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ORIGINAL ARTICLE
BACTERIAL VAGINOSIS, ALTERATIONS
IN VAGINAL FLORA AND HIV GENITAL
SHEDDING AMONG HIV-1-INFECTED
WOMEN IN MOZAMBIQUE
Robert D Kirkcaldy1, MD, MPH
Jennifer Mika1, MPH
Lori M Newman1, MD
Judite Langa1, MD
Linhui Tian1, MD, MS
Ilesh Jani2, MD, PhD
Ron Ballard1, PhD
Lisa Nelson1, MD, MPH, MSc
Elena Folgosa3, MD, PhD
1Centers for Disease Control and Prevention, Atlanta, GA, USA
2National Institute of Health, Ministry of Health, Mozambique
3Eduardo Mondlane University, Mozambique
Objectives. We investigated whether abnormal vaginal flora, including bacterial vaginosis (BV), are associated
with detection of cervical HIV-1 RNA among HIV-infected women in Mozambique.
Methods. We obtained clinical data and vaginal specimens from HIV-infected women registering for their first visit
at one of two HIV care clinics in Mozambique. We compared women with detectable cervical HIV viral load (<=40
copies/ml) with women with undetectable cervical HIV.
Results. We enrolled 106 women. Women with abnormal vaginal flora (intermediate Nugent scores, 4 - 6) were
more likely to have detectable cervical HIV RNA than women with normal vaginal flora (adjusted odds ratio 7.2
(95% confidence interval 1.8 - 29.1), adjusted for CD4 count). Women with BV had a non-significantly higher
likelihood of detectable cervical HIV than women with normal flora.
Conclusions. Abnormal vaginal flora were significantly associated with cervical HIV expression. Further research
is needed to confirm this relationship.
HIV genital shedding enhances HIV transmission to sexual partners.1 We investigated whether abnormal
vaginal flora, including bacterial vaginosis (BV), are associated with cervical HIV-1 RNA expression among
HIV-infected women in Mozambique.
METHODS
Women were enrolled from October 2007 to March 2008 as part of an evaluation of reproductive tract infections
among HIV-infected individuals registering for a first visit at one of two HIV care clinics in Mozambique: Xai Xai
Provincial Hospital and Mavalane General Hospital.2
We collected demographic and clinical data, and plasma and vaginal specimens. Cervical lavage specimens
were obtained by application of 10 ml of sterile saline to the cervix and collection from the posterior fornix
after 3 minutes. Diagnosis of BV was based on Nugent’s criteria. Diagnoses of Trichomonas vaginalis, Chlamydia
trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium were done by real-time multiplex polymerase
chain reaction testing. HIV RNA levels were determined by nucleic acid sequence-based amplification assay,
with a lower limit of detection of 40 copies/ml. Patients were treated according to the 2006 Mozambique Ministry
of Health treatment guidelines and offered partner notification cards. The evaluation protocol, consent form
and questionnaires were approved by Mozambique’s National Health Bioethics Committee and the CDC
Institutional Review Board.
Data were analysed using SAS version 9.2 (SAS Institute, Cary, NC). Nugent scores were categorised
as normal (0 - 3), intermediate vaginal flora (4 - 6) and BV (7 - 10). Cervical HIV RNA was dichotomised as
detectable (>=40 copies/ml) or undetectable. Women with detectable cervical HIV were compared with women
without detectable cervical HIV by the chi-square or Fisher’s exact test for categorical variables, and the
t-test for continuous variables. We used multivariable logistic regression models to test whether abnormal
vaginal flora (intermediate vaginal flora or BV) were associated with detectable cervical HIV RNA. Plasma
viral load, CD4 count, trichomoniasis and age were considered for inclusion; variables were excluded if they
were not significant (p>=0.05) or disrupted the model’s goodness of fit (e.g. CD4 count was included in the final
model and plasma viral load was not). Missing data were excluded from the analyses.
