STIs & Sexual Health Flashcards
1
Q
What organism causes chlamydia?
A
Chlamydia trachomatis
2
Q
What type of bacteria is chlamydia trachomatis?
A
Gram negative obligate intracellular bacteria
3
Q
What is an obligate intracellular bacteria?
A
Organisms that absolutely require an eukaryotic host to survive and replicate
4
Q
Transmission of chlamydia trachomatis?
A
- Sexual contact
- Perinatal transmission from infected mother to baby during vaginal birth
5
Q
How can chlamydia present in a newborn?
A
- neonatal conjunctivitis (ophthalmia neonatorum)
- pneumonia
6
Q
What 2 types of swabs are used in sexual health testing?
A
1) Charcoal swabs
2) Nucleic acid amplification test (NAAT) swabs
7
Q
How do charcoal swabs work?
A
Charcoal swabs allow for microscopy (looking at the sample under the microscope), culture (growing the organism) and sensitivities (testing which antibiotics are effective against the bacteria).
Charcoal swabs look like a long cotton bud that goes into a tube with a black transport medium at the end.
8
Q
What is the transport medium called for charcoal swabs?
A
Amies transport medium, and contains a chemical solution for keeping microorganisms alive during transport.
9
Q
After taking a charcoal swab, microscopy is done. What does this involve?
A
Microscopy involves gram staining and examination under a microscope. A stain is used to highlight different types of bacteria with different colours.
10
Q
What conditions can charcoal swabs confirm?
A
1) Bacterial vaginosis
2) Candidiasis
3) Gonorrhoeae (specifically endocervical swab)
4) Trichomonas vaginalis (specifically a swab from the posterior fornix)
5) Other bacteria, such as group B streptococcus (GBS)
11
Q
What is NAAT testing used to test specifically for?
A
1) Chlamydia
2) Gonorrhoea
Rectal and pharyngeal NAAT swabs can also be taken to diagnose chlamydia in the rectum and throat.
12
Q
How does NAAT testing work?
A
Nucleic acid amplification tests (NAAT) check directly for the DNA or RNA of the organism.
They are not useful for other pelvic infections (except where specifically testing for Mycoplasma genitalium)
13
Q
In women, a NAAT can be performed on what 3 methods of sample collecting?
A
- Vulvovaginal swab (a self-taken lower vaginal swab)
- Endocervical swab
- First-catch urine sample
The order of preference is endocervical, vulvovaginal, and then urine.
14
Q
In men, a NAAT can be performed on what 2 methods of sample collecting?
A
- First catch urine
- Urethral swab
15
Q
If gonorrhoea is suspected or demonstrated on a NAAT test, what happens next?
A
An endocervical charcoal swab is required for microscopy, culture and sensitivities.
16
Q
Presentation of chlamydia in females?
A
Chlamydia is asymptomatic in approximately 70% of females
- Abnormal vaginal discharge
- Proctitis (inflammation of lining of rectum)
- Post-coital bleeding (may indicate cervicitis)
- Intermenstrual bleeding
- Cervicitis on vaginal examination
- Painful urination (dysuria)
- Painful sex (dyspareunia)
- Pelvic pain
Note - Chlamydial infection can lead to pelvic inflammatory disease (PID), and patients may present with pelvic pain with signs of systemic infection.
Note - Ophthalmic chlamydial infection can cause conjunctivitis, and oropharyngeal infection can cause pharyngitis.
17
Q
Presentation of chlamydia in males?
A
Asymptomatic in approx 50%.
- Urethral discharge or discomfort
- Painful urination (dysuria)
- Epididymo-orchitis
- Reactive arthritis
18
Q
How can ophthalmic chlamydial infection present?
A
conjunctivitis
19
Q
How can oropharyngeal chlamydial infection present?
A
Pharyngitis
20
Q
Potential examination findings in chlamydia?
A
Pelvic or abdominal tenderness
Cervical motion tenderness (cervical excitation)
Inflamed cervix (cervicitis)
Purulent discharge
21
Q
How is chlaymdia diagnosed?
A
NAAT:
- Women –> vulvovaginal (self taken or clinician taken) or endocervical swab, or first catch urine (less reliable)
- Men –> first catch urine or urethra swab
May also need rectal swab (after anal) and/or pharyngeal swab (after oral)
22
Q
1st line management for uncomplicated chlamydia?
A
Doxycycline (oral), 100mg administered twice a day for 7 days.
23
Q
Contraindications for doxycycline in treatment of chlamydia?
A
1) pregnancy
2) breastfeeding
24
Q
Alternatives options for doxycycline in treatment of chlamydia incases of pregnancy/breastfeeding?
A
Azithromycin 1g stat then 500mg once a day for 2 days
Erythromycin 500mg four times daily for 7 days
Erythromycin 500mg twice daily for 14 days
Amoxicillin 500mg three times daily for 7 days
25
When is a test of cure recommended for chlamydia?
a) for rectal cases of chlamydia
b) in pregnancy
c) where symptoms persist.
26
If left untreated, what are the complications of chlamydia?
- Pelvic inflammatory disease (PID)
- Epididmyo-orchitis (leading to scrotal pain and swelling)
- Prostatitis
- Reactive arthritis
- Chronic pelvic pain
- Lymphogranuloma venereum
- Infertility & ectopic pregnancy
27
What can PID increase the risk of?
Infertility and ectopic pregnancy, chronic pelvic pain
28
What must be discussed with patient during chlamydia appointment?
Abstain from sex for seven days of treatment of all partners to reduce the risk of re-infection
Refer all patients to genitourinary medicine (GUM) for contact tracing and notification of sexual partners
Test for and treat any other sexually transmitted infections
Provide advice about ways to prevent future infection
Consider safeguarding issues and sexual abuse in children and young people
29
What are some potential pregnancy related complications of chlamydia?
- Preterm delivery
- Premature rupture of membranes
- Low birth weight
- Postpartum endometritis
- Neonatal infection (conjunctivitis and pneumonia)
30
What is Lymphogranuloma venereum (LGV)?
A condition affecting the lymphoid tissue around the site of infection with chlamydia.
Caused by a serotype of Chlamydia trachomatis.
31
Who does LGV most commonly present in?
MSM presenting with anal discharge and pain, or anyone presenting with rectal chlamydia.
32
Management of LGV?
LGV requires a longer course of antibiotics (21 days)
33
What is a crucial differential diagnosis of Chlamydial Conjunctivitis and should always be tested?
Gonococcal conjunctivitis --> can result in severe complications such as vision loss if the bacteria penetrate further and cause corneal ulceration and scarring
34
Causative organism of gonorrhoea?
Neisseria gonorrhoeae
35
What type of bacteria is Neisseria gonorrhoeae?
gram-negative diplococcus bacteria
36
What does neisseria gonorrhoeae infect?
It infects mucous membranes with a columnar epithelium, such as the endocervix in women, urethra, rectum, conjunctiva and pharynx.
37
Transmission of N. gonorrhoea?
1. Sexual contact
2. Vertical transmission during childbirth
38
How can N. gonorrhoea present in neonates?
Ophthalmia neonatorum (similar to chlamydial conjunctivitis) BUT the onset of gonococcal conjunctivitis is EARLIER than chlamydial conjunctivitis.
39
Presentation of gonorrhoea in women?
More likely to be symptomatic than infection with chlamydia.
- Odourless purulent discharge, possibly green or yellow
- Dysuria
- Pelvic pain
40
Presentation of gonorrhoea in men?
Similar to women
- Odourless purulent discharge, possibly green or yellow
- Dysuria
- Testicular pain or swelling (epididymo-orchitis)
41
What can rectal gonococcal infection cause?
Proctitis leading to rectal pain, bleeding and discharge.
42
What can oropharyngeal gonococcal infection cause?
pharyngitis
43
What can ophthalmic gonococcal infection cause?
conjunctivitis
44
How is gonorrhoea diagnosed?
Nucleic Acid Amplification Test (NAAT)
Men --> first pass urine sample
Women --> vulvovaginal swab, first pass urine (less sensitive)
45
Why should a standard charcoal endocervical swab also be taken from the symptomatic area in all patients with symptoms of gonorrhoea?
This is to test for sensitivities and monitor patterns of antimicrobial resistance.
46
Why is a standard charcoal swab for microscopy, culture and sensitivities so essential in gonorrhoea (as well as NAAT tests)?
NAAT tests are used to check if a gonococcal infection is present or not by looking for gonococcal RNA or DNA. They do not provide any information about the specific bacteria and their antibiotic sensitivities and resistance.
47
Where microscopy is available, Gonorrhea can be diagnosed (and immediately treated) at the point of examination by identifying what?
Gram-negative intracellular diplococci.
48
1st line management for gonorrhoea?
Ceftriaxone 1g IM injection
OR ciprofloxacin 500mg orally (only used when antimicrobial sensitivities are known before treatment)
49
what class of antibiotic is ceftriaxone?
Cephalosporin
50
what class of antibiotic is cirpofloxacin?
fluoroquinolone
51
Why should ALL patients with gonorrhoea have a follow up 'test of cure' 2 weeks after treatment?
Given the high antibiotic resistance
52
Complications of gonorrhoea?
- Pelvic inflammatory disease (PID): increases the risk of ectopic pregnancy and infertility
- Epididmyo-orchitis (leading to scrotal pain and swelling) and balanitis
- Prostatitis
- Disseminated gonococcal infection (DGI): a rare complication of gonococcal infection leading to systemic features (including arthritis, skin lesions and arthralgia)
53
What is a key complication of gonorrhoea in neonates?
Gonococcal conjunctivitis - this is contracted from the mother during birth
Neonatal conjunctivitis is called ophthalmia neonatorum. This is a medical emergency and is associated with sepsis, perforation of the eye and blindness.
54
What is ophthalmia neonatorum? What can it lead to?
Neonatal conjunctivitis
This is a medical emergency and is associated with sepsis, perforation of the eye and blindness.
55
What is disseminated gonococcal infection (GDI)?
A complication of untreated gonococcal infection, where the bacteria spreads to the skin and joints.
56
What are the signs/symptoms of GFI?
- Various non-specific skin lesions
- Polyarthralgia (joint aches and pains)
- Migratory polyarthritis (arthritis that moves between joints)
- Tenosynovitis
- Systemic symptoms such as fever and fatigue
57
Causative organism of syphilis?
Treponema pallidum
58
Transmission of syphilis?
1) Acquired --> usually via direct sexual contact (exposure to a lesion) but can also occur via blood-borne route (e.g. IV drug use, transfusions)
2) Congenital --> occurs in infants occurs due to trans-placental transmission (vertical transmission)
59
What are potential complications of syphilis infection during pregnancy?
Increases risk of:
- Miscarriage
- Stillbirth
- Congenital abnormalities
60
What is the incubation period of syphilis (i.e. time from inital infection to symptom presentation)?
Approx 21 days
61
What type of bacteria is Treponema pallidum?
a spirochete, a type of spiral-shaped bacteria
62
Syphilis is a multi-stage and multi-system disease.
Congenital syphilis (i.e., present from birth) can be broken down into two stages.
What are these?
1) Early congenital syphilis: presents in those <2 years old
2) Late congenital syphilis: presents in those >2 years old
63
How does congenital syphilis present at birth?
Two-thirds of infants with congenital syphilis will be asymptomatic at birth. Most will develop symptoms by five weeks.
64
What stages can acquired syphilis be broken down into?
1. Primary
2. Secondary
3. Latent
4. Late latent
5. Tertiary
65
How does PRIMARY syphilis present?
Development of an indurated painless ulcer (chancre) on the genitals.
This tends to resolve over 3-8 weeks.
66
When does SECONDARY syphilis typically present?
Secondary syphilis typically starts after the chancre has healed
67
How does secondary syphilis typically present?
Widespread non-pruritic maculopapular rash (if involving the soles and palms, is almost pathognomonic for syphilis)
Condylomata lata (grey wart-like lesions around the genitals and anus)
Low-grade fever
Lymphadenopathy
Alopecia (localised hair loss)
Oral lesions
68
What sign seen in secondary stage syphilis is almost pathognomonic for syphilis?
widespread non-pruritic maculopapular rash involving the soles and palms
69
What is latent syphilis?
What is late latent syphilis?
Latent --> Asymptomatic infection (confirmed by positive diagnostic serology) acquired WITHIN the last two years
Late latent --> Asymptomatic infection (confirmed by positive diagnostic serology) acquired MORE than two years prior
70
When does tertiary syphilis occur?
occurs >2 years following infection
71
How does tertiary syphilis present?
Tertiary syphilis can present with several symptoms depending on the affected organs.
Key features to be aware of are:
- Gummatous lesions (gummas are granulomatous lesions that can affect the skin, organs and bones)
- Aortic aneurysms
- Neurosyphilis
72
When does neurosyphilis present?
Neurosyphilis can occur at any stage if the infection reaches the central nervous system
73
Symptoms of neurosyphilis?
- Headache
- Altered behaviour
- Dementia
- Tabes dorsalis (demyelination affecting the spinal cord posterior columns)
- Ocular syphilis (affecting the eyes)
- Paralysis
- Sensory impairment
74
75
What is Argyll-Robertson pupil? What is it found in?
A specific finding in neurosyphilis.
It is a constricted pupil that accommodates when focusing on a near object but does not react to light.
They are often irregularly shaped.
76
What is the mainstay of diagnosis of syphilis?
serology (i.e. antibody testing)
N.B. following successful treatment, parts of the syphilis serology will remain positive (can be lifelong).
77
In patients with lesions, how can syphilis be diagnosed?
syphilis PCR swab of the lesion
78
Interpretation of syphilis serology is an art and not an exact science. The serology must be interpreted alongside a comprehensive sexual history to reach an accurate diagnosis.
What conditions can affect the interpretation of syphilis serology?
- Immunological medical conditions (e.g. SLE and HIV)
- Pregnancy
79
What is the window period of syphilis?
The window period refers to the time between syphilis exposure and when a test can detect syphilis in your body.
