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1.  Compartmentalized Cytomegalovirus Replication and Transmission in the Setting of Maternal HIV-1 Infection 
In human immunodeficiency virus–infected women, cervical cytomegalovirus (CMV) reactivation during pregnancy was correlated with higher CMV levels in breast milk. Low maternal CD4 count and high CMV levels in breast milk were independently associated with infant CMV infection.
Background. Cytomegalovirus (CMV) infection is associated with adverse outcomes in human immunodeficiency virus (HIV)–exposed infants. Determinants of vertical CMV transmission in the setting of maternal HIV-1 infection are not well-defined.
Methods. CMV and HIV-1 levels were measured in plasma, cervical secretions, and breast milk of 147 HIV-1–infected women to define correlates of maternal CMV replication and infant CMV acquisition.
Results. Although few women had detectable CMV in plasma (4.8%), the majority had detectable CMV DNA in cervical secretions (66%) and breast milk (99%). There was a strong association between cervical CMV detection during pregnancy and later breast milk levels (β = 0.47; P = .005). Plasma HIV-1 level and CD4 counts were associated with CMV in the cervix and breast milk. However HIV-1 levels within the cervix and breast milk were not associated with CMV within these compartments. Maternal breast milk CMV levels (hazard ratio [HR], 1.4; P = .003) and maternal CD4 < 450 cells/mm3 (HR, 1.8; P = .008) were independently associated with infant CMV acquisition; each log10 increase in breast milk CMV was associated with a 40% increase in infant infection. The breast milk CMV level required to attain a 50% probability of CMV transmission increased with higher maternal CD4 counts, increasing from 3.55 log10 CMV DNA copies/mL at a CD4 count of 350 cells/mm3 to 5.50 log10 CMV DNA copies/mL at a CD4 count of 1000 cells/mm3.
Conclusions. Breast milk CMV levels and maternal CD4 count are major determinants of CMV transmission in the setting of maternal HIV-1. Maternal immune reconstitution or lowering breast milk CMV levels may reduce vertical CMV transmission.
PMCID: PMC3905754  PMID: 24192386
cytomegalovirus; human immunodeficiency virus; neonates; opportunistic infection; compartmentalization
2.  High Rates of Relationship Dissolution Among Heterosexual HIV-Serodiscordant Couples in Kenya 
AIDS and behavior  2014;18(1):189-193.
HIV-1 serodiscordant couples may experience increased risks of relationship dissolution; however, longitudinal stability of these relationships is poorly understood. We determined rates and correlates of separation among 469 serodiscordant couples in Nairobi and found that 113 (24 %) separated during 2 years of follow-up. Couples with a female HIV-1 infected partner (F+M–) and no income were more likely to separate than M+F– couples without income (HR = 5.0; 95 % CI 1.1–25.0), and F+M– and M+F– couples with income (HR = 2.4; 95 % CI 1.3–4.5 and HR = 2.3; 95 % CI 1.2–4.8, respectively). High separation rates may be important for couple support services and for conducting discordant couple studies.
PMCID: PMC3981202  PMID: 23728523
HIV-1 serodiscordant couples; Relationship dissolution; Separation; HIV-1 transmission; Poverty; Women
3.  The Clinical Education Partnership Initiative: an innovative approach to global health education 
BMC Medical Education  2014;14:1043.
Despite evidence that international clinical electives can be educationally and professionally beneficial to both visiting and in-country trainees, these opportunities remain challenging for American residents to participate in abroad. Additionally, even when logistically possible, they are often poorly structured. The Universities of Washington (UW) and Nairobi (UoN) have enjoyed a long-standing research collaboration, which recently expanded into the UoN Medical Education Partnership Initiative (MEPI). Based on MEPI in Kenya, the Clinical Education Partnership Initiative (CEPI) is a new educational exchange program between UoN and UW. CEPI allows UW residents to partner with Kenyan trainees in clinical care and teaching activities at Naivasha District Hospital (NDH), one of UoN’s MEPI training sites in Kenya.
UW and UoN faculty collaborated to create a curriculum and structure for the program. A Chief Resident from the UW Department of Medicine coordinated the program at NDH. From August 2012 through April 2014, 32 UW participants from 5 medical specialties spent between 4 and 12 weeks working in NDH. In addition to clinical duties, all took part in formal and informal educational activities. Before and after their rotations, UW residents completed surveys evaluating clinical competencies and cross-cultural educational and research skills. Kenyan trainees also completed surveys after working with UW residents for three months.
UW trainees reported a significant increase in exposure to various tropical and other diseases, an increased sense of self-reliance, particularly in a resource-limited setting, and an improved understanding of how social and cultural factors can affect health. Kenyan trainees reported both an increase in clinical skills and confidence, and an appreciation for learning a different approach to patient care and professionalism.
After participating in CEPI, both Kenyan and US trainees noted improvement in their clinical knowledge and skills and a broader understanding of what it means to be clinicians. Through structured partnerships between institutions, educational exchange that benefits both parties is possible.
Electronic supplementary material
The online version of this article (doi:10.1186/s12909-014-0246-5) contains supplementary material, which is available to authorized users.
