Leptospirosis in American Samoa 2010: Epidemiology, Environmental Drivers, and the Management of Emergence

Abstract

Abstract. Leptospirosis has recently been reported as an emerging disease worldwide, and a seroprevalence study was undertaken in American Samoa to better understand the drivers of transmission. Antibodies indicative of previous exposure to leptospirosis were found in 15.5% of 807 participants, predominantly against three serovars that were not previously known to occur in American Samoa. Questionnaires and geographic information systems data were used to assess behavioral factors and environmental determinants of disease transmission, and logistic regression was used to identify factors associated with infection. Many statistically significant factors were consistent with previous studies, but we also showed a significant association with living at lower altitudes (odds ratio [OR] ¼ 1.53, 95% confidence interval [CI]: 1.03-2.28), and having higher numbers of piggeries around the home (OR ¼ 2.63, 95% CI: 1.52-4.40). Our findings support a multifaceted approach to combating the emergence of leptospirosis, including modification of individual behavior, but importantly also managing the evolving environmental drivers of risk.

ANALISIS ESPACIAL Y EPIDEMIOLOGICO SOBRE LEPTOSPIROSIS HUMANA EN PUERTO RICO, 1996 a 2014

“…Sin embargo, aunque las precipitaciones han sido asociadas con la leptospirosis, una alta precipitación no necesariamente conduce a un aumento de los casos de leptospirosis. Esto puede indicar que otros factores climáticos y ambientales pueden reducir o aumentar el riesgo (Lau et al 2012, Raghavan et al 2011, Vinetz et al 2005. Por otra parte, la leptospirosis se ha relacionado a ciertas condiciones socio-económicas, demográficas-socioeconómicas y climatológicas que favorecen la endemicidad entre los reservorios animales y la exposición humana (Pappas et al 2008).…”

“…Actualmente, muchos investigadores opinan que todavía falta mucho por entender sobre la dinámica ecológica de la leptospirosis, sobre el rol de los factores ambientales y climáticos, en especial los factores hidrológicos; y cómo éstos pueden variar temporal, espacial y geográficamente de una ubicación a otra (Batchelor et al 2012, Cann et al 2013, Lau et al 2012, Mohan et al 2009, Raghavan et al 2012, Vinetz et al 2005, VegaCorredor y Opadeyi 2014. Por tal razón, en años recientes, los Sistemas de Información Geográfica han tomado mayor protagonismo en estudios de salud pública, salud ambiental y epidemiología incorporando estadísticas espaciales, información satelital y análisis ecológico de enfermedades infecciosas 2016, Vega-Corredor y Opadeyi 2014: "Análisis espacial y epidemiológico sobre leptospirosis humana en Puerto Rico, 1996", GeoFocus (Artículos), nº 21, p. 227-251.…”

A framework for assessing and predicting the environmental health impact of infectious diseases: a case study of leptospirosis

“…The details of the fi ndings of the assessment have been described in earlier publications (20,21) . In summary, the assessment included 807 adults from 65 villages on fi ve islands of AS.…”

“…The details of the methodology, goodness of fi t of the models, and model validation statistics have been described in earlier publications (20,21) . The alternative scenarios explored in this assessment included the following: The seroprevalence prediction charts in Figure 4 show the combined effects of indicators in determining overall infection risk and provide a more accurate estimate of seroprevalence than individual indicators or a simple count of the number of indicators.…”

“…Table 2 shows the ten indicators of risk factors that were found to be signifi cantly associated with previous infection and the odds ratios of being infected compared with participants without those risk factors. Six of these indicators were associated with individual-level risk factors (male gender, outdoor occupation/fi sh cleaners, income, lack Table 2 Indicators and risk factors associated with the presence of Leptospira antibodies and used to defi ne the reference scenario (20,21 Swimming or walking in rain puddles…”