Advanced HIV disease (AHD) remains a significant burden, despite the widespread use of antiretroviral therapy (ART) programs. Individuals with AHD are at a high risk of death even after starting ART. We characterized treatment naïve and treatment experienced clients presenting with AHD in western Kenya to inform service delivery and program improvement. We conducted a retrospective study using routinely collected program data from October 2016 to September 2019 for AHD clients in eight facilities in Homa Bay County, Kenya. Demographic and clinical data were abstracted from the medical records of AHD clients, defined as HIV-positive clients aged ≥ 5 years with documented CD4 count < 200 cells/mm3 and/or WHO clinical stage II/IV. Associations were assessed using Pearson's chi-square and Mann-Whitney Rank-Sum tests at 5% level of significance. Of the 19,427 HIV clients at the eight facilities, 6649 (34%) had a CD4 count < 200 cells/mm3 or a WHO III/IV stage. Of these, 1845 were randomly selected for analysis. Over half (991) of participants were aged 45 + years and 1040 (56%) were female. The median age was 46.0 years (interquartile range: 39.2-54.5); 1553 (84%) were in care at county and sub-county hospitals; and 1460 (79%) were WHO stage III/IV at enrollment. At ART initiation, 241 (13%) had tuberculosis, 192 (10%) had chronic diarrhea, and 94 (5%) had Pneumocystis jiroveci pneumonia. At the time of data collection, 89 (5%) participants had died and 140 (8%) were lost to follow-up. Eighteen percent (330) of participants were ART-experienced (on ART for ≥ 3 months). The proportions of ART-experienced and -naïve clients regarding age, sex and marital status were similar. However, a higher proportion of ART-experienced clients received care at primary care facilities, (93(28%) vs. 199 (13%); P < .001); were WHO stage 3/4 at AHD diagnosis, 273 (84%) vs. 1187 (79%) (P = .041); and had died or been LTFU, (124 (38%) vs. 105 (7%); P < .001). With increasing prevalence of patients on ART, the proportion of AHD treatment-experienced clients may increase without effective interventions to ensure that these patients remain in care.

Despite large numbers of patients accessing antiretroviral treatment (ART) in Kenya, few studies have explored factors associated with virologic failure in Western Kenya, specifically. We undertook a study in Homa Bay County, Kenya to assess the extent of virologic treatment failure and factors associated with it. This was an observational retrospective study conducted from September 2020 to January 2021. Data were abstracted from the records of patients who had been on ART for at least six months at the time of data collection after systematic sampling stratified by age group at ART initiation (0-14 and 15+ years), using probability proportion to the numbers of patients attending the facility. Confirmed viral treatment failure was defined as viral load ≥1000 copies/ml based on two consecutive viral load measurements after at least three months of enhanced adherence counseling. Data were analyzed using descriptive statistics and Cox regression modeling. Of the 2,007 patients sampled, 160 (8.0%) had confirmed virologic treatment failure. Significantly higher virologic treatment failure rates were identified among male patients 78/830 (9.4%) and children 115/782 (14.7%). Factors associated with virologic treatment failure (VTF), were age 0-14 years, adjusted hazard ratio (AHR) 4.42, (95% Confidence Interval [CI], 3.12, 6.32), experience of treatment side effects AHD: 2.43, (95% CI, 1.76, 3.37), attending level 2/3 health facility, AHR: 1.87, (95% CI: 1.29, 2,72), and history of opportunistic infections (OIs), AHR: 1.81, (95% CI, 1.76, 3.37). Children, attendees of level 2/3 health facilities, patients with a history of OIs, and those experiencing treatment side-effects are at risk of VTF. Increased focus on children and adolescents on screening for drug resistance, administration of and adherence to medication, and on effective information and education on side-effects is critical. Additionally, there is need for increased training and support for health care workers at primary level care facilities.

