Household‐level water, sanitation and hygiene factors and interventions and the prevention of relapse after severe acute malnutrition recovery: A systematic review

Severe acute malnutrition (SAM) is the most serious form of acute malnutrition and is associated with high mortality risk among children under 5. While the Community‐based Management of Acute Malnutrition (CMAM) approach, recommended for treating cases of uncomplicated SAM, has increased treatment coverage and recovery outcomes, high relapse rates have been reported. Several risk factors for SAM relapse, such as insufficient food intake and high infectious disease burden in the community, have been identified. However, the role of household water, sanitation and hygiene (WASH) conditions remains unclear. This systematic review: (1) assesses the effectiveness of WASH interventions on preventing SAM relapse and (2) identifies WASH‐related conditions associated with relapse to SAM among children aged 6–59 months discharged as recovered following SAM CMAM treatment. We performed electronic searches of six databases to identify relevant studies published between 1 January 2000 and 6 November 2023 and assessed their quality. After deduplication, 10,294 documents were screened by title and , with 13 retrieved for full‐text screening. We included three studies ranging from low‐ to medium‐quality. One intervention study found that providing a WASH kit during SAM outpatient treatment did not reduce the risk of relapse to SAM. Two observational studies found inconsistent associations between household WASH conditions—unimproved sanitation and unsafe drinking water—and SAM relapse. Despite the paucity of evidence, the hypothesised causal pathways between WASH conditions and the risk of relapse remain plausible. Further evidence is needed to identify interventions for an integrated postdischarge approach to prevent relapse. This systematic review highlights a paucity of evidence on the role of household water, sanitation and hygiene (WASH) for the prevention of relapse to severe acute malnutrition (SAM). Nonetheless, hypothesised causal pathways remain plausible. Further research is needed to identify effective WASH interventions for an integrated postdischarge approach to prevent relapse. Key messages This systematic review highlights a paucity of evidence on the relationship between household water, sanitation and hygiene (WASH) conditions and the prevention of severe acute malnutrition (SAM) relapse. There are limited high‐quality studies assessing the effectiveness of household‐level WASH interventions in preventing uncomplicated SAM relapse among children 6–59 mon