This document discusses strategies for the prevention of sexually transmitted infections (STIs) including HIV. It covers biomedical interventions like pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), microbicides, voluntary medical male circumcision, and vaccines. It also discusses behavioral interventions like condom promotion and proper condom and lubricant use, as well as structural interventions like STI clinical services, health education, and integrating HIV/STI services. The document emphasizes that a comprehensive prevention approach combining biomedical, behavioral and structural interventions is most effective.

1. Dr Jayadarie Ranatunga
Consultant Venereologist
Teaching Hospital
Ragama

2. Introduction
 An essential part of STI care is prevention
 Actions intended for prevention of transmission,
acquisition or complications of STI/HIV
 HIV and STI are considered together since they share
many aspects including modes of transmission,
behavioural and other cofactors and potential control
measures
 The well established fact that STIs enhance the
transmission of HIV permits us to consider them
together when prevention interventions are
considered

3. STI/HIV control strategy
A comprehensive STI control strategy includes
 Targeted community-based interventions
 Promotion and provision of the means of prevention
 Effective clinical services
Within an enabling environment, as well as reliable
data to guide the response.

4. STI/HIV prevention programmes
 With the emergence of the HIV epidemic, STI control
efforts were defined in relation to HIV programme
priorities.
 The separation of HIV for funding and implementation
has led to neglected STI control efforts in many countries
leading to increasing HIV trends
 In Sri lanka, we have an integrated HIV/STI services in
stand alone clinics, with specialists in many, which has
contributed to keep the HIV prevalence at a low level over
the years.

5. Evolution of prevention of STI
 Before HIV, the main focus was on treating
STIs
After HIV, initially limited to education
Later it was recognized that social & behavioral
science-based interventions were more effective
A comprehensive approach, sustained over
time and tailored to local needs, is necessary.

6. Prevention of STI including HIV
The interventions should be a combination of
 Biomedical,
 Behavioral
 Structural interventions at
Individual ,group and community-level

8. Behaviour change programmes
 Sexual health promotion is the desired outcome .
1. Promote safer sexual behaviours( abstinence or delaying,
reducing the number of partners,reducing the number of
concurrent partners, consistent condom use)
2. Reaching high risk subpopulations by out reach and peer
education
3. Increasing knowledge on STI/HIV and to promote health
seeking behaviour
4. Increase the knowledge on available services
Advocacy for hierarchy on the burden, cost effectiveness
, legal and ethical issues is necessary

9. Behavioural interventions for
prevention of STI/HIV
 Behavioral Interventions – Levels
1. Individual-level approaches – one client at a time
2. Group-level approaches – small groups of people
with similar life experiences & circumstances
3. Community-level approaches – broadly reaching
persons with similar life experiences & circumstances

10. Individual interventions
 Aims at changing individual level modifiable factors
1. Increased infectivity or increased susceptibility
2. Intervention may be biological or behavioral

11. Group level interventions
 Most evaluated type of intervention
 Because GLIs work with a group – typically 6-12
people/group –Have been shown to be effective in many
risk groups
 The group members need to have enough in common for
the intervention to be relevant . Eg
1. Youth
2. Men who have sex with men (MSM)
3. Injecting drug users (IDUs)
4. PLHIV

12. Community level interventions
 The reach is very extensive
 Goals
1. Changing community norms,
2. Reaching those that do not come into services
/clinics for care,
3. Empower community members

13. Broader community level
interventions
 Mass media campaigns
 Social marketing
 Community mobilization

14. Structural interventions
They are designed as a broader effort to end social inequality or to
promote social change.
 Community mobilisation
 Integration of HIV services with STI and reproductive health
services or more broader sexual health services
 Changing of laws and policies
 Economic and educational interventions
it is well understood that structural interventions are
difficult to implement but long lasting than individual
interventions

15. Individual vs structural
 Individual-focused approaches assume that the
relationship between individuals and society is one in
which individuals have considerable autonomy to
make and act on their choices,
 Structural approaches view individual agency as
constrained or shaped by social structures.