Viral suppression is suboptimal among children and adolescents on antiretroviral therapy (ART) in Kenya. We implemented and evaluated a standardized enhanced adherence counseling (SEAC) package to improve viral suppression in children and adolescents with suspected treatment failure in Homa Bay and Turkana. The SEAC package, implemented from February 2019 to September 2020, included: standard procedures operationalizing the enhanced adherence counseling (EAC) process; provider training on psychosocial support and communication skills for children living with HIV and their caregivers; mentorship to providers and peer educators on EAC processes; and individualized case management. We enrolled children and adolescents aged 0 to 19 years with suspected treatment failure (viral load [VL] >1000 copies/mL) who received EAC before standardization as well as those who received SEAC in a pre-post evaluation of the SEAC package conducted in 6 high-volume facilities. Pre-post standardization comparisons were performed using Wilcoxon-Mann-Whitney and Pearson's chi-square tests at a 5% level of significance. Multivariate logistic regression was performed to identify factors associated with viral resuppression. The study enrolled 741 participants, 595 pre- and 146 post-SEAC implementation. All post-SEAC participants attended at least 1 EAC session, while 17% (n = 98) of pre-SEAC clients had no record of EAC attendance. Time to EAC following the detection of high VL was reduced by a median of 8 days, from 49 (interquartile range [IQR]: 23.0-102.5) to 41 (IQR: 20.0-67.0) days pre- versus post-SEAC (P = .006). Time to completion of at least 3 sessions was reduced by a median of 12 days, from 59.0 (IQR: 36.0-91.0) to 47.5 (IQR: 33.0-63.0) days pre- versus post-SEAC (P = .002). A greater percentage of clients completed the recommended minimum 3 EAC sessions at post-SEAC, 88.4% (n = 129) versus 61.1% (n = 363) pre-SEAC, P < .001. Among participants with a repeat VL within 3 months following the high VL, SEAC increased viral suppression from 34.6% (n = 76) to 52.5% (n = 45), P = .004. Implementation of the SEAC package significantly reduced the time to initiate EAC and time to completion of at least 3 EAC sessions, and was significantly associated with viral suppression in children and adolescents with suspected treatment failure.

BACKGROUND: Adolescents living with HIV (ALHIV) experience higher mortality and are more likely to have poor antiretroviral therapy (ART) adherence and unsuppressed viral load (VL) compared to adults. Enhanced adherence counseling (EAC) is a client-centered counseling strategy that aims to identify and address barriers to optimal ART use and can be tailored to the unique needs of adolescents. This study aimed to better understand adherence barriers among ALHIV with suspected treatment failure and their experience with EAC to inform future programming. METHODS: A qualitative study was conducted in Homa Bay and Turkana counties, Kenya in 2019 with adolescents and caregivers of children and adolescents living with HIV with suspected treatment failure after 6months on ART and who had received 1 EAC sessions. Sixteen focus group discussions (FGDs) were conducted; five FGDs each were held with adolescents 12-14years (n=48) and 15-19years (n=36). Caregivers (n=52) participated in six FGDs. Additionally, 17 healthcare workers providing pediatric/adolescent HIV services participated in in-depth interviews. Audio recordings were transcribed and translated from Kiswahili or Dholuo into English and coded using MAXQDA software. Data were thematically analyzed by participant group. RESULTS: Participants identified adolescents' fear of being stigmatized due to their HIV status and their relationship with and level of support provided by caregivers. This underpinned and often undermined adolescents' ART-taking behavior and progress towards more independent medication management. Adolescents were generally satisfied with EAC and perceived it to be important in improving adherence and reducing VL. However, problems were noted with facility-based, individual EAC counseling, including judgmental attitudes of providers and difficulties traveling to and keeping EAC clinic appointments. Participant-suggested improvements to EAC included peer support groups in addition to individual counseling, allowing for greater flexibility in the timing and location of sessions and greater caregiver involvement. CONCLUSIONS: The findings provide opportunities to better tailor EAC interventions to promote improved ALHIV adherence and caregiver-supported disease management. Multi-prong EAC interventions that include peer-led and community approaches and target adolescent and caregiver treatment literacy may improve EAC delivery, address issues contributing to poor adherence, and position adolescents to achieve viral suppression. TRIAL REGISTRATION: ClinicalTrials.gov : NCT04915469.

