Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clinical Micro > Lecture 7 STI > Flashcards

Lecture 7 STI Flashcards

1
Q

In the UK STIs are the second most communicable disease problem , T or F

A

False, it is the greatest communicable disease problem!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many attendances at GUM clinics in uk are accounted to STIs

A

> 1.5 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Wwhat is the STI cost burden to NHS per year

A

£750 million/annum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the cost of HIV and other STI respectively to nhs each year

A

Hiv £580 million

Others £65 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which social groups are most likely to be affected by STI

A

MSM (homosexual men)
Young people high risk lifestyles - multiple partners and lack of condoms use
Disadvantaged socio-economic communities (africa, secondary schools (lower understanding))

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What bacteria are associated with STIs and what conditions do they cause

A

Chlamydia trachomatis - non specific urethritis (approx 200,000 new cases in uk per year

Neisseria gonorrhoae - Gonorrhoea (approx 40,000 new cases in uk per year

Treponema pallidum - syphilis (approx 5,000 new cases in uk per year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what viruses are associated with STIs and what diseases do they cause

A

Human papilloma virus (DNA virus) - genital warts - (approx 68,000 new cases in uk per year

Herpes simplex - genital herpes (approx 33,000 new cases in uk per year
Hepatitis B/C - hepatitis - 5 million in uk
HIV - AIDS - (approx 6000 new cases in uk per year - 54% MSM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What fungi is associated with STIs and what disease does it cause

A

C albicans and thrush (approx 80,000 new cases in uk per year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What parasites are associated with STIs and what disease do they cause

A

Trichomonas vaginalis - vaginitis - (approx 8,000 new cases in uk per year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What arthropods are associated with STIs and what disease do the cause

A 
Sarcoptes scabei - genital scabies
Phthirus pubis (crab louse) - pediculosis pubis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name some capnophilic organisms and explain what it means

A

Microorganisms that thrive in presence of high conc of co2. E.g. Gram negative cocci Neisseria spp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What symptom does parasitic vaginitis cause

A

Inflammation with frothy green vaginal discharge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How has the morning after pill and contraceptive pill contributed to STI

A

Prevent pregnancy but doesnt protect against sti

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the correlation between grindr use and gonorrhoea& syphilis increase

A

More likely for casual one night stands - very quick contact with people

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name some factors linked with an increase in STI cases

A

Drugs/alcohol - lowered inhibitions
MSM- more likely for partner exchange
Contraceptive pill
Lack of education / awareness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In what year was the outbreak of super-gonorrhoea in leeds

A

2015

Resistant to every antibiotic !!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which microbe causes chlamydia

A

Chlamydia trachomatis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is chlamydia spread

A

Vaginal, anal and oral sex and can be transmitted during pregnancy from mother to baby

Incubation time 1-3 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the clinical manifestations of chlamydia

A

Often asymptomatic - 75% o women and 50% of men therefore become reservoirs.
If symptoms:
Male - urethritis (watery, white discharge)
Female - urethritis/cervicitis/vaginitis and dysuria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What complications can occur from chlamydia

A

Pelvic inflammatory disease )PID) in 40% of cases
Infertility in males (descend into tests and high affinity for sperm attachment) and F ( ascend into fallopian tube)
Occular infection e.g conjunctivitis in neonates (chlamydia conjuvictis of newborn baby) and adults.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What programme was established in 2003 for chlamydia

A

The national chlamydia screening programme (NCSP) - control and prevention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What was the aim of the NCSP in 2003

A

Detect and treat asymptomatic carriers of chlamydia, targeting people <25 sexually active in contraceptive services, GP surgeries, community pharmacies, outreach clinics etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Between 2003 and 2012 how many tests were performed and chlamydia infections detected by NCSP

A

5.5 million tests

370,000 ‘silent infection’ diagnoses from urine samples.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What statistic regarding under 25s and chlamydia was stated by NCSP

A

1:10 who are sexually active carried chlamydia and didnt know they had it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the treatment for chlamydia q

A

Clamelle (azithromycin) single day dose of 2 tablets at 500mg

Or doxycycline (vibramycin) for 7-14 days at 200mg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which 4 antigenic types HPV virus cause more than 70% of infections

A

6,11,16,18. 16/18 risk for cervical cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which antigenic types of HPV are mainly responsible for genital warts

A

6 and 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where do genital warts occur?