16. Biomedical interventions
 PrEP
 Post-exposure prophylaxis
 Treatment as prevention
 Suppressive therapy for HSV
 Diagnosis and treatment of sexually transmitted infections
 Prevention of mother-to-child transmission of HIV
 Contraception to prevent unplanned pregnancy among women
with HIV
 Voluntary medical male circumcision
 Blood safety
 Injection safety
 Microbicides
 Male and female condoms and other barrier methods

17. Pre exposure prophylaxis (PrEP)
 Is an HIV prevention intervention whereby an HIV-
negative individual takes antiretroviral medications
(ARVs) regularly in order to reduce their risk of
contracting HIV.
 An example medication for PrEP is Truvada, an ARV
containing tenofovir disoproxil fumarate and
emtricitabine (TDF/FTC).
 Truvada was approved as PrEP by the United States
Food and Drug Administration (USFDA) in 2012.
 Clinical trials have shown that PrEP reduced risk of
HIV acquisition by 44% to 80%.

18. Effectiveness (%)
Study
-130 -60 -40 -20 0 20 40 60 80 100
Effect size (CI)
MTN003/VOICE – daily Tenofovir gel
(Women – South Africa, Uganda, Zimbabwe)
15% (-21; 40)
CAPRISA 004 – coital Tenofovir gel
(Women – South Africa)
39% (6; 60)
FEMPrEP – daily Truvada
(Women – Kenya, South Africa, Tanzania)
6% (-52; 41)
MTN003/VOICE – daily Truvada
(Women – South Africa, Uganda, Zimbabwe)
-4% (-49; 27)
MTN003/VOICE – daily Viread
(Women - South Africa, Uganda, Zimbabwe)
-49% (-129; 3)
iPrEx – daily Truvada
(MSM - America’s, Thailand, South Africa)
44% (15; 63)
TDF2 – daily Truvada
(Heterosexuals men and women- Botswana)
62% (22; 84)
Partners PrEP – daily Truvada
(Discordant couples – Kenya, Uganda)
75% (55; 87)
Partners PrEP – daily oral Tenofovir
(Discordant couples – Kenya, Uganda)
67% (44; 81)
OralPrEPTopicalPrEP
IPERGAY – on demand Truvada
(MSM – France & Canada)
86% (39; 99)
PROUD – daily oral Truvada
(MSM – United Kingdom)
86% (62; 96)
Overall evidence for PrEP- 2015
FACTS 001– coital Tenofovir gel
(Women – South Africa)
0% (-40, 30)

19. PrEP Summary
 Effective
 FDA approved
 Well-tolerated
Considerations
 Only short term evidence is available
 Daily adherence required
 Side effects
 Drug resistance in acute infection
 Non adherence to safe sex
 Cost
 Logistics
CDC: http://www.cdc.gov/hiv/pdf/prepguidelines2014.pdf

21. Post- exposure prophylaxis (PEP)
 Post-exposure prophylaxis (PEP) is a biomedical HIV prevention
intervention .
 individual who is HIV-negative takes ARVs following a potential
exposure to HIV.
 PEP involves taking ARVs immediately following exposure – usually
within 72 hours – and continues for 28 days.
 PEP does not reduce risk of HIV acquisition to zero, but is highly
effective.
PEP has been used to reduce transmission following
1. Occupational exposures (needle sticks, scalpel cuts, etc)
2. Sexual exposures (sex without a condom, condom failure, sexual
assault, etc) PEPSE
3. Percutaneous exposure from injection drug use
4. Neonates exposed to HIV through breast milk or during birth

22. A comprehensive approach to PEP
 Integration into a comprehensive prevention program
 Prevention, care and support services
 Adherence counseling and support
 Risk-reduction counseling
 Psychological counseling and trauma support
 Mental health and addiction services
 Advocacy to improve access
22

