10. STIs Flashcards
Name the 4 STI syndromes?
Genital discharge
Genital warts
Genital ulcers
Sexually transmitted and bloodborne viruses
What is the main presentation of HPV?
Genital warts found on:
- Shaft of penis (male)
- Vagina, vulva, cervix (female)
What is the main presentation of chlamydia trachomatis?
Urethritis
What is the main presentation of candida albicans?
vaginal thrush
What is the main presentation of trichomonas vaginalis?
Vaginitis
Lymphogranuloma venereum
What is the main presentation of Herpes simplex virus?
Genital herpes
What is the main presentation of neisseria gonorrhoeae?
Gonorrhoea
What is the main presentation of HIV?
AIDS
What is the main presentation of treponema pallidum?
Syphilis
What is the main presentation of hep b?
Hepatitis
What is the main presentation of Hsemophilus ducreyi?
Chancroid
STI risk factors?
Young age Failure to use barrier contraceptives Non-regular sexual relationships Homosexuality IV drug use African origin Social deprivation Prostitution Poor access to advice and treatment of STIs
What individual factos predispose to risky sexual behaviour?
Low self-esteem
Lack of skills
Lack of knowledge of the risks of unsafe sex
What external influences predispose to risky sexual behaviour?
Peer pressure
Attitude
Prejudices of society
Which service provisions predispose to risky sexual behaviour?
Accessibility of sexual health services
Lack of resources such as condoms
HPV, mechanism?
Induces hyperplastic epithelial lesions
Types exhibit tissue/cell specificity
Incubation period of HPV
1-6 months
which HPV types are most important?
Types 6, 11, 16 and 18 most important
What is are variety of consequences of HPV?
Cervical carcinoma
Urogenital warts
Laryngeal papillomas
Common, flat and plantar warts
Identification and treatment of HPV?
Seen on colposcopy after staining
Treatment:
- Podophyllum
- Cryo
- Laser
- Surgery
HPV vaccine, what is available?
Based on VLP1 (papillomavirus-like particle) a major capsid protein
Two killed vaccines available:
1. Cervarix
2. Gardasil
What is the current administration plan for HPV?
To girls 12-13yrs before they are sexually active
Protection against most cases of cervical cancer.
Characteristics of chlamydia trachomatis?
Obligate
Intracellular
Gram neg
What do the following serotypes of chlamydia cause:
A,B, C?
D-K?
L1, L2, L3?
A,B, C: Trachoma
D-K: Genital infection
L1, L2, L3: Lymphogranuloma venereum, cancer
Although often asymptomatic infection
Female chlamydia symptoms?
Vaginal/anal discharge Post-coital bleeding Abdominal tenderness Pelvic tenderness Infertility Reiter's syndrome (Arthritis, cervicitis, conjunctivitis) Proctitis (anus and rectum inflammation) Pharyngitis Perihepatitis: Upper abdominal pain
Male chlamydia symptoms?
Urethral/anal discharge Epididymal tenderness Prostatitis Reiter's syndrome (Arthritis, cervicitis, conjunctivitis) Proctitis (anus and rectum inflammation) Pharyngitis Perihepatitis: Upper abdominal pain
What is a NAAT test?
A nucleic acid test (NAT) or nucleic acid amplification test (NAAT) is a molecular technique used to detect a particular pathogen (virus or bacterium) in a specimen of blood or other tissue or body fluid.
What are the investigations available for chlamydia?
Urine- NAATs
Endocervical swab- Cell culture
Treatment of chlamydia?
Azithromycin resistance increasing
Tetracycline (doxycycline)
Candida albicans:
- Presentation?
- Diagnosis?
- Treatment?
Presents as intensely itchy vaginitis.
Diagnosed by microscopy and cell culture. Dismiss presentation as UTI.
Treatment: Oral fluconozole plus topical nystatin
What is trichomonas vaginalis?
Anaerobic, single cell, flagellated protozoa
MoA of trichmonas vaginalis?
Attaches to squamous epithelium and infects vagina and urethra.
Incubation: 4d-3wks
–> Trichomoniasis
Presentation of trichomonas vaginalis infection?
Yellowish vaginal discharge
Which is dianosed by dark-phase microscopy
Treatment of trichomonas vaginalis infection?
