Water, sanitation, and hygiene interventions in outbreak response: a synthesis of evidence

Abstract

Water, sanitation, and hygiene (WASH) interventions are key to reducing the burden of disease associated with outbreaks, and are commonly implemented in emergency response. However, there is a lack of summarized evidence on the efficacy and effectiveness of these interventions. We conducted a systematic review of published and grey literature by developing theory of change models, developing inclusion criteria, conducting the search, selecting evaluations for inclusion, assessing the quality of the evidence, and analysing the included evaluations. Overall, 15,026 documents were identified and 51 evaluations from 47 studies met inclusion criteria. Interventions from 19 countries were included, primarily in response to cholera (86 per cent). Most included evaluations (70 per cent) were at high risk of bias and nearly half were from grey literature (49 per cent). We found that WASH interventions consistently reduced both the risk of disease and the risk of transmission in outbreak contexts; however, programme design and beneficiary preferences were important considerations to ensure WASH intervention effectiveness. Critical programme design characteristics included simple interventions that were appropriately timed, community-driven, and had linkages between relief and development. Beneficiary preferences, barriers, and facilitators to WASH interventions in outbreak response were taste and smell of water treatment, communication methods, inaccurate perception of efficacy, and trust/fear. Research on commonly implemented but severely under-researched WASH interventions is recommended. It is also recommended that responders implement interventions that are: efficacious, simple, well-timed, community-driven, link relief and development, and address barriers and facilitators to use with communities.

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines

“…Accordingly, all, or some subset of, the 20 consistently recommended WASH interventions could be considered as the "minimum standard" interventions that organisations have proposed for effective cholera response programmes. Neither hygiene nor water improvements are new to public health nor to cholera control [1,70,[108][109][110], but in addition to controlling cholera outbreaks, these interventions could prevent recurrent epidemics in endemic areas. Additionally, if governments and organisations move away from diseasespecific efforts and towards systems strengthening, these interventions may be viewed in terms of their broader effects on WASH-related diseases and other health outcomes [111,112].…”

“…radio, television, SMS and social media)". Whilst there is some evidence to support radio as a preferred or trusted communication means in cholera outbreaks [110], guidelines would benefit from more explicitly incorporating the evidence base on the other delivery modalities and platforms available. Behaviour change interventions that were recommended across the guidelines should also consider the limited effect of health education and messaging alone [117][118][119], and incorporate activities to improve the role of collective or community engagement in response activities [111,120].…”

“…For example, hygiene and health promotion and the distribution of hygiene kits at the point of care have been observed as an effective delivery channel in cholera control [63,78,113], and in other disease reduction efforts [124][125][126], yet recommendations on the location of intervention delivery was either omitted or limited in all eight of the guidelines. Prepositioning of supplies for distribution has also been noted as an important consideration to allow for timely response in case-centred and mass-delivered strategies [110].…”

Responding to epidemics in large-scale humanitarian crises: a case study of the cholera response in Yemen, 2016–2018

“…First, protocols are needed for improving the specificity of RDTs under field conditions and their systematic use for monitoring epidemics where laboratory capacity is low 55. Second, evidence for the optimal timing and effectiveness of the RRT model, for the effectiveness of the individual health and WASH interventions in the rapid reduction of secondary transmission and the composition of an integrated package of health and WASH interventions are needed 35 56–58. Third, protocols for case management among pregnant women and severely malnourished children are urgent priorities to avoid excess mortality 29.…”

Efficacy of locally-available cleaning methods in removing biofilms from taps and surfaces of household water storage containers

“…This cholera data align with development context studies on risks/benefits of safe/unsafe water storage 17 . Given the known risks of unsafe storage, container cleaning activities are commonly promoted 18 . In emergency contexts, evaluations of three jerrican disinfection programs (using 2.5 mg/L to 5% chlorine solutions) documented short-term increases in free chlorine residual and reductions in microbiological indicators, and regrowth of microbiological indicators in hours to days after cleaning [11][12][13] .…”