A

Upon point of contact e.g. Mouth, vagina, penis etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is HPV transmitted

A

Vaginal,anal and oral sex

Incubation period 1-6 months or even years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What age range are mostly affected by HPV infections

A

17-33 year olds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does HPV infection manifest clinically

A

Warts (90% by HPV types 6/11.) . Multiple, dry, keratinised, ‘cauliflower in appearance’ but painless.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is neoplastic conversion in regards to HPV

A

Cervical cancer caused by high risk HPV 16/18

33
Q

What percentage of cervix cancers in 2002 was caused by HPV

A

100%

34
Q

What are the treatment options for HPV genital warts

A

Podophyllin (cytotoxic)- 50% success

Imiquimod (immunostimulatory agent which boost immune response)

35
Q

What are the treatment options for HPV cervical/intraurethral

A

Co2 laser removal deep within anatomy

36
Q

What are the prevention options for HPV

A

Vaccination using Gardasil against HPV 6,11,16 and 18

Girls currently vaccinated

37
Q

What microbe causes herpes

A

Herpes simplex virus (HSV1 = 40% HSV2 = 60%)

38
Q

How is herpes transmitted

A

Vaginal, anal and oral sex with an incubation of 3-7 days

39
Q

What are the primary clinical manifestations of Herpes

A

Primary - asymptomatic 70%, symptoms constitutional and localised such as feeling unwell in general, untreated can last approximately 28 days however it becomes latent.

40
Q

What are the reactivation clinical manifestations of Herpes

A

Tenderness, pain and burning at site of eruption lasting 2hr to 2 days.
Women - lesions on labia and perineum
Men - lesions on the shaft, prepuce (foreskin), glans

Lesions heal in 7-10 days, dissemination and encephalitis

41
Q

When may reactivation occur and why

A

Herpes lives in nerve cells and can reactivate due to stress and get oral or genital herpes.

If immunocompromised then virus can spread and cause mild inflammation of the brain (encephalitis - fevers, headaches and seizures)

42
Q

What is the treatment and prevention for herpes

A

Acyclovir (zovirax) : 200mg 5x daily for one week

Famciclovir : 200-250mg 3x daily for 1 week

Safe sex

43
Q

What microorganism causes gonorrhoea

A

Neisseria gonorrhoeae

44
Q

N gonorrhoeae is a obligate human pathogen , t or f

A

true

45
Q

How is gonorrhoea transmitted

A

Vaginal, anal, and oral sex
Incubation period 2-7 days

Only through DIRECT CONTACT

46
Q

What other infection may occur with gonorrhoea

A

Rectal infection may follow anal intercourse and in women by local spread of gonococcus from vaginal introitus .
Often asymptomatic but pain, itching, tenesmus (feeling of need to empty bowel constantly), discharge and bloody diarrhoea may occur

47
Q

What are the transmission rates after one exposure with an infected individual for M and F and explain why

A

Males - 20%
Females 80%

Ejaculate contain more bacteria so women more likely to get infected

48
Q

When may conjunctivitis occur with gonorrhoea

A

Mother to baby transmission

49
Q

What is the epidemiology of gonorrhoea

A

Rates higher in urban regions esp london
Men form 70% of these - of which MSM and black ethnic groups account for 1/3 of these

Female 16-19 years, male 20-24years

50
Q

What are the clinical manifestations of gonorrhoea in males and females

A

Asymptomatic in many cases (70% female, 10% male)

Male - urethritis , dysuria, thick purulent penile discharge (due to LPS on gram neg surface- high inflammatory response)

