Integrated serological surveillance (serosurveillance) involves testing for antibodies to multiple pathogens (or species) simultaneously and can be achieved using multiplex bead assays (MBAs). This systematic review aims to describe pathogens studied using MBAs, the operational implementation of MBAs, and how the data generated were synthesised. In November and December 2023, four databases were searched for studies utilising MBAs for the integrated serosurveillance of infectious diseases. Two reviewers independently screened and extracted data regarding the study settings and population, methodology, seroprevalence results, and operational implementation elements. Overall, 4765 studies were identified; 47 were eligible for inclusion, of which 41% (n = 19) investigated multiple malaria species, and 14% performed concurrent surveillance of malaria in combination with other infectious diseases (n = 14). Additionally, 14 studies (29%) investigated a combination of multiple infectious diseases (other than malaria), and seven studies examined a combination of vaccine-preventable diseases. Haiti (n = 8) was the most studied country, followed by Ethiopia (n = 6), Bangladesh (n = 3), Kenya (n = 3), and Tanzania (n = 3). Only seven studies were found where integrated serosurveillance was the primary objective. The synthesis of data varied and included the investigation of age-specific seroprevalence (n = 25), risk factor analysis (n = 15), and spatial analysis of disease prevalence (n = 8). This review demonstrated that the use of MBAs for integrated surveillance of multiple pathogens is gaining traction; however, more research and capabilities in lower- and middle-income countries are needed to optimise and standardise sample collection, survey implementation, and the analysis and interpretation of results. Geographical and population seroprevalence data can enable targeted public health interventions, highlighting the potential and importance of integrated serological surveillance as a public health tool.
30 January 2025 in International Journal of Infectious Diseases
Contrasting evidence is emerging on the long-term effectiveness of triple-drug therapy for elimination of lymphatic filariasis (LF) in the Pacific region. We evaluated the effectiveness of ivermectin, diethylcarbamazine and albendazole (IDA) for sustained clearance of microfilariae (Mf) in Samoa. We enrolled two cohorts of Mf-positive participants. Cohort A were Mf-positive participants from 2018, who received directly observed triple-drug therapy in 2019 and were retested and retreated in 2023 and 2024. Cohort B were Mf-positive and treated in 2023 and retested in 2024. Participants were tested for LF antigen and Mf. In Cohort A, eight of the 14 participants from 2018/2019 were recruited in 2023; six were Mf-positive. In 2024, six participants were retested, and two were Mf-positive. Cohort B included eight participants, and two remained Mf-positive in 2024. Mf prevalence in 2023 for Cohort A (71.4%, 95% CI 29.0%-96.3%) was significantly higher than among their household members (12.0%, 95% CI 2.5%-31.2%). One or two doses of directly observed IDA was not sufficient for sustained clearance of Wuchereria bancrofti Mf in Samoa. The high Mf prevalence in treated individuals compared to household members suggests recrudescence rather than reinfection.
20 October 2023 in Australian and New Zealand Journal of Public Health
Calculate the incidence of SARS-CoV-2 (COVID-19) infection notifications and the influence of area-level geographic and socioeconomic factors in Queensland using real-time data from the COVID-19 Real-time Information System for Preparedness and Epidemic Response (CRISPER) project. Population-level ecological study and spatial mapping of the incidence of COVID-19 infection notifications in Queensland, by postcode, 2020-2022. Proportions and distribution of COVID-19 infection notifications by year, age-group, socioeconomic disadvantage, and geospatial mapping. Incidence rate ratios (IRRs) were calculated. Between 28 January 2020 and 30 June 2022, a total of 609,569 cases of COVID-19 associated with a Queensland postcode were recorded. The highest proportion of cases occurred in 2022 (96.5%), and in the 20- to 24-year age category (IRR = 1.787). In non-Major City areas, there was also a higher incidence of COVID-19 cases in lower socioeconomic areas (IRR = 0.84) than in higher socioeconomic areas (IRR = 0.66). Queensland experienced its highest proportion of COVID-19 cases once domestic and international borders opened. However, geographic and socioeconomic factors may have still contributed to a higher incidence of COVID-19 cases across some Queensland areas. Although Australia has moved from the emergency response phase of the COVID-19 pandemic, we need to ensure ongoing prevention strategies target groups and areas that we have identified with the highest incidence.
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.
Integrated serological surveillance involves testing for antibodies to multiple pathogens (or species) simultaneously and can be achieved using multiplex bead assays (MBA). This systematic review aims to describe: pathogens studied using MBA; the operational implementation of MBA, and how data generated was synthesised. In November and December 2023, four databases were searched for studies utilising MBA for integrated surveillance of infectious diseases. Two reviewers independently screened and extracted data regarding study settings and population, methodology, seroprevalence results, and operational implementation elements. Overall, 4,765 studies were identified; 47 were eligible for inclusion, of which 43% investigated multiple malaria species, and 17% for concurrent surveillance of malaria and other infectious diseases (including lymphatic filariasis and tetanus). Only seven studies were found where integrated serosurveillance was the primary objective. Synthesis of data varied and included investigation of age-specific seroprevalence (n=25), risk factor analysis (n=15), and spatial analysis of disease prevalence (n=8). This review demonstrated that the use of MBA for integrated surveillance of multiple pathogens is gaining traction; however, more research and capabilities in lower- and middle-income countries are needed to optimise and standardise sample collection, survey implementation, and analysis and interpretation of results.