Circulating filarial antigen (Ag) is used by elimination programs to monitor lymphatic filariasis (LF) transmission; however, antifilarial antibodies (Ab) may be more sensitive than Ag for detecting LF. Our objectives were to describe Ab seroprevalence, identify risk factors for Ab seropositivity, investigate age-specific associations between Ag and Ab, and evaluate geographic clustering of seropositivity. Community-based serosurveys of participants aged ≥5 years were conducted in 35 primary sampling units (PSUs). Ag-positivity was detected using Alere™ Filariasis Test Strips and Ab-seropositivity using multiplex bead assays. Seroprevalence was adjusted for study design. Of 3795 participants (range:5-90 years), adjusted prevalence for Ag, Bm14 Ab, Wb123 Ab, and Bm33 Ab were 3.7% (n=117), 20.3% (n=583), 32.2% (n=987), and 51.0% (n=1659), respectively. Male sex, older age, and residents of suspected hotspots had higher odds of seropositivity to all seromarkers. Seroprevalence was lower in 5-9-year-olds vs ≥10-year-olds (P<0.001). Clustering was significantly higher in households (intra-cluster correlation for Ag:0.45; Bm14 Ab:0.32; Bm33 Ab:0.31; Wb123 Ab:0.29) compared to PSUs or region. Abs enabled identification of risk factors for seropositivity and geographical clustering to inform targeted interventions for LF programmes. Further research is needed to define Ab thresholds for active versus past infection and elimination targets.

Samoa is not immune to the growing global incidence of cancer, which is disproportionately high in low- and middle-income countries. As a preliminary step to upscale our population-based cancer registry initiatives in Samoa, we conducted a 10-year survey of cancer incidences in Samoa from 2007 to 2016. We reviewed all laboratory and clinically confirmed cases of cancer from 2007 to 2016 covering both government and nongovernment facilities. Cancer incidence increased steadily from 2007 (28.5 per 100 000) to 2012 (67.1 per 100 000). The incidence rate decreased in 2013 (from 67.1 cases in 2012 to 51.4 cases per 100 000 in 2013); and in 2015 (from 65.1 cases in 2014 to 54.3 cases per 100 000 in 2015). From 2012 to 2016, the incidence rate fluctuates between 50 and 65 cases per 100 000. Cancers of female genitalia, breast, and digestive system were the most common types in female and males, respectively.

Introduction: Seroprevalence of antibodies for vaccine-preventable diseases (VPDs), due to vaccination or previous infection, can provide a more accurate estimate of immunity compared to vaccination coverage data alone. This study aimed to examine the seroepidemiology and spatial distribution of VPD seroprevalence in Samoa in 2018 and 2019. Methods: Dried blood spot (DBS) samples were collected from two nationally representative community-based surveys of participants aged ≥5 years from the Surveillance and Monitoring to Eliminate Lymphatic Filariasis and Scabies from Samoa (SaMELFS) project. DBSs were tested using multiplex bead assays (MBAs) to detect antibodies against measles, rubella, diphtheria, and tetanus. Seroprevalence was estimated at the national and primary sampling unit (PSU) levels, and cluster analysis was completed using SaTScan. Results: Overall, 8394 valid MBA results were analysed across 35 PSUs. The highest overall seroprevalence was observed for tetanus (91.0%; 95% CI: 90.2–91.7), followed by diphtheria (83.7%; 95% CI: 82.7–84.7), rubella (79.3%; 95% CI: 78.2–80.3), and measles (45.8%; 95% CI: 44.8–46.9) with substantial heterogeneity across PSUs. Clusters of seronegativity to measles (relative risk [RR]: 1.16, p < 0.001) and diphtheria (RR: 1.16, p < 0.001) were also identified. Conclusions: These findings demonstrate significant variation in seroprevalence and pockets of low population immunity to multiple VPDs, highlighting the key advantage of an integrated rather than siloed approach. The relatively high seroprevalence to rubella suggests potential community transmission, emphasising the need to strengthen congenital rubella surveillance and improve vaccination coverage. Identifying low immunity to VPDs can provide an early warning to potential outbreak risk and support the Ministry of Health to target public health interventions in higher-risk areas.

We conducted a systematic review of infectious disease (ID) prevalence studies in the Samoan Islands from 2000 to 2024 and aimed to synthesise the prevalence of IDs, the purpose of the studies, and the potential utility of survey results for informing public health decision-making. We searched five academic databases, the Western Pacific Region Index Medicus, and grey literature up until April 2024. English language publications of ID surveys in American Samoa and Samoa were included. Each study’s aim, design, and prevalence results were extracted and categorised by disease and data sources. We identified 46 publications reporting the prevalence of 15 different IDs; 42 publications (91%) reported data from 31 original surveys, of which three (9%) investigated the prevalence of multiple IDs. Twenty-eight (62%) publications primarily aimed to report prevalence to inform public health interventions. Samples from one survey, initially conducted for leptospirosis, were subsequently tested to confirm transmission, describe prevalence, and investigate risk factors for seven other diseases. We emphasise the valuable contribution of prevalence studies in supporting evidence-based public health interventions. The extensive prevalence studies in the Samoan Islands illustrate the need for adopting integrated multipathogen approaches to surveillance to reduce costs, document burden, and generate actionable insights to support evidence-based decisions to prevent, control, and eliminate infectious diseases.