HIV and STIs Flashcards
HIV Transmission
Bodily fluids: blood, breast milk, semen, vaginal fluids
Blood: needle stick, contaminated surgical equipment
Sex = biggest mode of transmission
MTCT (Mother to child transmission)
Trends of HIV epidemiology
initially lots of people dying & lots of cases then peak 1990s/early 2000s then started to drop off due to effectiveness of treatment etc. (but on a graph number of people living with hiv going up (because people are living – not dying). Number of cases decreasing (partly because viral load is decreasing due to treatment so less infectious (U=U etc.))
Scale of HIV
(How many new cases, how many total, how many deaths)
worldwide
1.5 million new infections 2021
38.4 million people living with HIV 2021
650,000 AIDS related deaths 2021
Globally where are the most cases
Eastern & Southern Africa
Western & Central Africa
Southern Asia
Stages of HIV epidemic
Nascent: <5% Prevalence in all risk groups
Concentrated: >5% prevalence in one or more risk group
Generalised >5% prevalence in general population
What does who is most likely to be infected depend on
Where you are in the world and what stage the pandemic is in that area
E.g. in areas where epidemic is nascent or concentrated –> highest prevalence is in risk groups. Whereas in areas where HIV is endemic: more of the burden is in the heterosexual community
High risk groups for HIV
Sex workers
IVDU
Migrants from endemic countries
MSM
Clients of sex workers
Transgender women
Where do HIV cases come from UK (historically and now)
Initially cases were imported.
Now roughly 50% imported & 50% home grown
What percentages of cases are in high risk groups in Europe compared to E&S Africa
Europe: 99% infections in high risk groups
Eastern & Southern Africa: 25% in high risk groups - most cases in general population
What stage of the HIV Epidemic is the UK in
Concentrated phase
What is the UK prevalence of HIV
(& rough african)
UK: 0.2%
Some African Countries: 20%
Goals of HIV testing services
- Provide a high quality service for identifying HIV
- HIV treatment
- HIV Care
- HIV Support
- Prevent Transmission (PMTCT - prevention of mother to child transmission; VMMC - voluntary medical male circumcision; PrEP; PEP
Aim to close the gap and get people on ART asap
Need to identify high risk groups e.g. TB patients
5 Cs of WHO HIV Testing Services
Consent (for testing, treatment etc. - don’t force people)
Confidentiality
Counselling (psychological trauma, often get diagnosed with multiple diseases at once e.g. TB & HIV)
Correct test results
Connection /linkage to prevention, care & treatment - no point testing if not going to treat
What is the new focus to address the HIV testing gap
Emphasis on quality, efficiency, yield & linkage
o Improving quality to prevent misdiagnosis
o Getting testing out into communities
o Supporting better linkage
o Better focus and appropriate targeting.
Common reasons for HIV misdiagnosis
Clerical/technical errors (mislabelling, poor records etc.)
User error (of tests)
Cross reactivity (antibodies from intercurrent infection, late stage AIDS etc.)
Incorrect/suboptimal testing strategy
Poor management & supervision
How to test for HIV
combination of rapid diagnostic tests (RDTs) and/or enzyme immunoassays which, when used together, achieve at least a 99% positive predictive value.
How many HIV tests to do in lower burden countries
Lower burden = <5% prevalence
3 consecutive reactive tests
How many HIV tests to do in high burden countries
High burden = >5% prevalence
2 consecutive reactive tests
How to get testing out into communities
Rapid diagnostic tests (finger prick)
Lay testers & task shifting
Self testing
Home, mobile & outreach testing (moonlight testing, schools, workplaces, religious facilities etc.)
Rapid tests in shopping centres etc.
Occupational health
Screening for pregnant women
HIV Testing: linkage to care and prevention
Don’t just test: if positive counselling & linkage to treatment
If negative: link to prevention services - condoms etc.
Who are the key populations to target for HIV testing
o Pregnant women
o Couples & partners
o Men
o Infants, children, adolescents
o TB
o Sex workers
o IVDU
o MSM
o Transgender people
How else to target key populations HIV testing
HIV partner services: couples/contacts testing & counselling
Facility based HIV testing services – entry via HIV and ART services – test for TB. And entry via TB services – test for HIV etc.