PMCID: PMC4335420  PMID: 25547408
International; Clinical rotation; Medical education; Residents; Kenya
4.  Daily Acyclovir to Decrease Herpes Simplex Virus Type 2 (HSV-2) Transmission from HSV-2/HIV-1 Coinfected Persons: A Randomized Controlled Trial 
The Journal of Infectious Diseases  2013;208(9):1366-1374.
Background. Daily suppressive therapy with valacyclovir reduces risk of sexual transmission of herpes simplex virus type 2 (HSV-2) in HSV-2–serodiscordant heterosexual couples by 48%. Whether suppressive therapy reduces HSV-2 transmission from persons coinfected with HSV-2 and human immunodeficiency virus type 1 (HIV-1) is unknown.
Methods. Within a randomized trial of daily acyclovir 400 mg twice daily in African HIV-1 serodiscordant couples, in which the HIV-1–infected partner was HSV-2 seropositive, we identified partnerships in which HIV-1–susceptible partners were HSV-2 seronegative to estimate the effect of acyclovir on risk of HSV-2 transmission.
Results. We randomly assigned 911 HSV-2/HIV-1–serodiscordant couples to daily receipt of acyclovir or placebo. We observed 68 HSV-2 seroconversions, 40 and 28 in acyclovir and placebo groups, respectively (HSV-2 incidence, 5.1 cases per 100 person-years; hazard ratio [HR], 1.35 [95% confidence interval, .83–2.20]; P = .22). Among HSV-2–susceptible women, vaginal drying practices (adjusted HR, 44.35; P = .004) and unprotected sex (adjusted HR, 9.91; P = .002) were significant risk factors for HSV-2 acquisition; having more children was protective (adjusted HR, 0.47 per additional child; P = .012). Among HSV-2–susceptible men, only age ≤30 years was associated with increased risk of HSV-2 acquisition (P = .016).
Conclusions. Treatment of African HSV-2/HIV-1–infected persons with daily suppressive acyclovir did not decrease risk of HSV-2 transmission to susceptible partners. More-effective prevention strategies to reduce HSV-2 transmission from HIV-1–infected persons are needed.
PMCID: PMC3789565  PMID: 23901094
HSV-2; HIV-1; acyclovir; transmission; serodiscordant couples; Africa
5.  Traumatic near amputation secondary to hippopotamus attack: lessons for surgeons 
The Journal of surgical research  2013;188(1):58-63.
A 34-y-old man presented to Naivasha District Hospital (NDH) in Naivasha Town, Kenya, with near-complete below-knee amputation and hemorrhage after a hippopotamus attack. Residents from the University of Washington (UW), Departments of Surgery, Anesthesia, and Medicine, were rotating at NDH with the Clinical Education Partnership Initiative, a joint venture of UW and University of Nairobi. These providers met the patient in the operating theater. The leg was mangled with severely traumatized soft tissues and tibia–fibula fractures. The visiting UW Surgery resident (R3) and an NDH medical officer (second-year house officer) performed emergency below-knee completion amputation—the first time either had performed this operation. The three major vessel groups were identified and ligated. Sufficient gastrocnemius and soleus were preserved for future stump construction. The wound was washed out, packed with betadine-soaked gauze, and wrapped in an elasticized bandage. Broad-spectrum antibiotics were initiated. Unfortunately, the patient suffered infection and was revised above the knee. After a prolonged course, the patient recovered well and was discharged home. NDH house officers and UW trainees collaborated successfully in an emergency and conducted the postoperative care of a patient with a serious and challenging injury. Their experience highlights the importance of preparedness, command of surgical basics, humility, learning from mistakes, the expertise of others, a digitally connected surgical community, and the role of surgery in global health. These lessons will be increasingly pertinent as surgical training programs create opportunities for their residents to work in developing countries; many of these lessons are equally applicable to surgical practice in the developed world.
PMCID: PMC4209841  PMID: 24411302
Surgical education; Global health; Traumatic amputation; Surgical training; Preparedness
6.  Incident HSV-2 Infections Are Common Among HIV-1-discordant Couples 
The Journal of Infectious Diseases  2013;208(7):1093-1101.
Background. The synergy between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) is well known, but lack of knowledge about the epidemiology of HSV-2 acquisition in HIV-1-discordant couples hampers development of HSV-2 prevention interventions that could reduce HIV-1 transmission.
Methods. HIV-1-discordant couples were enrolled in Nairobi, Kenya, and followed for up to 2 years. HSV-2 status was determined using HerpeSelect HSV-2 ELISA. Correlates of prevalence and incidence were assessed.
Results. Of 469 HIV-1-discordant couples, at baseline, 353 (75.3%) were affected by HSV-2, of which 189 (53.5%) were concordantly HSV-2 seropositive and 164 (46.5%) were HSV-2-discordant. Prevalence was lowest among HIV-1-uninfected men (39.9%) compared to HIV-1-infected women (64.8%), HIV-1-infected men (66.7%), and HIV-1-uninfected women (68.5%). During follow-up, HSV-2 seroincidence was 14.9 per 100 person-years. Incidence was 1.6-fold higher among females compared to males (95% confidence interval [CI], 1.00–2.48) and 2.5-fold higher in HIV-1-infected compared to uninfected women (95% CI, 1.12–5.74). At least 30% of incident HSV-2 infections originated from an outside partner.
