Maternal Valacyclovir and Infant Cytomegalovirus
Acquisition: A Randomized Controlled Trial among HIV-
Alison C. Roxby1*, Claire Atkinson7, Kristjana A´sbjo ¨rnsdo ´ttir2, Carey Farquhar1,2,3, James N. Kiarie9,
Alison L. Drake3, Anna Wald1,2,5,10, Michael Boeckh1,10,11, Barbra Richardson3,4,10, Vincent Emery8,
Grace John-Stewart1,2,3,6, Jennifer A. Slyker3
1Department of Medicine, University of Washington, Seattle, Washington, United States of America, 2Department of Epidemiology, University of Washington, Seattle,
Washington, United States of America, 3Department of Global Health, University of Washington, Seattle, Washington, United States of America, 4Department of
Biostatistics, University of Washington, Seattle, Washington, United States of America, 5Department of Laboratory Medicine, University of Washington, Seattle,
Washington, United States of America, 6Department of Pediatrics, University of Washington, Seattle, Washington, United States of America, 7Centre for Virology,
Department of Infection, School of Biomedical and Life Sciences, University College London, London, United Kingdom, 8Department of Microbial and Cellular Science,
University of Surrey, Guildford, United Kingdom, 9Department of Obstetrics and Gynaecology, University of Nairobi, Nairobi, Kenya, 10Division of Vaccine and Infectious
Disease, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America, 11Division of Clinical Research, Fred Hutchinson Cancer Research
Center, Seattle, Washington, United States of America
Background: Studies in HIV-1-infected infants and HIV-1-exposed, uninfected infants link early cytomegalovirus (CMV)
acquisition with growth delay and cognitive impairment. We investigated maternal valacyclovir to delay infant acquisition
Methods: Pregnant women with HIV-1, HSV-2 and CD4 count .250 cells/ml were randomized at 34 weeks gestation to
500 mg twice-daily valacyclovir or placebo for 12 months. Maternal CMV DNA was measured in plasma at 34 weeks
gestation, in cervical secretions at 34 and 38 weeks gestation, and in breast milk at 7 postpartum timepoints; infant CMV
DNA was measured in dried blood spots at 8 timepoints including birth.
Results: Among 148 women, 141 infants were compared in intent-to-treat analyses. Maternal and infant characteristics were
similar between study arms. Infant CMV acquisition did not differ between study arms, with 46/70 infants (66%) in placebo
arm and 47/71 infants (66%) in the valacyclovir arm acquiring CMV; median time to CMV detection did not differ. CMV DNA
was detected in 92% of 542 breast milk specimens with no difference in CMV level between study arms. Change in cervical
shedding of CMV DNA between baseline and 38 weeks was 0.40-log greater in the placebo arm than the valacyclovir arm
Conclusions: In this cohort of HIV-1-seropositive mothers, two-thirds of infants acquired CMV by one year. Maternal
valacyclovir had no effect on timing of infant CMV acquisition or breast milk CMV viral loads, although it modestly reduced
cervical CMV shedding. Maternal prophylaxis to reduce infant CMV acquisition warrants further evaluation in trials with
Trials Registration: ClinicalTrials.gov NCT00530777
Citation: Roxby AC, Atkinson C, A´sbjo ¨rnsdo ´ttir K, Farquhar C, Kiarie JN, et al. (2014) Maternal Valacyclovir and Infant Cytomegalovirus Acquisition: A Randomized
Controlled Trial among HIV-Infected Women. PLoS ONE 9(2): e87855. doi:10.1371/journal.pone.0087855
Editor: T. Mark Doherty, Glaxo Smith Kline, Denmark
Received September 18, 2013; Accepted December 24, 2013; Published February 4, 2014
Copyright: ? 2014 Roxby et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This research was funded by an Emerging Opportunity Grant to J.A.S. through a Center for AIDS Research (CFAR) award to the University of
Washington (P30AI027757) and by K01 AI087369 (PI J.A.S.), both from the National Institute of Allergy and Infectious Diseases. The randomized trial was
conducted with the support of US National Institutes of Health (NIH) research grants [R03 HD 057773, R03 HD 057773-02S1, R01 AI076105; K24 AI087399 to C.F.,
K24 HD 054314 to G.J.S., K24 AI071113 and PO1 AI30731 to A.W., K24 HL093294 to M.B.]; a Puget Sound Partners for Global Health Research and Technology
Grant, and a University of Washington Royalty Research Fund Grant. GlaxoSmithKline donated study drug and matched placebo, but had no role in the study.
