Assessment of the Current Surveillance System for Human Leptospirosis in Ecuador by Decision Analytic Modeling

Abstract

Leptospirosis is a globally disseminated zoonotic disease with no national surveillance systems. On the other hand, surveillance is crucial for improving population health, and surveillance systems produce data that motivates action. Unfortunately, like many other countries, Ecuador put in place a monitoring system that has never been tested. The goal of this study was to use scenario tree modeling to assess the sensitivity of Ecuador's current national surveillance system to human leptospirosis as the basis for an economic assessment of the system. We created a decision-tree model to analyze the current system's sensitivity. The inputs were described as probabilities distributions, and the model assessed the program's sensitivity as an output. The model also considers the geographical and weather variations across Ecuador's three continental regions: Andean, Amazonia, and the Coast. Several data sources were used to create the model, including leptospirosis records from Ecuador's Ministry of Public Health, national and international literature, and expert elicitation, all of which were incorporated in a Bayesian framework. We were able to determine the most critical parameters influencing each scenario's output (CSU) sensitivity through sensitivity analysis. The Coast region had the best sensitivity scenario, with a median of 0.85% (IC 95% 0.41–0.99), followed by the Amazonia with a median of 0.54% (CI 95% 0.18–0.99) and the Andes with a median of 0.29% (CI 95% 0.02–0.89). As per the sensitivity study, the most influential criteria on the system's sensitivity were “Attendance or probability of going to a health center” and “probability of having symptoms,” notably for the Coast and Amazonia Regions.

Utility of surveillance data for planning for dengue elimination in Yogyakarta, Indonesia: a scenario tree modelling approach

“…Another study applied the scenario tree modelling approach to estimate the sensitivity of surveillance for leptospirosis in Ecuador, where leptospirosis is endemic [36]. This study estimated surveillance sensitivity at substantially higher design prevalence than used here (ranging from 1% to 30% across three geographic regions), consistent with the goal of monitoring an endemic disease rather than demonstrating elimination.…”

Leptospirosis una enfermedad zoonótica, breve revisión de la situación en el Ecuador

“…Mientras que Calero Y Monti en una investigación donde evalúan al sistema de monitoreo que establece el Ecuador para la vigilancia de leptospirosis donde se establece que la región con un alto índice es la región Costa con una mediana de 0,85% (IC 95% 0,41-0,99), mientras que la región oriental con una mediana de 0,54% (IC 95% 0,18-0,99) y la región sierra con una mediana 0.29 % (IC 95% 0,02-0,89). También establece que la "Asistencia o probabilidad de acudir a un centro de salud" y "Probabilidad de tener síntomas", fueron los criterios principalmente que influyeron (35). En tanto Barragan et al en el 2016 (36), determinaron en dos comunidades rurales de la región costa de Ecuador donde identificaron Leptospira ssp en pacientes humanos que presentaban fiebre utilizando PCR en tiempo real y secuenciación de amplicones (14.7% de presencia) en donde pudieron determinar las especies (L. borgpetersenii, L kirschnerii, L santarosai, L. interrogans, L noguchii, L. clado wolffii).…”

Ocular leptospirosis: lack of awareness among ophthalmologists and challenges in diagnosis

“…It showed the best sensitivity scenario. (median of 0.85%, 95% CI 0.41–0.99), followed by Amazonia (median of 0.54%, 95% CI 0.18–0.99), whereas Andes had poor sensitivity (median of 0.29%, 95% CI 0.02–0.89) [42 ▪ ] It could cause significant underdetection in other low prevalent areas. Clinicians in a low prevalence zone had limited ability to diagnose and medical students also lack awareness.…”

“…Each nation at risk should bring out national surveillance systems that produce data to improve patient care [42 ▪ ]. One Health approach is necessary for reducing zoonotic leptospira infections, in which interactions between humans, animals, and the environment play a critical role [1 ▪▪ ].…”

“…Ecuador surveillance study across three continental regions: Andean, Amazonia, and the Coast showed, Coastal region to have the best sensitivity scenario [median of 0.85%, 95% confidence interval (CI) 0.41–0.99], followed by the Amazonia (median of 0.54%, 95% CI 0.18–0.99), whereas Andes had poor sensitivity (median of 0.29%, 95% CI 0.02–0.89) [42 ▪ ].…”