Conclusions. The high HSV-2 prevalence and incidence in HIV-1-discordant couples in sub-Saharan Africa suggest HSV-2 treatment and prevention could be an effective targeted strategy to reduce HSV-2 and HIV-1 transmission in this high-risk population.
PMCID: PMC3762386  PMID: 23840044
HSV-2; herpes; HIV; discordant; serodiscordant; couples; genital ulcer disease; Kenya; incidence; prevalence; transmission; prevention; Africa; antiviral; seroconvert; ELISA
7.  Prevalence, Perceptions and Correlates of Pediatric HIV Disclosure in an HIV Treatment Program in Kenya 
AIDS care  2012;25(9):1067-1076.
Disclosure to HIV-infected children regarding their diagnosis is important as expanding numbers of HIV-infected children attain adolescence and may become sexually active. In order to define correlates of pediatric disclosure and facilitate development of models for disclosure, we conducted a cross-sectional survey of primary caregivers of HIV-1 infected children aged 6 to 16 years attending a pediatric HIV treatment program in Nairobi, Kenya. We conducted focus group discussions with a subset of caregivers to further refine perceptions of disclosure.
Among 271 caregiver/child dyads in the cross-sectional survey, median child age was 9 years (IQR: 7, 12 years). Although 79% of caregivers believed children should know their HIV status, the prevalence of disclosure to the child was only 19%. Disclosure had been done primarily by health workers (52%) and caregivers (33%). Caregivers reported that 5 of the 52 (10%) who knew their status were accidentally disclosed to. Caregivers of older children (13 vs. 8 years; p<0.001), who were HIV-infected and had disclosed their own HIV status to the child (36% vs. 4%; p=0.003), or who traveled frequently (29% vs. 16%, p=0.03) were more likely to have disclosed. Children who had been recently hospitalized (25% vs. 44%, p=0.03) were less likely to know their status and caregivers with HIV were less likely to have disclosed (p=0.03). Reasons for disclosure included medication adherence, curiosity or illness while reasons for non-disclosure included age and fear of inadvertent disclosure.
Our study found that disclosure rates in this Kenyan setting are lower than observed rates in the United States and Europe but consistent with rates from other resource-limited settings. Given these low rates of disclosure and the potential benefits of disclosure, strategies promoting health worker trainings and caregiver support systems for disclosure may benefit children with HIV.
PMCID: PMC3626761  PMID: 23256520
disclosure; pediatric; HIV; stigma; adherence
8.  Mode of delivery and postpartum HIV-1 disease progression and mortality in a Kenyan cohort 
There are limited data on the impact of cesarean section delivery on HIV-1 infected women in Sub-Saharan Africa. The purpose of this study was to assess the effect of mode of delivery on HIV-1 disease progression and postpartum mortality in a Kenyan cohort.
A prospective cohort study was conducted in Nairobi, Kenya from 2000–2005. We determined changes in CD4+ counts, HIV-1 RNA levels and mortality during the first year postpartum between HIV-1 infected women who underwent vaginal delivery (VD), non-scheduled cesarean section (NSCS) and scheduled cesarean section (SCS) and received short-course zidovudine. Loess curves and multivariate linear mixed effects models were used to compare longitudinal changes in maternal HIV-1 RNA and CD4+ counts by mode of delivery. Kaplan Meier curves, the log rank test, and Cox proportional hazards regression were used to assess difference in mortality.
Of 501 women, 405 delivered by VD, 74 delivered by NSCS and 22 by SCS. Baseline characteristics were similar between the VD and NSCS groups. Baseline antenatal CD4+ counts were lowest and HIV-1 RNA levels highest in the NSCS group but HIV-1 RNA levels were similar between groups at delivery. The rate of decline in CD4+ cells and rate of increase in HIV-1 RNA did not differ between groups. After adjusting for confounders, women who underwent NSCS had a 3.39-fold (95% CI 1.11, 10.35, P = 0.03) higher risk of mortality in the first year postpartum compared to women with VD.
Non-scheduled cesarean section was an independent risk factor for postpartum mortality in HIV-1 positive Kenyan women. The cause of death was predominantly due to HIV-1 related infections, and not direct maternal deaths, however, this was not mirrored by differential changes in HIV-1 progression markers between the groups.
PMCID: PMC4133616  PMID: 25086834
HIV; Mode of delivery; Cesarean section; HIV-1 disease progression; Maternal mortality
9.  Performance of the Integrated Management of Childhood Illness (IMCI) Algorithm for Diagnosis of HIV-1 Infection among Kenyan Infants 
AIDS (London, England)  2012;26(15):1935-1941.
Early infant HIV-1 diagnosis and treatment substantially improve survival. Where virologic HIV-1 testing is unavailable, Integrated Management of Childhood Illness (IMCI) clinical algorithms may be used for infant HIV-1 screening. We evaluated the performance of the 2008 WHO IMCI HIV algorithm in a cohort of HIV-exposed Kenyan infants.
From 1999–2003, 444 infants had monthly clinical assessments and quarterly virologic HIV-1 testing. Using archived clinical data, IMCI sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using virologic testing as a gold standard. Linear regression and survival analyses were used to determine the effect of age on IMCI performance and timing of diagnosis.