Female - dysuria, cervicitis , thick purulent (sometimes bloody) vaginal discharge

Rectal infection with anal discharge and pain on anal sex
Throat infection : tonsilitis and purulent exudate

51
Q

What other sexually transmitted infections may you see with gonorrhoea

A

chlamydia and genital warts

52
Q

What complications can arise from untreated gonorrhoea in males, females and newborns

A

Males; epididymitis and prostatitis
Females (20%); spread to Fallopian tubes (salpingitis) , pelvic inflammatory disease (PID) , infertility

Ophthalmia neonatorum (like conjunctivitis but thicker and more purulent)

If immunosuppressed disseminated gonococcal infection (DGI) - organism in blood stream and get sepsis

53
Q

Laboratory diagnosis of gonococcal infection - sample collection process

A

Sample collection
Males - urethral swab (3cm insertion and rotation)
Females - multiple swabs, urethral/endocervical/vaginal

Other samples depend on patient history e.g. Throat, rectal or blood cultures

Transported in stuarts medium - preferably to GUM clinic lab

54
Q

What is important to consider with gonorrhoea transportation

A

Very fastidious organism - need good transport media e.g. Stuarts

55
Q

What non culture techniques can be used to diagnose gonorrhoea

A

Direct microscopy of discharge - presumptive diagnosis if positive and initiate treatment - if see lots of WBC and diplococci as urethra is sterile except for the tip

Nucleic acid amplification tests - PCR based 0 rapid detect/amplifies specific DNA; bacteria doesnt need to be viable.

56
Q

What culture techniques can be used to diagnose gonorrhoea

A

Enriched agar such as blood or chocolate agar - will not grow on nutrient!
Selective agar : modified thayer-martin/New york city agar; vancomycin , colistin, nystatin, trimethoprim (can get contamination from urethral tip)

57
Q

What colonies would you expect for gonorrhoea after 48hr incubation at 37dg with 5% co2.

A

Opaque, convex, grey, glistening colonies approx 2mm

58
Q

Why are there antimicrobials in selective agar

A

Prevent bacteria and fungi growth

59
Q

What ID tests can be performed after isolated colonies from culture

A

Gram neg diplocci on gram stain
Oxidase positive - test for cytochrome c oxidase in ETC (aerobes have it)
Catalase +
CHO fermentation (glucose + but maltose and sucrose negative) FROM API. Other neisseria may also have maltose and sucrose but gonorrhoea is ONLY GLUCOSE +

Prolyl aminopeptidase (gonochek II) - other neisseria dont have enzyme

60
Q

What percentage of gonoiccoal infections are resistant to
I) penicillin
II) ciprofloxacin
III) tetracycline

A

I) 18%
II) 22%
III) 48%

61
Q

What are the guidelines of single antibiotic (not combination) dosages etc - non drug resistant

A

Ceftriaxone (250mg, Intramuscularly, injection X1) and cefixime (400mg, oral, single dose) both high spectrum cephalosporin (beta lactam antibiotics)

Also can treat with azithromycin (2g single dose)

62
Q

When should combination therapy be used for gonorrhoea and what is the treatment

A 
Uncomplicated drug resistant gonorrhoea 
500mg ceftriaxone (single dose IM) AND 1g azithromycin (single dose, orally)
63
Q

Why has there been an increase in resistant to azithromycin

A

Hypothesised to be due to treat chlamydia therefore n gonorrhoeae exposed to it and become resistant - super strains

64
Q

What can prevent gonorrhoea infections

A

Safe sex

  • minimise number of sexual partners
  • use condoms during mouth to penis sex, vaginal and anal intercourse
65
Q

What is the trial drug in phase 3 against Neisseria gonorrhoeae and what is its MOA

A

2017 trial for ETX-0914, worked against all strains so far, patients successfully treated

MOA: act on topiosomeriase type II - like old quinolone

66
Q

What are n gon adherence and endocytosis mechanisms

A

Pili (attach to nonciliated columnar epithelial cells found in urethra, mucus membranes, throat and eye. Hence diseases conjunctivitis, urethritis, tonsilitis