A.L.D. was supported by NIH-funded University of Washington CFAR Training Grant (T32 AI07140-32), A.C.R. was a scholar in the International AIDS Research and
Training Program, funded by the Fogarty International Center, NIH (D43 TW000007) and was a Fogarty International Clinical Research Fellow (R24 TW007988). The
funders had no role in study design, data collection and analysis, or preparation of the manuscript. The content is solely the responsibility of the authors and does
not necessarily represent the official views of the National Institutes of Health.
Competing Interests: Please note that GlaxoSmithKline donated valacyclovir and matched placebo to the study. This does not alter our adherence to all the
PLOS ONE policies on sharing data and materials.
* E-mail: firstname.lastname@example.org
PLOS ONE | www.plosone.org1 February 2014 | Volume 9 | Issue 2 | e87855
In the setting of maternal HIV-1, infant CMV infection is
associated with impaired growth and development  and HIV-
1/CMV co-infected infants have a high risk of mortality ,
neurologic deficits , and HIV-1 disease progression . Infants
may acquire CMV in utero, during delivery, or postnatally through
breast milk or saliva . Maternal CMV antibodies protect against
congenital disease and infection; but postnatal protection wanes
rapidly . In sub-Saharan Africa, .80% of children acquire
CMV during the first year of life , and acquisition may occur
earlier if mothers have HIV-1 .
We evaluated maternal prophylaxis with valacyclovir as a
potential intervention to delay infant CMV acquisition. Valacy-
clovir is often used to suppress genital herpes simplex type-2
(HSV-2) infection during pregnancy, and acyclovir has been used
successfully at high doses to reduce CMV reactivation in
transplant recipients ; in HIV-1-infected adults, prophylaxis
with high-dose valacyclovir resulted in a 33% risk reduction of
CMV disease compared to acyclovir [8,9]. We hypothesized that
maternal valacyclovir could reduce CMV transmission by
reducing maternal CMV replication both antenatally to prevent
in utero transmission, and postnatally by reducing breast milk
CMV. We further hypothesized that small reductions in maternal
CMV replication, as expected with this low dose of valacyclovir,
could delay infant acquisition, an important consideration since
infants acquire CMV at very young ages. Our final hypothesis was
that valacyclovir converts to acyclovir and is present in breast milk
in low levels, and might therefore prophylax the infant. Our aims
were to measure the impact of maternal valacyclovir on maternal
CMV levels, especially in breast milk, and on the rate of infant
All participants provided written informed consent; mothers
provided written consent for both themselves and their child; the
study was approved by ethical review committees at the University
of Washington and Kenyatta National Hospital.
This study was a secondary aim of a randomized double-blind,
placebo-controlled clinical trial (RCT) evaluating the effect of
valacyclovir prophylaxis (500 mg twice daily versus placebo) on
maternal HIV-1 RNA levels; the study design, methods and main
NCT00530777) . An off-site, independent statistician gener-
ated random sequentially-numbered study identifiers using a 1:1
allocation scheme with block sized of 20. Participants were
sequentially enrolled and no staff at the study site had knowledge
of any participant allocation. The original trial protocol and
CONSORT checklist are attached as supplementary information.
(Protocol S1, Checklist S1).
Pregnant women were recruited in Nairobi from April 2008 to
June 2009; inclusion criteria were seropositive for HIV-1 and
HSV-2, CD4 count .250 cells/ml, WHO stage 1 or 2, and #34
weeks gestation; women qualifying for HIV-1 treatment were
excluded. Participants were randomized at 34 weeks gestation and
continued taking valacyclovir or placebo through 12 months
postpartum. Samples were collected at 34 and 38 weeks gestation
(maternal plasma and cervical swabs) and postpartum at 2, 6, and
14 weeks and 6, 9, and 12 months (maternal plasma and breast
milk; infant dried blood spots (DBS) from heel-prick). Infants
received standard care and immunizations, and were tested for
HIV DNA at 6 weeks, 6 months and 1 year, with additional testing
of earlier samples if HIV was detected. Women were counseled to
breastfeed exclusively for 6 months, and received prevention of
mother-to-child transmission of HIV-1 (PMTCT) prophylaxis
according to contemporaneous Kenyan guidelines (maternal
zidovudine from 28 weeks, maternal and infant single-dose
nevirapine, and 6 weeks of infant zidovudine prophylaxis).
