Lecture 29 - Epidemiology of STIs Flashcards Preview

MIIM20002 - Microbes, Infections, Responses > Lecture 29 - Epidemiology of STIs > Flashcards

Flashcards in Lecture 29 - Epidemiology of STIs Deck (32):
1

What are the local clinical syndromes due to STIs?

• Genital lesions (ulcers, warts)
• Urethritis, vaginitis, cervicitis
• Proctitis (rectal infection)
• Pharyngitis (throat infection)
• Pelvic inflammatory disease (PID)

2

What are the systemic clinical syndromes due to STIs?

HIV–AIDS
• Primary HIV infection
• Immunodeficiency & complications (“opportunistic” infections & malignancies)

Syphilis
• Primary (genital ulcer “chancre”)
• 2o (skin), 3o (brain, spinal cord, blood vessels) • Congenital syphilis infection

3

What are the ways we can diagnose STIs?

• swabs
• microscopy
• culture
• antigen detection assay
• PCR

4

What is an ideal treatment for an STI?

• on the spot
• single dose
• no side effects
• cheap
• effective prevents
• efficient partner treatment

5

What is the reality of treatment that we have to face?

• asymptomatic infection
• multiple infections
• long course treatment needed
• antibiotic resistance
• latency, reactivation
• partners unknown
• no prevention

6

How do we measure the spread of infection?

Reprouctive rate - Ro

Average number of secondary cases produced by one primary case

7

What happens when Ro > 1?

Epidemic
• spread of the disease to many people

8

What happens when Ro = 1?

Endemic

9

What happens when Ro < 1?

Disease eventually disappears

10

What are the determinants of Ro?

Ro = B x c x d

B: transmissability
c: n° of contacts
d: duration of infectivity

Largely dependent on rate of different sexual partners

11

Why do we want to reduce transmission of disease?

Less people potentially infected

12

How do we reduce transmissability?

• condoms
• reduction of other STIs

13

How do we reduce duration of infectivity?

• treatment

14

How can we reduce the n° of contacts?

• core group interventions
• community-wide behavioural change

15

What are the different groups in society?

• general population
• bridging population
• core transmitters

16

How do we manage STIs in Australia?

• Public awareness
• Health services:
- GPs
- Rural
- Sexual health cilics
• Partner tracing and treatment
• Screening
• Vaccination (i.e. HPV)
• Surveillance
• Promotion of safe sex

17

Why is screening important for management of STIs?

People need to know that they are infected so that they don't spread it to others

18

Describe promotion of safe sex

• education in schools
• facilitation

19

Describe surveillance of STIs

• Diagnosis:
- State health departments etc.
• Antimicrobial resistance

20

Describe the difficulties faced in the Indigenous populations

• Higher rates of STIs
- chlamydia
- gonorrhoea
- syphilis
- Donovanosis (Klebsiella)

• Treatment obstacles
- limited care access
- difficult partner tracing

21

Compare Gonorrhoea in Indigenous populations and in Melbourne

Rural populations: gonorrhoea is penicillin sensitive

Melbourne: resistance: beta-lactamase producers

22

Describe the trends in chlamydia infection

10% increase per year in Victoria

23

Which age groups are most at risk of Chlamyia infection?

Males: 20-29
Females: 15-19

24

Describe the Chlamydia iceberg

Tip of the iceberg:
• 2500 cases that we see

Underwater:
• tests
• thousands of cases that are being missed

25

What are the control strategies of Chlamydia?

• Surveillance
• Targeted screening of high risk groups
• Education
• Increased community awareness
• Partner notification processes

26

Describe Partner notification processes

• 'Let them know'
• Trackers
- don't necessarily know who the person is
• Direct discussion with partner

27

Describe the trends in Gonococcal infections

late 1980s: noted rise in 'men who have sex with men'

• after HIV treatment, there was a complacency, and a subsequent increase in rates

28

Which groups are most affected by Gonorrhoea?

Males 20-24 yo

29

Describe the trends in Syphilis

2000-2007: increase in incidence

2007-2011: declining due to campaigns

30

Describe the trends in HIV

Late 80's: rapidly increase
80's -2000: decreased
2000's stabilised

31

Which communities are affected by HIV?

Africa: heterosexual population
Australia: men who have sex with men

32

What are the HIV control strategies in Australia??

• testing
• surveillance
• treatment
• Health promotion
- across many different groups