Citizen science in public health: Social Media insights into bedbug infestations, control methods and psychosocial effects in Lusaka, Zambia

Background Bedbugs are blood-feeding parasites that infest human dwellings, causing discomfort and distress. Individuals affected by such infestations often feel too ashamed to seek help publicly. Social media including Facebook provides a space where people freely share their experiences as it offers some level of anonymity, making it a platform for real-time, community-driven insights. This reflects the concept of informal citizen science, where individuals voluntarily share lived experiences. Objective This study investigated bedbug infestations in Lusaka using publicly available social media (Facebook) data. Methods A qualitative case study design was employed using inductive thematic analysis of 1566 publicly available Facebook comments and replies posted between January 2021 and May 2025. Posts discussing bedbugs in Lusaka were purposefully selected using keyword searches. The selected data for thematic analysis came from 3120 comments and replies. Data were analysed using NVivo 12.3, supported by generative AI while quantitative data was generated in excel. Results Most participants identified public transport, low-cost lodges, social visits, schools, and poor hygiene as common sources of infestation, with long-distance buses cited most frequently. Chemical insecticides were the most used control method but were widely viewed as ineffective, leading to the adoption of hot water, paraffin, and home chemical remedies among others. Many expressed frustrations over recurring infestations and the adaptability of bedbugs, prompting calls for government intervention. Psychological impacts were evident, with reports of sleep loss, anxiety, and physical discomfort. Social stigma was also prominent, with infestations often linked to poor hygiene, causing embarrassment, strained relationships, and social withdrawal. Conclusion Facebook served as a rich source of informal citizen science, offering real-time, community-level insights into bedbug infestation patterns, lived experiences, and coping strategies. In contexts with limited formal data, Facebook-based citizen science can inform responsive, community-centred interventions for public health and surveillance.