BACKGROUND: For HIV-infected pregnant and breastfeeding women, antiretroviral therapy (ART) is known to reduce the mother's risk of passing the infection to her child. However, concerns remain about possible associations between various components of different ART regimens and adverse fetal and infant outcomes. As part of a clinical trial in western Kenya for the prevention of mother-to-child transmission (PMTCT) of HIV, pregnant women received one of two different ART regimens. METHODS: The original PMTCT study conducted in Kenya enrolled 522 HIV-infected, ART-naive pregnant women. These women were assigned to receive an ART regimen that included either nevirapine, a nonnucleoside reverse transcriptase inhibitor (NNRTI), or nelfinavir, a protease inhibitor. This substudy involves 384 women from the original study who had baseline CD4 counts at least 250 cells/mul, and compares the risks of adverse fetal and infant outcomes between the two ART regimens. RESULTS: There were 386 live births (including multiples) and 7 (1.8%) stillbirths. Among live births, there were 67 preterm deliveries, 37 low-birth weight infants, and 14 infant deaths by 6 months. There were no statistically significant differences between the two ART regimens for any of the reported adverse outcomes. CONCLUSION: Although these data do not show significant differences between the NNRTI-based or protease inhibitor-based regimens in serious adverse fetal and infant outcomes, more studies need to be done and careful vigilance is needed to ensure infant safety.

OBJECTIVE: The prevalence of anaemia during pregnancy is estimated to be 35-75% in sub-Saharan Africa and is associated with an increased risk of maternal mortality. We evaluated the frequency and factors associated with anaemia in HIV-infected women undergoing antiretroviral (ARV) therapy for prevention of mother-to-child transmission (PMTCT) enrolled in The Kisumu Breastfeeding Study 2003-2009. METHODS: Maternal haematological parameters were monitored from 32 to 34 weeks of gestation to 2 years post-delivery among 522 enrolled women. Clinical and laboratory assessments for causes of anaemia were performed, and appropriate management was initiated. Anaemia was graded using the National Institutes of Health Division of AIDS 1994 Adult Toxicity Tables. Data were analysed using SAS software, v 9.2. The Wilcoxon two-sample rank test was used to compare groups. A logistic regression model was fitted to describe the trend in anaemia over time. RESULTS: At enrolment, the prevalence of any grade anaemia (Hb < 9.4 g/dl) was 61.8%, but fell during ARV therapy, reaching a nadir (7.4%) by 6 months post-partum. A total of 41 women (8%) developed severe anaemia (Hb < 7 g/dl) during follow-up; 2 (4.9%) were hospitalised for blood transfusion, whereas 3 (7.3%) were transfused while hospitalised (for delivery). The greatest proportion of severe anaemia events occurred around delivery (48.8%; n = 20). Anaemia (Hb ≥ 7 and < 9.4 g/dl) at enrolment was associated with severe anaemia at delivery (OR 5.87; 95% CI: 4.48, 7.68, P < 0.01). Few cases of severe anaemia coincided with clinical malaria (24.4%; n = 10) and helminth (7.3%; n = 3) infections. CONCLUSION: Resolution of anaemia among most participants during study follow-up was likely related to receipt of ARV therapy. Efforts should be geared towards addressing common causes of anaemia in HIV-infected pregnant women, prioritising initiation of ARV therapy and management of peripartum blood loss.

BACKGROUND: Anemia results in increased morbidity and mortality, underscoring the need to better understand its pathophysiology amongst HIV-exposed and infected children in sub-Saharan Africa, the region where most infant HIV exposure and infections occur. METHODS: This analysis used samples obtained from children in the Kisumu Breastfeeding Study (KiBS). KiBS was a longitudinal phase IIB, open-label, one-arm clinical trial, designed to investigate the safety, tolerability and effectiveness of a maternal triple-antiretroviral (ARV) regimen for prevention of mother-to-child transmission (PMTCT) of HIV, during late pregnancy and early infancy while breastfeeding. Blood samples from 482 children were obtained at birth, 2, 6, 10 and 14 weeks and 6, 9, 12, 18 and 24 months. Severity of anemia was graded using the NIH Division of AIDS (DAIDS) toxicity tables. We describe the proportion of children with anemia and anomalies in red blood cell parameters at various time points over 24 months and compare rates of anemia between HIV-infected and HIV-uninfected children and by mothers' ARV regimen and infant malaria infection. RESULTS: The proportion of children with anemia significantly increased after the breastfeeding period in both HIV-infected and HIV-uninfected children with higher proportion among HIV-infected children compared to HIV-uninfected children (RR: 1.72; CI: 1.22-2.44, p = 0.002). Maternal triple-antiretroviral regimen was not associated with infant anemia (p = 0.11). There was no significant difference in mean hemoglobin between HIV-uninfected children with and without malaria at each time point except at 24 months. CONCLUSION: A relatively lower proportion of children with severe anemia during the breastfeeding period suggest that exposure to mother's triple antiretroviral combinations through breast milk, posed minimal risk of hematologic toxicity.