Overall IMCI sensitivity, specificity, PPV, and NPV value were 58%, 87%, 52%, and 90%, respectively. Sensitivity (1.4%) and PPV (14%) were lowest at 1 month of age, when 81% of HIV-infections already had occurred. Sensitivity increased with age (p<0.0001), but remained low throughout infancy (range=1.4–35%). Specificity (range=97–100%) was high at each time point and was not associated with age. Fifty-eight percent of HIV-1 infected infants (50/86) were eventually diagnosed by IMCI, and use of IMCI was estimated to delay diagnosis in HIV-infected infants by a median of 5.9 months (p<0.0001).
IMCI had low sensitivity during the first month of life, when the majority of HIV-1 infections had already occurred, and initiation of treatment is most critical. Although sensitivity increased with age, the substantial delay in HIV-1 diagnosis using IMCI limits its utility in early infant HIV-1 diagnosis.
PMCID: PMC4113472  PMID: 22824627
IMCI; HIV; infant; Africa; clinical algorithm; pediatric
10.  A prospective cohort study comparing the effect of single-dose 2g metronidazole on Trichomonas vaginalis infection in HIV-seropositive versus HIV-seronegative women 
Sexually transmitted diseases  2013;40(6):499-505.
This analysis compared the frequency of persistent Trichomonas vaginalis (TV) among HIV-seropositive and HIV-seronegative women.
Data were obtained from women enrolled in an open cohort study of sex workers in Kenya. Participants were examined monthly, and those diagnosed with TV by saline microscopy were treated with single-dose 2g oral metronidazole. All women on antiretroviral therapy (ART) used nevirapine-based regimens. Generalized estimating equations with a logit link were used to compare the frequency of persistent TV (defined as the presence of motile trichomonads by saline microscopy at the next exam visit within 60 days) by HIV status.
Three-hundred and sixty participants contributed 570 infections to the analysis (282 HIV-seropositive and 288 HIV-seronegative). There were 42 (15%) persistent infections among HIV-seropositive participants versus 35 (12%) among HIV-seronegative participants (adjusted odds ratio [aOR]=1.14; 95% confidence interval [CI] (0.70, 1.87)). Persistent TV was highest among HIV-seropositive women using ART (21/64 [33%]) compared to HIV-seropositive women not using ART (21/217 [10%]). Concurrent bacterial vaginosis (BV) at TV diagnosis was associated with an increased likelihood of persistent TV (aOR=1.90; 95% CI 1.16, 3.09).
The frequency of persistent TV infection following treatment with single-dose 2g oral metronidazole was similar by HIV status. Alternative regimens, including multi-day antibiotic treatment, may be necessary to improve cure rates for women using nevirapine-based ART and women with TV and concurrent BV.
PMCID: PMC3676301  PMID: 23677023
Trichomonas vaginalis; metronidazole; efficacy; persistence; HIV infection; nevirapine; antiretroviral therapy
11.  Systems analysis and improvement to optimize pMTCT (SAIA): a cluster randomized trial 
Despite significant increases in global health investment and the availability of low-cost, efficacious interventions to prevent mother-to-child HIV transmission (pMTCT) in low- and middle-income countries with high HIV burden, the translation of scientific advances into effective delivery strategies has been slow, uneven and incomplete. As a result, pediatric HIV infection remains largely uncontrolled. A five-step, facility-level systems analysis and improvement intervention (SAIA) was designed to maximize effectiveness of pMTCT service provision by improving understanding of inefficiencies (step one: cascade analysis), guiding identification and prioritization of low-cost workflow modifications (step two: value stream mapping), and iteratively testing and redesigning these modifications (steps three through five). This protocol describes the SAIA intervention and methods to evaluate the intervention’s impact on reducing drop-offs along the pMTCT cascade.
This study employs a two-arm, longitudinal cluster randomized trial design. The unit of randomization is the health facility. A total of 90 facilities were identified in Côte d’Ivoire, Kenya and Mozambique (30 per country). A subset was randomly selected and assigned to intervention and comparison arms, stratified by country and service volume, resulting in 18 intervention and 18 comparison facilities across all three countries, with six intervention and six comparison facilities per country. The SAIA intervention will be implemented for six months in the 18 intervention facilities. Primary trial outcomes are designed to assess improvements in the pMTCT service cascade, and include the percentage of pregnant women being tested for HIV at the first antenatal care visit, the percentage of HIV-infected pregnant women receiving adequate prophylaxis or combination antiretroviral therapy in pregnancy, and the percentage of newborns exposed to HIV in pregnancy receiving an HIV diagnosis eight weeks postpartum. The Consolidated Framework for Implementation Research (CFIR) will guide collection and analysis of qualitative data on implementation process.
This study is a pragmatic trial that has the potential benefit of improving maternal and infant outcomes by reducing drop-offs along the pMTCT cascade. The SAIA intervention is designed to provide simple tools to guide decision-making for pMTCT program staff at the facility level, and to identify low cost, contextually appropriate pMTCT improvement strategies.
