicated Infection
Uncomplicated infection needs presence of effective a_ntimicrobial therapy_ for at least _2 reproductive cycle_s (i.e. about 5 days) to treat (azithromycin 1g stat or doxycycline 100mg 2x/d 7d)
- Doxycycline 100mg bid 7 days (efficacy 97-100%)
-
Azithromycin 1 gm stat (equally efficacious to doxycycline)
- High level of patient adherence
- Pregnancy category B1 (limited, no harm)
Complicated disease requires longer Rx (e.g. course of doxycycline).
Fortunately, little in way of antibiotic resistance reported
Describe Azithromycin
-how it works
Azithromycin is azalide (a macrolide subclass). It i_nhibits translation of bacterial mRNA_ (binding to 50S subunit of bacterial ribosome)
- 3-5% patients experience GI side-effects
- Tissue levels >50X plasma levels (long tissue half life
- Risk factor in long QT syndrome
- In chlamydia, resistance is rare
How would you treat a pregnant woman who has Chylamydia?
Pregnancy
In pregnant or breastfeeding women use:
- Azithromycin 1g stat
- Aoxycillin 500mg tid for 7 days (test of cure should be performed 3-4 weeks after completing amoxicillin therapy)
What would happen with the partner of of an individual who was diagnosed with Chylamydia?
Partner Treatment
Partner notification include all partners within last 60-90 days, or last partner if > 60 days ago
- Test of cure of required not required (also, if using NAAT may get false positive)
T_reat partner(s) (_even if their test is negative)
- Expedited partner treatment (patient-delivered partner therapy (PDPT) is a possibility in some jurisdictions)
- Advise to practice protected sex during treatment
Describe the bacteria that causes gonorrhoea
Neisseria gonorrhoea is Gram-negative diplococcus.
Humans are only natural host. It infects non-cornified epithelial cells (intracellular replication).
- Oxidase positive
- Fastidious growth
- Chromosomal or plasmid mediated antibiotic resistance
Describe Specimen Collection and Transport for suspected Gonorrhoea
Always from the site with symptoms/signs, and also from other areas identified in sexual history at risk
If symptomatic, take a sample for culture
- Specimen for culture can be left at room temp for up to 5 hours without loss of viability (but don’t tolerate drying)
- Amies’ or Stuart’s only for transport where inoculation of growth medium will occur within 4-8 hours (not overnight)
What can gonorrhoea cause in males?
Urethral Infection In Males
- Most are symptomatic (incubation period 1-14 days (2-5 is common))
- Anterior urethritis (discharge and dysuria, erythema of meatus is variable (meatitis))
- Untreated men are 95% asymptomatic after 6 months
What is a method of Diagnosing Gonorrhoea?
1) Gram stain : Presumptive diagnosis
2) Culture by site
3) NAAT
Diagnostic: NAAT (Nucleic Acid Amplification Testing)
NAAT has high sensitivity. Specificity varies by brand and specific method.
- Should be confirmed by supplemental testing
- 2 targets for GU samples
- 3 targets for extra-genital (non-genital) samples
NAAT has high patient acceptability, can be done on self-collected samples
No antibiotic sensitivities (still a need for culture to enable surveillance of antimicrobial resistance)
Chlamydia NAAT typically combined on modern versions [CT/NG NAATs]
