M6 - Genitourinary Infections Flashcards
(42 cards)
What groups of people are mainly at risk
- Young heterosexuals
- Male homosexuals
- Minority ethnic groups
What are some of the underlying causes of increases of STD prevalence in the UK
- More tolerance towards sexual diversity and behaviour
- Inconsistent use of condoms, especially among the younger groups of people
- High levels of asymptomatic infection
- Poor access to GUM clinics and sexual health services
- GUM clinics running at capacity
What bacteria causes gonorrhoea
Neisseria Gonorrhoeae
What are the characteristics of neisseria gonorrhoeae
- Human pathogen spread by sexual contact, acute and relatively easy to treat
- Gram -ve cocci
- Aerobic
- Catalase +ve
- Oxidase +ve
- Best growth in 5-10% CO2, moist atmosphere
- Occur in pairs, spherical
How does gonorrhoea present
- Purulent infection of the mucous membrane of the urethra and cervix (also rectal and pharyngeal)
- Purulent discharge, dysuria
- Microscope = bacteria seen inside polymorphonuclear cells of the inflammatory exudate
If gonorrhoea is left untreated, what complications can occur
- Epididymitis, can spread to testicle - possibility of infarction (necrosis)
- Salpingitis inflammation of the fallopian tube - can lead to pelvic inflammation disease and sterility
- Purulent conjunctivitis in newborn - blindness possible
- Disseminated gonorrhoea (fever, painful joints, skin lesions)
Describe the treatment of gonorrhoea
Penicillin - slow release intramuscular also tetracycline, ceftriaxone
N.B. Beta-lactamase mediated penicillin resistance
What are spirochaetes
Spiral bacteria
What is the causative organism of syphilis
Treponema Pallidum (spirochaete)
Describe the characteristics of treponema pallidum
- Spiral shaped bacterium
- Rigid cell
- Motile - polar flagella enclosed in outer membrane
What can be used to observe treponema pallidum
- Visible through dark ground microscopy, UV microscopy using anti-treponema antibodies linked to fluorescein
How does T.pallidum enter the body
Enters by penetration of intact mucosa or through abraded skin
N.B low no. of cells probably required for infection
Describe primary syphilis
- Bacteria multiply at entry site
- Lesion at approx 3 wks (painless) frequently on external genitalia
- Chancre (lesion) heals after approx 6 wks.
Describe secondary syphilis
2-12 wks after primary infection
- Macular or pustular lesion/rash esp on trunk and extremities
- Highly infectious lesions
- Also flu-like illness
What oral manifestation suggests secondary syphilis
Snail track ulcer
Describe Tertiary syphilis
3-30 years later if left untreated
- Slow, progressive destructive inflammatory disease that can affect any organ - neurosyphilis, CVS, gummatous (bones and skin lesions)
Describe the features of congenital syphilis
In-utero transmission of T.pallidum to baby after 3 months of pregnancy
- Possible death of foetus
- Congenital abnormalities/deformities
- Facial and tooth deformities arising a few years later
Name a tooth deformity associated with congenital syphilis
Hutchinson’s teeth - moon shaped edges to teeth/incisors
Describe the diagnosis of syphilis and why its hard
Cant be grown on agar in lab
- Microscopy + serological (antibodies)
Describe the non-specific diagnosis test for syphilis
Cardiolipin antibody test - screening - if positive will then take specific test
Describe the specific diagnosis test for syphilis
Use treponemal antigens e.g. VDRL - T.Pallidum antibody tests - Treponema pallidum immobilisation test (TPI) live treponemes immobilised by antibodies in the patient’s serum
What is the treatment route for syphilis
Penicillin or Tetracyclines, erythromycin, chloramphenicol
What is the causative agent of chlamydia std infection
Chlamydia. trachomatis
there are other chlamydias that cause other forms of chlamydia infection
Describe the basic morphology of chlamydia bacteria
- Small bacteria
- Obligate intracellular parasites