Metronidazole
What is the difference between HSV1 and HSV2?
Herpes simplex virus
HSV type 1: Usually affects the oral region and causes cold sores
HSV type 2: Associated with genital infection (penis, anus, vagina)
However, both can infect the mouth and/or genitals due to oral sex or autoinoculation
Transmission of genital herpes?
By sexual contact or during birth (30-40% risk)
Neonatal infection may result in desseminated infection often involving CNS
Presentation of genital herpes during the primary infection?
Febrile flu-like prodome (5-7 days)
Tingling neuropathic pain in genital areas/ buttocks/legs
Extensive BILATERAL crops of PAINFUL blisters/ulcers in the genital area (inc cervix and vagina)
Tender inguinal lymph nodes
Local oedema
Dysuria
Vaginal or urethral discharge
Treatment of genital herpes primary infection
Aciclovir
What is the process of genital herpes recurrence?
After primary infection, the virus becomes dormant in local sensory ganglia
Periodic reactivation can cause:
-Symptomatic lesions
-Asymptomatic viral shedding (still infectious)
HSV-2 has more frequent reactivation
Diagnosis of HSV?
- Clinical appearance
- Viral culture
- DNA detection using NAAT of swab from the base of ulcer / vesicle fluid.
- Serology occasionally to identify those with asymptomatic infection and to distinguish between HSV1 and HSV2
Features of neisseria gonorrhoeae infective agent?
Gram negative
Intracellular diplooccus
Human only host
Infects epithelial cells of mucous membrane of GU tract or rectum.
Develops localised infection with pus production
Describe the consequences of gonorrhoea?
Male patients: Acute inflammation and discharge
Female patients: Cervical discharge
Male homosexuals: Rectal infectons
Oral pharyngitis contracted by oral-genital contact
Disseminated infection –> Septic arthritis
Female presentation/symptoms of gonorrhoea?
Dysuria Rectal infection= Asymptomatic Salpingitis (fallopian tube inflammation), PID Pharyngeal infection Post-coital bleeding Septic arthritis
Male presentation/symptoms of gonorrhoea?
Urethral discharge Anal discharge, pain and bleeding Epididymal tenderness Pharyngeal infection Septic arthritis
Babies presentation/symptoms of gonorrhoea?
Ophthalmia neonatorum- Blindness
What is ophthalmia neonatorum?
How do babies get it?
Conjunctivitis contracted by newborns during delivery
Mothers infected with N. gonnorrhoeae or C. trachomatis
Without treatment can cause blindness.
Lab diagnosis of gonorrhoea?
Light microscopy of gram-stained genital specimens to look for gram negative diplococci
NAAT- Can use urine or swabs
PMN in urethral pus
Treatment of gonorrhoea?
For confirmed, uncomplicated infection in adults… give single dose of one of the following:
- Cleftriaxone 250mg IM
- Cefizime 400mg oral
- Ciprofloxacin 500mg oral (if beta-lactam allergy)
Infection of preponema pallidum leads to..
Syphillus
What are the three stages of syphilis?
PRIMARY: Hard genital or oral ulcer (chancre) at the site of infection after 3 weeks
-Can be asymptomatic for up to 24 weeks
SECONDARY: Red maculopapular rash anywhere plus pale moist papules in urogential region and mouth (condylomas)
TERTIARY: Degeneration of nervous system, aneurysms and granulomatous lesions in liver, skin and bones (gummas) in about 40% of patients
How is syphilis transferred congenitally?
Placental transfer after 10-15 weeks of pregnancy
Infection can cause death or spontaneous abortion of foetus
Survivors develop secondary syphilis symptoms
Syphilis diagnosis?
From lesions or infected lymph nodes in early symphilis
Dark field microscopy
Direct fluorescent antibody (DFA) test
NAAT
EIA- Can be for ImM for early infection of IgG for week 5+
Major side effect of haemophilus ducreyi?
Chancroid (venereal infection causing ulceration of groin lymph nodes)
Cause by gram negative bacterium
Characterised by painful genital ulcers
Diagnosis and treatment of chancroid?
Diagnosed by microscopy/culture
Treatment: Macrolide (e..g erythromycin or ceftriaxone)
How to reduce risk of STI?
Less sexual partners
Use condoms
