25 - Introduction to STIs Flashcards
name 3 venereal diseases in UK?
syphilis
gonorrhoea
chancroid
what organism causes syphilis?
treponema pallidum pallidum
what organism causes gonorrhoea?
neisseria gonorhoeae
what organism causes chancroid?
haemophilus ducreyi
name 3 bacterial STIs in the UK?
chlamydia trachomatis
klebsiella granulomatis
mycoplasma genitalium
name 3 viral STIs in the UK?
HSV
HIV
HPV
Molluscum Contagiosum
name 3 parasitic STIs in the UK?
Pthirus pubis
Sarcoptes scabei
Trichomonas vaginalis
define Commensal micro-organism?
micro-organism that derives food or other benefits from another organism without hurting or helping it
define Pathogen?
micro-organism that can cause disease
define Infection?
The invasion of all or part of the body by a micro-organism
define Sexually transmissible organism?
A virus, bacteria, protozoan, insect or arthropod which can be spread by sexual contact
define Sexually transmitted infection (STI)?
infection by a pathogen which is sexually transmissible and which is unlikely to be transmitted by non-sexual means
define Sexually transmitted disease (STD)?
disorder of structure or function caused by a sexually transmitted pathogen
name 4 diseases which are not classed as STI in UK but may be considered as such elsewhere?
Mycoplasma hominis
Ureaplasma urealyticum
Bacterial vaginosis
Genital candidosis
name 2 STI pathogens which are not classed as STI in UK but may be considered as such elsewhere?
Sars-Cov-2
Zika
Ebola
what does the type of STI contracted depend on?
the level of sexual contact
list the following from lowest risk of catching STI to highest -
group sex
fellatio
anal sex
mutual masturbation
cunnilingus
vaginal sex
LOW RISK
mutual masturbation
fellatio
cunnilingus
vaginal sex
anal sex
group sex
HIGH RISK
describe 4 STIs transmitted by skin only contact?
pubic lice (Pthirus pubis)
Scabies (Sarcoptes scabeii)
Warts (human papilloma virus types 6 &11)
Herpes (Herpes Simplex Virus types 1 & 2)
name an STI which poses a high risk of transmission during group sex?
Hep C
name 5 reasons which highlight the importance of STIs?
cause morbidity
cause mortality
unpleasant symptoms
psychological distress
very costly and time-consuming to treat
name 5 systemic symptoms related to STIs?
Fever
Rash
Lymphadenopathy
Malaise
Arthralgia and arthritis
give an example of a late complication if chlamydia is left untreated?
infertility in females
give an example of a late complication if HPV is left untreated?
cervical cancer
give an example of a late complication if syphilis is left untreated?
adverse pregnancy outcomes
give 2 possible reasons to why trends in STI diagnoses change over time?
1 - true difference in no of cases
2 - change in diagnoses but no real change in difference of no of cases
what equation is used for calculating the true difference in the no of cases?
R0=BcD
R0 = reproductive number (average number of infections produced)
B = likelihood of transmission per encounter
c = rate of acquiring new partners
D = duration of infectivity
describe the results of R0=BcD if R0 > 1 or if R0 < 1?
R0 > 1 = epidemic is sustained
R0 < 1 = epidemic reduces
what is the best way of ensuring no transmission of HPV? (B)
vaccination of unaffected patients
describe 5 changes of rate of new partners (c) in current times?
increased no of partners
increased no of concurrent partners
increased no of people having anal sex
increased no of men having sex with men
increased condom use
describe an example which supports the theory that there is a change in diagnoses but no real change in difference of no of cases for STIs?
there is a greater awareness of STIs - therefore more tests being carried out - therefore more cases found
describe the theory of cores and assortative mixing in explaining why some STIs are more prevalent in certain groups?
cores and assortative mixing - people tend to have sex with people who are similar to them
therefore -
infection is reinforced within a small group
describe the theory of chains and random mixing in explaining why some STIs are more prevalent in certain groups?
e.g. men who have sex with woman - this is a big core of people
therefore -
spreads more widely but with decreased prevalence
describe 4 pillars of taking a good STI history?
1 - thorough history
2 - health promotion
3 - partner notification (if STI confirmed)
4 - HIV test (if STI confirmed)
describe 3 components of a general history which would be relevant?
standard (PMH etc.)
gynae history
direct questions about symptoms
give 3 reasons for taking a thorough sexual history?
to determine cause of symptoms
to detect high-risk behaviour
tracing contacts
6 questions which are important to ask men to determine longer-term sexual risks?
Have you ever had sexual contact with another man?
Have you ever injected drugs?
Sexual contact with:
anyone who’s injected drugs/ someone from outside the UK?
Medical treatment outside UK?
Paid for sex or been paid?
describe 2 ways of partner notification?
Patient tells contacts “client referral”
NHS tells contact “provider referral”
if someone has a confirmed case of STI, what should they be tested for?
HIV
5 examples of health promotion?
use of condoms
inform that oral sex also carries a risk of STIs
address hazardous drug/ alcohol use
vaccination
HIV pre-exposure prophylaxis