For maternal blood, breast milk, and cervical specimens, DNA
was extracted from 200 ml of maternal plasma, breast milk
supernatant or cervical fluid extract using the Qiagen UltraSens
kit (Qiagen, California). Blood was extracted from 366 mm infant
DBS using the QIAsymphony DNA minikit. Real-time quantita-
tive PCR was used to detect the CMV glycoprotein B gene .
CMV levels in plasma, breast milk and cervical fluid were reported
as DNA copies/ml with a lower limit of detection (LLD) of 100
copies/ml. CMV levels in cervical fluid were adjusted for a
concentration factor at extraction, ensuring comparability. CMV
DNA levels from DBS were normalized to copies/million cells
against a b-globin standard  with a LLD of 100 copies/million
Assuming a cumulative CMV incidence in Kenyan infants of
94% at 1 year, a sample size of 74 infants per arm had 90% power
to detect 50% reduction in CMV acquisition between arms
(a=0.05, 2-sided test). This sample also provided 80% power to
detect a minimum difference of breast milk CMV DNA of 0.5
log10copies/ml between arms. Power calculations assumed up to
15% attrition of mother-baby pairs.
Statistical analyses were conducted as intent-to-treat, using
Stata SE v11. All p-values represent 2-tailed tests with
alpha=0.05. For infants, Kaplan-Meier survival analyses and
log-rank tests were used to compare time to CMV DNA detection
and duration of viremia between arms. CMV infection was
defined as the first detection of CMV DNA; CMV clearance was
defined as the first of two consecutive negative tests following a
Viral levels were log10-transformed, and levels below the LLD
were assigned a value of half the LLD. Fisher’s exact test was used
to compare proportions, and the independent T test or Mann-
Whitney U test was used to compare means between groups.
Generalized estimating equations (GEE) with robust standard
errors and exchangeable correlation matrix were used to measure
the change in cervical CMV over time; the binomial link function
was used to analyze cervical CMV DNA detection as a
dichotomized outcome and a linear model with Gaussian
distribution was used to analyze CMV level as a continuous
From the trial, 147 women consented to CMV testing; a total of
141 infants underwent CMV testing (Figure 1). Ten infants
acquired HIV-1, of whom 2 later died; 94% of women completed
12 months of follow-up. All mothers received PMTCT. Baseline
maternal characteristics were similar between arms (Table 1 and
Maternal Valacyclovir and Infant CMV Infection
PLOS ONE | www.plosone.org2 February 2014 | Volume 9 | Issue 2 | e87855
Infant CMV Acquisition
Of infants tested at birth, twice as many infants had detectable
CMV in the placebo arm (4/58, 6.9%) compared to the
valacyclovir arm (2/61, 3.3%), but this was not statistically
significant (p=0.4). None of these infants had signs or symptoms
of congenital CMV. At 2 weeks, 6/68 infants (8.8%) in the placebo
arm and 5/70 infants (7.1%) in the valacyclovir arm had
detectable CMV DNA (p=0.8).
In the placebo arm, a cumulative total of 46/70 infants (66%)
had CMV detected by 1 year, compared to 47/71 infants (66%) in
the valacyclovir arm (p=1.0). Median time to CMV detection did
(95%CI=702270) and 98 days in the valacyclovir arm
(95%CI=702270) (Figure 2A). When excluding HIV-1-infected
infants (6 of whom acquired CMV), there remained no differences
in CMV acquisition between arms (p=1.0, data not shown).
98 daysin the placebo
Infant CMV DNA Levels and Duration of CMV Viremia
Infant CMV DNA levels are shown in Figure 2B. Among
HIV-1-exposed, uninfected (HIV-EU) infants, CMV DNA levels
ranged between 2.2–6.1 log10copies/million cells. There was no
difference in mean peak CMV DNA level between placebo (4.2
log10copies/million cells, SE +0.87) and valacyclovir arms (4.1
log10copies/million cells, 6SE=0.82; p=0.6), and CMV DNA
levels were similar at each visit between arms (data not shown).