23. nPEP
Non-occupational Post-exposure Prophylaxis
 High risk exposure
 As soon as possible
 Given for 28 days
 Tenofovir/emtricitabine + LPV/r / raltegravir
www.hivguidelines.org

24. Hepatitis B PEP
 Most health-care workers vaccinated against hepatitis
B
 Hepatitis B PEP: immunization + HBIG (hepatitis B
Immune Globulin)
 HBIG effective up to one week following exposure

25. Male
condoms
and
compatible
lubricants

26. Condoms and compatible
lubricants
 Male condoms are sheaths of latex or another material
used during anal, vaginal, or oral sexual intercourse.
 Condoms create a physical barrier between the
genitals and sexual fluids of the partners engaging in
sexual intercourse.

27. Male condom
Although male condoms are having a >95%
effectiveness
 Is not accepted by some populations and
 It is used only with selected partners.
 As opposed to contraception use, which varies with the
cycle, protection against infection requires consistent
use
 Immediate availability is a limiting factor.

28. Lubricants
Lubricants
 Promoting condom use must be accompanied by
emphasis on the use of appropriate lubricants.
 This is especially important for anal intercourse
because the anus does not produce its own lubrication.
 Gay men and other MSM should be educated on the
benefits of and need to use condom-compatible
lubricants to ensure that condoms do not break.
Many report difficulty in accessing lubricants

29. Female
condom

30. Female condom
 Use of male condoms depends on the willingness of
men to use them.
 The female condom provides a physical barrier that
prevents exposure to genital secretions

31. Female condom
Barriers for use
 Some clinical trials have shown , increased rates of
semen exposure (detected by postcoital prostate-
specific antigen test)
 Self-reported mechanical difficulties when compared
with the male condom ,
which suggests lower effectiveness of female
condoms for prevention of transmission.

32. Cervical caps and diaphragms
 Cervical caps and diaphragms with topical
microbicide combination could be more effective.

33. Limitations for using condoms
why sex without a condom?
Reasons for not using condoms are many and varied.
Some reasons include:
 Discomfort
 Inconvenience
 Reduced sexual sensation
 Reduced intimacy with their partner
 Inability to discuss condom use
 Allergy to latex
 Inability to maintain an erection

34. Voluntary male medical
circumcision
 There is strong evidence (53% for general populations
and 69% for high-risk populations) that male
circumcision protects against HIV and several other
STIs
 The considerations are adverse effects, low uptake,
risk of surgery, reduced efficacy due to early return to
sex after surgery, disinhibition, and ethical issues.

35. MICROBICIDES
FOR STI
PREVENTION

36. Microbicides for prevention of
STI/HIV
 Microbicides are compounds that can be applied
inside the vagina or rectum to protect against sexually
transmitted infections (STIs) including HIV.
 They can be formulated as gels, creams, films, or
suppositories.
 Microbicides may or may not have spermicidal activity
(contraceptive effect).

37. Multi purpose prevention technologies
(MPT)
 MPTs are designed to prevent HIV other STIs and in
some cases unintended pregnancies
CONRAD study- A ring that contains tenofovir
(TFV), an antiretroviral that has the potential to
prevent HIV replication in susceptible cells and
protect against HSV-2 (herpes) infection, plus
levonorgestrel (LNG), an established hormonal
contraceptive.
 GRFT CG- intravaginal ring, for HIV, HSV,HPV
 PPC cm- gel- HIV, HSV, HPV and pregnancy

38. Tenofovir 1% gel
 The CAPRISA 004 trial assessed effectiveness and safety of a 1% vaginal
gel formulation of tenofovir, a nucleotide reverse transcriptase
inhibitor, for the prevention of HIV acquisition in women.
 It has shown some benefit on HSV prevention also
 HIV incidence was 54% lower (p=0.025) in the tenofovir gel arm.
 Tenofovir gel reduced HIV acquisition by an estimated 39%
overall, and by 54% in women with high gel adherence.

