Sexually transmitted diseases Flashcards
What are some STIs caused by bacteria?
Syphilis - Treponema pallidum
Gonorrhoea - Neisseria gonorrhoeae
Non-gonococcal urethritis - Chlamydia trachomatis
Lymphogranuloma venereum (LGV) - Chlamydia trachomatis
Others (FYI)
- Non-gonococcal urethritis (Ureaplasma urealyticum, Mycoplasma genitalium)
- Chancroid - Haemophilus ducreyi
- Granuloma inguinale - Calymmatobacteria granulomatis
What are some STIs caused by viruses?
Ano-genital herpes - herpes simplex virus (HSV) type 1 and 2
Others (FYI)
Ano-genital warts - human papillomavirus (HPV)
Viral Hepatitis - Hepatitis A, B, C virus
AIDS/HIV infection - human immunodeficiency virus (HIV) type 1 and 2
Molluscum contagiosum - molluscum contagiosum virus
What are some STIs caused by fungi? FYI
Vaginal candidiasis - candida albicans
What are some STIs caused by parasites? FYI
Scabies - Sarcoptes scabiei
Pediculosis pubis - Phthirus pubis (public lice)
What is a key local legislation regarding STIs in SG?
- STIs* are legally notifiable (within 72h of diagnosis) for monitoring and evaluating national control programs
- Partner notification is mandatory in HIV/AIDs
*Gonorrhoea, non-gonococcal urethritis, syphilis, chlamydia, genital herpes, HIV/ AIDS, Viral Hepatitis
How can STIs be transmitted?
Mainly by sexual contact
- Direct contact of broken skin with open sores, blood or genital discharge
- Receiving contaminated blood
- From an infected mother to her child during:
Pregnancy (eg syphilis, HIV) or
Childbirth (eg chlamydia, gonorrhea, HSV) or
Breastfeeding (eg HIV)
Can STIs be contracted through kissing?
Dry kissing is generally safe. Some STIs can be transmitted through deep, wet kissing. Syphilis, gonorrhoea, chlamydia and herpes may be present in the mouth/throat of infected persons.
However, STIs are not commonly transmitted through kissing.
Can a person be infected with more than one STI?
Yes, this is possible and not uncommon. This is why it is always important to be tested for other STIs if you have already been diagnosed with one.
Can someone inherit an STI from his or her parents,
i.e. is it a genetic disease?
STIs are acquired infections; they are not inherited. However, mothers with STIs can pass on their infection to the baby during pregnancy, delivery or breastfeeding. Early treatment of an infected pregnant mother can prevent infection in her baby.
What are the risk factors for STIs?
- Unprotected sexual intercourse
- Those with multiple sexual partners are more likely to
acquire and transmit STI - Those with sexual contact with people who have
multiple sexual partners - MSM (gay sex)
- Prostitution (CSW)
- Illicit drug use*
*as STI can be transmitted via blood and affected cognition due to drugs -> increased risky behavior
How can an individual prevent STIs?
- Abstinence and reduction of number of sexual partners
- Barrier contraceptive methods, when used correctly
- Avoid drug abuse and sharing needles
- Pre-exposure vaccination i.e. HPV (Human papilloma virus), Hep B
- Post-exposure prophylaxis (HIV)
Why is management and prevention of STIs important?
- To reduce related morbidity, progression to
complicated disease - To prevent HIV infection
- To prevent serious complications in women (main preventable cause of infertility and reduces cervical
cancer risk) - To protect the babies
What is the causative organism of Gonorrhoea?
Neisseria gonorrhoeae (intracellular gram-negative diplococci)
How can gonorrhoea be transmitted?
Sexual contact, mother-to-child during childbirth
How is Gonorrhoea diagnosed?
Gram-stain of genital discharge, culture, PCR
Are Gonorrhea infections limited to the genital area?
No. Can infect various sites Urethritis Cervicitis Proctitis Pharyngitis Conjunctivitis Disseminated
What are some symptoms of a gonorrhoea infection?
Purulent urethral/vaginal discharge, dysuria,
urinary frequency
Patients can be asymptomatic as well
What are some complications of an untreated Gonorrhoea infection?
