Transcript PRO Series - IUSTI Marrakesh 2016 :: Home

The Vaginal Microbiome &
Sexually Transmitted Infections
Jeanne Marrazzo, MD, MPH
UAB Division of Infectious Diseases
17th IUSTI World Congress,
Marrakech
May 2016
Discussion
 Does a BV-like vaginal microbiome




Act like an STI?
Predict the presence of STI/HIV?
Predispose women to acquisition of STIHIV?
Increase risk of women transmitting STI &
HIV to sex partners?
 Shedding? Inflammation?
 If so…
 Are some BV-associated bacteria more
important than others?
 Does restoring key Lactobacillus species
prevent these outcomes?
Does BV Act Like an STI?
Role of Unprotected
Sexual Activity
• Well described in prospective studies
– Condom use reduced recurrence in Peru (Sanchez
2004) and was associated with normal flora over time
(Schwebke 2005)
– Women with circumcised partners had lower BV
incidence (OR 0.60, 95% CI .38-.94) in subsequent
year (Gray, AJOB 2008)
– Circumcision effected change in penis microbiome:
less anaerobic diversity (Price 2010)
• However, sex isn’t always simple…
Why is Unprotected Sex a Risk for BV?
• May depend on exposure site: vaginal, oral,
anal sex
– Anal sex (Bukusi 2006, Cherpes 2008, Fethers 2008)
– Oral sex and new partner with history of BV in cohort
of WSW (Marrazzo 2011; Fethers/Bradshaw); women
share unique LB strains through sex (Marrazzo 2009)
• Re-exposure to partners’ microbiome (other
anatomic sites as reservoirs)
• Exposure to other ‘unfavorable factors’ in
partners’ secretions (semen) or with sex
– Alkaline pH of semen
– Vaginal lubricants (Brotman 2010; Marrazzo 2011)
Longitudinal Studies of BV &
Incident STI Risk
Figure courtesy of Rebecca Brotman
• 3620 nonpregnant women 15–44 years assessed for
Nugent score quarterly for 1 year in Birmingham,
Alabama
• Pooled logistic to estimate hazard ratios for the
comparison of trichomonal, gonococcal, and chlamydial
• infection incidence in participants by Nugent score at
prior visit. Participants censored at first visit with positive
trichomonal, gonococcal, and/or chlamydial infection
Brotman 2010
• Of 10,606 eligible visits, 37.96% were classified by BV
and 13.3% by positive detection of trichomonal,
gonococcal, and/or chlamydial infection
• Intermediate state or BV at prior visit was associated
with a 1.5–2-fold increased risk for incident trichomonal,
gonococcal, and/or chlamydial infection
Brotman 2010
• Of 10,606 eligible visits, 37.96% were classified by BV
and 13.3% by positive detection of trichomonal,
gonococcal, and/or chlamydial infection
• Intermediate state or BV at prior visit was associated
with a 1.5–2-fold increased risk for incident trichomonal,
gonococcal, and/or chlamydial infection
BV & HIV Acquisition
Atashili 2006
BV & Increased HIV Acquisition
• Loss of H2O2 (directly virucidal)
• Activation of CD4 by alkaline pH
• Upregulation of cytokines that promote local HIV
replication (TNF-alpha, IL-1 beta) & increased shedding
– HIV shedding increased with intermediate flora or BV
(Rebbapragada 2008; Coleman 2007; Sha 2005; Tanton 2011)
• Not in all prospective studies (Wang 2001; Moreira 2009)
– Successful BV treatment: decreases in IL-1 beta, IL8, RANTES & activated CD4 T-cells at endocervix,
including those expressing CCR5 and CD69
(Rebbapragada 2008)
– Kyongo 2015; Cone 2015
Model
HR
Adjusted HR*
3.62 (1.74-7.52)
3.06 (1.35-6.95)
Current visit BV
5.30 (2.21-12.74)
3.97 (1.67-9.43)
More severe BV status
7.19 (2.59-19.94)
6.98 (2.12-23.0)
Primary analysis
Pre-visit BV
Sensitivity Analyses
*Fixed covariates: age, geographic region, partner HSV-2 status,
circumcision, randomization assignment and STD;
Time-dependent covariates: pregnancy, hormonal contraception, plasma
HIV-1 RNA, unprotected sex with study partner, CD4 count, outside
partners, no. of sex acts with study partner, genital ulcer disease.
