Background Achieving universal access to safe and affordable drinking water remains a critical global challenge, particularly in low- and middle-income countries where intermittencies in water supply are common. We aimed to examine relationships between water intermittency and multiple outcomes, including microbial water contamination, child health, and caregiver stress. Methods We conducted a cross-sectional study with 237 households with a child <5 years old in a peri-urban neighborhood of Blantyre, Malawi. We conducted a structured questionnaire with primary caregivers to record water intermittencies, water handling and hygiene practices, caregiver-reported child diarrhea and acute respiratory infection (ARI) symptoms, and stress among caregivers. Drinking water samples were tested for E. coli and cefotaxime-resistant E. coli using IDEXX Quanti-Tray/2000. We used generalized linear models to evaluate how intermittency occurrence, frequency, and duration influenced outcomes, adjusting for sociodemographic and WASH factors. Findings Of 237 households, 32.5% reported ≥ 1 water intermittency in the past month. These households were more likely to experience water insecurity, skip bathing and laundry, and report less handwashing after animal contact or outdoor work. E. coli was detected in 65.7% and cefotaxime-resistant E. coli in 8.4% of water samples. Intermittency was not associated with impaired water quality. Children in intermittent households had higher prevalence of diarrhea (PR=1.94, 95% CI: 1.11-3.39) and ARI with fever (PR=2.00, 95% CI: 1.11-3.60). Rare/short intermittencies were more strongly associated with diarrhea; frequent/long intermittencies were more strongly associated with ARI. Caregivers in households with short and frequent intermittencies reported higher stress. Interpretation Water intermittencies were associated with impaired hygiene, child illness, and caregiver stress. Frequency and duration modified the associations, suggesting that short- vs. long-term behavioral adaptations may differently influence exposure to enteric and respiratory pathogens and stress responses. Interventions like low-flow handwashing stations and water reuse may help reduce health risks in intermittent water settings.

The authors have declared no competing interest.

This study was funded by the National Science Foundation.

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Research Ethics Committee (MZUNIREC) of Mzuzu University gave ethical approval for this work(MZUNIREC/DOR/24/38) Ethics committee/IRB of University of North Carolina, Greensboro gave ethical approval for this work (UNC-Greensboro IRB #: 20-0245)

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