Trial registration NCT02023658
PMCID: PMC4019370  PMID: 24885976
Systems analysis; Quality improvement; pmtct; Value stream mapping; Cascade analysis; Cluster randomized trial; Industrial engineering; Implementation science; Mozambique; Kenya; Côte d’Ivoire
12.  Plasma Viral Loads During Early HIV-1 Infection Are Similar in Subtype C– and Non-Subtype C–Infected African Seroconverters 
The Journal of Infectious Diseases  2013;207(7):1166-1170.
Recent data suggest that infection with human immunodeficiency virus type 1 (HIV-1) subtype C results in prolonged high-level viremia (>5 log10 copies/mL) during early infection. We examined the relationship between HIV-1 subtype and plasma viremia among 153 African seroconverters. Mean setpoint viral loads were similar for C and non-C subtypes: 4.36 vs 4.42 log10 copies/mL (P = .61). The proportion of subtype C–infected participants with viral loads >5 log10 copies/mL was not greater than the proportion for those with non-C infection. Our data do not support the hypothesis that higher early viral load accounts for the rapid spread of HIV-1 subtype C in southern Africa.
PMCID: PMC3583276  PMID: 23315322
HIV-1; group M subtype; plasma viral load; early infection; Africa
13.  Delayed initiation of antiretroviral therapy among HIV-discordant couples in Kenya 
AIDS care  2012;25(3):265-272.
Timely initiation of antiretroviral therapy (ART) is particularly important for HIV-discordant couples because viral suppression greatly reduces the risk of transmission to the uninfected partner. To identify issues and concerns related to ART initiation among HIV-discordant couples, we recruited a subset of discordant couples participating in a longitudinal study in Nairobi to participate in in-depth interviews and focus group discussions about ART. Our results suggest that partners in HIV-discordant relationships discuss starting ART, yet most are not aware that ART can decrease the risk of HIV transmission. Additionally, their concerns about ART initiation include side effects, sustaining an appropriate level of drug treatment, HIV/AIDS related stigma, medical/biological issues, psychological barriers, misconceptions about the medications, the inconvenience of being on therapy, and lack of social support. Understanding and addressing these barriers to ART initiation among discordant couples is critical to advancing the HIV “treatment as prevention” agenda.
PMCID: PMC3523215  PMID: 22866934
HIV/AIDS; serodiscordant couples; serodiscordant; antiretroviral therapy; Africa
14.  Long-term Virologic Response and Genotypic Resistance Mutations in HIV-1 Infected Kenyan Children on Combination Antiretroviral Therapy 
HIV-infected children may require the use of combination antiretroviral treatment (cART) into adulthood. However, regimens are limited to first- and second-line in many African settings. Therefore, understanding the long-term rate of virologic failure and drug resistance during prolonged antiretroviral treatment is important for establishing treatment strategies in African pediatric cohorts.
Children ages 18 months to 12 years initiated first-line cART and were followed every 1–3 months, for up to 5.5 years. Treatment was switched to second-line based on clinical and immunologic criteria according to national guidelines. Virologic failure was determined retrospectively as defined by ≥2 viral loads >5000 copies/mL. Drug resistance was assessed during viral failure by population-based sequencing.
Among 100 children on first-line cART followed for a median 49 months, 34% experienced virologic failure. Twenty-three (68%) of the 34 children with viral failure had detectable resistance mutations, of whom 14 (61%) had multi-class resistance. Fourteen (14%) children were switched to second-line regimens and followed for a median of 28 months. Retrospective analysis revealed that virologic failure had occurred a median of 12 months prior to the switch to second-line. During prolonged first-line treatment in the presence of viral failure, additional resistance mutations accumulated, however, only 1 (7%) of 14 children had persistent viremia during second-line treatment.
Virologic suppression was maintained on first-line cART in two-thirds of HIV-infected children for up to 5 years. Switch to second-line based on clinical/immunologic criteria occurred ~1 year after viral failure, but the delay did not consistently compromise second-line treatment.
PMCID: PMC3593972  PMID: 23196827
15.  Maternal Valacyclovir and Infant Cytomegalovirus Acquisition: A Randomized Controlled Trial among HIV-Infected Women 
PLoS ONE  2014;9(2):e87855.
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 of CMV.
Pregnant women with HIV-1, HSV-2 and CD4 count >250 cells/µl 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.
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 (p = 0.05).
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 antiviral agents.
Trials Registration NCT00530777
PMCID: PMC3913686  PMID: 24504006
16.  Immune Response to Hepatitis B Virus Vaccination Among HIV-1 Infected And Uninfected Adults in Kenya 
The Journal of Infectious Diseases  2012;207(3):402-410.
Background. In studies from high-income countries, human immunodeficiency virus type 1 (HIV-1)–infected persons have diminished responses to hepatitis B virus (HBV) vaccination, compared with HIV-1–uninfected persons, but data from other settings are limited.
Methods. We compared the immune response to HBV vaccination among HIV-1–infected and HIV-1–uninfected Kenyan adults and assessed the response of HIV-1–infected initial nonresponders to revaccination with a standard HBV vaccine series.