Among 87 HIV-EU infants who had $2 tests following first
detection of CMV, the proportion of infants who cleared viremia
(p=0.8), and duration of CMV viremia (p=0.9) was similar
between arms. In the placebo arm, 73% (32/44) of infants cleared
CMV at a median of 23 days (95%CI=152193), and in the
valacyclovir arm, 70% (30/43) of infants cleared CMV at a
median of 42 days (95%CI=302193). Among the 10 infants who
acquired HIV-1, 6 also acquired CMV; their CMV DNA levels
ranged between 3.3 26.1 log10copies/million cells.
Figure 1. Study flow chart.
Table 1. Maternal and Infant Characteristics.
Median (IQR) or N (%)
Maternal characteristics (N=147)7473
Plasma CMV tested at 34 weeks 74 (100%) 73 (100%)
Cervical CMV tested at 34 weeks74 (100%)73 (100%)
Cervical CMV tested at 38 weeks 49 (66%)50 (68%)
Breast milk CMV tested 71 (96%)72 (99%)
No. of visits breast milk CMV tested4 (3–4)4 (4–4)
Maternal deaths2 (2.7%)1 (1.4%)
Infant characteristics (N=141) 7071
Follow-up time in days364 (356–368)365 (357–369)
Visits tested for CMV8 (7–8)8 (7–8)
Acquired HIV-1 4 (5.7%)6 (8.5%)
Acquired CMV46 (66%) 47 (66%)
Infant deaths9 (12%) 3 (4.1%)
Maternal Valacyclovir and Infant CMV Infection
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Maternal Plasma and Breast Milk CMV DNA Levels
Pre-randomization, only 7/145 (4.8%) women had detectable
CMV in their plasma, and we lacked power to compare study
arms. Of 143 women who provided breast milk, CMV DNA was
detected in 142 women (99%), and in 499/542 of their specimens
(92%). At each time-point, there was no significant difference in
the mean quantity of CMV DNA between arms (p.0.05, all
comparisons, data not shown). The mean peak CMV viral load in
breast milk was also similar between placebo (5.7 log10copies/ml
Figure 2. Valacyclovir and infant CMV acquisition. A) Kaplan-Meier survival curves show cumulative probability of CMV DNA detection in
infant dried blood spots (DBS) in all infants by randomization arm. P value for log-rank test. B) Loess curves fitted to mean CMV DNA level. HIV-
infected infant CMV DNA levels are indicated by Xs, HIV-exposed uninfected infant CMV DNA levels are indicated by closed circles; black indicates
placebo and red valacyclovir arm. Dotted line indicates assay limit of detection (100 copies/million cells).
Maternal Valacyclovir and Infant CMV Infection
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6SD=1.0, p=0.2). In both arms, mean breast milk CMV levels
declined over time, with the highest levels noted at 2 weeks
postpartum. (Figure 3A).
Maternal Cervical CMV Shedding
Among 99 women with serial sampling of cervical secretions,
the proportion with detectable CMV DNA increased between
baseline and 38 weeks in the placebo arm (from 41% to 63%;
p=0.003), but did not change in the valacyclovir arm, (from 56%
to 60%, p=0.6; Figure 3B). Similarly, in the placebo arm CMV
DNA levels increased significantly over time (baseline medi-
an=1.7 log10copies/ml, IQR=1.722.7 log10copies/ml, 38 week
median=2.6 log10 copies/ml, IQR=1.723.5 log10 copies/ml;
p=0.001) but did not change significantly in the valacyclovir arm
(baseline median 1.9 log10 copies/ml, IQR=1.722.8 log10
IQR=1.723.5 log10copies/ml; p=0.4, Figure 3C).
In this RCT of valacyclovir dosed for HSV-2 suppression, we
found that valacyclovir at a dose of 500 mg twice daily had a
Figure 3. Valacyclovir and maternal CMV levels. A) Loess curves fitted to mean CMV DNA levels in breast milk samples collected at 2, 6 and 14
weeks postpartum, and 6, 9 and 12 months postpartum. Red line and markers indicate women randomized to valacyclovir. Dotted line indicates assay
limit of detection (100 copies/ml). Note: few women were breastfeeding after 180 days postpartum. B) Bars show proportion of women with
detectable CMV DNA in the cervix at pre-randomization (34 weeks gestation) and 4 weeks post-randomization (38 weeks gestation). P values below
the graph compare the proportion of detectable responses between arms, p values above graph compare the proportion of detectables within each
arm, over the two time-points. C) Plots show individual CMV DNA levels for women at baseline and post-randomization, red middle bars show group
medians, red whiskers show upper and lower quartiles. P values below the graph show comparison of CMV DNA levels between arms, p values above
graph compare CMV DNA levels within each arm, over the two time-points.