Opa (opacity) proteins aid attachment alongside pili. Also can attach to LOS of microorganisms next to them to form microcolonies of neisseria gonorrhoeae forming inside urethra . LOS another mechanism of adherence

Por proteins - form pores in cells and become intracelullar - survive inside WBC

67
Q

What evasion virulence factors do n gon have

A

Sialic acid capsule - molecular mimicry of human cells

IgA protease - break down IgA common in genitourinary system

68
Q

What attack mechanisms does n gon use

A

Formation of transferrin and lactoferrin binding receptors
Tbp1, Tbp2
Lbp1
Genitourinary system is low in iron content therefore produce surface proteins that bind to transferrin and lactoferrin (blood proteins carrying iron which n gon can extract.

69
Q

What is unusual in structure for neisseria spp in their cell wall structure

A

Normal gram neg envelope but outer leaflet of outer membrane contains lipooligosaccharide (LOS) instead of lipopolysaccharide (LPS).

70
Q

How does the LOS core polysaccharide of gonoccous and meningococcus express a variety of epitopes on cell surface

A

Via undergoing antigenic variation

71
Q

What type of pili is present on gonococcal and meningococcal spp and describe the structures (with their binding partners)

A

Type IV pili, composed of polymers of structural protein PilE. PilC is located at the tip of the pilus as is the adhesin which mediates initial attachment of bacterium of surface of mucosal epithelium.

PilC binds CD46 - a complement regulatory protein that has a co-factor activity that inactivates the complement components c3b and c4b by serum factor I

72
Q

How many groups can the Opa proteins be divided into and why of gonoccus and meningococcus

A

2 major groups based on cellular receptors they bind.

Opa HS - bind heparan sulfate and ECM molecules fibronectin and vitronectin

Opa CEA - bind carcinoembryonic antigen-related- cell-adhesion molecule (CEACAM).

73
Q

What do Opa HS and Opa CEA mediate

A

Internalisation of gonoccoci by human cells. Directly through engagment with heparan sulfate proteoglycans on cell surface or indirectly using fibronectin or vitronectin to bridge Opa HS type proteins and cell surface integrins - the actin cytoskeleton of epithelial cell signalled to rearrange for engulfment of bacterial celll.

Opa CEA with members of CEACAM receptor family trigger actin cytoskeleton rearrangement -permitting internalisation by Neutrophils, macs and other cells.

74
Q

After rearrangement of the actin cytoskeleton, what stages occur for internalisation and spread of gonococci

A

Bacteria pass through the cells via transcytosis and released at basolateral surface into the subepithelial space where infection is established. From here gonococci may spread to bloodstream and finally joints and skin

Upregulation of CEACAM1 on endothelium from LOS and inflammatory cytokines contributes to bacteria transgression into the blood

75
Q

What does innate immunity in female and male urinary tract primarily compose of

A

Antimicrobial proteins b -defensins (HBD), cathelicidin, lactoferrin and lipocalin.

76
Q

What is Tamm-Horsfall protein and what does it do

A

Tamm- Horsfall protein (THP) is an abnbdant urinary glycoprotein that binds specific mannosylated residues and blocks adhesion of certain bacterial urinary tract pathogens such as escherichia coli.

77
Q

Fill in the gaps.

The endocervix provides a protective mucus layer rich in _, _, _ and _ for the vagina

A

HBD-1
HD-5
Lysozyme
Lactoferrin

78
Q

Fill in the gaps
LOs and other components of the outer cell membrane of gonococci ( as well as IgA protease) are _ -inflammatory and induce release of _, _, _ and _ from phagocytes which induces a florid inflammatory reaction

A 
Pro
TNFa
IL-1b
IL6
IL8
79
Q

Despite local and systemic antibodies, why do they tend not to protect against re-infection

A

Extensive and rapid variation of pili, LOS and Opas

Clinical Micro (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions