INF2 - E. STIs-COVERED Flashcards
1
Q
what are bacterial STIs
A
- chlamydia
- gonorrhoea
- syphilis
2
Q
what are viral STIs
A
- HPV
- HSV
- hep B
- HIV
3
Q
what are parasitic STIs
A
- trichomoniasis
4
Q
chlamydia
A
- caused by chlamydia trachomatis
- gram -ve bacteria
- most common
- 7-8% <25 in UK infected
- 70% women and 50% men show no symptoms
- regular screening and barrier contraception
5
Q
life cycle of chlamydia
A
- bacterium exists in elementary body (infectious) and the reticulate body (intracellular and can replicate)
- infection starts with EBs attaching to cell membrane of urogenital tract
- EBs enter cell and transformed into RBs which grow and divide over next hours
- RBs transform into EBs and 2-3 days after infection, host cell bursts to release more infectious EBs
6
Q
symptoms of chlamydia in men
A
- untreated: can cause urethritis and chronic prostatitis
- poorer sperm quality so fertility affected
- mucus-like or clear, watery discharge
- painful/burning urination
7
Q
symptoms of chlamydia in women
A
- urethritis, PID, scarring in pelvis (uterus and fallopian tubes)
- effects on fertility
- ectopic pregnancy, miscarriage, premature rupture of membranes
- white/yellow/gray discharge: smelly
- painful intercourse
- bleeding in between periods
- increase urination
- painful/burning urination
- pus in urine
- painful periods
- dull pain in lower abdomen
- itching/burning in and around vagina
8
Q
screening and diagnosis of chlamydia
A
- NAATs and cell culture
- females: vaginal swabs
- males: urine tested
9
Q
gonorrhoea
A
- caused by neisseria gonorrhoeae
- gram -ve diplococcus bacterium
- infects mucus membranes of reproductive tract
- often asymptomatic
- regular screening, free test kits
10
Q
life cycle of gonorrhoea
A
- adhere to host epithelial cells
- replicates and forms micro colonies, colonising and invading epithelium tissue
- bacteria release molecules that activate macrophages and dendritic cells
- activation of inflammatory transcription factors and release of cytokines and chemokines
- pro-inflam mediators trigger neutrophils
- neutrophils phagocytose bacteria
- purulent exudate aids transmission (bad!)
11
Q
symptoms of gonorrhoea in men
A
- untreated: urethritis and epididymitis
- infertility in rare cases
- white/green/yellow discharge from penis
- testicular pain and swollen testicles
- painful/burning urination
- sore throat
- itchy, pain when poop
- can spread to blood: disseminated gonococcal infection - life threatening
12
Q
symptoms of gonorrhoea in women
A
- spread to uterus/fallopian tubes = PID
- fertility
- ectopic pregnancy
- white/yellow discharge
- pain during intercourse
- bleeding between periods
- painful/burning urination
- pain in lower abdomen/pelvis
- sore throat
- itchy, pain when poop
- can spread to blood: disseminated gonococcal infection - life threatening
13
Q
screening and diagnosis of gonorrhoea
A
- NAATs and cell culture
- females: endocervical/vagibnal swabs
- males: urine/urethral swabs
14
Q
syphilis
A
- caused by treponema pallidum
- gram -ve spirochete bacterium
- vertical transmission during pregnancy
- adhere to epithelial cells in genital tract and extracellular matrix components
- regular screening
15
Q
disease progression of syphilis
A
- infects epithelium, then multiplies locally
- begins to invade lymphatic system and bloodstream
- penetration of BBB in 40% inds with untreated syphilis
16
Q
symptoms of syphilis
A
primary stage
- genital sores (chancre) develop on genitals
secondary stage
- rash and flu-like symptoms
latent stage
- asymptomatic period but infection still present
tertiary syphilis
- develops in rare subset of untreated infections from 10-30 years after
- multiple organs, fatal
- neurosyphilis
- ocular syphilis
- otosyphilis
17
Q
screening and diagnosis of syphilis