Maternal Valacyclovir and Infant CMV Infection
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modest effect on the pattern of maternal cervical CMV shedding,
but had no effect on maternal breast milk CMV DNA levels or
infant CMV acquisition and viremia. To our knowledge, this is the
first RCT evaluating the effect of maternal antiviral prophylaxis to
prevent CMV transmission to children. Including these secondary
endpoints into an ongoing RCT enabled rapid evaluation of the
potential benefit of an affordable, well-tolerated drug at doses
routinely used in pregnancy, and allowed us to evaluate this
intervention in a population of HIV-1-exposed infants in Kenya
who are vulnerable to early CMV infection.
Detection of early CMV infection in 7% of infants by 2 weeks of
age confirms high prevalence of early infant acquisition of CMV
found in an earlier cohort studied in Kenya, where 6% of HIV-1-
seronegative infants born to HIV-1-seropositive mothers had
CMV detected at birth and 20% detected by one month .
Lower prevalences of early infant CMV have been observed
among HIV-1-seropositive mothers who start triple antiretroviral
therapy before or during pregnancy: 3.6% of infants born to HIV-
1 infected mothers had CMV detected at birth in a US cohort 
and 1.2% of similar infants had CMV detected at birth in the
French ANRS cohort . This high prevalence of early infant
CMV infection in our cohort, where women received zidovudine
monotherapy and perinatal nevirapine, suggests that HIV-exposed
infants are at risk of early acquisition of CMV due to maternal
factors such as immunosuppression. In this cohort, mothers had T
cell counts .250 cells/ml but had only a few months of exposure to
zidovudine at delivery. One mechanism to explain the high
prevalence of infant CMV may be the observation that HIV-1
infected mothers may transfer less protective antibody to their
infants perinatally .
Valacyclovir treatment was previously shown in this cohort to
reduce maternal HIV-1 RNA levels by ,0.5 log10copies/ml in
plasma and breast milk . Previous studies report correlations
between CMV and HIV-1 levels in plasma and breast milk [2,16].
HIV-induced immunosuppression impairs CMV containment,
and in vitro studies have demonstrated bi-directional cellular
interactions between the two viruses that reciprocally enable
infectivity and replication . In light of this synergy, reductions
in breast milk CMV DNA secondary to HIV-1 RNA reduction
were expected, but were not observed.
The dose of valacyclovir was inadequate to impact breast milk
CMV DNA levels, even though valacyclovir penetrates the breast
compartment. Prophylaxis studies against CMV disease in organ
transplant patients have used much higher doses of acyclovir (1.5–
8 g/day) [7,18] with significant effect. A pilot study reported using
8 g of valacyclovir in pregnancy  to treat mothers of fetuses
with congenital CMV infection. Controlled trials in pregnancy or
breastfeeding with acyclovir or novel antivirals have not been
conducted. Despite the limitations of 500 mg twice-daily dosing of
valacyclovir in preventing CMV reactivation, our hypothesis was
that our more realistic goal of small reductions in the high CMV
load in breast milk would translate into delays in infant acquisition.
These delays may be significant: in newborn infants living in areas
of high infant mortality, delaying CMV acquisition by even 2–4
weeks could translate into morbidity and mortality benefits. Our
trial results, however, showed conclusively that this dose of
valacyclovir did not benefit HIV-1 exposed infants.
We found a modest effect of valacyclovir on maternal cervical
CMV shedding. In a prior study in the Gambia, maternal genital
shedding of CMV was associated with both congenital and early
infant infections . Few studies have examined effects of antiviral
therapy on CMV levels in the genital tract; an RCT in HIV-1-
infected men found no effect of 500 mg twice daily valacyclovir on
semen CMV levels . In our placebo arm, cervical CMV
shedding increased between 34 and 38 weeks, consistent with
reports of increased shedding during late pregnancy , but this
increase was attenuated in the valacyclovir arm. CMV shedding
has been observed to increase during the luteal phase of the
menstrual cycle, and is associated with progesterone and estradiol
levels , suggesting hormonal cervical changes may be
determinants of local CMV replication. The genital tract was
the only compartment where we saw a difference in CMV
shedding, which may be due to valacyclovir’s penetration to
cervical and vaginal tissues.