PLoS Med 2012
Log10 HIV RNA concentration in plasma and
female genital secretions compared by
vaginal flora category
Vaginal Flora
Log10 HIV
Mean ±
SD
P-Value
P-Value*
vs. normal vs. normal
vaginal
vaginal
flora
flora
Genital HIV RNA
Modest
increase:
0.2 log10
Normal vaginal flora
3.04 ± 0.99
N/A
N/A
Intermediate vaginal flora
3.25 ± 1.01
0.0035
0.058
BV
3.23 ± 0.99
0.0023
0.095
Normal vaginal flora
3.81 ± 1.00
N/A
N/A
Intermediate vaginal flora
3.96 ± 1.07
0.037
N/A
BV
3.99 ± 1.07
0.0056
N/A
Plasma HIV RNA
*After controlling for plasma HIV RNA
Cohen PloS Med 2012
Log10 HIV RNA concentration in plasma and
- Modest
in HIV shedding
unlikely
femaleincrease
genital secretions
compared
by to
account forvaginal
increased
HIV
transmission
risk
flora category
observed
Vaginal Flora
- Increases
to BV, not
Log10 HIV
P-Value
P-Value*
vs. normal are
vs. normal
Mean ± cytokines
in characteristic
due
SD
vaginal
vaginal
HIV (Mitchell 2012) flora
flora
Genital HIV RNA
- In this
cohort, 35%, 15%,
and 52%
had BVN/Aat
3.04 ± 0.99
N/A
Normal vaginal flora
enrollment,
throughout follow-up,0.0035
and at least
0.058
Intermediate vaginal flora 3.25 ± 1.01
one BV
time over 2 years 3.23 ± 0.99 0.0023
0.095
Modest
increase:
0.2 log10
Plasma HIV RNA
- Attributable
risk of abnormal
vaginal
bacteria
to
3.81 ± 1.00
N/A
Normal vaginal flora
N/A
HIV Intermediate
acquisition
risk
substantial,
even
3.96be
± 1.07
0.037
vaginal
floramay
N/A if
other
0.0056
BVSTI not common3.99 ± 1.07
N/A
*After controlling for plasma HIV RNA
Cohen PloS Med 2012
BV & Increased HIV Transmission
• Bacteria may activate Langerhans cells
and CD4+ T-cells (Donoval, 2006; deJong
2009)
• May involve direct stimulation by BVAB of
relevant immune targets in male genitalia
• BVAB / LB shared in male & female partners
(Bukusi 2011; Gray 2009; Marrazzo 2009)
• Male circumcision changes microbiota of
penis, and reduces women’s risk of
subsequent BV (Price 2010; Gray 2008; Liu 2013)
Kyongo 2015
Balkus J Infect Dis 2016
BV & STIs: Causal relationship?
Women
with BV &
at risk for
STIs
Intervention
BV
 STI
acquisition
Control
BV
STI
acquisition
®
Step 1
Step 2
Need to adequately suppress BV
Assess
BV & STI
Preventing Vaginal Infections (PVI) trial demonstrated a 35% reduction in BV over
12 months among women who received monthly period presumptive treatment
(PPT) with intravaginal metronidazole + miconazole versus placebo
McClelland et al. JID (2015)
PVI trial design & analysis population
234 women
enrolled in
PVI trial
• HIV-negative, non-pregnant women
enrolled at 4 sites between 2011-2012:
• Nairobi, Kenya (two sites)
• Mombasa, Kenya
221 consented
for future
specimen testing
111 women in
PPT arm
110 women in
placebo arm
• Birmingham, USA
• Eligible participants had a vaginal
infection detected at screening:
• Bacterial vaginosis
• Vulvovaginal candidiasis
• Trichomonas vaginalis
PVI study schedule
Screening visit
Intravaginal metronidazole 750 mg plus
miconazole 200 mg suppositories vs.
