DNA nucleotides Blast in NCBI and Phylogeny using MEGA Xi.pptx
Condoms & Microbicides
1. LOGO
Condoms And Microbicides
Presented by
Dr Fredrick Stephen (P.G in Community Medicine)
2. Introduction
•The term condom first appears in the early 18th century
•Dr Condum recommended one for King Charles II
•The first rubber condom was produced in 1855
•Condoms have been used for at least 400 years
•Since 19th century - one of the most popular methods of
contraception in the world
4. Types
• Synthetic condoms - AT-10 resin and polyisoprene.
• Natural Latex condoms- They can be stretched in excess of 800%
before it is broken.
• Spermicidal condoms – Manufactured by lubricating condoms
with a small amount of nonoxynol-9, which is a spermicidal chemical.
• Lambskin condoms – Produce more body warmth and tactile
sensation than any other condoms.
5. Effectiveness of Condoms
• In longitudinal studies among heterosexuals condoms have
shown to decrease the decrease the risk of HIV by 80-97%*
• Sero-conversions in discordant couples who used condoms
Consistently = 0% per person-year (n=124)
Inconsistently = 4.8% per person-year (n=121)**
* - Weller S & Davis K, The Cochrane Library 2004
** - N Engl J De Vincenzi Med 1994
6. Merits
• Simple , safe and Cheap
• No side effects
• Protects against STD’s
• Easily usable
• Available without prescription
• Easily Disposable
8. Merits
• Controlled by women
• Prevents both pregnancy & STD’s
• As effective as male condoms in preventing STIs
• No apparent side effects
• Generally used to complement male condoms
• No allergy/ contraindications
• Data support impermeability to HIV
9. Demerits
• Are several times more expensive than male condoms
• Issues related to reuse are not totally defined
• Ignorance due to poor promotional drive
• Hesitancy – for insertion
• Yet to gain universal acceptability
11. Rationale for Diaphragm
• Female initiated and controlled
• Worn inside the vagina- unobtrusive
• Creates a physical barrier over the cervix site believed
to be most vulnerable to HIV
• If effective, could be combined with an effective
Microbicide
12. Demerits
• Failure rate is 10 to 20 per 100 women years of
exposure (HWYE)
• Insertion should be demonstrated by medical practitioner
• Contra indications- Prolapse, cystocele, Too long/ short
cervix
• If left for long time may lead to TSS
14. Demerits of Condoms
• Consistent condom use is difficult to achieve
• Even those who use condoms with “outside” partners, may be
unwilling or unable to use them with a primary partner
• In cultures where childbearing is linked to a person’s self
worth, the prospect of childlessness often outweighs the risk
of HIV infection
• Prevention burnout
• Violence within relationship makes it difficult for people to
negotiate condom use
16. Microbicides
• A microbicide is any substance that can substantially reduce
transmission of sexually transmitted infections (STIs) when
applied in the vagina or the rectum
• A microbicide could be produced in many forms- Gels,
creams, films, suppository, sponge, vaginal ring or vaginal
wipe
17. Advantages
• Could be used frequently without irritation
• Some Would prevent pregnancy
• Will be available over the counter
• Are likely to be inexpensive
• Will be effective against more than one STI
• Could be used without the partner’s cooperation, or even awareness
• Development of microbicides in liquid form
mouth rinse for protection during oral sex
potentially low-cost way of reducing perinatal transmission via vaginal
washing prior to delivery
18. Microbicides benefits to HIV+ women
• Help protect against re-infection with other HIV strains
• Help them protect their partners -- bi-directional effect
• Help protect against other STDs, chlamydia and bladder
infections
• May help them get pregnant safely and increase their
chances of having HIV negative babies
19. Action of microbicides
1. Preventing HIV and other pathogens from reaching the
target cells by creating a physical barrier.
2. Maintaining an acidic vaginal pH which enhances the
natural defense mechanism
3. Killing or disabling pathogens by disruption of the
protective outer cover
4. Preventing virus replication after it enters the cell.
20. Microbicide Clinical Trials
• Pre-clinical: This includes laboratory and in-vivo animal studies
• Phase I -- a few volunteers (usually 10-50) use product to see
how they react to it
• Phase II -- a slightly larger number (50-200) use the product to
see if it is safe for most women to use
• Phase 1/2 trials - Either a combination of Phase I and II designs,
or designed for Phase I to merge with Phase II
21. Phase III -- a large number (500-5,000) are enrolled to
confirm its effectiveness against HIV and other STIs &
monitoring of side effects
Acceptability studies: To determine acceptability of the
microbicide in partners of the women using the candidate
microbicide.
22. Method of Protection Product Examples
Kills or immobilizes the pathogen Non-oxynol-9 (N-9)
Savvy
Sodium Docecyl Sulfate
(SDS)
Creates a barrier between the
pathogen and the cell wall
PRO 2000
Carageenan
“Invisible Condom”
Prevent infection from taking hold
once the virus enters the body
Tenofovir
Nevirapine
Boost vaginal defense system BufferGel
LB Suppositories
Plantibodies
23. Field challenges
• No validated surrogate endpoints exist, primary endpoint is HIV infection
• Thousands of high risk women required for trials
• Efficacy trials must measure the incremental effect of the potential
microbicide over and above known effective methods-condom use and
HIV treatment
• If efficacy is less than condoms, it may be hard to show
• Placebo gel may be protective through lubricating effects
• Adherence of participants may be difficult to measure
24. Microbicide trials in India
•No phase III trials in India because of less than expected HIV incidence
to conduct such research
•Phase 1 trials of Buffer gel and PRO 2005 have been completed in Pune
•Tenofovir gel and Praneem Polyherbal vaginal tablets have completed
Phase II trials.
•Cellulose Sulfate - the Phase III study had to be stopped in 2007
because more participants using the gel were becoming infected than
those in the placebo group.
•Similar experience was reported in studies pertaining to Carraguard gel
conducted in other country sites
25. Future of Microbicides
• Vital to raise awareness about the potential availability of a device such
as a microbicide against HIV/AIDS in the community.
• Involvement of Non-Governmental Organizations and community
stakeholders along with political commitment is required to prioritize
microbicide research
• Phase III trials should be conducted with due attention to ethical
concerns given the lesson learnt from Carraguard and Cellulose Sulfate
trials.
• Public health professionals to play a major role by sensitizing the
community about microbicides and creating motivation to participate in
clinical trials