Males – epididymitis, prostatitis, urethral stricture,
disseminated* disease
Females – Pelvic inflammatory disease, ectopic
pregnancy, infertility, disseminated* disease
*Disseminated – skin lesions, tenosynovitis,
monoarticular arthritis.
Are FQs used in the tx of Gonorrhoea?
Neisseria gonorrhoeae (intracellular gram-negative diplococci)
No. High local resistance to FQs
What is the abx tx strategy when it comes to Gonorrhoea?
Dual Antibiotics Therapy
- Slows emergence of resistance and
- Improves treatment efficacy
- Also treats Chlamydia trachomatis, a usual co-infection with uncomplicated gonococcal infections
What is the 1st line tx for Gonorrhoea?
IM ceftriaxone 250mg single dose + PO Azithromycin 1g single dose (concurrently)
Advantage of azithromycin
+ Single dose hence improve compliance
+ Substantially lower resistance compared to tetracycline
What abx should we provide for a Gonorrhoea patient who is allergic to azithromycin?
IM ceftriaxone 250mg single dose + doxycycline 100mg bid x 7 days
*alternative + longer duration due to more resistance for doxy
What abx should we provide for a Gonorrhoea patient who is allergic to penicillin and cephalosporins?
- IM spectinomycin 2g single dose + PO azithromycin 2g single dose OR
- IM gentamicin 240mg single dose + PO azithromycin 2g single dose
*spectinomycin and gentamicin not as effective as ceftriaxone –> larger azithro dose
Is there a need to perform testing on the patient to confirm cure for Gonorrhoea?
Test of cure not required unless symptoms persist
What are the monitoring considerations for Gonorrhoea pts on abx tx?
Some GI side effects and allergies (monitor and come back to doctor if s/sx of allergies)
- low dose and IM –> shouldnt stay in body for too long –> nth much to monitor for
What is the causative organism for Chlamydia?
Chlamydia trachomatis
What are the clinical presentations for Chlamydia?
Presentation similar to gonorrhoea, perhaps milder*
(commonly co-infection tgt with gonorrhoea)
Purulent urethral/vaginal discharge, dysuria,
urinary frequency
*Patients can be asymptomatic as well, causing them to not get tx and develop complications
How is Chlamydia diagnosed?
Diagnosis using NAAT (PCR) or antigen detection
What are the complications of Chlamydia?
- Same as Gonorrhoea
Males – epididymitis, prostatitis, urethral stricture,
disseminated* disease
Females – Pelvic inflammatory disease, ectopic
pregnancy, infertility, disseminated* disease
*Disseminated – skin lesions, tenosynovitis,
monoarticular arthritis.
How can Chlamydia be transmitted?
Sexual contact, mother-to-child during childbirth
What is the 1st line tx for Chlamydia?
Azithromycin PO 1g single dose*
OR
Allergic to Azithromycin: Doxycycline 100mg PO BD x 7days
*Azithromycin as single dose is possible due to its prolonged serum and tissue half-life
What are some 2nd line tx for Chlamydia?
Erythromycin base 500mg PO QDS x 7days OR Erythromycin ethylsuccinate PO QDS x 7days OR Levofloxacin 500mg OD x 7days OR Ofloxacin 300mg PO BD x 7days
Erythromycin might be less efficacious than azithromycin or doxycycline.
Levofloxacin and ofloxacin are effective while other fluoroquinolone did not consistently eradicate chlamydial infection.
Is Test of cure necessary for Chlamydia?
Treatment is highly effective, test-of-cure is not required unless specific concerns (eg pregnancy, non-adherence) or symptoms persist*
*likely due to re-infection rather than tx failure
What is the organism that causes syphilis?
Treponema pallidum
How is syphilis transmitted?
Sexual transmission only when mucocutaneous syphilitic lesions are present.
Non-sexual:
- Transplacental from mother to child.
- Contaminated blood.
What are the 5 stages syphilis can present as?
- Primary
- Secondary
- Latent
- early < 1 year from infection
- late > 1 year from infection - Tertiary
- Neurosyphilis