Results. Of 603 participants, 310 (51.4%) were HIV-1–infected, for whom the median CD4+ T-cell count was 557 cells/μL (interquartile range, 428–725 cells/μL); none were receiving antiretroviral therapy. Nonresponse to HBV vaccine was higher among HIV-1–infected participants, compared with HIV-1–uninfected participants (35.8% vs 14.3%; odds ratio, 3.33; P < .001). Of 102 HIV-1–infected initial nonresponders, 88 (86.3%) responded to revaccination, for an overall response, including to revaccination, of 94.9%. Among HIV-1–infected individuals, lower CD4+ T-cell counts and male sex were independent predictors of nonresponse to initial vaccination, and lower body mass index, higher plasma HIV-1 RNA levels, and longer time to revaccination predicted nonresponse to revaccination.
Conclusions. Kenyan adults had similar HBV vaccination responses as persons from high-income countries. Timely revaccination of HIV-1–infected nonresponders increased response to the vaccine to 95%.
PMCID: PMC3537443  PMID: 23175769
HBV vaccine; HIV-1; Africa
17.  Correlates and outcomes of preterm birth, low birth weight, and small for gestational age in HIV-exposed uninfected infants 
Preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) contribute to neonatal mortality. Maternal HIV-1 infection has been associated with an increased risk of PTB, but mechanisms underlying this association are undefined. We describe correlates and outcomes of PTB, LBW, and SGA in HIV-exposed uninfected infants.
This was a retrospective analysis of cohort study. Between 1999–2002, pregnant, HIV-infected women were enrolled into an HIV-1 transmission study. Logistic regression was used to identify correlates of PTB, LBW and SGA in HIV-negative, spontaneous singleton deliveries. Associations between birth outcomes and mortality were measured using survival analyses.
In multivariable models, maternal plasma (OR = 2.1, 95% CI = 1.1-3.8) and cervical HIV-1 RNA levels (OR = 1.6, 95% CI = 1.1-2.4), and CD4 < 15% (OR = 2.4, 95% CI = 1.0-5.6) were associated with increased odds of PTB. Abnormal vaginal discharge and cervical polymorphonuclear leukocytes were also associated with PTB. Cervical HIV-1 RNA level (OR = 2.4, 95% CI = 1.5-6.7) was associated with an increased odds of LBW, while increasing parity (OR = 0.46, 95% CI = 0.24-0.88) was associated with reduced odds. Higher maternal body mass index (OR = 0.75, 95% CI = 0.61-0.92) was associated with a reduced odds of SGA, while bacterial vaginosis was associated with >3-fold increased odds (OR = 3.2, 95% CI = 1.4-7.4). PTB, LBW, and SGA were each associated with a >6-fold increased risk of neonatal death, and a >2-fold increased rate of infant mortality within the first year.
Maternal plasma and cervical HIV-1 RNA load, and genital infections may be important risk factors for PTB in HIV-exposed uninfected infants. PTB, LBW, and SGA are associated with increased neonatal and infant mortality in HIV-exposed uninfected infants.
PMCID: PMC3897882  PMID: 24397463
Preterm birth; Low birth weight; Small for gestational age; Pediatric HIV
18.  Partner Characteristics Predicting HIV-1 Set Point in Sexually Acquired HIV-1 Among African Seroconverters 
Plasma HIV-1 RNA set point is an important predictor of HIV-1 disease progression. We hypothesized that inoculum size and HIV-1 exposure prior to HIV-1 transmission may modulate set point. We evaluated predictors of set point among 141 African HIV-1 seroconverters and their HIV-1-infected study partners. We compared characteristics of seroconverters and their HIV-1-infected partners and HIV-1 set point. Data were from a clinical trial of genital HSV-2 suppression with acyclovir to reduce HIV-1 transmission in HIV-1 serodiscordant couples with HIV-1 transmission linkage assigned through virus sequencing. Our analysis includes data from all transmissions including those with transmission linkage to the HIV-1-infected “source partner” and those that were not linked to their HIV-1-infected study partner. In multivariable analysis, higher plasma HIV-1 in source partners was associated with higher seroconverter set point (+0.44 log10 copies/ml per log10 source partner plasma HIV-1, p<0.001). In addition, bacterial vaginosis (BV) among female source partners near the time of infection was associated with higher set point in their male seroconverters (+0.49 log10, p=0.04). Source partner characteristics associated with lower set point included male circumcision (−0.63 log10, p=0.03) and assignment to acyclovir (−0.44 log10, p=0.02). The proportion of variation in set point explained by plasma HIV-1 RNA of the source partner, after controlling for other factors, was 0.06. Source partner plasma HIV-1 level is the most significant predictor of seroconverter set point, possibly reflecting characteristics of the transmitted virus. Acyclovir use, BV among women source partners, and circumcision among male source partners may alter the set point by affecting transmitted virus inoculum in the source partners' genital compartment.
PMCID: PMC3537302  PMID: 23061422
19.  Short Communication: T Cell Activation in HIV-1/Herpes Simplex Virus-2-Coinfected Kenyan Women Receiving Valacyclovir 
Herpes simplex virus-2 (HSV-2) suppression with acyclovir or valacyclovir reduces HIV-1 viral RNA levels; one hypothesis is that HSV-2 suppression reduces immune activation. We measured T cell immune activation markers among women participating in a randomized placebo-controlled trial of valacyclovir to reduce HIV-1 RNA levels among pregnant women. Although valacyclovir was associated with lower HIV-1 RNA levels, the distribution of both CD4+ and CD8+ CD38+HLA-DR+ T cells was not different among women taking valacyclovir when compared to women taking placebo. Further study is needed to understand the mechanism of HIV-1 RNA reduction following herpes suppression among those coinfected with HIV-1 and HSV-2.
