STIs

Question 1

Define a sexually transmitted organism?

Answer 1

• A virus, bacteria, protozoan, insect or arthropod which can be spread by sexual contact
• Commensal
• Pathogen

Question 2

What makes a sexually transmitted infection and disease?

Answer 2

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

STD: A disorder of structure or function caused by a sexually transmitted pathogen

Question 3

Why are STIs so important?

Answer 3

1- Cause morbidity and mortality
2- They drain resources
 Managing infertility due to chlamydia: cost of IVF.
 Cost of HIV medication/ management of HIV related health conditions
 Taking time off work to get your warts frozen.

3- They are common
• More than 1M new STIs acquired every day.
• More than 500M people have genital herpes

Question 4

The number of STI diagnoses has increased over time, why do you think this is?

Answer 4

May be more cases, due to increasde number of parteners, anal sex and MSM

May be more diagnoses but not more cases as public and medical awareness increases as well as better tests

Question 5

What models do we use to map spread of STIs?

Answer 5

Cores AND Assortative mixing

Chains and random mixing

Question 6

How does assortative mixing work?

Answer 6

A subpopulation (“Core”) have sex with eachother but not the wider community
E.g. a minority ethnicity
Therefore you see a high prevalence amongst the core but without spreading to the wider community

E.g. HEP C infections amongst Hiv +VE MSM

Question 7

How does random mixing work?

Answer 7

A very big population e.g. hetero men and women

Chains of sexual partners form rather than a tangled core and you get a disease of low prevalalence but a very wide dissemination

Question 8

What questions are important when investigating a possible STI?

Answer 8

• Last Sexual Contact?
• Casual or regular partner?
• Nationality &gender of partner?
• Nature of sexual contact?
• Condom?
• Contraception?
• MSM?
• Injected drugs or had sex with someone who has?
• Medical treatment outside Uk?
• Involvement in sex industry?

Question 9

How do we go about notifying patients partner’s of their possible STI?

Answer 9

Client referral (patient does the telling)
Provider notification (NHS tells the contacts)

Question 10

What further testing should be offered if an STI diagnosis is reached?

Answer 10

Other STI: HIV testing should be done as an STI is a risk factor for other STIs an HIV

Question 11

What areas of health promotion should we educate STI patients on?

Answer 11

Condoms and what they do/dont prevent
Oral sex carries risks too
Alcohol and drug abuse

Question 12

Venereal diseases organisms

Answer 12

• Syphilis (Treponema pallidum)
• Gonorrhoea (Neisseria gonorhoeae)
• Chancroid (Haemophilus ducreyi)

Question 13

Other common ST organisms in the UK?

Answer 13

Bacteria
• Chlamydia trachomatis
• Klebsiella granulomatis
• Mycoplasma genitalium

Viruses
•	HSV
•	HIV
•	HPV
•	Molluscum contagiosum virus

Question 14

Features of an STI?

Answer 14

• Transmissable
• Asymptomatic
• Always manageable. Not always curable
• Avoidable

Question 15

Implications of an STI?

Answer 15

 Partner notification
 So hard to eradicate from a population. Need to prevent.
 Treatment & prevention of complications
 Primary prevention - education

Question 16

Presentation of an STI?

Answer 16

• Rash
• non vaginal discharge
• lumps
• ulceration

Question 17

Systemic symptoms of an STI?

Answer 17

• Fever
• Rash
• Lymphadenopathy
• Malaise
• Infertility
• Cancer.

Question 18

How to manage an STI case?

Answer 18

1- GOOD HISTORY
2- PARTNER NOTIFICATION
3- HIV TESTING
4- HEALTH PROMOTION