The window period for syphilis is 12 weeks. Therefore, testing should be repeated at least 12 weeks following the last exposure.
80
1st line pharmacological management of syphilis?
A single deep IM dose of benzathine benzylpenicillin.
The exact treatment regime will vary depending on the stage of syphilis.
81
What else is involved in management of syphilis?
- full sexual health screen
- contact tracing and partner notification need to be undertaken
- all forms of sexual intercourse need to be avoided until all parties are tested and have completed treatment.
82
What is a Jarisch-Herxheimer reaction?
A Jarisch-Herxheimer (JH) reaction can occur following the initial treatment of syphilis in some patients. This phenomenon causes a sepsis-like picture due to the release of toxins from treponemal bacterium breakdown.
83
What are the two main strains of the herpes simplex virus (HSV)?
HSV-1 and HSV-2
84
After initial infection, where does HSV lie dormant?
In the associated sensory nerve ganglia.
N.B. HSV is, therefore, a lifelong infection with periods of reactivation and symptoms.
85
What are the 2 main presentations of HSV?
1) Cold sores
2) Genital herpes
86
Which sensory nerve ganglia is affected in cold sores?
HSV has become latent (and then reactivates) in the trigeminal nerve ganglion
87
Which sensory nerve ganglia is affected in genital herpes?
Sacral nerve ganglia
88
Transmission of HSV?
- Direct contact with affected mucous membranes
- Viral shedding in mucous secretions.
N.B. The virus can be shed even when no symptoms are present, meaning it can be contracted from asymptomatic individuals.
89
When is asymptomatic shedding in HSV infection more common?
Asymptomatic shedding is more common in the first 12 months of infection and where recurrent symptoms are present.
90
Give some potential signs/symptoms of HSV infection
1) Cold sores
2) Genital herpes
3) Aphthous ulcers (small painful oral sores in the mouth
4) Herpes keratitis (inflammation of the cornea in the eye)
5) Herpetic whitlow (a painful skin lesion on a finger or thumb)
91
What is a herpetic whitlow?
a painful skin lesion on a finger or thumb
92
When is HSV-1 normally contracted?
In childhood (before five years)
93
What can HSV-1 lead to?
1) Cold sores (particularly in times of stress)
2) Genital herpes
94
How is genital herpes caused by HSV-1 spread?
It is usually contracted through oro-genital sex, where the virus spreads from a person with an oral infection to the person that develops a genital infection.
95
What does HSV-2 typically cause?
Genital herpes (mostly a sexually transmitted infection)
(but can also cause lesions in the mouth)
96
Are anogenital infections more likely to cause recurrent symptoms if the infection is caused by HSV-1 or HSV-2?
Anogenital infections caused by HSV-2 are around four times more likely than HSV-1 to cause recurrent symptoms.
97
Does infection with HSV-1 confer immunity to HSV-2 (and vice versa)?
No
98
Clinical features of HSV?
The initial episode is often the most severe, and recurrent episodes are milder.
- Ulcers or blistering lesions affecting the genital area
- Neuropathic type pain (tingling, burning or shooting)
- Flu-like symptoms (e.g. fatigue and headaches)
- Dysuria (painful urination)
- Inguinal lymphadenopathy
99
How is HSV infection diagnosed?
HSV is diagnosed using PCR from swabs of lesions.
100
How should a swab of HSV be taken?
The lesion should be BURST and a swab taken from the BASE of the ulcer.
101
What must be present for HSV testing?
Lesions
However, the diagnosis can be made clinically based on the history and examination findings.
102
1st line management of HSV?
Symptomatic episodes --> aciclovir 400mg orally TDS for 5 days (an antiviral)
Treatment should be commenced within five days of symptom onset.
Additional measures:
- Paracetamol
- Topical lidocaine 2% gel (e.g. Instillagel)
- Cleaning with warm salt water
- Topical vaseline
- Additional oral fluids
- Wear loose clothing
- Avoid intercourse with symptoms
103
What is the main issue with genital herpes during pregnancy?
The risk of neonatal herpes simplex infection contracted during labour and delivery --> high morbidity and mortality
104
Some patients with HSV experiencing multiple episodes or wishing to reduce onward transmission can take what for prophylactic treatment?
Prophylactic treatment (aciclovir 400mg BD daily)
105
Complications of HSV?
- Urinary retention: may require catheterisation
- HSV keratitis: dendritic lesion on the cornea
- Aseptic meningitis
- Herpes proctitis
- Neonatal HSV: an increased risk if the mother becomes infected in the third trimester
- Herpetic whitlow
106
What is the causative agent of genital WARTS?
Human papillomavirus (HPV) 6 and 11 (in most cases)
107
Tranmission of genital warts?
This double-stranded DNA virus is mainly transmitted via direct skin-to-skin contact, and more rarely can be transmitted perinatally.
N.B. Infection with HPV is very common in sexually active individuals, and most will not develop visible warts.
108
Incubation period of genital warts?
The incubation period from exposure to infection can be up to 8 months.
109
Clinical features of genital warts?
- Can vary in size, number, colour and texture but mostly appear as textured, soft growths.
- The anus, cervix and urethral meatus can all be affected.
- Anogenital warts can be keratinised (hard surface) or non-keratinised (soft surface).
- Genital warts are usually asymptomatic.
- However, itching, bleeding and pain can occur.
N.B. this is different to the lesions seen in genital HERPES
110
Diagnosis of genital warts?
The diagnosis of anogenital wards in clinical, based on characteristic examination findings.
However, if lesions appear atypical or suspicious, a biopsy should be performed to exclude an oncogenic HPV virus type.
111
What should be excluded if genital wart lesions appear atypical or suspicious?
Oncogenic HPV virus type
112
What risk factor is known to increase the risk of genital wart recurrence?
Smoking
113
Topical treatments for genital warts?
- Topical podophyllotoxin (Warticon® and Condyline®)
- Topical imiquimod (patients should be made aware that this damages condoms)
114
What are some physical ablation therapy options for genital warts?
- Cryotherapy
- Surgical excision
115
Does the HPV vaccine treat existing genital warts?
No
116
Complicatoins of genital warts?
- Ano-genital cancer
- Scarring following treatment
117
What is trichomoniasis?
An STI caused by a parasite.
118
Causative organism of trichomoniasis?
Trichomonas vaginalis
119
What is Trichomonas vaginalis classed as?
A protozoan, and is a single-celled organism with flagella.
120
Where does trichomonas live?
lives in the urethra of men and women and the vagina of women.
121
Clinical presentation of trichomoniasis?
Up to 50% of cases of trichomoniasis are asymptomatic. When symptoms occur, they are non-specific:
- Vaginal discharge
- Itching
- Dysuria (painful urination)
- Dyspareunia (painful sex)
- Balanitis (inflammation to the glans penis)
- Strawberry cervix on speculum examination
122
How is vaginal discharge typically described in trichomoniasis?
Frothy and yellow-green, although this can vary significantly. It may have a fishy smell.
123
What can examination of the cervix in trichomoniasis reveal?
Can reveal a characteristic “strawberry cervix” (also called colpitis macularis).
This is caused by inflammation (cervicitis) relating to the trichomonas infection. There are tiny haemorrhages across the surface of the cervix, giving the appearance of a strawberry.
124
Vaginal pH in trichomoniasis?
Raised pH, >4.5 (similar to bacterial vaginosis)
125
Diagnosis of trichomoniasis?
Testing for trichomoniasis does not form a part of a routine asymptomatic sexual health screen in the UK.
- Cn be confirmed with a standard charcoal swab with microscopy
- Swabs should be taken from the posterior fornix of the vagina (behind the cervix) in women. A self-taken low vaginal swab may be used as an alternative.
- A urethral swab or first-catch urine is used in men.
126
Management of trichomoniasis?
Metronidazole
N.B. Alcohol should be avoided during treatment and for 72 hours afterwards.
127
Complications of trichomoniasis?
Can increase risk of:
- Contracting HIV by damaging the vaginal mucosa
- Bacterial vaginosis
- Cervical cancer
- Pelvic inflammatory disease (can increased risk of ectopic pregnancy and infertility)
- Pregnancy-related complications such as preterm delivery
- Prostatitis
128
What is Mycoplasma genitalium?
Mycoplasma genitalium (MG) is a bacteria that causes non-gonococcal urethritis. It is a sexually transmitted infection.
There are developing problems with antibiotic resistance, particularly with azithromycin.
129
Transmission of Mycoplasma genitalium ?
Is a sexually transmitted, the bacteria invade epithelial cells and can remain there for many years if left untreated.
130
Clinical features of Mycoplasma genitalium?
In the vast majority of cases, infection with Mycoplasma genitalium is asymptomatic.
The presentation is very similar to chlamydia, and patients may be infected with both organism.
Urethritis is a key feature
Other features:
- Females --> dysuria, post-coital bleeding, or signs of pelvic inflammatory disease.
- Males --> urethral discharge(often clear), dysuria or epididymo-orchitis.
131
Investigations of Mycoplasma genitalium (MG)?
Traditional cultures are not helpful in isolating MG, as it is a very slow-growing organism.
The samples recommended by BASHH guidelines (2018) are:
1) First urine sample in the morning for men
2) Vaginal swabs (can be self-taken) for women
NAATs are the gold standard for diagnosis
132
1st line management of uncomplicated Mycoplasma genitalium?