(&STI, Hepatitis, Antenatal)
How to address HIV (generally)
Regular STI testing (STIs all augment each other)
Education - condoms, awareness etc.
PrEP & PEP
Address stigma
Outreach programmes for risk groups
Should a HIV positive mother breast feed
Risk of transmission from mother to child while breast feeding.
But in many LMICs the risks of not breast feeding are really high: malnutrition, immune system etc.
Best practice: treat mother with ARTs so U=U and baby safe for breastfeeding
Can HIV be transmitted on saliva
No/very low.
Don’t need to worry about contaminated utensils etc.
Strategies for preventing HIV transmission
- PrEP
- Blood supply screening
- Condoms
- Education/behaviour modification
- Clean syringes
- Treatment/prevention of drug/alcohol abuse
- Microbicides
- STI treatment
- Medical male circumcision
- Treatment as prevention
- HIV testing/counselling
- PMTCT
Most effective –> least effective HIV prevention strategies
ART
PrEP
VMMC
STI treatment
Microbicide
HIV vaccine
Issues with condoms
Only work if used properly - before any sexual contact
Need to challenge cultural norms: “doesn’t feel as good with a condom etc.” (and can be difficult to get condoms)
Other risk factors for HIV
Sexual violence
Why does circumcision work
*By removing foreskin, circumcision reduces the ability of HIV to penetrate due to keratinization of the inner aspect of the remaining foreskin.
* The inner part of the foreskin contains many Langherhans cells, that are prime targets for HIV. Some of these are removed with the foreskin.
* Ulcers, characteristic of some STI’s that can facilitate HIV transmission, often occur on the foreskin. By removing the foreskin, the likelihood of acquiring these infections is reduced.
* The foreskin may suffer abrasions or inflammation during sex that could facilitate the passage of HIV.
How to prevent HIV transmission through IVDU/syringes
Needle & syringe programmes
Drug dependency treatment - in particular opioid substitution therapy
Close compulsory drug detention & rehab centres
Management of TB & viral hep
Clean syringes
Discourage needle sharing
How to reduce MTCT of HIV
Comprehensive antenatal HIV screening & appropriate ART
HIV retesting during 3rd trimester
Encourage breastfeeding
What are the ‘rules’ of ART
3 drugs - minimises risk of resistance
Start early
Adherence - if don’t = resistance issues & not U=U
AE & interactions
CD4 & VL response
Timely 2nd line treatment options
What makes ART delivery challenging
It is human resource driven - countries with a shortage of HCPs struggle
Price of ART can also be prohibitive
HIV & TB
1/3 of AIDS deaths were due to TB in 2018
HIV makes TB worse and vice versa & makes you more likely to get it
Higher risk of drug resistance
How to prevent comorbidity in HIV
- All chronic diseases of age are more common in HIV (especially now as living longer)
- Management of comorbidities is usually the same
- But diagnostic overshadowing: HCPs attribute all symptoms of a HIV positive patient to their HIV and don’t investigate – so other conditions are underdiagnosed and undertreated.
- Drug to drug interactions can also be an issue.
Summary Exam Q: how to mitigate the impact of HIV
(Would need to go into more detail, but main points):
- Preventing advanced disease (Robust HIV testing services)
- Preventing transmission (Multifaceted approach)
- Preventing advanced disease (ART access and delivery)
- Preventing opportunistic disease (Screening)
- Preventing co-morbidity (Integrated NCD diagnosis and management)
What STIs have recently been emerging
Mpox
Shigella sonnei (MSM)
Neisseria meningitidis
Ebola virus
Zika virus
List 13 common STIs
Chlamydia
Gonorrhoea
Syphilis
Trichomonas Vaginalis (TV)
Mycoplasma Genitalium
Chancroid
Donovanosis
HSV (cold sores)
HPV
Hep A,B,C
HIV
Why are STIs increasing
People are no longer so scared of HIV so don’t bother with condoms - because HIV treatment has been so successful
How many STIs acquired daily worldwide
> 1 million
(most asymptomatic)
What are the top 4 most common STIs
Chlamydia, Gonorrhoea, Syphilis, Trich
(all curable) (these are the only curable?)
