Larval source reduction with a purpose: Designing and evaluating a household- and school-based intervention in coastal Kenya

Jenna E Forsyth; Arielle Kempinsky; Helen O Pitchik; Catharina J Alberts; Francis M Mutuku; Lydiah Kibe; Nicole M Ardoin; A Desiree LaBeaud

doi:10.1371/journal.pntd.0010199

Larval source reduction with a purpose: Designing and evaluating a household- and school-based intervention in coastal Kenya

PLoS Negl Trop Dis. 2022 Apr 1;16(4):e0010199. doi: 10.1371/journal.pntd.0010199. eCollection 2022 Apr.

Authors

Jenna E Forsyth¹, Arielle Kempinsky², Helen O Pitchik³, Catharina J Alberts², Francis M Mutuku⁴, Lydiah Kibe⁵, Nicole M Ardoin¹, A Desiree LaBeaud²

Affiliations

¹ Stanford Woods Institute for the Environment, Stanford University, Stanford, California, United States of America.
² Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America.
³ Division of Epidemiology, School of Public Health, University of California, Berkeley, California, United States of America.
⁴ Technical University of Mombasa, Mombasa, Kenya.
⁵ Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.

Abstract

Background: Since Aedes aegypti mosquitoes preferentially breed in domestic containers, control efforts focus on larval source reduction. Our objectives were to design and test the effectiveness of a source reduction intervention to improve caregiver knowledge and behaviors in coastal Kenya.

Methodology/principal findings: We conducted a cluster-randomized controlled trial with 261 households from 5 control villages and 259 households from 5 intervention villages. From each household, one child (10-16 years old) and his or her primary caregiver participated in the intervention. We assessed caregiver knowledge and behavior at baseline, as well as 3 and 12 months after the intervention. We assessed household entomological indices at baseline and 12 months after the intervention to avoid seasonal interference. We conducted qualitative interviews with 34 caregivers to understand barriers and facilitators to change. We counted and weighed containers collected by children and parents during a community container clean-up and recycling event. After 12 months, caregiver knowledge about and self-reported behavior related to at least one source reduction technique was more than 50 percentage points higher in the intervention compared to control arm (adjusted risk differences for knowledge: 0.69, 95% CI [0.56 to 0.82], and behavior: 0.58 [0.43 to 0.73]). Respondents stated that other family members' actions were the primary barriers to proper container management. The number of containers at households did not differ significantly across arms even though children and parents collected 17,200 containers (1 ton of plastics) which were used to planted 4,000 native trees as part of the community event.

Conclusions/significance: Our study demonstrates that source reduction interventions can be effective if designed with an understanding of the social and entomological context. Further, source reduction is not an individual issue, but rather a social/communal issue, requiring the participation of other household and community members to be sustained.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Aedes*
Animals
Child
Dengue*
Female
Humans
Kenya
Larva
Male
Mosquito Control / methods
Plant Breeding

Grants and funding

Financial support was provided by Stanford University’s Child Health Research Institute Bechtel Faculty Scholar Award to A.D.L., Stanford’s Emmett Interdisciplinary Program in Environment and Resources and Stanford’s Center for African Studies Awards to J.E.F., and a Medical Scholars’ award to A.K. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.