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
What cell count is important in HIV?
CD4 T Lymphocyte count
How does primary HIV present?
- up to 80% present with symptoms
- onset average 2-4 weeks after infection
combination of
- fever
- rash (maculopapular)
- myalgia
- pharyngitis
- headache/aseptic meningitis
very high risk of onward transmission
oral lesions
What oral lesions may be present in primary HIV?
- aphthous ulcers
- candidiasis
What can late stage HIV present as in the mouth?
mucosal candidiasis
gingivitis
- relating to other lifestyle issues including IVDU
Kaposi’s sarcoma
oral hairy leukoplakia
seborrhoeic dermatitis
What can present in the mouth/head/neck that may be associated with HIV?
- HPV
- HSV
- Varicella Zoster
- Idiopathic Immune thrombocytopenia
- Lymphoma
- Salivary gland disease and xerostomia
- unexplained lymphadenopathies
When should HIV be tested for?
when HIV falls within the differential diagnoses an HIV test should be performed regardless of risk factors
How is HIV tested for?
blood test
- possible false negative result in first 6 weeks of infection
- specific verbal consent to test for HIV
- often from GP or clinic
As a dentist how should you approach treating patient’s with HIV?
- ask patients if they are on treatment
- be aware of drug interactions
- do not be scared of patients with HIV
What does post-exposure prophylaxis for HIV include?
- combination of anti-retro viral drugs
- 4 week course
- off license indication - reduce risk of transmission by 80%
What are the indications for post-exposure prophylaxis?
- high risk injury + high risk source + high risk fluid
- sexual
- occupational
What are methods of wider HIV prevention?
- behaviour change interventions
- address substance use
- needle exchange/harm reduction
- STI management
- prevention of mother-child transmission
- circumcision
- condoms
- treatment as prevention
- PrEP
What types of HSV are orally transmittable?
HSV 1 and 2
How does a primary HSV infection present in the mouth?
- gingivostomatitis
- pharyngitis
- +/- systemic symptoms
What type of herpes is usually responsible for recurrent orolabial herpes?
type 1
What percentage of adults are seropositive for HSV-1?
56-85% and declining with time
How can HSV present in HIV?
- more frequently recurring
- extensive lesions
- hypertrophic lesions
- may be resistant to aciclovir
How is orolobial herpes managed?
- self-limiting 7-10 days
- usually no treatment
- symptom control
- avoid kissing
- avoid oral sex
- wash hands are touching
- reassurance
How many strains of HPV are there?
more than 100, of which 50 affect oral and genital mucosa
What types of HPV cause 95% of genital warts?
HPV 6 and 11
What types of HPV are high-risk oncogenic types?
HPV 16 and 18
In addition to genital warts, what can low risk strains of HPV cause?
orolabial warts - oral sex common route of infection