39. Tenofovir 1% gel
 No increase in the overall adverse event rates was
observed including renal.
 There were no changes in viral load and no tenofovir
resistance in HIV seroconvertors.
Introduction needs addressing availability
acceptability and other necessary structural
interventions

40. Recent studies on microbicides
 ASPIRE STUDY (MTN-020) showed that a vaginal
ring releasing the experimental antiretroviral drug
dapivirine provided a modest level (61%) of
protection with consistent use against HIV infection
in women.
 The RING STUDY also tested the dapivirine ring for
safety and efficacy in women. The Ring Study
investigators found an overall effectiveness of 31 %.

41. Overall, microbicides provide moderate
degree of protection but need structural
interventions for uninterrupted supply

42. Provision of STI care

43. Main components in an ideal STI
service
 Clinical services
 Laboratory services
 Partner management services
 Health promotion and education

44. Clinical services
 Activities are designed and delivered to reduce the duration
of infectivity
 Specific protocols to deliver care and referral services
 Biomedical interventions to reduce the efficiency of
transmission
 Individual counselling (provision of condoms and risk
reduction) to reduce transmission and acquisition
 On site laboratory – microscopy, PCR, HIV testing
 Partner services
 Timely reporting

45. R0 = (βCD)
reproductive rate of infection in the community
 Duration of Infectiousness= D
Curative treatment shortens duration of D
 Probability of transmission per sexual act= β
Suppressive antiviral therapy reduces transmisssion= β
 Average number of sexual partnerships between an
infected and susceptible individuals= c
All reduces the R0
Biomedical interventions on index patients is
secondary prevention at individual level but
primary prevention at population level

46. Treating STIs in resource limited
high prevalent settings
 People with STIs should be offered syndromic
management in resource limited settings
 Periodic testing for asymptomatic urethral and rectal N.
gonorrhoeae and C. trachomatis infections using nucleic
acid amplification tests (NAATs) and Periodic serological
testing for asymptomatic syphilis infection for high risk
populations is strongly recommended.
 periodic presumptive treatment (PPT) when testing is
limited

47. Challenges with viral STIs
Bacterial STIs are curable
 Viral STIs are treatable – but not curable so, in
addition to medical treatments – prevention of viral STIs
involves behavior change and suppressive therapy for
HSV
Some viral STIs are vaccine-preventable – these vaccines
are both highly effective & safe.
Hepatitis A & Hepatitis B (HAV & HBV) , Human
Papilloma Virus (HPV)

48. Prevention with positives
 Treatment for prevention is adopted by many
countries ( treat ALL) including Sri Lanka

49. Prevention with positives
 Several sexual risk reduction interventions for persons
living with HIV have been developed .
 Behavior change for HIV risk reduction is difficult, in
part because behaviors that result in HIV transmission
are deeply ingrained and highly pleasurable.
 Clients must have the right information in order to
change HIV risk behaviors,
 Knowledge alone is insufficient to produce lasting
behavior change.

50. Risk reduction strategies
 Strategic/sero positioning – insertive partner is at a
low risk of acquisition than the receptive partner.
 Overall, oral sex poses very little risk for transmission
of HIV. but , other STIs may easily be spread through
this route.
 Viral load measurements- lower viral loads report
reduced rates of transmission
 Sero sorting – HIV positive partners finding people
with same sero- status

52. Vaacine to
prevent
HPV
infection

53. Vaccines to prevent HPV infections
 Three vaccines are approved by the FDA to prevent HPV
infection Gardasil, Gardasil 9, andCervarix.
 All three vaccines prevent infections with HPV types 16 and
18, two high-risk HPVs that cause cervical cancers
 Gardasil which is a quadrivalent vaccine also prevents
infection with HPV types 6 and 11, which cause 90 percent
of genital warts.
 Gardasil 9 prevents infection with the same four HPV types
plus five additional high-risk HPV types (31, 33, 45, 52, and
58) and is therefore called a 9-valent, vaccine.
 All three vaccines are given through a series of three
injections over a 6-month period.