RESULTS
Of 258 women enrolled in the larger study, 106 agreed to have cervical lavage specimens collected; there were
no significant differences between women who agreed and did not agree to cervical lavage. The mean age of
the 106 participating women was 33 years and most of them were from Xai Xai (Table I). None of the women
was receiving antiretroviral therapy.
Lower CD4 counts (p=0.01) and abnormal vaginal
flora (p=0.04) were associated with cervical HIV RNA
detection (Table I). In multivariable logistic regression modelling, women with intermediate vaginal flora had
higher odds of detectable cervical HIV RNA than women with normal vaginal flora (adjusted odds ratio (aOR)
7.2 (95% confidence interval (CI) 1.8 - 29.1), adjusted for CD4 count). Women with BV had non-significantly
higher odds of detectable cervical HIV RNA compared with women with normal vaginal flora (aOR 2.7 (95% CI
0.8 - 8.7), adjusted for CD4 count). Mean Nugent scores of women with detectable cervical HIV were comparable
to those of women without detectable cervical HIV (5.7 v. 5.3, p=0.64).
Compared with women with plasma viral loads of >=100 000 copies/ml, women with plasma viral loads of
<10 000 copies/ml more often had abnormal vaginal flora (58% v. 21%, p=0.049). On stratified analysis,
there was a non-significant trend towards higher plasma viral load and cervical HIV RNA detection among women
with normal Nugent’s scores or BV, yet there was no association between plasma viral load and cervical HIV
among women with intermediate vaginal flora.
CONCLUSIONS
We found positive associations between intermediate vaginal flora and BV and detection of cervical HIV
RNA among HIV-infected women in Mozambique, suggesting that abnormal vaginal flora might enhance
HIV genital viral shedding. Previously published work demonstrated associations between the presence of BV
and detection of cervical HIV RNA,3
,
4
possibly because of immune activation.5
It was surprising that although intermediate vaginal flora were significantly associated
with genital HIV expression, BV was not. It is possible that intermediate vaginal flora are more conducive to HIV
viral shedding than BV, yet the explanatory mechanism is unclear. It is also possible that our study lacked
adequate power to detect a significant association between BV and detectable cervical HIV due to a small
sample size: this may be reflected in the wide confidence intervals. Limitations include that we did not control for
menstrual cycle timing, contraceptive use, possible semen contamination of cervical specimens and herpes
simplex viral infection, and cold-chain interruptions may have occurred. We did not find a clear overall
association between plasma HIV viral load and cervical HIV expression, although the association may have
been confounded by the presence of abnormal vaginal flora. Despite these limitations, these data suggest
that abnormal vaginal flora might enhance HIV genital shedding and thus potentially enhance HIV transmission
to sexual partners. Further research is needed to confirm this association.
REFERENCES
1. Chakraborty H, Sen PK, Helms RW, et al. Viral burden in genital secretions
determines male-to-female sexual transmission of HIV-1: a probabilistic empiric
model. AIDS 2001;15:621-627.
1. Chakraborty H, Sen PK, Helms RW, et al. Viral burden in genital secretions
determines male-to-female sexual transmission of HIV-1: a probabilistic empiric
model. AIDS 2001;15:621-627.
2. Langa J, Gaspar F, Folgosa E, et al. Integration of sexually transmitted infection (STI)
management into HIV outpatient clinics in Mozambique, 2008 [O8.5.5]. Presented
at the 11th World Congress of the International Union against Sexually Transmitted
Infections, 11 November 2009, Cape Town.
2. Langa J, Gaspar F, Folgosa E, et al. Integration of sexually transmitted infection (STI)
management into HIV outpatient clinics in Mozambique, 2008 [O8.5.5]. Presented
at the 11th World Congress of the International Union against Sexually Transmitted
Infections, 11 November 2009, Cape Town.
