Award Date

12-15-2025

Degree Type

Thesis

Degree Name

Master of Public Health (MPH)

Department

Environmental and Global Health

First Committee Member

Louisa Messenger

Second Committee Member

Francisco Sy

Third Committee Member

Chad Cross

Fourth Committee Member

Andrew Reyes

Number of Pages

108

Abstract

Climate change is reshaping environmental conditions across Southeast Asia (SEA) through rising temperatures, altered precipitation patterns, and increased droughts. These changes alter transmission dynamics of neglected tropical diseases (NTDs) by shifting spatial distribution, increasing larval development rates, faster pathogen growth development, and increasing transmission rates. NTDs are a group of preventable and treatable infections that disproportionately affect more than 1 billion people globally, specifically in tropical and subtropical regions. A subgroup of NTDs, parasitic helminth infections (PHIs) - particularly schistosomiasis, soil-transmitted helminths, and lymphatic filariasis remains a public health concern in the Southeast Asian region. PHIs and their ecological responses to climate variability are not well researched in SEA. PHIs cause short- and long-term health consequences, such as gastrointestinal issues, kidney damage, intestinal bleeding, or cancer. While PHIs affect human populations, it can disproportionately affect vulnerable populations such as pregnant women, and children living in the poorest countries. This cross-sectional geospatial study integrated parasitic helminth prevalence data from the Global Atlas of Helminth Infection and its companion database, This Wormy World—both open-access repositories of georeferenced survey data on helminth infections—together with 103 published studies (1956–2024). These data were merged with climatic, bioclimatic, and environmental variables from WorldClim and MODIS. ArcGIS, a geographic information system (GIS)-based mapping and analysis software, was used to generate hotspot maps (using the Getis-Ord Gi* statistic), and conduct correlation analyses (r-values) to evaluate spatial clustering and climate–infection associations across nine Southeast Asian countries. A total of n=181,525 study participants were examined in nine countries of SEA. Various diagnostic testing methods, including stool and blood samples, indicate PHI was present in n=57,233 individuals (31.52%). Vietnam had the most prevalence of all PHIs (46.62%). Out of all observed species, Schistosomiasis japonicum had the highest prevalence (44.55%). Among climatic factors, maximum temperature of the warmest month (BIO5) and average maximum temperature yielded the highest prevalence rates of 50.51% and 49.97%, respectively. Solar radiation and mean diurnal range (BIO2) both showed the strongest inverse associations with helminth prevalence (r=-0.99). Minimum temperature of the coldest month (BIO6) yielded the most substantial positive association of helminth prevalence (r=+0.99). These findings highlight the strong influence of environmental conditions and population dynamics on parasitic helminth prevalence across SEA. As climate change continues to intensify, continuous subnational helminth surveillance through geospatial analysis may provide guidance for targeted interventions and improving public health strategies.

Keywords

Climate Data; Disease Distribution; Environmental Determinants; Geospatial Analysis; GIS Mapping; Helminth Prevalence

Disciplines

Environmental Health | Environmental Health and Protection | Parasitology | Public Health

File Format

PDF

File Size

2500 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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