1st line in uncomplicated urogenital infection:
1) Doxycycline 100mg twice daily for 7 days
2) Followed by azithromycin 1g as a single dose then 500mg daily for 2 days
(total 10 days of antibiotic treatment)
133
Management of complicated Mycoplasma genitalium?
Moxifloxacin 400mg daily for 14 days
134
Potential complications of Mycoplasma genitalium?
- Sexually acquired reactive arthritis (SARA)
- Pelvic inflammatory disease (increases the risk of ectopic pregnancy and infertility)
- Pre-term delivery
135
What does AIDS stand for? When does it occur?
Acquired immunodeficiency syndrome (AIDS)
136
What human cells does HIV infect?
Preferentially infects CD4+ T helper lymphocytes, resulting in the progressive destruction of the immune system and the onset of AIDS
136
What species of virus is HIV?
Lentivirus - an RNA retrovirus
136
What are the 2 types of HIV?
HIV-1
HIV-2
137
Which type of HIV is most common?
HIV-1
138
Where is HIV-2 mainly found?
West Africa
139
7 stage life cycle of HIV?
1. Binding
2. Fusion
3. Reverse transcription
4. Integration
5. Replication
6. Assembly
7. Budding
140
Describe stage 1 of the HIV life cycle (binding)
Viral protein gp120 on the surface of HIV binds host glycoprotein CD4+ and host co-receptor CCR5 or CXCR4.
This is blocked by CCR5 antagonists.
141
What is the protein on the surface of HIV that binds to CD4+?
gp120
142
Describe stage 2 of the HIV life cycle (fusion)
Viral protein gp41 penetrates the cell membrane, allowing the fusion of the virus and cell.
This is blocked by cell fusion inhibitors.
143
Describe stage 3 of the HIV life cycle (reverse transcription)
Viral reverse transcriptase converts HIV single-stranded RNA to double-stranded DNA.
This is blocked by non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTIs).
144
Describe stage 4 of the HIV life cycle (integration)
Viral integrase enzymes allows HIV DNA to insert into the host DNA.
This is blocked by integrase inhibitors.
145
Describe stage 5 of the HIV life cycle (replication)
host machinery transcribes and translates new HIV RNA and polyproteins.
146
Describe stage 6 of the HIV life cycle (assembly)
The new HIV proteins and HIV RNA move to the cell membrane and assemble the immature, non-infectious virion.
147
Describe stage 7 of the HIV life cycle (budding)
The new HIV virion exits the cell and viral protease cleaves the long HIV protein chains to form the mature, infectious virion.
This is blocked by protease inhibitors.
148
What are the 3 stages of HIV infection?
1. Primary HIV infection (seroconversion)
2. Chronic HIV infection (asymptomatic infection/clinical latency)
3. AIDS
149
On which cells is a CD4+ receptor found?
Found on the surface of T helper lymphocytes, monocytes, macrophages and dendritic cells (collectively named CD4+ cells)
150
What happens during the primary HIV infection stage (seroconversion)?
The infected CD4+ cell dies and releases large numbers of new virions, which disseminate through the blood to infect more CD4+ cells, primarily in lymphoid tissue.
151
When does the seroconversion period develop after exposure?
This period develops within 2-4 weeks after exposure - during which time there is a high level of viral replication, making the individual highly infectious.
152
What symptoms are seen in seroconversion illness in HIV?
The immune response to primary HIV infection (PHI) can cause mild-to-moderate non-specific symptoms that are often described as being similar to flu or infectious mononucleosis
- Fever
- Malaise
- Muscle aches (myalgia)
- Joint pain (arthralgia)
- Headache
- Fatigue
- Loss of appetite
- Oral ulcers
153
What symptoms are seen during HIV chronic infection stage?
The infection is then asymptomatic until the condition progresses to immunodeficiency.
Disease progression may occur years after the initial infection.
154
When does AIDS begin?
When the persistent HIV infection compromises the ability of the immune system to replenish CD4+ cells, the CD4+ cell count drops below 200 cells/µL, which is sufficient for a diagnosis of AIDS.
155
What CD4+ cell countis sufficient for a diagnosis of AIDS?
<200 cells/µL
156
If left untreated, when will AIDS cause death?
Within around 20 months
157
Transmission of HIV?
1) Unprotected anal, vaginal or oral sexual activity
2) Vertical transmission --> mother to child at any stage of pregnancy, birth or breastfeeding
3) Mucous membrane, blood or open wound exposure to infected blood or bodily fluids (e.g., sharing needles, needle-stick injuries or blood splashed in an eye)
158
What is an AIDS defining illness?
Certain serious and life-threatening diseases that occur in HIV-positive people are called "AIDS-defining" illnesses.
