Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PBL Week 16 > Sexually transmitted pathogens > Flashcards

Sexually transmitted pathogens Flashcards

1
Q

Risk factors for developing STD?

A

Unprotected sex

multipel partners

history of infection

alcohol or drug abuse

Sex workers

Men who have sex w. men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are some reasons for increasing prevalence of STIs

A
  • The absence of vaccines for almost all STIs, except HPV
  • Increasing density & mobility of human populations
  • Difficulty of engineering changes in human sexual behaviour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What should you remember if one STI is present?

A

The chances there will be another one due to co-infection is high - so always test for others!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the most common STIs in the UK?

A
  • Genital chlamydia
  • Gonorrhoea
  • Genital warts (HPV)
  • Herpes (HSV)
  • HIV/AIDS
  • Syphilis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What’s the importance of early detection of STIs?

A
  • Reduces the spread of infection
  • May avoid or delay serious complications and consequences
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the causative organism for chlamydia?

A

Chylamydia trachomatis

  • D-K serotypes = non-specific urethritis
  • L serotypes = lymphogranuloma venereum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What’s the transmission of chlamydia?

A
  • Horizontal - sexual contact
  • Vertical - perinatal transmission from infected mother to baby during vaginal delivery is possible. Can lead to neonatal conjunctivitis & pneumonia.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does chlamydia present?

A

Asymptomatic in over 80% of cases

Males:
- Mucopurulent urethral discharge
- dysuria
- scrotal pain
- proctitis

Females:
- Mucopurulent vaginal discharge
- cervicitis
- cervical bleeding upon contact
- proctitis
- post-coital bleeding
- intermenstrual bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can you test for chlamydia?

A

Nucleic Acid Amplification Test (NAAT)
- Males: First pass urine
- Women: Vulvovaginal swab
- If applicable, oropharyngeal & rectal sites also swabbed

Can take up to 14 days from exposure for infection w/ to show up on NAAT test, therefore screening should be repeated after this window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is chlamydia managed?

A

Doxycycline or azithromycin

Full STI screen including blood tests

All forms of sexual intercourse need to be avoided until all parties are tested & treated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What complications can be had from chlamydia?

A

Women: Pelvic inflammatory disease (PID) - increases risk of infertility &ectopic pregnancy

Men: Epididymitis & prostatitis

Reactive arthritis

Lymphogranuloma venererum (LGV) - caused by a more invasive serotype of chalymdia trachomatis & treated w/ 3 weeks of Doxycycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the causative organism for gonorrhoea?

A

Neisseria gonorrhoeae/gonococcus

Gram negative coccus bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is gonorrhoea transmitted?

A

Same as chlamydia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What’s a microbial strategy of gonorrhoea?

A

Virulence factors give pathogens their transmission potential e.g. pilus in Gonorrhoeae give it a big advantage in infecting genitals

Host defence: Integrity of mucosal surface
Microbial strategy: Specific attachment mechanism

Also:

Host defence: Phagocytes
Microbial strategy: Resists phagocytosis using its capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does gonorrhoea present?

A

Males: Urethral discharge (can be thick yellow/green discharge from penis and vagina)

Women: Often asymptomatic but may have vaginal discharge

Both:
- Rectal infection
- Oropharyngeal infection
- pain on urination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can you test for gonorrhoea?

A

Cultures taken prior to antibiotics to assess antibiotic susceptibility

Nucleic Acid Amplification Test (NAAT)- same as chlamydia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is gonorrhoea managed?

A

High rates of antimicrobial resistance reported therefore treatment should be guided by guidelines.
- e.g. rising resistance to penicillin
- Dual therapy of more than 1 drug is more effective due to this resistance.

Cephalosporin e.g. ceftriaxone & azthromycin

Test of cure following two weeks after treatment using NAAT is recommended

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What complications can be had from gonorrhoea?

A

Can disseminate to cause skin & synovial infections

Pelvic inflammatory disease (PID) - increases risk of infertility & ectopic pregnancy

Fitz-Hugh-Curtis syndrome- secondary to PID there’s inflammation of the hepatic capsule leading to perihepatic adhesions

Chronic pelvic pain in females

Infertility in males secondary to epididymitis

19
Q

What is the causative organism for herpes?

A

Herpes simplex virus (HSV) 1 & 2

  • HSV-1 is the usual cause of labial (oral) & anogenital herpes infections
  • HSV-1: Oral & genital herpes
  • HSV-2: Genital herpes
20
Q

What’s the transmission of herpes?

A
  • Mucosal surfaces or broken skin

Infection can be:
- Primary or secondary
- Episodes symptomatic or asymptomatic
- Clinical manifestations initial or recurrent infection

Infection w/ HSV is lifelong as the virus lies dormant w/in local sensory ganglia
- Intermittent reactivation can be symptomatic w/ lesions to the skin
- or asymptomatic w/ unnoticed active viral shedding.

21
Q

How does herpes present?

A

Most individuals asymptomatic

Blisters which progress to painful ulcers around anogenital area

Dysuria, discharge & inguinal lymphadenopathy

In primary infection, systemic symptoms e.g. pyrexia & myalgia can occur

Symptoms from primary infection tend to be more severe than those of recurrent infection

22
Q

How can you test for herpes?

A

HSV PCR from swabs taken from lesions- when taking sample, burst lesion & swab base of the ulcer.

NAAT testing is also used in some centres.

