An intro to STIs

Question 1

Sub-clinical vs clinical infection?

Answer 1

Sub-clinical - no symptoms

Clinical - symptoms

Question 2

Sexually transmissible infection definition

Answer 2

An infection by a pathogen which is sexually transmissible and which is unlikely to be transmitted by non-sexual means

Question 3

Sexually transmitted disease definition

Answer 3

A disorder of structure or function caused by a sexually transmitted pathogen
e.g Pelvic inflammatory disease or Genital warts

Question 4

Name some bacteria that are considered to be sexually transmissible organisms within the UK

Answer 4

Chlamydia trachomatis
Klebsiella granulomatis
Mycoplasma genitalium

Question 5

Name some viruses that are considered to be sexually transmissible organisms within the UK

Answer 5

HSV
HIV
HPV
Molluscum contagiosum virus

Question 6

Name some parasites that are considered to be sexually transmissible organisms within the UK

Answer 6

Pthirus pubis
Sarcoptes scabei
Trichomonas vaginalis

Question 7

Common characteristics of STIs

Answer 7

They’re contagious

Asymptomatic most of the time

Unpredictable minority suffer significant complications

Totally avoidable

Question 8

What are the most high risk forms of sexual contact?

Answer 8

From most high risk to least. 
Group sex
Anal sex 
Vaginal sex
Oral sex - cunnilingus
Oral sex - fellatio
Touching someone else’s genitals with your genitals.
Mutual masturbation

Question 9

What conditions can be spread by skin contact only?

Answer 9

Pubic lice (Pthirus pubis)
Scabies (Sarcoptes scabeii)
Warts (human papilloma virus types 6 &11)
Herpes (Herpes Simplex Virus types 1 & 2)

Question 10

What infection is the main concern for someone who participates in group sex?

Answer 10

Hep C - anal sex where a 3rd person moves from one man to another

Question 11

What sorts of things might you see on examination of a patient with an STI?

Answer 11

Ulceration - syphilis, herpes simplex

Lumps - genital warts, molluscum contagiosum

Genital discharge - Gonorrhoea, chlamydia or mycoplasma genitalium

Non-genital discharge - gonorrhoea or chlamydia in the eyes

Rashes - scabies, syphilis and HIV.

Question 12

What systemic symptoms may be present with STI? and which STIs are more likely to show systemic involvement?

Answer 12

Fever
Rash 
Lymphadenopathy 
Malaise
Arthralgia and arthritis

HIV or syphilis

Question 13

Give examples of some late complications associated with common STIs

Answer 13

Infertility - chlamydia

Cancer - HPV

Adverse pregnancy outcomes - syphilis

Question 14

How can STIs be costly?

Answer 14

Managing infertility due to chlamydia - IVF cost

Cost of HIV medication/ long term management of HIV related health conditions

Taking time off work to get your warts frozen etc

Question 15

What is the R number?

Answer 15

The reproductive number - applies to every communicable disease.

It is the average number of secondary infections produced by a single infected person. Shows the spread of a disease.

Question 16

What factors influence the R number in relation to STI spread?

Answer 16

Likelihood of transmission per encounter

Rate of acquiring new partners

Duration of infectivity

Question 17

What is the best way to prevent transmission of an organism/disease?

Answer 17

Vaccinations

Question 18

What is the biggest factor in clinic attendees and the reason for their sexual activity?

Answer 18

Alcohol

Question 19

In terms of sexual network analysis what is a ‘core’?

Answer 19

Theory that some people likely to have sex with people who are like them in some way – similar lifestyle, ethnicity etc this can lead to a particularly high prevalence in a small population i.e the ‘core’..

e.g syphilis in people who exchange sex for drugs and HCV in gay men

That core can branch out wider though if say a man who has sex with men also then has sex with a woman.

Question 20

What is considered good management of someone with symptoms suggestive of an STI?

Answer 20

A good history
HIV testing - if high risk
Partner notification
Health promotion - condoms, risk of oral sex, HIV prep etc

Question 21

Why might you need to know a patient’s sexual history?

Answer 21

Determining possible cause of symptoms

Detecting high-risk behaviour and advising on risk reduction.

Tracing contacts

Question 22

What would you ask to find out more about their sexual history?

Answer 22

When did you last have sexual contact? Was it casual or with a ‘regular’ partner?

How long were you going out with them for?

Were they male or female?

Asking about nature of sex act sometimes useful i.e if they have anxiety about a specific incident? or if it’s going to alter where you swab from

Did you use condoms?

Other contraception used

Nationality of contact

Question 23

High risk assessment

Answer 23

Have you ever had sexual contact with another man?

Have you ever injected drugs? – both genders

Sexual contact with anyone who’s injected drugs? Or someone from outside the UK? (clarify)

Medical treatment outside UK? (clarify)

Paid for sex or been paid?