BACKGROUND: In 2012, the World Health Organization (WHO) amended their 2010 guidelines for women receiving limited duration, triple-antiretroviral drug regimens during pregnancy and breastfeeding for prevention of mother-to-child transmission of HIV (tARV-PMTCT) (Option B) to include the option to continue lifelong combination antiretroviral therapy (cART) (Option B+). We evaluated clinical and CD4 outcomes in women who had received antiretrovirals for prevention of mother-to-child transmission and then discontinued antiretrovirals 6-months postpartum. METHODS AND FINDINGS: The Kisumu Breastfeeding Study, 2003-2009, was a prospective, non-randomized, open-label clinical trial of tARV-PMTCT in ARV-naive, Kenyan women. Women received tARV-PMTCT from 34 weeks' gestation until 6-months postpartum when women were instructed to discontinue breastfeeding. Women with CD4 count (CD4) <250cells/mm3 or WHO stage III/IV prior to 6-months postpartum continued cART indefinitely. We estimated the change in CD4 after discontinuing tARV-PMTCT and the adjusted relative risk [aRR] for factors associated with declines in maternal CD4. We compared maternal and infant outcomes following weaning-when tARV-PMTCT discontinued-by maternal ARV status through 24-months postpartum. Compared with women who continued cART, discontinuing antiretrovirals was associated with infant HIV transmission and death (10.1% vs. 2.4%; P = 0.03). Among women who discontinued antiretrovirals, CD4<500 cells/mm3 at either initiation (21.8% vs. 1.5%; P = 0.002; aRR: 9.8; 95%-confidence interval [CI]: 2.4-40.6) or discontinuation (36.9% vs. 8.3%; P<0.0001; aRR: 4.4; 95%-CI: 1.9-5.0) were each associated with increased risk of women requiring cART for their own health within 6 months after discontinuing. CONCLUSIONS: Considering the serious health risks to the woman's infant and the brief reprieve from cART gained by stopping, every country should evaluate the need for and feasibility to implement WHO Option B+ for PMTCT. Evaluating CD4 at antiretroviral initiation or 6-months postpartum can identify pregnant women who would most benefit from continuing cART in settings unable to implement WHO Option B+.

We compared adverse events among breastfeeding neonates born to Kenyan mothers receiving triple-antiretroviral therapy including either nevirapine or nelfinavir. Nevirapine-exposed infants had an absolute increase in risk for rash but no significant risk differences for hepatotoxicity or high-risk hyperbilirubinemia compared with nelfinavir-exposed infants. From an infant-safety perspective, nevirapine-based regimens given during pregnancy and breastfeeding are viable options where alternatives to breast milk are not safe, affordable, or feasible.

BACKGROUND: Health benefits and survival of an exclusively breastfed infant is dependent on the mother's health; thus the need for antiretroviral (ARV) intervention for PMTCT. Achieving maternal health benefits from these regimens requires adherence to the treatments and close monitoring. We evaluated virologic, immunologic responses and adherence among women receiving maternal triple antiretroviral prophylaxis consisting of lamivudine/zidovudine and nevirapine or nelfinavir in the Kisumu Breastfeeding Study. METHODS: We analyzed baseline demographic data, trends in CD4+ count and viral load (VL) at enrollment (32-34 weeks gestation), delivery, 14 and 24 weeks postpartum among 434 women who remained in the study at 24 weeks postpartum. Adherence rates were determined using pill counts reinforced by self-report and drug calendar. We dichotomized adherence as ≥95% versus <95%. RESULTS: Among the 434 women, 84% (n=366) had adherence ≥95%. Women with undetectable VL (<400 copies/ml) increased from 6% at baseline to 79% and women with CD4+ count <250cells/mcL decreased from 23% (100) at baseline to 5% (22) at 24 weeks postpartum. In discrete-survival model, time to achieving VL suppression was associated with baseline VL <5.0 log copies/ml, parity ≥2, and use of nelfinavir versus nevirapine-based ARV. Association between undetectable VL with duration of therapy (p<0.0001); and adherence with suppression of VL (p=0.001) was observed. CONCLUSIONS: High baseline VL and short exposure to ARVs for PMTCT are risk factors for failing to achieve undetectable VL. These findings support the new WHO guidelines for early initiation of ARV prophylaxis for PMTCT for maximal reduction of maternal VL.