When a person gets one of these illnesses, he or she is diagnosed with the advanced stage of HIV infection known as AIDS
159
Give some examples of AIDS-deining illnesses
- Kaposi’s sarcoma
- Pneumocystis jirovecii pneumonia (PCP)
- Cytomegalovirus infection
- Candidiasis (oesophageal or bronchial)
- Lymphomas
- Tuberculosis
160
Which demographic groups are considered high risk for HIV infection?
- Men who have sex with men (MSM)
- Female sexual contacts of MSM
- Those originating from areas with a high prevalence of HIV
- Those in current or former serodiscordant relationships (in which a HIV-negative individual is partnered with a HIV-positive individual)
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Lifestyle and social risk factors for HIV?
- Intravenous drug use
- Occupational exposure (such as accidental needlestick injury)
- Sexual risk factors such as unprotected anal or vaginal sex with one or multiple partners, and having another sexually transmitted infection such as hepatitis B or hepatitis
- Unsafe blood transfusion or transplant
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What are some potential haematology clinical features of longstanding HIV infection?
- Unexplained neutropenia
- Unexplained anaemia
- Unexplained thrombocytopenia
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What are some potential respiratory clinical features of longstanding HIV infection?
- Cough
- Breathlessness
- Infection with pneumocystis jirovecii, tuberculosis, bacterial pneumonia
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What are some potential constitutional clinical features of longstanding HIV infection?
- Fever/sweats
- Weight loss
- Lymphadenopathy (especially if >3 months, occurring in 2 or more extra-inguinal sites)
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What are some potential neurological clinical features of longstanding HIV infection?
- Confusion
- Personality change
- Seizures
- Focal neurological symptoms
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What are some potential oral clinical features of longstanding HIV infection?
- Aphthous ulcers
- Candidiasis
- Hairy leukoplakia
- Gingivitis
- Dental abscess
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What are some potential GI clinical features of longstanding HIV infection?
- Oesophageal candidiasis
- Diarrhoea
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What are some potential dermatological clinical features of longstanding HIV infection?
- Dark purple/brown skin lesions (Kaposi's sarcoma)
- Fungal skin and nail infection
- Pityriasis versicolor
- Shingles
- Warts
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What are some potential genitourinary clinical features of longstanding HIV infection?
- Candidiasis
- Herpes simplex
- Warts
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What are some potential malignancy clinical features of longstanding HIV infection?
Dark purple/brown intradermal skin lesions
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Who does NICE recommend testing for HIV?
1. Patients who belong to high-risk groups
2. Those presenting with another STI
3. New patients at a GP practice in an area of high prevalence as part of routine antenatal care
4. Those who request it
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What is the aim of ART?
Aims to suppress HIV viral replication to the point where it is undetectable and cannot be transmitted.
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ART comprises a minimum of how many different drugs? Why?
3
HIV is highly mutagenic and can quickly develop drug resistance, so ART comprises a minimum of 3 different drugs to target different parts of the HIV life cycle.
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What is the regimen of choice of ART?
1) A backbone of two nucleoside reverse transcriptase inhibitors (NRTIs) e.g. tenofovir disoproxil plus emtricitabine
Combined with either;
2) An integrase inhibitor (e.g. bictegravir) or;
3) A non-nucleoside reverse transcriptase inhibitor or;
4) A boosted protease inhibitor
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Give 2 examples of nucleoside reverse transcriptase inhibitor (NRTIs)
1. Tenofovir disoproxil fumarate
2. Emtricitabine
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Give some classes of drugs used in ART
1. NRTI
2. NNRTI
3. Protease inhibitor
4. Integrase inhibitor
5. CCR5 inhibitor
6. Fusion inhibitor
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What is the treatment aim of ART?
Treatment aims to achieve a normal CD4 count and undetectable viral load.
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Potential adverse effects of ART?
- Hypersensitivity
- Mood/behaviour/sleep changes
- Hyperlipidaemia
- Lipodystrophy
- Renal impairment
- Hepatic toxicity
- Peripheral neuropathy
- Bone marrow suppression
- Pancreatitis
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What can be given to adults at high risk of HIV?
Pre-exposure prophylaxis (PrEP)
This is taken daily before exposure to the virus to reduce the risk of HIV acquisition.
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What is PrEP a combination of?
Emtricitabine + tenofovir disoproxil (both NRTIs)
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Who may be offered PrEP?
Men or transgender individuals who have sex with men and HIV-negative sexual partners of HIV-positive individuals with a detectable or unknown viral load.
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What can be given immediately after exposure to HIV?
Post-exposure prophylaxis (PEP)
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When must PEP be commenced after HIV exposure?
Must be commenced within a short window of opportunity (less than 72 hours). The sooner it is started, the bette
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What is PEP a combination of?
Emtricitabine, tenofovir disoproxil and raltegravir for 28 days
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How long does it take to suppress the virus after ART initiation?