Prevalence of genital HSV 1 infection
> 500 million people aged 15-49 globally
What % of 4 main curable STIs are in developing countries
75-85%
Relationship between STIs and HIV
Facilitiates HIV transmission
Contributes to high HIV prevalence
Impact of STIs
Huge impact on reproductive and child health
(and ultimately total physical health)
What helps drive the STI epidemic
- Poor sexual education
- Lack of access (to testing, treatment etc.)
- Poverty/social deprivation
- Migration & displacement – wars, labour, natural disasters
- Rapid urbanisation with the sociocultural changes that come with that (husband moves to city etc casual sex outside of relationship)
- Economic and political instability war
- Early sexual debut
- Multiple and concurrent partners
- Absence of visible symptoms
- Unprotected sex
- Substance misuse – leads to increased risk taking
- High prevalence of antimicrobial resistance for some pathogens (e.g. gonorrhoea superbug a few years ago)
- Lack of public awareness
- Lack of training of health workers
- Long-standing widespread stigma.
- Sex tourism.
- Religion – shame etc.
Why are adolescents/young adults particularly at risk of STIs
- more likely to have multiple sexual partners
- may have difficulty using barrier protection
- may be more likely to have higher risk partners & take higher risk behaviours
- may have less access to STI care
Reasons for low access to STI care in some young people
- Lack of awareness
- Non disclosure of sexual activity (don’t want to tell parents etc.)
- fear of being found out by parents
- Restrictive policies of clinics (needing parental accompanyment etc.)
- Lack of money to pay for care
% asymptomatic chlamydia
70% women
50% men
Asymptomatic cases help drive the epidemic
Universal risk factors for STIs
several partners
frequent partner change
unprotected sex
Consequences of poor sexual health
Poor reproductive & maternal health (infertility, PID, ectopics)
MTCT
Anogenital cancers (HPV)
Transmission of HIV
HepB
Consequences of MTCT of STIs
Eye infections (Chlamydia & gonorrhoea) can cause blindness
Sepsis
Stillbirth
Low birth weight
neonatal death
Prematurity
Congenital deformities (congenital syphilis)
How much does an untreated STI increase risk of acquiring & transmitting HIV
Up to 10 times increased risk
STI trend in UK today
Diagnosis of STIs on the increase
Highest among young people, some minority ethnic groups & MSM
Recent rise in >45s
Why has there been a rise in STIs in >45s UK
Online dating – increasing access to different pools of people
STIs such as syphilis weren’t an issue when currenet >45s were younger – so lack of knowledge/awareness – not taking preventative steps
Which vulnerable groups & why do STIs disproportionately effect
Young people
Minority ethnic groups
Those effected by poverty & social exclusion
IVDU
Sex workers & their contacts
MSM
Big role of culture/religion/stigma – young people not being able to buy condoms etc.
Primary prevention of STIs
Counselling & behavioural interventions & education
Barrier methods
Interventions targeted at high risk groups
Immunisation
(Trials ongoing for pre/post EP Abx for STIs (not HIV)
What dont condoms protect against
STIs that cause extra genital ulcers (syphilis or genital herpes) or HPV
What STIs can be immunised against
Hep A (not routine except for high risk e.g. MSM for STIs)
Hep B (MSM, Sex workers and their contacts, IVDU & contacts, people from high risk areas & their contacts (Africa, Asia, Far East, Eastern Europe)
HPV
MPox
Primary prevention of HIV
PrEP
PEP
TasP (treatment as prevention)
PMTCT
Male circumcision
Tenofovir gel
How to take PrEP
take before exposure
reduces risk of being infected if exposed
Can be taken on an event basis or daily
How to take PEP
Short course of HIV meds taken within 72 hours of possible exposure
Continued for 28 days
What is TasP
Treatment as Prevention (for HIV)
Start treatment asap after diagnosis to ensure viral load remains undetectable
U=U
How to do PMTCT
all pregnant women offered STI screening at antenatal booking. All HIV positive pregnant women are treated with HIV medication as soon as possible to ensure viral load is undetectable at the time of delivery and therefore reduce the risk of infection.
