Sexually Transmitted Infections Flashcards
Definition of a sexually transmitted infection
An infection which is predominately sexually transmitted
STI vs STD
STI is the infection e.g. HPV
STD is the disease it causes e.g. warts
What is the activity of identification and informing sexual contacts of someone with an STI called?
‘partner notification’ or
‘contact tracing’
What is gonnorhoea caused by?
Neisseria Gonnorhoea
Which is more common, chlamydia or gonnorhoea?
Chlamydia
What gender is gonnorhoea more common in?
Men, often MSM
What does MSM mean?
Men who have sex with men
Incubation period of gonorrhoea
Average 5-6 days
Range 2 days - 2 weeks (if get symptoms at all)
Male symptoms of gonnorhoea
Thick, profuse yellow discharge
Dysuria
Rectal and pharyngeal infection often asymptomatic
10% with no symptoms
What % of males have no gonorrhoea symptoms?
10%
What % of women have no gonorrhoea symptoms?
> 50%
Women symptoms of gonnorhoea
>50% asymptomatic Vaginal discharge Dysuria Intermenstrual bleeding Post coital bleeding
Investigations for gonnorhoea
NAAT from urine or swab from exposed site (vagina, rectum, throat)
gram stain smear from urethra/cervix/rectum in symptomatic people
To confirm antibiotic sensitivity -> culture of swab obtained specimen from exposed site using highly selective lysed blood agar
NAAT means….
Nucleic acid amplification test
Treatment of gonnorhoea
Blind treatment with
- ceftriaxone 500mg IM once
PLUS
- Azithromycin 1g
Follow up after treatment for gonnorhoea infection
Test of cure at 2 weeks
Test of re infection at 3 months
Male complications of gonorrhoea
Epididymitis
Acute monoarthritis usually elbow or shoulder
Disseminated gonococcal infection; skin lesions - pustular with halo
Women complications of gonorrhoea
PID
Bartholin’s Abscess (gonococcal opthalmia neonatorum)
Acute monoarthritis (especially eblow or shoulder)
Disseminated gonococcal infection; skin lesions - pustular with halo
Causative organisms of chlamydia
Chlamydia trachomatis serovars D to K
Which type of causative organism of chlamydia is rare and causes lymphogranuloma and symptoms of severe proctitis?
Serovar Lb2
Who is chlamydia most commonly seen in?
mostly < 25 y/os
Especially in sexually active teenage women
Male symptoms of chlamydia
> 70% asymptomatic
Slightly watery discharge
Dysuria
Conjunctivitis
What % of males have asymptomatic chlamydia?
> 70%
What % of females have asymptomatic chlamydia?
> 80%
Female Symptoms of chlamydia
>80% asymptomatic Vaginal discharge Dysuria Intermenstrual bleeding Post coital bleeding Conjunctivitis
Investigations of chlamydia
First void urine in men
Self taken or clincial taken swab from cervix, urethra, rectum as appropriate
All tested using NAAT
Treatment of chlamydia
Azithromycin 1g po once OR
Doxycycline 7 days
Follow up after chlamydia treatment
Test for reinfection 3-12 months
Earlier test of cure not needed unless symptoms present
Male complications of chlamydia
Epididymitis
Reactive arthritis
Reiter’s syndrome - urethritis/cervicitis + conjunctivitis + arthritis
Women complications of chlamydia
PID ->hence ectopic pregnancy, pelvic pain and infertility
Reactive arthritis
Reiter’s syndrome - urethritis/cervicitis + conjunctivis + arthritis
What % of women who get chlamydia will develop a problem with their fertility?
1%
What is herpes caused by?
Herpes simplex virus types 1 and 2
What is HSV2 an important co factor for?
HIV transmission
Approx. what % of the UK population has herpes?
15-20% - very common
Which strain of herpes is more common in genital infection?
Both strains equally common
Which gender is herpes most common in?
Roughly equal in both sexes
Incubation period of herpes
5 days to months
what % of people have no symptoms of herpes?