Strengths of this study include its prospective randomized design
and robust power to detect differences in infant acquisition and
breast milk CMV levels. Women had high adherence to the study
protocol, verified by valacyclovir detection in breast milk  and
HIV-1 suppression. Because no infant blood was obtained, we
were unable to confirm CMV infection using serology, and we
may underestimate the true number of infant infections, partic-
ularly those with low-level or short-duration viremia. Additionally,
comparison of plasma and DBS specimens demonstrates lower
sensitivity of DBS with low CMV levels (Atkinson, in preparation).
However, even if some infant CMV infections were missed, the 93
transmission events observed were adequate to detect a significant
impact on CMV transmission, and our randomized design
preserves our ability to discern effects even with possible under-
ascertainment. We are unable to comment on the effects of
valacyclovir on HIV-1-seronegative women or HSV-2- seroneg-
ative coinfected women and their infants.
In conclusion, maternal valacyclovir had a modest impact on
cervical CMV shedding in late pregnancy, but did not affect infant
CMV acquisition or breast milk CMV levels. Early CMV infection
may be one of a series of concurrent infections that adversely affect
infant health, growth and survival in developing countries,
especially among HIV-1-exposed infants. Maternal antiretroviral
therapy has reduced infant CMV infection among HIV-1-exposed
infants in developed countries, but may not be as effective in
developing countries, where most CMV acquisition occurs in the
first year of life, and where breastfeeding continues to be
recommended for infants of HIV-1-seropositive mothers. Mater-
nal antiviral prophylaxis with higher doses of valacyclovir or novel
antiviral agents to prevent or delay infant CMV acquisition in the
early postnatal period may warrant further study.
This research was presented as a poster abstract G16 at CMV 2012, San
Francisco, California, October 29-November 2, 2012.
Conceived and designed the experiments: JAS CF AW MB VE GJS ALD
CA KA. Performed the experiments: CA KA JAS MB VE. Analyzed the
data: JAS ALD BAR GJS CF. Wrote the paper: AR JAS GJS CF JK AW
KA CA VE BR MB ALD. Conducted the clinical trial: AR AD CF JK.
Maternal Valacyclovir and Infant CMV Infection
PLOS ONE | www.plosone.org6 February 2014 | Volume 9 | Issue 2 | e87855
References Download full-text
1. Gompels UA, Larke N, Sanz-Ramos M, Bates M, Musonda K, et al. (2012)
Human cytomegalovirus infant infection adversely affects growth and develop-
ment in maternally HIV-exposed and unexposed infants in Zambia. Clin Infect
Dis 54: 434–442.
2. Slyker JA, Lohman-Payne BL, John-Stewart GC, Maleche-Obimbo E, Emery S,
et al. (2009) Acute cytomegalovirus infection in Kenyan HIV-infected infants.
AIDS 23: 2173–2181.
3. Kapetanovic S, Aaron L, Montepiedra G, Burchett SK, Kovacs A (2012) T-cell
activation and neurodevelopmental outcomes in perinatally HIV-infected
children. AIDS 26: 959–969.
4. Kovacs A, Schluchter M, Easley K, Demmler G, Shearer W, et al. (1999)
Cytomegalovirus infection and HIV-1 disease progression in infants born to
HIV-1-infected women. Pediatric Pulmonary and Cardiovascular Complications
of Vertically Transmitted HIV Infection Study Group. N Engl J Med 341: 77–
5. Kaye S, Miles D, Antoine P, Burny W, Ojuola B, et al. (2008) Virological and
immunological correlates of mother-to-child transmission of cytomegalovirus in
The Gambia. J Infect Dis 197: 1307–1314.
6. Manicklal S, Emery VC, Lazzarotto T, Boppana SB, Gupta RK (2013) The
‘‘silent’’ global burden of congenital cytomegalovirus. Clin Microbiol Rev 26:
7. Winston DJ, Wirin D, Shaked A, Busuttil RW (1995) Randomised comparison
of ganciclovir and high-dose acyclovir for long-term cytomegalovirus prophy-
laxis in liver-transplant recipients. Lancet 346: 69–74.
8. Feinberg JE, Hurwitz S, Cooper D, Sattler FR, MacGregor RR, et al. (1998) A
randomized, double-blind trial of valaciclovir prophylaxis for cytomegalovirus
disease in patients with advanced human immunodeficiency virus infection.