BACKGROUND: Few studies have evaluated the risk of nevirapine (NVP)-associated hepatotoxicity among HIV-infected pregnant women with a CD4 count ≥250 cells/mm(3). METHODS: We enrolled HIV-infected pregnant Kenyan women who initiated triple antiretroviral therapy (ART) at 34 weeks gestation. We compared the rates of severe hepatotoxicity (grades 3-4 hepatotoxicity) and rash-associated hepatotoxicity (rash with ≥grade 2 hepatotoxicity) with NVP and nelfinavir (NFV), respectively. RESULTS: We initiated triple ART in 522 pregnant women; severe hepatotoxicity and rash-associated hepatotoxicity occurred in 14 (3%) and 9 (2%) women, respectively. Women who initiated NVP had higher rates of severe hepatotoxicity (5% vs 1%; P = .03) and rash-associated hepatotoxicity (4% vs 0%; P = .003) when compared with NFV. Among women who initiated NVP (n = 254), a baseline CD4 count ≥250 cells/mm(3) was not associated with severe hepatotoxicity (5% vs 3%; P = .52) or rash-associated hepatotoxicity (4% vs 3%; P = .69). CONCLUSION: Nevirapine use but not CD4 count ≥250 cells/mm(3) was associated with hepatotoxicity.

BACKGROUND: Effective strategies are needed for the prevention of mother-to-child HIV transmission (PMTCT) in resource-limited settings. The Kisumu Breastfeeding Study was a single-arm open label trial conducted between July 2003 and February 2009. The overall aim was to investigate whether a maternal triple-antiretroviral regimen that was designed to maximally suppress viral load in late pregnancy and the first 6 mo of lactation was a safe, well-tolerated, and effective PMTCT intervention. METHODS AND FINDINGS: HIV-infected pregnant women took zidovudine, lamivudine, and either nevirapine or nelfinavir from 34-36 weeks' gestation to 6 mo post partum. Infants received single-dose nevirapine at birth. Women were advised to breastfeed exclusively and wean rapidly just before 6 mo. Using Kaplan-Meier methods we estimated HIV-transmission and death rates from delivery to 24 mo. We compared HIV-transmission rates among subgroups defined by maternal risk factors, including baseline CD4 cell count and viral load. Among 487 live-born, singleton, or first-born infants, cumulative HIV-transmission rates at birth, 6 weeks, and 6, 12, and 24 mo were 2.5%, 4.2%, 5.0%, 5.7%, and 7.0%, respectively. The 24-mo HIV-transmission rates stratified by baseline maternal CD4 cell count <500 and ≥500 cells/mm(3) were 8.4% (95% confidence interval [CI] 5.8%-12.0%) and 4.1% (1.8%-8.8%), respectively (p = 0.06); the corresponding rates stratified by baseline maternal viral load <10,000 and ≥10,000 copies/ml were 3.0% (1.1%-7.8%) and 8.7% (6.1%-12.3%), respectively (p = 0.01). None of the 12 maternal and 51 infant deaths (including two second-born infants) were attributed to antiretrovirals. The cumulative HIV-transmission or death rate at 24 mo was 15.7% (95% CI 12.7%-19.4%). CONCLUSIONS: This trial shows that a maternal triple-antiretroviral regimen from late pregnancy through 6 months of breastfeeding for PMTCT is safe and feasible in a resource-limited setting. These findings are consistent with those from other trials using maternal triple-antiretroviral regimens during breastfeeding in comparable settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT00146380 Please see later in the article for the Editors' Summary.