3. Cu-Uvin S, Hogan JW, Caliendo AM, et al. Association between bacterial vaginosis
and expression of human immunodeficiency virus type 1 RNA in the female genital
tract. Clin Infect Dis 2001;33:894-896.
3. Cu-Uvin S, Hogan JW, Caliendo AM, et al. Association between bacterial vaginosis
and expression of human immunodeficiency virus type 1 RNA in the female genital
tract. Clin Infect Dis 2001;33:894-896.
4. Sha BE, Zariffard MR, Want QJ, et al. Female genital-tract HIV load correlates
inversely with Lactobacillus species but positively with bacterial vaginosis and
Mycoplasma hominis. J Infect Dis 2005;191:25-32.
4. Sha BE, Zariffard MR, Want QJ, et al. Female genital-tract HIV load correlates
inversely with Lactobacillus species but positively with bacterial vaginosis and
Mycoplasma hominis. J Infect Dis 2005;191:25-32.
5. Rebbapragada A, Howe K, Wachihi C, et al. Bacterial vaginosis in HIV-infected
women induces reversible alterations in the cervical immune environment. J AIDS
2008;49:520-522.
5. Rebbapragada A, Howe K, Wachihi C, et al. Bacterial vaginosis in HIV-infected
women induces reversible alterations in the cervical immune environment. J AIDS
2008;49:520-522.
This analysis has not been presented at scientific conferences or published elsewhere. External funding was not used to support this work.
TABLE I. CHARACTERISTICS OF ENROLLED WOMEN AND ASSOCIATION WITH DETECTION OF CERVICAL HIV RNA
Detection of cervical HIV RNA
N
Yes (N(%))
No (N(%))
p
Total
106
75 (71)
31 (29)
--
Study site (N=106)
Xai Xai
70
48 (69)
22 (31)
0.49
Maputo
36
27 (75)
9 (25)
Education (N=84)
No education
2
1 (50)
1 (50)
0.51
Primary
66
45 (68)
21 (32)
Secondary or mid-level
16
10 (63)
6 (37)
Marital status(N=81)
Single
38
24 (63)
14 (67)
0.93
Unmarried, in relationship
32
22 (69)
10 (31)
Married
2
1 (50)
1 (50)
Widowed
9
6 (67)
3 (33)
Prior antiretroviral therapy(N=84)
Yes
1
0 (0)
1 (100)
0.15
No
83
56 (67)
27 (33)
CD4 count (cells/µl)(N=106)
<50
14
12 (86)
2 (14)
0.01
50 - 199
31
25 (81)
6 (19)
200 - 349
26
21 (81)
5 (19)
>= 350
35
17 (49)
18 (51)
HIV-1 plasma viral load (copies/ml)(N=76)
<10 000
12
5 (42)
7 (58)
0.006
10 000 - 99 999
31
24 (77)
7 (23)
>=100 000
33
24 (73)
9 (27)
Abnormal vaginal flora categories* (N=106)
Bacterial vaginosis
47
32 (68)
15 (32)
0.04
Intermediate vagina flora
34
29 (85)
5 (15)
Normal vaginal flora
25
14 (56)
11 (44)
Mycoplasma genitalium† (N=103)
Positive
14
9 (64)
5 (36)
0.62
Negative
89
63 (71)
26 (29)
Trichomonas vaginalis† (N=103)
Positive
54
41 (76)
13 (24)
0.16
Negative
49
31 (63)
18 (37)
Chlamydia trachomatis† (N=103)
Positive
1
1 (100)
0 (0)
0.51
Negative
102
71 (70)
31 (30)
Neisseria gonorrhoeae† (N=103)
Positive
1
1 (100)
0 (0)
0.51
Negative
102
71 (70)
31 (30)
*
Diagnosed by Nugent’s criteria (normal 0 - 3, intermediate 4 - 6, bacterial vaginosis 7 - 10).
†
Diagnosed by polymerase chain reaction of vaginal specimens.