Who does male circumcision help
Reduces risk of female to male transmission (by up to 60%) and provides protection against some other STIs e.g. HSV & HPV
Does Tenofovir gel work?
when used as a vaginal microbicide, has had mixed results in terms of the ability to prevent HIV acquisition, but has shown some effectiveness against HSV-2
Purpose of secondary prevention
to identify & detect disease in its earliest stages before it becomes noticable
Secondary prevention for STIs
STI Screening
HIV testing (universal testing: sexual health clinics, antenatal clinics, GP practices where prevalence >2%, sometimes ICU/AE)
Integrating STI services into existing services (reproductive health, for new GP registrants)
National screening programmes e.g. o National Chlamydia Screening Programme
tertiary prevention of STIs
prompt and effective treatment (to cure disease, to prevent & limit complications/sequale, to prevent transmission)
Single dose regiments if possible to aid treatment compliance
What is a syndromic approach to STI treatment
When & why is it useful
Treatment based on constellation of clinical signs and symptoms – rather than actual diagnosis
Used in resource poor settings
Pragmatic: doesn’t require lab facilities, patients are treated at time of visit so not lost to follow up, all major pathogens are treated - avoiding missed treatment due to false negatives
How to prevent reinfection of STIs
o Abstinence until completion of treatment
o Identification and treatment of all sexual contacts (as far as is possible)
Aims/objectives of STI surveillance
Integral part of STI control programmes
Must be actively conducted, be purposeful and result in PH action.
AIMS:
o To obtain information on the burden of STIs in the population
o To determine and describe the demographic and geographical distribution of STIs
o To compare the situation and trends in different demographic and geographical situations
Components of STI surveillance
STI case reporting (etiologic or syndromic)
STI Prevalence assessment & monitoring (sentinel surveillance)
Specific activities (lab assessment of AMR, validation of syndromic management, required reporting e.g. resistant gonorrhoea.
Other: special surveys/studies e.g. behavioural surveillance
Examples of STI surveillance programmes UK
GRASP (gonoccocal AMR)
Enhanced Laboratory Surveilllance for Infectious Syphilis Programme
HARS: HIV and AIDS reporting system
Voluntary lab reporting
PHE reference lab - syphilis
What does HARS (HIV and AIDS Reporting System) aim to do
reduce the reporting burden for reporting sites
increase the efficiency of HIV surveillance
enhance standard HIV surveillance outputs
produce quality of care indicators
directly support commissioning services
Objectives of STI surveillance
o Estimate the STD problem’s magnitude; define needed resources, raise awareness and gather support
o Measure frequency, distribution and antimicrobial sensitivity; define and monitor procedures
o Monitor trends, reinforce political support, monitor and improve the existing programs
STI control in resource poor settings
- promotion of safe sex & primary prevention
- Condom programming (promotion, supply & distribution)
- Promotion of healthcare seeking behaviour
- integration of STI prevention & care into other programmes (primary care, antenatal etc.)
- comprehensive STI case management (syndromic approach)
- specific services for high risk populations
- prevention & care of congenital syphilis & conjunctivitis (often not thought about, mum not swabbed etc.)
- Early detection of symptomatic and asymptomatic infections
Why do STI control programmes often fail in developing countries
o Low priority for policy makers & planners for resources because perceived to result from discreditable behaviour
o Failure to recognise the magnitude of problem
o Failure to associate diseases with serious complications
o Control efforts concentrated on symptomatic patients (usually men) and failing to identify asymptomatic individuals (commonly women) until complications develop
o Lack of simple screening tests for cervical infections that could be used to screen women attending family planning, antenatal, or maternal and child health clinics
o Service delivery through specialised STI healthcare facilities which provide inadequate coverage and tend to confer stigma
o Treatment strategies focused on unrealistic requirements for definitive diagnosis rather than on practical decision making
o Ineffective low cost antibiotics continuing to be used for reasons of economy
o Little emphasis on educational and other efforts to prevent infection occurring in the first place, especially among adolescents in and out of school
o Absence of authoritative guidance on a rational, practical, and well-defined package of activities for prevention and care programmes
o Lack of attention to structural issues which impact STI transmission (poverty, literacy, conflict, repression of homosexuality and prostitution, societal attitudes to marginalised communities)
