ID and Sexual health Flashcards
What is chlamydia caused by
Chlamydia is the most prevalent sexually transmitted infection in the UK and is caused by Chlamydia trachomatis, an obligate intracellular pathogen.
Features of chlamydia
asymptomatic in around 70% of women and 50% of men
women: cervicitis (discharge, bleeding), dysuria
men: urethral discharge, dysuria
Potential complications of chlamydia
epididymitis
pelvic inflammatory disease
endometritis
increased incidence of ectopic pregnancies
infertility
reactive arthritis
perihepatitis (Fitz-Hugh-Curtis syndrome)
IX for chalmydia
nuclear acid amplification tests (NAATs) are now the investigation of choice
urine (first void urine sample), vulvovaginal swab or cervical swab may be tested using the NAAT technique
for women: the vulvovaginal swab is first-line
for men: the urine test is first-line
Chlamydiatesting should be carried out two weeks afte
How long after exposure should chlamydia testing be done
Two weeks after a possible exposure
What might be seen in a Pap smear that is typical of chlamydia
red inclusion bodies
Mx of chlamydia
Doxycycline (7 day course) if first-line
if doxycycline is contraindicated /pregnant/ not tolerated then either azithromycin (1g od for one day, then 500mg od for two days) should be used
Guidance regarding contacting sexual partners - chlamydia
for men with urethral symptoms: all contacts since, and in the four weeks prior to, the onset of symptoms
for women and asymptomatic men all partners from the last six months or the most recent sexual partner should be contacted
contacts of confirmed
Chlamydia cases should be offered treatment prior to the results of their investigations being known (treat then test)
What is bacterial vaginosis
Bacterial vaginosis (BV) refers to an overgrowth of bacteria in the vagina, specifically anaerobic bacteria.
It is not a sexually transmitted infection
What is BV caused by
Loss of the lactobacilli “friendly bacteria” in the vagina. Bacterial vaginosis can increase the risk of women developing sexually transmitted infections.
Purpose of lactobacilli in the vagina
Lactobacilli are the main component of the healthy vaginal bacterial flora.
These bacteria produce lactic acid that keeps the vaginal pH low (under 4.5).
The acidic environment prevents other bacteria from overgrowing. When there are reduced numbers of lactobacilli in the vagina, the pH rises.
This more alkaline environment enables anaerobic bacteria to multiply.
Examples of anaerobic bacteria associated with BV
Gardnerella vaginalis (most common)
Mycoplasma hominis
Prevotella species
Risk factors for BV
Multiple sexual partners (although it is not sexually transmitted)
Excessive vaginal cleaning (douching, use of cleaning products and vaginal washes)
Recent antibiotics
Smoking
Copper coil
In which women does BV occur less frequently in
Bacterial vaginosis occurs less frequently in women taking the combined pill or using condoms effectively.
BV presentation
Fishy-smelling watery grey or white vaginal discharge. Half of women with BV are asymptomatic.
Itching, irritation and pain are not typically associated with BV and suggest an alternative cause or co-occurring infection.
Appropriate examination in BV
Speculum examination
High vaginal swab to exclude other causes of symptoms
IX for BV
Vaginal pH can be tested using a swab and pH paper. The normal vaginal pH is 3.5 – 4.5. BV occurs with a pH above 4.5.
A standard charcoal vaginal swab can be taken for microscopy. This can be a high vaginal swab taken during a speculum examination or a self-taken low vaginal swab.
What is seen on microscopy in BV
Bacterial vaginosis gives “clue cells” on microscopy. Clue cells are epithelial cells from the cervix that have bacteria stuck inside them, usually Gardnerella vaginalis.
Mx of BV
Asymptomatic BV does not usually require treatment.
Metronidazole for symptomatic BV(given orally, or by vaginal gel)
Clindamycin is an alternative antibiotic
Provide advice and information about measures that can reduce the risk of further episodes of bacterial vaginosis, such as avoiding vaginal irrigation or cleaning with soaps that may disrupt the natural flora.
Complications of BV
Increased risk of STIs
Miscarriage Preterm delivery Premature rupture of membranes Chorioamnionitis Low birth weight Postpartum endometritis
What is vaginal candidiasis commonly referred to as
Thrush
What is vaginal candidiasis
vaginal infection with a yeast of the Candida family. The most common is Candida albicans.
Risk factors for thrush
Increased oestrogen (higher in pregnancy, lower pre-puberty and post-menopause)
Poorly controlled diabetes
Immunosuppression (e.g. using corticosteroids)
Broad-spectrum antibiotics
Presentation of vaginal candidiasis
Thick, white discharge that does not typically smell
Vulval and vaginal itching, irritation or discomfort
What can more severe vaginal candidiasis lead to
Erythema Fissures Oedema Pain during sex (dyspareunia) Dysuria Excoriation
IX for thrush
Testing the vaginal pH using a swab and pH paper can be helpful in differentiating between bacterial vaginosis and trichomonas (pH > 4.5) and candidiasis (pH < 4.5).
Charcoal swab with microscopy to confirm diagnosis
Treatment of candidiasis
Antifungal cream (i.e. clotrimazole) inserted into the vagina with an applicator Antifungal pessary (i.e. clotrimazole) Oral antifungal tablets (i.e. fluconazole)
What is an over the counter option for thrush
Canesten Duo is a
It contains a single fluconazole tablet and clotrimazole cream to use externally for vulval symptoms.
Treatment for recurrent thrush infections
Can be treated with an induction and maintenance regime over six months with oral or vaginal antifungal medications. This is an off-label use.
Advice regarding contraception when using anti fungal creams and pessaries
Warn women that antifungal creams and pessaries can damage latex condoms and prevent spermicides from working, so alternative contraceptive is required for at least five days after use.
What is CMV retinitis
Common in his patients with a low CD4 count(<50)
presents with visual impairment e.g. ‘blurred vision’. Fundoscopy shows retinal haemorrhages and necrosis, often called ‘pizza’ retina
Treatment for CMV retinitis
IV ganciclovir
How is CMV transmitted
Cytomegalovirus (CMV) is transmitted in leucocytes.
Purpose of irradiating blood products
Irradiated blood products are depleted of T-lymphocytes and used to avoid transfusion-associated graft versus host disease (TA-GVHD) caused by engraftment of viable donor T lymphocytes.
What precedes rheumatic fever
Rheumatic fever develops following an immunological reaction to recent(2-6 weeks ago) strep pyogenes infection
Pathogenesis of rheumatic fever
Streptococcus pyogenes infection → activation of the innate immune system leading to antigen presentation to T cells
B and T cells produce IgG and IgM antibodies and CD4+ T cells are activated
there is then a cross-reactive immune response (a form of type II hypersensitivity) thought to be mediated by molecular mimicry
the cell wall of Streptococcus pyogenes includes M protein, a virulence factor that is highly antigenic.
It is thought that the antibodies against M protein cross-react with myosin and the smooth muscle of arteries
What are Aschoff bodies
Describes the granulomatous nodules found in rheumatic heart fever
Testing for strep infection in rheumatic fever - ix
Raised or rising strep antibodies
Positive throat swab
Positive rapid group A strep antigen test
Clinical features of rheumatic fever
Erythema marginatum
Sydenham’s chorea: this is often a late feature
Polyarthritis
Carditis and valvulitis (eg, pancarditis)
Subcutaneous nodules
Mx of rheumatic fever
Antibiotics - oral pen v
NSAIDs
Treatment of any complications(heart failure)
What causes glandular fever
Epstein-Barr virus
Less frequently - CMV and HHV-6
Features of glandular fever
Sore throat Pyrexia Lymphadenopathy(anterior and posterior triangles of the neck) Malaise Palatal petechiae
Complications of infectious mononucleosis
Splenomegaly(splenic rupture)
Hepatitis(transient rise in ALT)
Lymphocytosis
Haemolytic anaemia secondary to cold agglutinins(IgM)
Maculopapular, pruritic rash develops in patients taking amoxicillin
Diagnosis of infectious mononucleosis
Heterophil antibody test(monospot test) - NICE guidelines suggest FBC and Monospot in the 2nd week of the illness to confirm a diagnosis of glandular fever.
Management of infectious mononucleosis
rest during the early stages, drink plenty of fluid, avoid alcohol
simple analgesia for any aches or pains
consensus guidance in the UK is to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture
Autoimmune causes of lymphadenopathy
SLE
rheumatoid arthritis
Common side effects of trimethoprim
Rashes, including photosensitivity
Pruritus
Suppression of haematopoiesis
What is a common cause of pneumonia in HIV patients
Pneumocystis jiroveci is an unicellular eukaryote, generally classified as a fungus but some authorities consider it a protozoa
PCP is the most common opportunistic infection in AIDS
At what point should HIV patients receive PCP prophylaxis
all patients with a CD4 count < 200/mm³ should receive PCP prophylaxis
Features of PCP
dyspnoea
dry cough
fever
very few chest signs
What is a common complication of PCP
Pneumothorax
Extrapulmonary manifestations of PCP
hepatosplenomegaly
lymphadenopathy
choroid lesions
IX for PCP
CXR: typically shows bilateral interstitial pulmonary infiltrates
exercise-induced desaturation
sputum often fails to show
PCP, bronchoalveolar lavage (BAL) often needed to demonstrate PCP (silver stain shows characteristic cysts)
Management of PCP
Co-trimoxazole
Most common cause of meningitis 6 yrs - 60 years
Neisseria meningitidis
Streptococcus pneumoniae
Most common cause of meningitis >60 years
Streptococcus pneumoniae
Neisseria meningitidis
Listeria monocytogenes
Antibiotic recommendation for meningitis < 50 years
Intravenous cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin)
Antibiotic - meningitis 3-50 years
Intravenous cefotaxime (or ceftriaxone)
Mx of meningitis caused by listeria
Intravenous amoxicillin (or ampicillin) + gentamicin