AIDS Clinical Trials Group Protocol 204/Glaxo Wellcome 123-014 Interna-
tional CMV Prophylaxis Study Group. J Infect Dis 177: 48–56.
9. Emery VC, Sabin C, Feinberg JE, Grywacz M, Knight S, et al. (1999)
Quantitative effects of valacyclovir on the replication of cytomegalovirus (CMV)
in persons with advanced human immunodeficiency virus disease: baseline
CMV load dictates time to disease and survival. The AIDS Clinical Trials
Group 204/Glaxo Wellcome 123-014 International CMV Prophylaxis Study
Group. J Infect Dis 180: 695–701.
10. Drake AL, Roxby AC, Ongecha-Owuor F, Kiarie J, John-Stewart G, et al.
(2012) Valacyclovir suppressive therapy reduces plasma and breast milk HIV-1
RNA levels during pregnancy and postpartum: a randomized trial. J Infect Dis
11. Atkinson C, Walter S, Sharland M, Tookey P, Luck S, et al. (2009) Use of stored
dried blood spots for retrospective diagnosis of congenital CMV. J Med Virol 81:
12. Lo YM, Tein MS, Lau TK, Haines CJ, Leung TN, et al. (1998) Quantitative
analysis of fetal DNA in maternal plasma and serum: implications for
noninvasive prenatal diagnosis. Am J Hum Genet 62: 768–775.
13. Frederick T, Homans J, Spencer L, Kramer F, Stek A, et al. (2012) The Effect of
Prenatal Highly Active Antiretroviral Therapy on the Transmission of
Congenital and Perinatal/Early Postnatal Cytomegalovirus Among HIV-
Infected and HIV-Exposed Infants. Clin Infect Dis.
14. Guibert G, Warszawski J, Le Chenadec J, Blanche S, Benmebarek Y, et al.
(2009) Decreased risk of congenital cytomegalovirus infection in children born to
HIV-1-infected mothers in the era of highly active antiretroviral therapy. Clin
Infect Dis 48: 1516–1525.
15. Glennie SJ, Nyirenda M, Williams NA, Heyderman RS (2012) Do multiple
concurrent infections in African children cause irreversible immunological
damage? Immunology 135: 125–132.
16. Gantt S, Carlsson J, Shetty AK, Seidel KD, Qin X, et al. (2008)
Cytomegalovirus and Epstein-Barr virus in breast milk are associated with
HIV-1 shedding but not with mastitis. AIDS 22: 1453–1460.
17. Griffiths PD (2006) CMV as a cofactor enhancing progression of AIDS. J Clin
Virol 35: 489–492.
18. Kalil AC, Levitsky J, Lyden E, Stoner J, Freifeld AG (2005) Meta-analysis: the
efficacy of strategies to prevent organ disease by cytomegalovirus in solid organ
transplant recipients. Ann Intern Med 143: 870–880.
19. Jacquemard F, Yamamoto M, Costa JM, Romand S, Jaqz-Aigrain E, et al.
(2007) Maternal administration of valaciclovir in symptomatic intrauterine
cytomegalovirus infection. BJOG 114: 1113–1121.
20. Zuckerman RA, Lucchetti A, Whittington WL, Sanchez J, Coombs RW, et al.
(2009) HSV suppression reduces seminal HIV-1 levels in HIV-1/HSV-2 co-
infected men who have sex with men. AIDS 23: 479–483.
21. Shen CY, Chang SF, Yen MS, Ng HT, Huang ES, et al. (1993)
Cytomegalovirus excretion in pregnant and nonpregnant women. J Clin
Microbiol 31: 1635–1636.
22. Mostad SB, Kreiss JK, Ryncarz A, Chohan B, Mandaliya K, et al. (2000)
Cervical shedding of herpes simplex virus and cytomegalovirus throughout the
menstrual cycle in women infected with human immunodeficiency virus type 1.
Am J Obstet Gynecol 183: 948–955.
23. Drake AL, Roxby AC, Kiarie J, Richardson BA, Wald A, et al. (2012) Infant
Safety during and after Maternal Valacyclovir Therapy in Conjunction with
Antiretroviral HIV-1 Prophylaxis in a Randomized Clinical Trial. PLoS One 7:
Maternal Valacyclovir and Infant CMV Infection
PLOS ONE | www.plosone.org7 February 2014 | Volume 9 | Issue 2 | e87855