BACKGROUND: Nevirapine and lamivudine given to mothers are transmitted to infants via breastfeeding in quantities sufficient to have biologic effects on the virus; this may lead to an increased risk of a breastfed infant's development of resistance to maternal antiretrovirals. The Kisumu Breastfeeding Study (KiBS), a single-arm open-label prevention of mother-to-child HIV transmission (PMTCT) trial, assessed the safety and efficacy of zidovudine, lamivudine, and either nevirapine or nelfinavir given to HIV-infected women from 34 wk gestation through 6 mo of breastfeeding. Here, we present findings from a KiBS trial secondary analysis that evaluated the emergence of maternal ARV-associated resistance among 32 HIV-infected breastfed infants. METHODS AND FINDINGS: All infants in the cohort were tested for HIV infection using DNA PCR at multiple study visits during the 24 mo of the study, and plasma RNA viral load for all HIV-PCR-positive infants was evaluated retrospectively. Specimens from mothers and infants with viral load >1,000 copies/ml were tested for HIV drug resistance mutations. Overall, 32 infants were HIV infected by 24 mo of age, and of this group, 24 (75%) infants were HIV infected by 6 mo of age. Of the 24 infants infected by 6 mo, nine were born to mothers on a nelfinavir-based regimen, whereas the remaining 15 were born to mothers on a nevirapine-based regimen. All infants were also given single-dose nevirapine within 48 hours of birth. We detected genotypic resistance mutations in none of eight infants who were HIV-PCR positive by 2 wk of age (specimens from six infants were not amplifiable), for 30% (6/20) at 6 wk, 63% (14/22) positive at 14 wk, and 67% (16/24) at 6 mo post partum. Among the 16 infants with resistance mutations by 6 mo post partum, the common mutations were M184V and K103N, conferring resistance to lamivudine and nevirapine, respectively. Genotypic resistance was detected among 9/9 (100%) and 7/15 (47%) infected infants whose mothers were on nelfinavir and nevirapine, respectively. No mutations were detected among the eight infants infected after the breastfeeding period (age 6 mo). CONCLUSIONS: Emergence of HIV drug resistance mutations in HIV-infected infants occurred between 2 wk and 6 mo post partum, most likely because of exposure to maternal ARV drugs through breast milk. Our findings may impact the choice of regimen for ARV treatment of HIV-infected breastfeeding mothers and their infected infants. TRIAL REGISTRATION: ClinicalTrials.gov NCT00146380 Please see later in the article for the Editors' Summary.

In the Kisumu Breastfeeding Study (KiBS), prevention of mother-to-child HIV transmission study, highly active antiretroviral therapy (HAART) is provided from 34 weeks gestation, through delivery to six months postpartum. The study recommends that women practice exclusive breastfeeding for six months, then wean abruptly. We sought to explore factors such as, education, family support, cultural norms, and sources of information about perinatal HIV transmission, which may influence a mother's decision to comply or not comply with the study's recommendation to stop breastfeeding when HAART is discontinued. We used semi-structured interviews of a purposive sample of 18 mothers participating in the KiBS. By interviewing 10 mothers who stopped breastfeeding and eight mothers who continued, it was possible to examine how different factors may have affected the groups of participants. All participants stated that it was not traditional to stop breastfeeding at six months. Participants who stopped breastfeeding reported more family support, were more educated, and were more likely to disclose their HIV status. Participants who continued breastfeeding more often expressed concern about stigma. Participants learned about mother-to-child transmission from clinics, churches, community groups, and other HIV-positive mothers. This substudy suggests that family support, education, and cultural norms are important factors that may influence a mother's decision regarding breastfeeding cessation. Thus, counseling and family support may play integral roles in the promotion of early breastfeeding cessation.

To reduce mother-to-child transmission of human immunodeficiency virus (HIV) in resource-poor settings, the World Health Organization recommends exclusive breast-feeding for 6 months, followed by rapid weaning if replacement feeding is affordable, feasible, available, safe, and sustainable. In the Kisumu Breastfeeding Study (trial registration: Clinicaltrials.gov identifier NCT00146380 ), infants of HIV-infected mothers who received antiretroviral therapy experienced high rates of diarrhea at weaning. To address this problem, mothers in the Kisumu Breastfeeding Study were given safe water storage vessels, hygiene education, and bleach for household water treatment. We compared the incidence of diarrhea in infants enrolled before (cohort A) and after (cohort B) implementation of the intervention. Cohort B infants experienced less diarrhea than cohort A infants, before and after weaning ([Formula: see text] and [Formula: see text], respectively); however, during the weaning period, there were no differences in the frequency of diarrhea between cohorts ([Formula: see text]). Testing of stored water in cohort B homes indicated high adherence (monthly range, 80%-95%) to recommended chlorination practices. Among infants who were weaned early, provision of safe water may be insufficient to prevent weaning-associated diarrhea.