Testing for HSV does not form part of routine STI screening in the UK

23
Q

How is herpes managed?

A
  • Primary episode: Aciclovir 400mg for 5 days
  • Recurrent episode: Aciclovir 800mg for 2 days
  • Prophylaxis in patients with >5 episodes per year: Aciclovir 400mg x2 daily

refrain from intercourse

Condoms

Full STI screening

24
Q

What complications can be had from herpes?

A

Urinary retention

HSV keratitis- dendritic lesion on the cornea

Aseptic meningitis

Herpes proctitis

25
Q

What’s HIV?

A

Retrovirus that infects & replicates in human lymphocytes & macrophages, eroding the integrity of the human immune system over a number of years

26
Q

What’s the transmission of HIV?

A
  • Mucosal surfaces, in particular cervicovaginal, penile & rectal
  • IV or percutaneous (skin) routes
27
Q

How does HIV present?

A

Primary HIV infection: mild mononucleosis-type illness

28
Q

How can you test for HIV?

A

HIV antibody or combination antibody/antigen test

confirmed using a more specific test (ELISA)

29
Q

How is HIV managed?

A

Post-exposure prophylaxis (PEP)
- reduces probability of HIV transmission by 80% when taken w/in 72 hours following exposure

  • All patients infected w/ HIV, regardless of CD4 cell count, should start on antiretroviral drugs as soon as possible
30
Q

What complications can be had from HIV?

A

AIDS- serious vulnerability to infections & illnesses w/ life expectancy of around 3 years

31
Q

What is the casusative organism for genital warts?

A

Human papillomavirus (HPV)

  • Low-risk strains of HPV cause genital warts
  • High-risk strains of HPV can cause cancer
32
Q

What’s the transmission of genital warts?

A
  • Direct skin to skin contact
  • Rare: perinatally
  • The incubation period from exposure to infection can be up to 8 months.
33
Q

Who is the HPV vaccine offered to?

A
  • All girls aged 12-13 in the UK
  • All MSMs (men who have sex w/ men) who attend a sexual health clinic in the UK & are 45 years old
34
Q

How does genital warts present?

A

Anogenital warts
- vary in size, number, colour and texture
- but mostly appear as Textured, soft growths around the vaginal opening & penis.
- anus, cervix & urethral meatus can also be affected

Predominantly genital warts are asymptomatic however itching, bleeding & pain can occur

35
Q

How can you test for genital warts?

A

speculum exam should be performed to visualise the cervix

Diagnosis is clinical however biopsies should be obtained if lesion bleeds is ulcerated or indurated

Testing for HPV does not form a part of routine STI screening in the UK

36
Q

How are genital warts managed?

A

In 1/3 of patients, warts will resolve without intervention
- Warts can re-occur after initial resolution-several treatment courses are often required
-Smoking is known to increase risk of recurrence

Topical:
- Podophyllotoxin
- Imiquimod

Physical ablation:
- Cryotherapy
- Surgical excision

A full STI screen including blood tests should be offered.

37
Q

What complications can be had from genital warts?

A
  • Ano-genital cancer
  • Scarring following treatment
38
Q

What is the causative organism for syphillis?

A

Treponema pallidum - a spirochetal bacterium

39
Q

What’s the transmission of syphillis?

A
  • Horizontal - direct sexual contact w/ infected individual who has a lesion on the skin or muscosa
  • Vertical - trans-placental transmission which increases risk of stillbirth & miscarriage; or congenital abnormalities
40
Q

How does syphillis present?

A

-Often asymptomatic

3stages - individual is most infectious during primary &secondary stages

  1. Primary: Development of:
    - hardened, painless ulcer on genitals called a chancre
  2. Secondary:
    -widespread non-pruritic maculopapular rash involving the palms & soles develop
    - alopecia
    - generalised lymphadenopathy
    - oral snail-track lesions
    - constitutions symptoms (pyrexia, fatigue, malaise)
  3. Tertiary: Untreated syphilis over many years can develop into neurosyphilis, cardiovascular syphilis & gummatous syphilis
41
Q

How can you test for syphillis?

A

Non-specific tests (screening):
- Cardiolipin serology tests are used as an indicator to measure disease activity, disease staging & treatment efficacy.
- Rapid Plasma Reagin (RPR) Test
- Venereal Disease Research Laboratory (VDRL) Test

Specific tests (diagnosis):
- ELISA - detects IgM & IgG
- The fluorescent treponemal antibody absorption (FTA-ABS) test.
- The microhaemagglutination assay for T. pallidum (MHA-TP)

Can take up to 12 weeks from exposure for tests to show positive result. Tests should, therefore, be repeated at 12 weeks post-exposurE

42
Q

How is syphillis managed?

A
  • Penicillin
  • Repeat serology testing at 3, 6 & 12 months.
43
Q

What complications can be had from syphillis?

A

Jarisch-Herxheimer reaction - antibiotic treatment of syphilis causes a sepsis-like picture due to release of toxins from treponemal bacterium breakdown,
- steroids are administered beforehand to prevent this.

If untreated, facilitates HIV transmission

44
Q

How can we prevent STDs?

A
  • Educate on how they’re spread
  • Eliminate stigma - so people are less embarassed to get tested
  • Encourage condom use
  • Encourage regular testing
  • Target prevention to at risk groups (homosexuals and drug addicts)

PBL Week 16 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions