The near-universal socio-economic and psychological burden of onchocerciasis in endemic communities of Bo District, Sierra Leone: an explanatory sequential mixed-methods study

Technical Summary: The Near-Universal Socio-Economic and Psychological Burden of Onchocerciasis in Bo District, Sierra Leone

Problem Statement
Despite decades of mass drug administration (MDA) with ivermectin, onchocerciasis (river blindness) persists in the Bo District of Sierra Leone. While programmatic efforts have successfully tracked parasitological and ocular outcomes, the broader socio-economic and psychological burden within affected communities remains poorly quantified. Existing biomedical frameworks often obscure the "welfare assault" of the disease, failing to capture productivity losses, catastrophic health expenditures, and profound psychological distress. This study addresses a critical gap: determining whether the non-clinical burden of onchocerciasis is concentrated in specific vulnerable subgroups or constitutes a generalized community condition, and whether it varies by geography or demography.

Methodology
The study employed an explanatory sequential mixed-methods design (QUAN→qual) involving 1,500 adults across five endemic chiefdoms (Bagbwe, Baoma, Gbo, Selenga, and Tikonko) in Bo District.

• Quantitative Phase:

  • Sampling: A multistage cluster sampling strategy was used, purposively selecting chiefdoms and stratifying villages by ecological and socio-economic characteristics. One eligible adult per household was selected using the Kish grid.
  • Measures: The researchers operationalized the burden using two formative composite indices:
    1. Socio-economic Impact Index (0–2): Sum of binary items regarding economic hardship (income loss/reduced capacity) and obstacles to education/employment.
    2. Psychological Impact Index (0–3): Sum of binary items regarding impaired emotional well-being (anxiety/sadness), social stigma/isolation, and negative shifts in self-esteem.
  • Validation: Instruments were forward- and back-translated into Mende, cognitively tested, and piloted (N=30), demonstrating strong internal consistency (Cronbach's α = 0.81 for stigma items) and stability. Data were collected via Android tablets using ODK Collect.
  • Analysis: Statistical analysis in JASP included descriptive statistics, chi-square tests, one-way ANOVA, independent-samples t-tests, and Spearman correlations to test for variations across chiefdoms, sex, and education.

• Qualitative Phase:

  • Data Collection: Eleven key informant interviews and eight focus group discussions (FGDs) with 40 community members were conducted.
  • Analysis: Thematic analysis was performed using a hybrid deductive–inductive approach informed by the Health Belief Model–Socio-Ecological Model (HBM–SEM) framework.

Key Results
The study found that the burden of onchocerciasis is near-universal and multidimensional, affecting the vast majority of respondents regardless of demographic or geographic factors.

• Magnitude of Burden:

  • Socio-economic: 89.9% of respondents experienced at least one socio-economic impact. Specific indicators included economic hardship (71.7%) and obstacles to education/employment (61.2%).
  • Psychological: 95.8% of respondents experienced at least one psychological impact. Social stigma or isolation was the most prevalent single indicator (69.6%), followed by impaired emotional well-being (65.9%) and self-esteem shifts (59.1%).
  • Healthcare Access: 71.2% reported obstacles to obtaining healthcare.

• Independence of Dimensions:

  • The socio-economic and psychological dimensions were statistically independent (Spearman ρ = .026, p = .311). This suggests the burden functions as a generalized community condition rather than a set of co-occurring, individually graded impairments.

• Uniformity of Distribution:

  • Geographic: There was no significant variation in socio-economic impact across the five chiefdoms (F(4,1495) = 1.91, p = .106).
  • Demographic: There was no significant difference in psychological impact between sexes (t(1498) = 0.26, p = .796).
  • Effect Sizes: All effect sizes regarding associations between specific impacts and chiefdom, sex, or education were trivial (all V ≤ .059).

• Qualitative Insights:

  • Productivity-Poverty Cycle: Physical impairment reduces agricultural output, leading to income loss that precludes healthcare access, compounding the cycle.
  • Stigma as "Social Death": Stigma manifests as comprehensive exclusion from ceremonies, marriage, and community life, described by participants as a "tainting" of bloodlines.
  • Gendered Caregiving: Women bear an invisible, unrecognized burden of caregiving when family members are incapacitated.

Significance and Claims
The paper claims that onchocerciasis imposes a pervasive, uniformly distributed dual burden in Bo District that is invisible to standard parasitological surveillance.

• Programmatic Implications: Because the burden is community-wide rather than concentrated in identifiable subgroups, the authors argue that morbidity management, stigma reduction, and psychosocial support should be delivered via population-wide approaches integrated into primary healthcare and MDA delivery, rather than targeted at specific demographic risk groups.
• Intervention Strategy: The independence of the socio-economic and psychological dimensions implies that economic support and psychosocial support address partly different needs and should be designed as distinct, parallel pathways.
• Feasibility: The authors propose low-cost, feasible entry points, such as training community drug distributors to recognize psychological distress during ivermectin delivery and embedding stigma-reduction messaging into community engagement.

The study concludes that while biological transmission is geographically focal, the resulting social and economic "ripples" act as a generalized community stressor, necessitating a shift from purely clinical surveillance to holistic welfare management.