Sexually Transmitted Infections Flashcards
(28 cards)
List the 4 routes of transmission for STIs
Oral-genital contact
Vaginal intercourse
Anal intercourse
Anilingus
List 5 STIs that can be spread by oral-genital contact
Chlamydia Gonorrhoea HSV Syphilis HPV
List 5 STIs that can be spread by anilingus
Amoeba Cryptosporidia Giardia Shigella HAV
What type of bacteria is N. gonorrhoeae?
Gram negative diplococci
What kind of cells does N. gonorrhoeae colonise?
Columnar epithelium
What is the incubation period of N. gonorrhoeae?
2-7 days (relatively short)
What are the symptoms of gonorrhoea in males?
Urethritis with a thick, creamy urethral discharge (can block the urethra and cause pain)
May be asymptomatic (10%)
What are the symptoms of gonorrhoea in females?
Mostly asymptomatic (80%) Causes cervicitis
What are the symptoms of gonorrhoea transmitted via the oral-genital route?
May have pharyngitis and lymphadenopathy
May be asymptomatic
What is the hypothesised reason for increasing rates of antibiotic resistance in N. gonorrhoeae?
Many other members of Neisseria colonise mucous membranes of the body (including the throat) as normal flora; these organisms can all exchange genes, including those encoding for antibiotic resistance
In what % of untreated cases does disseminated gonorrhoea occur?
0.5-3%
What are the symptoms of disseminated gonorrhoea?
Arthritis Maculopapular rash Meningitis Endocarditis Epididymitis Peri-hepatitis (Fitz-Hugh-Curtis syndrome)
What is Fitz-Hugh-Curtis syndrome?
A peri-hepatitis caused by the ascension of N. gonorrhoeae up the female genital tract, into the abdominal cavity via the ovaries, where it causes infection of the liver capsule and produces “violin-string adhesions”
What increases the risk of gonorrhoea dissemination?
Risk increases post menses
What are the 2 possible complications of gonorrhoea?
Dissemination
PID
What are the possible consequences of untreated PID?
Tubal scarring
Infertility (10-20%)
What are some possible abnormal findings in PID?
Pain on bimanual palpation of the cervix
Fluid, abscesses on imaging
What is the characteristic presentation of neonatal gonococcal opthalmia?
Gross purulent conjunctivitis in first week of life
Mild disease indistinguishable from other causes
What are the possible consequences of untreated neonatal gonococcal opthalmia?
Perforation and blindness in days 2-5
What is the treatment for neonatal gonococcal opthalmia?
Cefotaxime 50mg/kg IV, 8-hourly for 7 days
Regular irrigation of eyes
Treatment of mother and sexual contacts
What diagnostic specimens may be required for gonorrhoea screening?
Cervical swab into charcoal transport
Male urethral swabs
Urine (first void, ~10mL)
Other specimens: conjunctiva, pharynx, skin lesions, anal, CSF, blood, synovial fluid
What kind of media are used for laboratory investigations into gonorrhoea?
Non-selective (chocolate blood agar in CO2) used for CSF, joint fluid aspirate
Selective (Thayer-Martin agar) used for swabs taken from an area with normal flora
Culture for antibiotic sensitivities
What makes up Thayer-Martin agar? What does each agent do?
Colistin: inhibits growth of Gram negatives
Vancomycin: inhibits growth of Gram positives
Nystatin: anti-fungal
What samples are required for nucleic acid amplification tests (NAAT) for gonorrhoea?
Genital (cervical or vaginal) swabs
First void urine
