Sexually transmitted infections

Question 1

Outline clinical features, mode of spread, investigation and treatment of infection by Treponema Pallidum

Answer 1

TP- syphilis- spirochaeate

Obligate human parasite, spiral bacterium- 5 to 15um long, limited repro ability in vitro

Features:
Acquired- primary, secondary, early and late
Congenital- early within 2 years of life, and late presents after first two years

• Primary syphilis- ulcer and regional lymphadenopathy Incubation 9-90 days
• Secondary- multisystem- glomerulonephritis, anterior uveitis, meningitis, CN palsies, skin lesions macular– nodular
• Latent- 30% of untreated develop this. Neurosyphilis, cardiovascular and gummatous
  Spread: sex, vertically

Diagnosis- primary microscopy
secondary/latent- serology
Suspected neuro- lumbar puncture and CSF exam

Treatment: procaine penicillin
Late- longer/benzathine penicillin
Suspected neuro- procaine+ probenecid or benzylpenicillin

Question 2

Outline the clinical features, mode of spread and investigation, and treatment of N gonorrhea

Answer 2

Neisseria gonorrhae- infects mucosal surfaces
Urethritis in males, endocervitis in females
- Opthalmic disease in newborns
- Amplify HIV- males infertile

Treatment resistance due to antigen variability and gene expression chamges due to penicillin, fluoroquinones and tetracyclines

Local spread common- prostatitis, vesiculitis, epididymitis
Endometritis, salpingitis, pelvic peritonitis

Diagnosis
NAA tests on urine
Gram stain g -ve diplococci
Urethral swabs

Treatment: 3rd gen cephalosphorins- ceftriaxone,
Resistance to pen, tetra, fluoro
or use ciprofloxacin

Question 3

Outline clinical features, mode of spread, investigation and treatment of Chlamydia

Answer 3

C trachomatis
- Obligate intracellular parasite of euk cells.
Exists as inert
in males- trachoma, LGV, urethritis, inclusion conjunctivitis, epididymitis,
F- trachoma, IC, LGV, urethritis, cervitis, PID

DIff serotypes affect outcome
D-K: occulogenital disease
L1,2,3: LGV, cervitis, proctitis
A, B, Ba, C- ocular trachoma

Diagnosis
Culture- high spec and sens, hybridisation, serology

Treat: doxycyline, azithromycin, or erythromycin

Question 4

Describe pelvic inflammatory disease

Answer 4

In 15% of women with cervicitis
Pelvic/abdo pain, pyrexia, vag discharge, tenderness
Cause of ectopic preg/infertility

Treat
Doxycycline
Metranidazole
Ceftriaxone

Question 5

Outline the epidemiology of HIV

Answer 5

AIDS- various opportunistic infections, Kaposi’s sarcoma, some lymphomas

Transmission- anal, needlestick, vert, sex
Common in Africa

Disease assoc with opportunistic infections and decreased CD4 count

Question 6

Outline the features of lung infections such as pneumocystitis jurocervipneumonia (fungi)

Answer 6

Increase rep in immunocompromised, injures type 1 alveolar cells
Fibronectin binding- pneumonitis
Subacute onset, dry cough, SOB
Steroid treatment
Bronchoscopy/biopsy

Question 7

List two neoplasms associated with HIV

Answer 7

Lymphoma

Kaposi’s sarcoma

Question 8

List 3 infections associated with HIV

Answer 8

Meningitis
Encephalitis
Focal features- space occupying lesions

Question 9

Describe tuberculosis meningitis

Answer 9

Raised lymphocytes
Protein, low glucose in CSF
In immunocomp- disseminated disease
RIPE + prednisolone

Question 10

Describe cryptococcal meningitis

Answer 10

Environmental fungus- cryptococcus neoformans inhaled- cause pneumonitis then dissemination
Diagnose- CSF or serum antigen
IV amphoterin then fluconazole

Question 11

Describe focal CNS lesions

Answer 11

Non infectious- tumours, primary CNS lymphomas, strokes
Infectious- bacterial abcesses, tuberculoma, immunocompromised

Toxoplasmosis encephalitis- gondii- dormant- reactivate

Question 12

Describe the management of HIV

Answer 12

Anti retrovirals- NRTIs, protease inhibitors, fusion inhibitor
More than 3 drugs
Life expectancy >10 years
Drug resistance with time