{ "abstract": "Social network interventions (SNIs) can leverage influential individuals within personal networks to amplify health behavior adoption and intervention diffusion. While SNIs are potentially effective in enhancing uptake of HIV prevention and other interventions, identifying optimal peer leaders remains challenging. This study assessed how social network-based approaches can improve peer leader identification compared to non-structural approaches (i.e., those that do not use network data for promoter selection). Between 8th October 2024 and 31st March 2025, we mapped the social connections among fishermen in two communities in Mangochi, Malawi. The communities had previously participated in a cluster-randomized trial (FISH), which aimed to create demand among fishermen for HIV and schistosomiasis services via peer-nominated leaders. Using Network Canvas and a photographic census, we conducted a network survey, capturing ties, support roles and interaction frequency. Whole-network maps were constructed, centrality measures and the key player problem positive (KPP-POS) algorithm were applied to identify the highest-ranking individuals as potential promoters. We compared the reach (i.e., proportion of nodes within two steps of a promoter) of peer-nominated leaders selected by FISH to these sociometric methods. We recruited 370 of 397 eligible fishermen (mean age 34.8years [SD 13.11]). Both communities exhibited sparse, low-reciprocity networks with long path lengths. One network had two dense cores, while the other featured a single core. There was no evidence of assortative mixing by education, age or village of residence. FISH trial peer leaders were not consistently central in the constructed maps. The KPP-POS algorithm identified alternative, more dispersed nodes, achieving the highest reach (66% in F001; 75% in F024) versus in-degree (58%, 67%), closeness (58%, 68%), betweenness (58%, 69%) and eigenvector (60%, 68%) promoter sets. Our findings highlight that strategically identified promoters can achieve good reach within social networks, crucial for effective public health programming in complex settings like fishing communities.", "abstract_shown": true, "affiliations": [ "Helse Nord Tuberculosis Initiative, Department of Pathology, Kamuzu University of Health Sciences, Blantyre, Malawi", "Department of Infectious Disease Epidemiology and International Health, London School of Hygiene and Tropical Medicine, London, United Kingdom", "Malawi-Liverpool-Welcome Clinical Research Programme, Blantyre, Malawi", "Malawi Epidemiology and Intervention Research Unit, Lilongwe, Malawi", "Department of Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom", "School of Public Health, University of the Witwatersrand, Johannesburg, South Africa", "Institute of Resilient Health Systems, Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom", "Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom", "School of Health and Wellbeing, University of Glasgow, Scotland, United Kingdom", "Department of Global Health, Amsterdam University Medical Centre, Amsterdam, The Netherlands", "Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom", "Institute for Global Health, University College London, London, United Kingdom", "Africa Health Research Institute, KwaZulu-Natal, South Africa" ], "article_type": "Research Article", "arxiv": null, "author_total": 13, "authors": [ { "affs": [ 0 ], "name": "Madalo Mukoka" }, { "affs": [ 1 ], "name": "Alison Price" }, { "affs": [ 2 ], "name": "Marriott Nliwasa" }, { "affs": [ 3 ], "name": "Owen Mhango" }, { "affs": [ 4 ], "name": "Mphatso Mwapasa" }, { "affs": [ 5 ], "name": "Moses K. Kumwenda" }, { "affs": [ 6 ], "name": "Hussein H. Twabi" }, { "affs": [ 7 ], "name": "Robina Semphere" }, { "affs": [ 8 ], "name": "Takondwa C. Msosa" }, { "affs": [ 9 ], "name": "Chisomo Msefula" }, { "affs": [ 10 ], "name": "Augustine T. Choko" }, { "affs": [ 11 ], "name": "Guy Harling" }, { "affs": [ 12 ], "name": "Katherine Fielding" } ], "bibtex": "https://research.draconitic.com/paper/7nzbaq8fnjajr.bib", "cited_by": 0, "doi": "10.1371/journal.pgph.0007185", "fulltext_url": "https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0007185", "id": "7nzbaq8fnjajr", "issns": [ "2767-3375" ], "landing_url": "https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0007185", "language": null, "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "journal", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "3109|Complex Network Analysis Techniques" ], [ "plos", "/Biology and life sciences/Microbiology/Medical microbiology/Microbial pathogens/Viral pathogens/Immunodeficiency viruses/HIV" ], [ "plos", "/Biology and life sciences/Microbiology/Medical microbiology/Microbial pathogens/Viral pathogens/Retroviruses/Lentivirus/HIV" ], [ "plos", "/Biology and life sciences/Organisms/Viruses/Immunodeficiency viruses/HIV" ], [ "plos", "/Biology and life sciences/Organisms/Viruses/RNA viruses/Retroviruses/Lentivirus/HIV" ], [ "plos", "/Biology and life sciences/Organisms/Viruses/Viral pathogens/Immunodeficiency viruses/HIV" ], [ "plos", "/Biology and life sciences/Organisms/Viruses/Viral pathogens/Retroviruses/Lentivirus/HIV" ], [ "plos", "/Computer and information sciences/Network analysis/Centrality" ], [ "plos", "/Computer and information sciences/Network analysis/Social networks" ], [ "plos", "/Medicine and health sciences/Clinical medicine/Clinical trials/Cluster trials" ], [ "plos", "/Medicine and health sciences/Medical conditions/Parasitic diseases/Helminth infections/Schistosomiasis" ], [ "plos", "/Medicine and health sciences/Medical conditions/Tropical diseases/Neglected tropical diseases/Schistosomiasis" ], [ "plos", "/Medicine and health sciences/Pathology and laboratory medicine/Pathogens/Microbial pathogens/Viral pathogens/Immunodeficiency viruses/HIV" ], [ "plos", "/Medicine and health sciences/Pathology and laboratory medicine/Pathogens/Microbial pathogens/Viral pathogens/Retroviruses/Lentivirus/HIV" ], [ "plos", "/Medicine and health sciences/Pharmacology/Drug research and development/Clinical trials/Cluster trials" ], [ "plos", "/Medicine and health sciences/Public and occupational health" ], [ "plos", "/Medicine and health sciences/Public and occupational health/Behavioral and social aspects of health" ], [ "plos", "/Physical sciences/Mathematics/Algebra/Linear algebra/Eigenvectors" ], [ "plos", "/Research and analysis methods/Clinical trials/Cluster trials" ], [ "plos", "/Social sciences/Sociology/Social networks" ] ], "openalex": "W7212067805", "pdf_url": "https://journals.plos.org/globalpublichealth/article/file?id=10.1371/journal.pgph.0007185&type=printable", "pmcid": null, "pmid": null, "published": "2026-09-09", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/7nzbaq8fnjajr.ris", "sources": [ { "first_seen": "2026-10-30T12:17:56Z", "native_id": "10.1371/journal.pgph.0007185", "source": "plos", "url": "https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0007185" } ], "subjects": [ { "field": "biology", "origin": "plos:microbiology", "subfield": "microbiology" }, { "field": "medicine", "origin": "plos:clinical trials", "subfield": "clinical-trials" }, { "field": "medicine", "origin": "plos:public and occupational health", "subfield": "epidemiology-public-health" } ], "title": "Optimizing peer-led health interventions: A social network analysis approach for identifying influential fishermen in Malawi", "title_text": "Optimizing peer-led health interventions: A social network analysis approach for identifying influential fishermen in Malawi", "type": "peer-reviewed", "updated_at": "2026-10-30T12:17:56Z", "url": "https://research.draconitic.com/paper/7nzbaq8fnjajr", "venue": "PLOS Global Public Health", "versions": [] }