PMCID: PMC3537320  PMID: 22852760
21.  Cervicovaginal HIV-1 Neutralizing IgA Detected among HIV-1-Exposed Seronegative Female Partners in HIV-1-Discordant Kenyan Couples 
AIDS (London, England)  2012;26(17):2155-2163.
Cervicovaginal HIV-1-neutralizing IgA was associated with reduced HIV-1 acquisition in a cohort of commercial sex workers. We aimed to define the prevalence and correlates of HIV-1-neutralizing IgA from HIV-1-exposed seronegative (HESN) women in HIV-1-serodiscordant relationships.
HIV-1-serodiscordant couples in Nairobi were enrolled and followed quarterly up to two years, and women in concordant HIV-1-negative relationships were enrolled as controls. Cervicovaginal, seminal, and blood samples were collected at enrollment and follow-up. Cervicovaginal IgA was assessed for HIV-1-neutralizing activity by a peripheral blood mononuclear cell-based assay using an HIV-1 clade A primary isolate.
HESN women in discordant relationships had significantly more HIV-1-neutralizing IgA detected in genital secretions compared to control women (36 of 155 [23%] vs. 4 of 70 [6%], respectively; odds ratio [OR] 5.0; 95% confidence interval [CI] 1.70–14.64; P=0.003). These responses persisted over time in all available follow-up cervicovaginal samples from women with detectable HIV-1-neutralizing IgA at baseline. Partner median HIV-1 plasma viral load was lower among women who had HIV-1-neutralizing IgA compared to women without detectable activity (4.3 vs. 4.8 log10 copies/ml, respectively; OR 0.70; 95% CI 0.51–0.94; P=0.02). A similar trend was found with partner seminal viral load (OR 0.57; 95% CI 0.32–1.02; P=0.06).
HESN women were 5-times more likely to have neutralizing IgA in cervicovaginal secretions than low-risk control women, and these responses were inversely associated with partner viral load. These observations support the existence of antiviral activity in the mucosal IgA fraction following sexual HIV-1 exposure.
PMCID: PMC3799883  PMID: 22948273
HIV; immunoglobulin A; discordant couple; exposed uninfected; Africa; neutralization; viral load
22.  Quantifying Ongoing HIV-1 Exposure in HIV-1–Serodiscordant Couples to Identify Individuals With Potential Host Resistance to HIV-1 
The Journal of Infectious Diseases  2012;206(8):1299-1308.
Background. Immunogenetic correlates of resistance to HIV-1 in HIV-1–exposed seronegative (HESN) individuals with consistently high exposure may inform HIV-1 prevention strategies. We developed a novel approach for quantifying HIV-1 exposure to identify individuals remaining HIV-1 uninfected despite persistent high exposure.
Methods. We used longitudinal predictors of HIV-1 transmission in HIV-1 serodiscordant couples to score HIV-1 exposure and define HESN clusters with persistently high, low, and decreasing risk trajectories. The model was validated in an independent cohort of serodiscordant couples. We describe a statistical tool that can be applied to other HESN cohorts to identify individuals with high exposure to HIV-1.
Results. HIV-1 exposure was best quantified by frequency of unprotected sex with, plasma HIV-1 RNA levels among, and presence of genital ulcer disease among HIV-1–infected partners and by age, pregnancy status, herpes simplex virus 2 serostatus, and male circumcision status among HESN participants. Overall, 14% of HESN individuals persistently had high HIV-1 exposure and exhibited a declining incidence of HIV-1 infection over time.
Conclusions. A minority of HESN individuals from HIV-1–discordant couples had persistent high HIV-1 exposure over time. Decreasing incidence of infection in this group suggests these individuals were selected for resistance to HIV-1 and may be most appropriate for identifying biological correlates of natural host resistance to HIV-1 infection.
PMCID: PMC3448964  PMID: 22926009
23.  Specificity of Four Laboratory Approaches for Cross-Sectional HIV Incidence Determination: Analysis of Samples from Adults with Known Nonrecent HIV Infection from Five African Countries 
AIDS Research and Human Retroviruses  2012;28(10):1177-1183.
Assays to determine cross-sectional HIV incidence misclassify some individuals with nonrecent HIV infection as recently infected, overestimating HIV incidence. We analyzed factors associated with false-recent misclassification in five African countries. Samples from 2197 adults from Botswana, Kenya, South Africa, Tanzania, and Uganda who were HIV infected >12 months were tested using the (1) BED capture enzyme immunoassay (BED), (2) avidity assay, (3) BED and avidity assays with higher assay cutoffs (BED+avidity screen), and (4) multiassay algorithm (MAA) that includes the BED+avidity screen, CD4 cell count, and HIV viral load. Logistic regression identified factors associated with misclassification. False-recent misclassification rates and 95% confidence intervals were BED alone: 7.6% (6.6, 8.8); avidity assay alone: 3.5% (2.7, 4.3); BED+avidity screen: 2.2% (1.7, 2.9); and MAA: 1.2% (0.8, 1.8). The misclassification rate for the MAA was significantly lower than the rates for the other three methods (each p<0.05). Misclassification rates were lower when the analysis was limited to subtype C-endemic countries, with the lowest rate obtained for the MAA [0.8% (0.2, 1.9)]. Factors associated with misclassification were for BED alone: country of origin, antiretroviral treatment (ART), viral load, and CD4 cell count; for avidity assay alone: country of origin; for BED+avidity screen: country of origin and ART. No factors were associated with misclassification using the MAA. In a multivariate model, these associations remained significant with one exception: the association of ART with misclassification was completely attenuated. A MAA that included CD4 cell count and viral load had lower false-recent misclassification than the BED or avidity assays (alone or in combination). Studies are underway to compare the sensitivity of these methods for detection of recent HIV infection.