A
- serologic testing to measure syphilis specific antibodies
- fluid from skin from syphilis sore taken then microscopy
18
Q
HPV
A
- can be caused by 100 strains of HPV
- infects cells in basal layer of stratified epithelium
- > 30 strains affect genital warts
- harmless which cause genital warts (HPV 6 and 11)
- can progress to cervical cancer (HPV 16 and 18)
- vaccination and cervical screening
- most people don’t know they have it
19
Q
structure of HPV
A
- naked
- circular dsDNA
- Baltimore group 1
- papillomaviridae
- 60nm
- continued in T=7 icosahedral capsid
20
Q
symptoms of HPV
A
- depends on strain
- may be asymptomatic
- genital warts
- PAP smear test - may find out
- may develop cancer
- no treatment, can only manage symptoms
21
Q
how to prevent HPV
A
- vaccine
- safe sex
- protect partner
- screened regularly
22
Q
screening and diagnosis of HPV
A
- no routine test
- cervical screening (smear test)
- those 25-64 can get
23
Q
herpes
A
- genital herpes caused by HSV2
- infects epithelial cells and keratinocytes
- asymptomatic
- genital ulcerative disease caused by herpes increases risk of transmission and infection with HIV
24
Q
structure of herpes
A
- enveloped
- linear dsDNA
- Baltimore group 1
- herpesviridae
- spherical/pleomorphic
- 150 nm
- T=16 icosahedral capsid
25
symptoms of herpes
first outbreak
- sores/lesions on skin and blisters on genitals/rectum/mouth
- vesicles break and leave painful ulcers
- fever, body aches, swollen lymph nodes
recurrent outbreak
- genital pain
- tingling/shooting pain in legs/hips/buttocks
- eruption of herpetic lesions
complications:
aseptic meningitis
26
diagnosis and screening of herpes
- NAATS
- risk of false negatives as viral shedding is intermittent b/n first and second outbreak (dormant stage)
- viral culture, type-specific virolgic tests and serologic tests
27
hepatitis B
- most cases caused by viruses
- excessive alcohol, trauma, injury can cause it
- most cases it only stays in body for 1-3 months (acute)
- can stay for 6 or more months (chronic) , may have no signs
- 25% with chronic have progressive liver disease leading to cirrhosis
- 10% will develop liver cancer
- transmitted by sexual intercourse, bodily fluids (blood and semen)
- blood-to-blood contact (needles, needle stick injuries)
- vertical transmission
28
structure of Hep B
- enveloped
- spherical
- 42nm
- Icosahedric capsule
- baltimore group 7 (dsDNA)
- HepB polymerase has reverse transcriptase activity
- non-retroviral virus which uses transcription as part of replication process
29
why do people get jaundice with hepatitis
- jaundice (icterus) of skin and eyes
- due to increased levels of bilirubin (haemoglobin breakdown product) in blood
- conjugated to form water-soluble bilirubin diglucuronide in healthy liver
- when liver impaired, not good at breaking down RBCs and recycling haem so we make more RBCs
- liver less capable of processing bilirubin
30
symptoms of hepatitis
- jaundice in 80% individuals >14
- less likely in children
- liver cirrhosis is a consequence of chronic liver disease
- fever
- loss of appetite
- nausea and vomiting
- abdominal pain
- weakness and fatigue
- joint pain
31
liver cirrhosis
- fibrosis - liver tissue replacement by collagenous scars with no function
- regenerative nodules attempts to repair damaged tissue
- irreversible damage
- liver transplant
32
screening and diagnosis of hepatitis B
- serologic testing to measure hepatitis B virus specific antigen and antibodies
- triple panel test
1. hepatitis B surface antigen (HBsAg)
2. antibody to hepatitis B surface antigen (anti-HBs)
3. total antibody to hepatitis B core antigen (if +ve, have had hepB. If have immunity from vaccine, don't have it. Appears at onset of symptoms in acute and doesn't provide protection against virus)
