STIs and HIV Flashcards
Name 4 causes of a vaginal discharge. (4)
* = STI Candida albicans Trichomonas vaginalis* Chlamidia trachomatis* Neisseria gonorrhoea* Herpes simplex* Bacterial vaginosis Chemical irritants Cervical polyps Neoplasia
What is the cause of gonorrhoea? (1)
What are the symptoms? (3)
Caused by neisseria gonorrhoea
Men: purulent urethral discharge and dysuria
Women: asymptomatic; dysuria, vaginal discharge and intermenstrual bleeding.
Name 2 complications of gonorrhoea infection. (2)
Men: epididymitis, prostatitis
Women: salpingitis, Bartholin’s abscess, perihepatitis.
Systemic: rash and asthritis
Neonate: opthalmia neonatorum.
How is gonorrhoea treated? (1)
Single dose of ceftriaxone 250mg IM>
What is the causative organism of chlamydia? (1)
What are the symptoms in men and women? (2)
Chlamydia trachomatis
Men: urethral discharge and dysuria
Women: asymptomatic; itch, dysuria.
What is the causative organism of syphilis? (1)
How is syphilis contracted? (2)
Spirochete: Treponema pallidum.
Acquired or transplacentally.
Describe the early features of syphilis. (2)
Primary infection: papule develops at site of inoculation, this then ulcerates to form a painless, firm chancre, which heals within 2-3 weeks.
Secondary: 4-10 weeks after primary lesion, constitutional symptoms of fever, sore throat and arthalgia. Generalised lymphadenopathy, widespread skin rash, superficial ulcers in mouth and on genitalia and condylomata lata.
In most symptoms will subside in 2-3 weeks.
Describe the late stages of syphilis. (2)
Tertiary syphilis: after a latent period of 2 years, characterised by a gumma (granulomatous, ulcerating) lesion in the skin, bones, liver and testes.
Cardiovascular and neurosyphilis can also develop.
What is the treatment of syphilis? (1)
Benzylpenicillin
Name 3 modes of HIV transmission. (3)
Sexual intercourse (vaginal and anal) Vertical (can occur inter but most are perinatally and breast milk) Contaminated blood products and organ donations Contaminated needles (mainly IVDU but also needle stick injuries to healthcare workers)
How does HIV cause increased risk of infection? (3)
- Core of HIV molecule is RNA and reverse transcriptase
- HIV molecule has surface glycoprotein gp120 that binds to CD4 molecules on lymphocytes
- On entering the cell, the RNA/RT combination allows the molecule to make it’s own DNA (retrovirus)
- Once DNA is made, it is inserted into host genome.
- Causing severe and progressive depletion of CD4 cells.
Why is treatment of HIV so complicated? (2)
The high viral turnover and high mutation rate allows the virus to form treatment resistant strains.
Describe the natural history of HIV. (3)
- Primary HIV infection (seroconversion): 2-4 weeks after infection. Symptoms of fever, maculopapular rash, myalgia, headache, aseptic meningitis. Illness up to 3 weeks.
- Clinical latency: Most are asymptomatic. Some have persistent generalised lymphadenopathy or splenomegaly.
- Category B: Early symptomatic HIV infection associated with increased viral load, fall in CD4 coutn and development of symptoms. Symptoms include: oral candidiasis, hairy leukoplakia, herpes zoster, ITP, PID and peripheral neuropathy.
- Category C. Patient with clinical conditions that indicate they have severe immunosuppression, (AIDS).
Frank thinks he may have contracted HIV from a one night stand last week. When would a negative HIV treat be reassuring? (1)
Can be negative for 6-12 weeks after infection.
So 12 weeks after exposure.
What monitoring will occur in a patient diagnosed with HIV? (2)
CD4 lymphocyte count (3 monthly) Viral load (indication of viral replication and long term prognosis)