PMCID: PMC3448109  PMID: 22283149
24.  Antiretroviral Prophylaxis for HIV-1 Prevention among Heterosexual Men and Women 
The New England journal of medicine  2012;367(5):399-410.
Antiretroviral pre-exposure prophylaxis (PrEP) reduces the incidence of acquisition of human immunodeficiency virus type 1 (HIV-1) in men who have sex with men and is a promising approach for preventing HIV-1 in heterosexual populations.
We conducted a randomized, three-arm trial of oral antiretroviral PrEP among heterosexual couples from Kenya and Uganda in which one member was HIV-1 seronegative and the other HIV-1 seropositive. Seronegative partners were randomly assigned to once-daily tenofovir (TDF), combination emtricitabine/tenofovir (FTC/TDF), or matching placebo and followed monthly for up to 36 months. At enrollment, HIV-1 seropositive partners were not eligible for antiretroviral therapy under national guidelines. All couples received standard HIV-1 treatment and prevention services, including individual and couples risk-reduction counseling and condoms.
4758 couples were enrolled; for 62%, the HIV-1 seronegative partner was male. For HIV-1 seropositive participants, the median CD4 count was 495 cells/μL (interquartile range 375–662). Of 82 post-randomization HIV-1 infections, 17 were among those assigned TDF (incidence 0.65 per 100 person-years), 13 among those assigned FTC/TDF (incidence 0.50 per 100 person-years), and 52 among those assigned placebo (incidence 1.99 per 100 person-years), indicating a 67% relative reduction in HIV-1 incidence for TDF (95% CI 44 to 81, p<0.001) and 75% for FTC/TDF (95% CI 55 to 87, p<0.001). HIV-1 protective effects of FTC/TDF and TDF were not significantly different (p=0.23), and both study medications significantly reduced HIV-1 incidence in both men and women. The rate of serious medical events was similar across the study arms.
Oral TDF and FTC/TDF provided substantial protection against HIV-1 acquisition in heterosexual men and women, with comparable efficacy of TDF and FTC/TDF. (Funded by the Bill and Melinda Gates Foundation; number NCT00557245)
PMCID: PMC3770474  PMID: 22784037
HIV-1 serodiscordant couples; pre-exposure prophylaxis; HIV-1 prevention; randomized clinical trial; Africa
25.  Breast milk cellular HIV-specific interferon γ responses are associated with protection from peripartum HIV transmission 
AIDS (London, England)  2012;26(16):2007-2016.
Breast milk is a major route of infant HIV infection, yet the majority of breast-fed, HIV-exposed infants escape infection by unknown mechanisms. This study aimed to investigate the role of HIV-specific breast milk cells in preventing infant HIV infection.
A prospective study was designed to measure associations between maternal breast milk HIV-specific interferon-γ (IFN-γ) responses and infant HIV-1 detection at 1 month of age.
In a Kenyan cohort of HIV-infected mothers, blood and breastmilk HIV-gag IFN-γ ELISpot responses were measured. Logistic regression was used to measure associations between breast milk IFN-γ responses and infant HIV infection at 1 month of age.
IFN-γ responses were detected in breast milk from 117 of 170 (69%) women. IFN-γ responses were associated with breast milk viral load, levels of macrophage inflammatory protein (MIP) 1α, MIP-1β, regulated upon activation, normal T-cell expressed, and secreted and stromal-cell derived factor 1 and subclinical mastitis. Univariate factors associated with infant HIV infection at 1 month postpartum included both detection and breadth of breast milk IFN-γ response (P =0.08, P =0.04, respectively), breast milk MIP-1β detection (P =0.05), and plasma (P =0.004) and breast milk (P =0.004) viral load. In multivariate analyses adjusting for breast milk viral load and MIP-1β, breast milk IFN-γ responses were associated with an approximately 70% reduction in infant HIV infection [adjusted odds ratio (aOR) 0.29, 95% confidence interval (CI) 0.092–0.91], and each additional peptide pool targeted was associated with an approximately 35% reduction in infant HIV (aOR 0.65, 95% CI 0.44–0.97).
These data show breast milk HIV-gag-specific IFN-γ cellular immune responses are prevalent and may contribute to protection from early HIV transmission. More broadly, these data suggest breast milk cellular responses are potentially influential in decreasing mother-to-child transmission of viruses.
PMCID: PMC3718292  PMID: 22948269
breastfeeding; breast milk cytotoxic T lymphocytes; cytokines; early postnatal transmission; infant; MIP-1β; pediatric; sub-Saharan Africa

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