STI's Flashcards
What is the primary mode of transmission of STI’s ?
Human-human transmission (sexual intercourse)
Go over the general principles of STI’s
- Immunity is rare
- Reinfection is common
- Co-infections are common - STI ppathogens move together e.g. chlamydia and gonorrhoea
- Vaccines have been difficult to develop
What are the typical organisms which colonise the vaginal flora
Lactobacillus spp. predominate and are protective e.g L.crispatus and L. jensenii.
Other organisms:
- +/- Group B beta-haemolytic Streptococcus
- +/- Candida spp. (small numbers)
- +/-Strep “viridans” group
What is the normal pH of the vagina and why?
- ACID pH is Normal (4 to 4.5)
- This is because the Lactobacillus spp. produce Lactic acid +/- hydrogen peroxide
What is the most common cause of candida infections ?
Candida albicans
What percentage of females are colonised with small numbers of Candida albicans?
30%
List the predisposing factors to a candida infection
- Recent antibiotic therapy
- High oestrogen levels (pregnancy, certain types of contraceptives)
- Poorly controlled diabetes
- Immunocompromised patients
Describe the presentation of a candida infection
- Intensely itchy white vaginal discharge (cottage cheese appearance)
- +/- occasionally pain on intercourse or urination

How is a candida infeciton diagnosed?
- 1st line = clinical diagnosis
- 2nd line = high vaginal swab for culture if the diagnosis if uncertain, or women who have severe or recurrent symptoms, or if there is treatment failure
What is the treatment for a candida infection?
- Oral Fluconazole AND
- Clotrimazole cream daily or Clotrimazole pessary + clotrimazole cream daily
What is shown in this pic

Candida balanitis - this is inflammation of the glans of the penis +/- the foreskin.
What are the signs/symptoms of candida balanitis ?
- A red, inflamed ‘spotty’ rash on the head and shaft of the penis or under the foreskin
- Itching or burning in the affected area
- A white, clumpy or yellowish discharge from the affected skin or from under the foreskin

What is the most common cause of candida balanitis ?
Non-specific dermatitis +/- candida albcians infection
What is the treatment of candida balanitis ?
Topical hydrocortisone + clotrimazole cream
What is the causative organism of gonorrhoea ?
Neisseria gonorrhoeae
Describe the microscopic appearance of gonorrhoea
Gram -ve intracellular dipplococci - Look like “2 kidney beans facing each other”
Note also a fastidious organism so doesnt survive outside ideal growth conditions

What part of the body does gonorrhoea infect?
The urethra, rectum, throat & eyes (♂&♀) endocervix (♀) (same as chlamydia)
What is the incubation period of gonorrhoea infections ?
2-5 days
Describe the presentation of gonorrhoea
Men:
- Urethral infection - purluent discharge and dysuria, asymptomatic (<10%).
- Rectal & pharyngeal infections - usually asymptomatic; may cause anal discharge (purulent) or perianal/anal pain (proctitis), pruritus, bleeding, tenesmus.
Women:
- Endocervical infection - frequently asymptomatic (up to 50%); may get increased or altered vaginal discharge, +/- sometimes lower abdominal/pelvic pain, intermenstrual bleeding or menorrhagia.
- Urethral infection - cause of dysuria (10-15%) without frequency.
- Rectal and pharyngeal infections - usually asymptomatic.
What are the potential complications of gonorrhoea infection?

What is shown in the pic and what infection can cause these complications
Bartholinitis (right) and tysonitis (left)
What is the treatment of gonorrhoea ?
- 1st line = IM ceftriaxone + oral azithromycin
- 2nd line = Oral cefixime + azithromycin
Why is azithromycin given in the treatment of gonorrhoea ?
Because there is often co-infection with chlamydia
Due to the high antibiotic resistance of gonorrhoea what is required following treatment ?
Test of cure to be sure patient is cured









