10- Sexually transmitted disease (viral) Flashcards
HPV
human paipilloma virus
- most common viral STI
- >100 strains
- 90% Type 6 and 11 ( cause external genital warts)- least harmful
- high risk HPV for neoplastic changes 16+18
HPV strain with highest risk of neoplastic change
16 and 18
pathophysiology of HPV
MOA of HPV
- sexual contact
- incubation period 2 weeks to 8 months
what do not give protection from HPV genital warts
condoms- skin to skin contact
HPV presentation
- multifocal infection of anogenital skin
- usually painless/ itchy
- psychological disress
- post sexual contact
tecture of HPV warts
internal HPV warts
DD for HPV warts
Buschke- Lowenstein
rare sexually transmitted disease caused by human papilloma virus infection in the anogenital area.
-Giant condyloms accuminata
- higher rate of malignant transformation than genital warts
Management of HPV
- screen for other STIs
- treatment largely aimed at getting rid of the appearanc eof warts but will not clear the virus, body clears over time
HPV counselling to prevent significant psychological distress
- often clears spontaeneously
- strains which cause warts dont generally cause cancer
- condoms may prevent transmission
HPV and patient applied therapy
more successful on softer warts
self applied over 4 weeks and then review
treatments include
- podophyllotoxin
- imiquimod
- catephen
podophyllotoxin
- antimitotic agent
- inhibits cell division
imiquimod
- immune response modifier- not directly anti-viral
- stimulates innate and acquired immune response
catephen
freen rea leaf extract
MOA unknown but effect vs placebo in trial
referral and HPV
have a low threshold to refer
national HPV immunisation england
quadrivalent vaccine: subtypes 6, 11, 16, 18
started in 2008- girls only
2018- MSM <45
2019- boys too
HPV and pregnancy
- common for warts to present for the first time during pregnancy
- linked to altered immune response
- difficult to treat - home treatment teratogenic
- HOWEVER risk of vertical transmission very low (shpuldnt influence mode of dleivery)
**management
- watch and wait
- cryoablation
- srufical removal for extreme cases
HPV and risk to baby
- 4/100,000 risk of **respiratory laryngeal papillomatosis
- tiny risk of obstruction to delivery
true false fact sheet about HPV
herpes simplex virus (HSV)
responsible for both cold sores (herpes labialis) and genital herpes
- many people have np symptoms
main strains of HSV
HSV-1
HSV-2
pathophysiology of HSV latency
- After an initial infection, the virus becomes latent in the associated sensory nerve ganglia.
- Typically this is the trigeminal nerve ganglion with cold sores and the sacral nerve ganglia with genital herpes.
other areas affected by HSV
- cause aphthous ulcers (small painful oral sores in the mouth)
- herpes keratitis (inflammation of the cornea in the eye) and
- herpetic whitlow (a painful skin lesion on a finger or thumb).
HSV mode of transmission
direct contact with affected mucous membranes or vrial sheeding in mucous secretions
- can be spread by asymptomatic (more common in first 12 months where recurrent symptoms present)
HSV-1
cold sores
It is often contracted initially in childhood (before five years), remains dormant in the trigeminal nerve ganglion and reactivates as cold sores, particularly in times of stress.
- can cause herpes in genitalia through oral sex
HSV-2
Genital herpes caused by HSV-1 is usually contracted through oro-genital sex, where the virus spreads from a person with an oral infection to the person that develops a genital infection.
presentation of genital herpes
incubation- 2 weeks
- asymptomatic
- initial presentation most severe
* Ulcers or blistering lesions affecting the genital area
* Neuropathic type pain (tingling, burning or shooting)
* Flu-like symptoms (e.g. fatigue and headaches)
* Dysuria (painful urination)
* Inguinal lymphadenopathy
-> symptoms can last for 3 weeks in primary infection
diagnosis of herpes
Ask about sexual contacts, including those with cold sores, to establish a possible source of transmission. They may have caught the infection from someone unaware they are infected and not experiencing any symptoms.
The diagnosis can be made clinically based on the history and examination findings.
A viral PCR swab from a lesion can confirm the diagnosis and causative organism.
managment of herpes
antiviral: aciclovir
additional measures
- paracetamol
- topical lidocaine 2% gel (instillagel)
- cleaning with warm salt water- key prevents secondary bacterial infection and drys up lesion
- topical vaseline
- additional oral fluid
- loose clothing
- avoid intercourse with symptoms
pregnancy and genital herpes
not related to pregnancy related issues or congenital abdnormalities.
- women can pass antibodies to the fetus to give passive immunity
- main risk: neonatal herpes simplex infection contracted during labour and delivery
neonatal herpes simplex infection
high rate of morbidity and mortality
- should be avoided and treated early
management of herpes during pregnancy
depends on scenario
1) primary genital herpes before 28 weeks gestation
2) primary genital herpes after 28 weeks
primary genital herpes before 28 weeks gestation
treatment:
- aciclovir during initial infection
- prophylactic aciclovir starting from 36 weeks to reduce risk of genital lesion during labour and delivery
- women who are asymptomatic at delivery can have a vaginal delivery
- woemn who are symptomatic should have a caesarean