54. Hepatitis B vaccine
 Standard This inactivated vaccine is administered as
follows: day 0; 1 month; 6 months.
 A rapid schedule of day 0, 1 month and 2 months with an
additional dose at 12 months
 The ultra rapid schedule - The ultra-rapid 0, 1, 3 week
regimen offers the advantage of a higher completion rates
and more rapid development of early immunity. Test for
response (anti-HBs >10 IU/l, ideally >100 IU/l) 4–12 weeks
after the last dose (1A).

55. A
vaccine
for HIV

56. Why do we need a vaccine for HIV
?
 Today, more people living with HIV than ever before
have access to antiretroviral therapy (ART), which
reduces the transmission.
 In addition, others who are at high risk for HIV
infection have access to pre exposure prophylaxis,
 Still more than 2 million people worldwide became
newly infected with HIV in 2015.
So, a powerful tool is needed

57. Vaccine trials
 The phase III VaxGen's AIDSVAXgp120 trial moved forward with
industry support.
 Unfortunately, two phase III gp120 vaccine trials in men who
have sex with men in the North America (VAX004) and injection
drug users in Thailand (VAX003) failed to demonstrate
protection .
 Disappointing results of VaxGen trial made HIV researchers to
turn from B-cell targeted vaccines designed to induce
neutralizing antibodies to T-cell targeted approach.
 The cytotoxic T lymphocyte (CTL) vaccine approach is to
develop a vaccine designed to lower viral set point and delay
disease progression, rather than to prevent initial infection

58. RV 144 trial
 Is a combination of AIDSVAX B/E gp 120 CD4+ T cell
stimulating ALVAC-HIV/AIDSVAX B/E
 Although it showed some efficacy in the beginning
(60%), it waned over time to 31.2%.
Clin Exp Vaccine Res. 2016 Jan; 5(1): 6–11.
Published online 2016 Jan 27. doi: 10.7774/cevr.2016.5.1.6

59. HVTN 071
 Is to start enrolling participants at the end of 2016
 Conducted in South Africa

60. Gene therapy for HIV
 HAART has transformed HIV infection in to a
chronic disease with the necessity of life long
treatment.
 Cost , toxicities , drug interactions and
resistance are well-known limitations of
prolonged HIV medication.

61. HIV CURE
 The first proof of concept that HIV infection could be
cured was the Berlin patient.
 By blocking infection of target cells, gene therapy may
allow viral clearance from carriers or prevention of
infection in newly exposed individuals.
 Advances in the field of gene-targeting strategies, T-
cell-based approaches and human stem cells are
upcoming in the field.
 A series of ongoing and planned trials are testing gene
therapy as HIV cure.

62. Gene therapy for HIV
 Developing treatment strategies that target viral reservoirs
and generate HIV resistance in a patient's own cells is
being experimented
 It is well known that Individuals homozygous for a deletion
in the CCR5 gene (CCR5Δ32) are largely resistant to
infection from R5-tropic HIV-1 strains, which are most
commonly transmitted.
 Several clinical trials evaluating the safety and efficacy of
CCR5 disruption are underway including NCT01252641,
NCT01044654 and NCT02500849.
Ultimate goal is to eliminate viral reservoirs and to end
the need for life long therapy

63. Future directions
 Programme collaboration and service integration
 Mathematical modelling
 Cost effectiveness analysis
 Structural interventions
 Network analysis
 Using web based technologies
 Biomedical interventions

64. References
 WHO Global Health Sector Strategies for HIV,
viral hepatitis, STIs, 2016-2021
 www.cochrane.org/.../STI_topical-microbicides-for-
prevention-of-sexually-transmitted infections Jun 13,
2016
 https://www.niaid.nih.gov/diseases
conditions/hivaids
 CDC treatment guidelines on sexually transmitted
diseases 2015

65.  THANK YOU