Infectious disease and liver disease Flashcards
How are infections transmitted during “sex”?
- sexual/genital secretions (many)
- direct inoculation (skin to skin) (e.g. HSV)
- trauma (e.g. HCV)
- ingestion (e.g. shigella)
- fomites (objects i.e. sex toys) (e.g. gonorrhoea)
- IVDU (injection drug use) (e.g. HIV, HCV)
What trends have been shows by NATSAL surveys?
- increased reporting of first sex before 16 years of age in successive birth cohorts
- greatest difference in women
- higher numbers of lifetime partners since NATSAL-1 (1990)
- greatest difference in women
- expanding repertoire of heterosexual activities
- increased reporting of AI and OI in each birth cohort
What are risk factors for STIs?
- <25 years old
- change sexual partner
- non condom use
- MSM
- past history of STI
- large urban areas
- social deprivation
- black ethnicity
What STIs affect the mouth?
- chlamydia trachomatis
- neisseria gonorrhoea
- treponema pallidum (syphilis)
- herpes simplex virus (HSV)
- human papilloma virus (HPV)
- human immunodeficiency virus (HIV)
What is syphilis caused by?
treponema pallium - a spirochaete
How long after exposure to syphilis would you expect to get symptomatic primary syphilis?
10-90 days (usually 14-21 days)
What is a “chancre” and where is it found?
- sort of ulcer at the site of infection in syphilis
- 70% painless
- commonly seen in mouth or other extra-genital sites
- resolves without treatment 3-6 weeks
- quite indurated, like a hard disc
What causes a chancre?
- spirochaete invaded intact mucosa or via microabrasions
- host cellular inflammatory response
papule —> ulcer
What may be present in association with a chancre?
+/- regional lymphadenopathy
What is the differential diagnosis for a chancre?
- trauma
- herpes simplex
- lymphogranuloma venereum
- tropical ulcers
- cancer
How long after primary syphilis will secondary syphilis develop?
usually 3-6 weeks but can be up to 2 years
What does secondary syphilis involve?
- haematogenous and lymphatic dissemination
- multi-system disease
What are the systemic symptoms of secondary syphilis?
- low-grade fever
- sore throat
- headache
- lymphadenopathy
- rash
(flu like/like glandular fever)
How often does secondary syphilis present as lesions in the mouth?
30% of cases
How does secondary syphilis present in the mouth?
white glistening patches
- greyish membrane
- hyperaemic halo
- coalesce to form “snail track” ulcer
soft palate, hard palate, gums, buccal mucosa
What conditions may secondary syphilis present with?
- meningitis
- hepatitis
- iritis
- uveitis
- glomerulonephritis
- periostitis
- condylomata lata
If secondary syphilis goes untreated and becomes latent, what can it go on to form?
30% interacted syphilis will progress to tertiary syphilis
What kind of issues can tertiary syphilis cause?
- neurological
- cardiovascular
- gummatous
How is syphilis diagnosed?
lesion - swab for treponema pallidum by PCR
venous blood - syphilis antibody and confirmatory tests, diagnosis and screening
How is syphilis treated?
antibiotics - benzathene penicillin IM or doxycycline (2nd line)
public health - partner notification, comprehensive STI testing, sexual abstinence, risk reduction
What is the UK and Tayside prevalence of HIV?
0.19% UK, ~ 0.15% Tayside
What is the late diagnosis rate for HIV?
43%, mortality rate higher
What are the modes of transmission of HIV?
- sexual transmission 79%
- injecting drug use 2.5%
- unknown 16.5%
- other 0.8%
What are the higher risk groups for HIV?
- MSM
- high prevalence countries
- injecting drugs
- sexual contact with the above