3-6 months
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What is the most common life-threatening opportunistic infection in AIDS?
Pneumonia
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Which mode of delivery is used in mothers with the following HIV viral loads:
a) under 50 copies/ml
b) over 50 copies/ml
c) over 400 copies/ml
a) normal vaginal delivery
b) consider a pre-labour c-section
c) pre-labour c-section is recommended
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What is given as an infusion during labour and delivery if the HIV viral load is unknown or above 1000 copies/ml?
IV zidovudine
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Can HIV be transmitted during breastfeeding?
Yes
The risk is reduced if the mother’s viral load is undetectable but not eliminated.
Therefore, the safest option is to avoid breastfeeding.
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What does standard STI screening consist of?
1) Chlamydia, gonorrhoea (NAAT):
- urine
- vulvovaginal swab (VVS)
2) HIV, syphilis (serology)
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What is the tailored STI screen for MSM?
Standard STI screen plus 3 site testing for chlamydia & gonorrhoea (NAAT): urine, rectum & pharynx.
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What does a 'strawberry cervix' indicate?
TV (trichomonas vaginalis)
Also classic frothy yellow discharge.
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What are some complications of chlamydia in females?
- PID, endometritis & salpingitis
- tubal infertility
- ectopic pregnancy
- sexually acquired reactive arthritis (SARA)
- perihepatitis (Fitz-Hugh Curtis syndrome)
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Investigation window period for chlamydia?
2 weeks - consider repeat test based on sexual history
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How long should patients with chlamydia avoid sex?
Avoid for 1 week until they and their partners have completed treatment
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When is a test of cure for gonorrhoea recommended?
Pregnancy
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Main contraindication for doxycycline?
Pregnancy & breastfeeding
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What are the primary sites of infection of gonorrhoea?
Mucous membranes: urethra, cervix, rectum, pharynx, conjunctiva
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Dose of doxycycline in chlamydia?
100mg BD
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What are some complications of gonorrhoea in males?
- epididymo-orchitis
- proctitis
- disseminated gonorrhoea
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Urethral symptoms in men in gonorrhoea vs chlamydia?
Gonorrhoea: 80% with urethral infection with have urethritis +/- yellow discharge
Chlamydia: urethral discharge typically clear/white
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What is lymphogranuloma venereum (LGV)?
STI caused by strain of Chlamydia.
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Who is LGV mainly found in?
MSM
202
Symptoms of LGV?
- asymptomatic
- swollen lymph glands in the groin
- ulcer or sore on penis or around anus
- anal symptoms: blood or pus, pain etc
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What are the 2 most common causes of non-gonococcal urethritis?
1) Chlamydia trachomatis
2) Mycoplasma genitalium
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Does urethral discharge always need investigation?
YES
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Give some common treatment options for anogenital warts
Physical ablation:
- cryotherapy
- excision
- electrocautery
Topical application:
- podophyllotoxin
- imiquimod
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What is molluscum contagiosum?
A common common skin infection caused by molluscum contagiosum virus (MCV).
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How is molluscum contagiosum transmitted?
By close personal contact, or directly via fomites e.g. shared towels and flannels.
Can be transmited sexually.
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Typical lesions seen in molluscum contagiosum?
Characteristic pinkish or pearly white papules with a central umbilication, which are up to 5 mm in diameter.
Can appear anywhere on body (except palms & soles): trunk, flexures, anogenital area, thighs, lower abdomen.
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Who is molluscum typically seen in?
The majority of cases occur in pre-school children (often in children with atopic eczema).
Can also occur in young adults as an STI.
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Management of molluscum contagiosum?
- Reassure is self-limiting (spontaneous resolution)
- Offer STI screening
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What is a chancre?
A painless, hard anogenital ulcer seen in 1ary syphilis (note: can be multiple & painful).
This heals within approximately 3 to 6 weeks.
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What symptom typically accompanies a chancre?
Local lymphadenopathy
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Management of 1ary, 2ary or early latent syphilis?
Benzathine penicillin IM single dose
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Management of late latent, CVS and gummatous syphilis?
Benzathine penicillin IM for 3 weeks
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What is balanitis?
Inflammation of the glans penis
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What is posthitis?
Inflammation of the prepuce
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Symptoms of balanoposthitis?
- local rash
- soreness
- itch
- odour
- inability to retract foreskin
- discarge from glans/behind foreskin
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Causes of balanoposthitis?
- poor hygiene in uncircumcised men
- dermatitis: irritant, allergic, atopic
- Candida
- anaerobic balanitis
- lichen sclerosus
- psoriasis
- premalignant conditions
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General advise for balanitis/vulval itching/discomfort?
1) Avoid soaps/irritants
2) Emollients can be used as soap substitute
3) Avoid tight fitting underwear
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