Characterising spatial patterns of neglected tropical disease transmission using integrated sero-surveillance in Northern Ghana

Abstract

Background As prevalence decreases in pre-elimination settings, identifying the spatial distribution of remaining infections to target control measures becomes increasingly challenging. By measuring multiple antibody responses indicative of past exposure to different pathogens, integrated serological surveys enable simultaneous characterisation of residual transmission of multiple pathogens. Methodology/Principal findings Here, we combine integrated serological surveys with geostatistical modelling and remote sensing-derived environmental data to estimate the spatial distribution of exposure to multiple diseases in children in Northern Ghana. The study utilised the trachoma surveillance survey platform (cross-sectional two-stage cluster-sampled surveys) to collect information on additional identified diseases at different stages of elimination with minimal additional cost. Geostatistical modelling of serological data allowed identification of areas with high probabilities of recent exposure to diseases of interest, including areas previously unknown to control programmes. We additionally demonstrate how serological surveys can be used to identify areas with exposure to multiple diseases and to prioritise areas with high uncertainty for future surveys. Modelled estimates of cluster-level prevalence were strongly correlated with more operationally feasible metrics of antibody responses. Conclusions/Significance This study demonstrates the potential of integrated serological surveillance to characterise spatial distributions of exposure to multiple pathogens in low transmission and elimination settings when the probability of detecting infections is low.

Burden and Epidemiology of Human Intestinal Giardia duodenalis Infection in Colombia: A Systematic Review

“…Giardiasis, defined by the World Health Organization (WHO) as a neglected tropical disease, represents a serious concern in public health not only for Colombians but for all people living in Latin America [ 61 ]. Annually, approximately 200 million people are estimated to develop Giardiasis symptoms in the developing countries [ 62 ].…”

Characterizing the spatial distribution of multiple malaria diagnostic endpoints in a low-transmission setting in Lao PDR

“…The antigens in Table 1 were chosen based on their known longevity in the immune system. Pf/PvMSP119 and Pf/PvAMA1 are known to persist in the blood for many years and can be used as a proxy for any previous exposure in an individual's lifetime ( 14 ). Etramp5.Ag1 and PvEBPII are known to be shorter-lived and are used here to represent exposure within 6–9 months ( 17 , 27 ).…”

“…Rather than solely capturing concurrent infections, serology measures specific antibody responses which reflect previous exposure to pathogens. Different malaria antigens elicit different antibody responses, each of which last for different durations in the immune system ( 13 , 14 ). Longitudinal research into antibody kinetics has resulted in a highly informative and diverse set of biomarkers being identified for P. vivax and P. falciparum infections.…”

“…Serological methods have been shown to be a useful complementary tool where traditional parasitological tools are not sensitive enough to estimate recent and active exposure and transmission intensity in low-transmission settings ( 11 , 19 ). Serological multiplex bead assays (MBA) make serological surveys operationally feasible and can be added as a supplemental aspect of population surveys, as they can measure a broad range of immune responses from a single blood spot ( 14 , 20 ). Measuring population-level serological responses using MBA can be useful in showing spatial heterogeneity of malaria exposure, finding clustering or hotspots of transmission and to predict receptive areas at risk of outbreaks ( 12 , 21 , 22 ).…”

“…Geostatistical methods are increasingly being applied in disease research to relate infection metrics with environmental, spatial and temporal covariates ( 14 ). In malaria research there are numerous recent analyses projects involving geostatistical mapping of malaria incidence, prevalence and other metrics ( 23 , 24 ).…”