80%
Herpes symptoms
80% asymptomatic
Rest have recurring symptoms (monthly/annually)
Burning/itching then blistering then tender ulceration
flu like symptoms
dysuria
neuralgic pain in back, pelvis and legs
Investigations of herpes
Clinical impression
Swab from lesion tested using PCR
Treatment of herpes
Primary outbreak - aciclovir e.g. for 5 days, 400mg td - Lidocaine ointment Infrequent recurrences - Lidocaine ointment - aciclovir 1.2 g once daily until symptoms gone (1-3 days) Frequent recurrences - acyclovir 400bd long term suppression
Complications of herpes
Autonomic neuropathy (urine retention)
neonatal infection
secondary infection
What does trichomonas vaginalis cause?
Trichomoniasis
Who usually gets trichomoniasis?
Middle aged women
Male symptoms of trichomoniasis
Usually asymptomatic
Female symptoms of trichomoniasis
10-30% asymptomatic
Profuse thin vaginal discharge
- greenish, frothy and foul smelling. vulvitis
What % of women are asymptomatic for trichomoniasis?
10-30%
Investigations for trichomoniasis
PCR on vaginal swab
Not on urine so no test for men
Microscopy of wet preparation of vaginal discharge
Treatment of trichomoniasis
Metronidazole 400mg po bd for 5 days or 2g single dose
Complications of trichomoniasis
Miscarriage and preterm labour
Causative organisms of anogenital warts
Human papilloma virus types 6 and 11 (occasionally type 1)
What % of the population has a HPV infection and warts
> 90% of UK population have a genital HPV infection at somepoint in their life
only 20% of those infected with a wart causing strain of HPV get warts
Symptoms of anogenital warts
Lumps with a surface texture of a small cauliflower
Occasionally itching or bleeding especially if perianal or intraurethral
Investigations of anogenital warts
Appearance
Biopsy unusual
When is a biopsy used to investigate anogenital warts?
To exclude intraepithelial neoplasia but this is rarely needed
Treatment of anogenital warts
Hormonal - podophyllotoxin - Imiquimod Cryotherapy Diathermy, scissor removal for bulky warts
Complications of anogenital warts
None common
Neonatal laryngeal papillomatosis
What is syphilis caused by?
Treponema pallidum subspecies pallidum
Common risk factor for syphilis
MSM
Incubation period of syphilis
9 to 90 until appearance of chancre but can be asymptomatic
Symptoms in the stages of syphilis
Often asymptomatic or mild symptoms Primary - local ulcer (chancre) Secondary - rash - mucosal ulceration - neuro symptoms - patchy alopecia - other symptoms Tertiary (all very rare) - neurological - Cardiovascular - gummatous - Skin lesions
Definition of early latent syphilis
No symptoms but < 2 years since caught
Definition of late latent syphilis
No symptoms but > 2 years since caught
Investigations for syphilis
Clincial signs
Serology for TP IgGEIA, TPPA, RPR
PCR sample from an ulcer
Treatment for syphilis
early (<2 years) and no neurological involvement
- Benzathine penicillin 2.4 MU IM once OR
- doxycycline 100mg bd po 2 weeks
Late (> 2 years) and no neurological involvement
- benzathine penicillin 2.4 MU IM weekly for 3 doses
- doxycycline 100mg bd po 28 days
Complications of syphilis
Neurosyphilis (cranial nerve palsies common)
Cardiac or aortal involvement
Congenital syphilis
What is the equation to do with STIs?
B x C x D
B = the probability of transmission
C = contact (number of sexual contacts in a year)
D = Duration
How can we reduce STIs?
Condoms/barrier methods Vaccines (HPV, HBV) PrEP (pre exposure prophylaxis) /ARVs (HIV) PEP (post exposure prophylaxis) Types of sex; education
How can we reduce the number of sexual contacts in a certain period of time?
Education
Cultural influences/role models/advertising
Alcohol
How can we reduce the duration of STIs?
Education of symptoms Accessibility of testing (stigma, appeal) Screening programmes - Cervical - HPV - Antenatal - HIV, Hep B, syphilis Resistance
Which STIs have a resistance problem?
HIV
Gonnorhoea
Investigation specifics for gonorrhoea
Due to resistance every swab has to be tested for drug resistance
If having gonnorhoea Tx, what must be done?
Abstain from sex for 2 weeks
Most common cause of PID
Chlamydia
Management of the baby if the mum is Hep B +ve
Hep B vaccine
0.5ml of HBIG within 12 hours of birth with a further vaccine at 1 - 2 months then another at 6 months