matching placebo
Screening visit two/Enrollment
(7 to 14 days after 1st screening)
M1
M2
Exam
M3
M4
Exam
----
M10
M11
Exam
End of study evaluation
Exam
• Study product dispensed at monthly treatment visits
• Women with self-reported vaginal discharge or odor received open label treatment
with oral metronidazole and fluconazole plus study product
Taking advantage of stored specimens
Genital fluid collected using Hologic/Gen-Probe Aptima kits
• Baseline exam visits for C. trachomatis and N. gonorrhoeae
• Baseline and follow-up exam visits for T. vaginalis testing at
the end of the study
• Calculated incidence of CT, GC and combined
bacterial STI outcome (CT and/or GC)
• Follow-up time censored following first incident infection
• Restricted to women STI- at enrollment
Participant characteristics at enrollment
Placebo
n=110
Age (years)
Education (years)
African or African-American race
Partnership status
Married or living with a partner
Separated, divorced or widowed
Never married
Number of live births
Ever engaged in sex in exchange
for goods/money/services
#of vaginal sex acts*
# of partners*
New partner*
Ever had anal sex
29 (23-34)
11 (8-12)
106 (96)
PPT
n=111
30 (24-34)
10 (8-13)
111 (100)
29
48
33
2
60
(26)
(44)
(30)
(1-3)
(55)
34
39
38
2
59
(31)
(35)
(34)
(1-3)
(53)
2
1
23
13
(1-4)
(1-2)
(21)
(12)
2
1
22
12
(1-3)
(1-2)
(20)
(11)
Data presented as N (%) or median (IQR); *In the past week
No differences in
baseline characteristics
by site
Median follow-up time
did not differ by arm
PPT: 11.2 months
(IQR 11.1-11.6)
Placebo: 11.4 months
(IQR: 11.2-11.7)
STIs & BV at enrollment
Intervention
8 (7%)
3 (3%)
41 (37%)
Placebo
8 (7%)
0 (0%)
40 (36%)
BV = asymptomatic BV by Nugent score (7-10)
Intervention effect on bacterial STI acquisition
N
# of Personevents years
Incidence1
(95% CI)
IRR2
(95% CI)
pvalue
Combined STI outcome
CT and/or GC, MG
177
63
135.6
46.5 (36.3, 59.5)
Intervention
84
22
67.4
32.6 (21.5, 49.6)
0.57 (0.32, 0.91)
Placebo
93
41
68.2
60.1 (44.3, 81.7)
1.00
205
21
179.6
11.7 (7.6, 17.9)
Intervention
103
7
90.0
7.8 (3.7, 16.3)
Placebo
102
14
89.6
15.6 (9.3, 26.4)
218
14
193.3
7.2 (4.3, 12.2)
Intervention
108
5
96.3
5.2 (2.2, 12.5)
0.56 (0.19, 1.67)
Placebo
110
9
96.9
9.3 (4.8, 17.8)
1.00
--
0.02
--
STIs as separate outcomes
CT
GC
1Incidence
per 100 person-years. Only includes first infection detected.
rate ratios from Poisson regression models.
2IRR=incidence
0.50 (0.20, 1.23)
1.00
--
--
0.13
-0.30
--
Effect of PPT on bacterial pathogens
Interpretation
• Randomized trial data from US/Africa
– Excellent adherence and retention
– STI testing using highly sensitive assays
– Study population
• Women with a recent vaginal infection
– Limited statistical power
• Monthly PPT may reduce bacterial STI risk
• Small sample size precluded detection of
significant associations
• Trials to assess effect of BV prevention on
STIs are necessary to definitively
determine if BV increases STI susceptibility
Do Individual BV-Associated
Bacteria Matter?
Condition
Cervicitis
Urethritis
Endometritis
Bacteria
M. indolicus
L. crispatus
Sneathia spp
References
Gorgos 2015
Sneathia spp
BVAB-1
Atopobium
vaginae
Haggerty 2016
Manhart 2013
)
Cervicitis in Women Attending an
STD Clinic: Association with
Specific BVAB
Gorgos , Sycuro (STD 2015)
Cervicitis
Associated
with friability
Gorgos , Sycuro
(STD 2015)
Conclusions
• A L. crispatus-dominant vaginal microbiome
is associated with lower prevalence and
incidence of common bacterial STI
(chlamydia, gonorrhea, trichomoniasis) &
HIV
• More research is needed on common viral
non-HIV STI
• Maintenance of this environment might
reduce the risk of acquiring these infections
and should be further studied
Acknowledgements
 Jen Balkus
 Rebecca Brotman
 Laura Sycuro