Poverty associated with the environmental contamination of gastrointestinal parasites in the Southern United States

Abstract

Gastrointestinal parasites are generally associated with lower-income countries in tropical and subtropical areas, but they are also prevalent in low-income and extreme low-income communities in the Southern United States. To date, studies characterizing the epidemiology of gastrointestinal parasites in the United States are limited, resulting in little comprehensive understanding of the challenge. This study investigates the environmental contamination of gastrointestinal parasites in the Southern United States by determining the contamination rate and burden of each parasite in five low-income communities. A total of 499 soil samples of approximately 50g were collected from public parks and private residences in Alabama, Louisiana, Mississippi, South Carolina, and Texas. A novel technique utilizing parasite floatation, filtration, and bead-beating was applied to concentrate and extract parasite DNA from samples. A multi-parallel qPCR-based molecular method detected Blastocystis spp (19.0%), Toxocara cati (6.01%), Toxocara canis (3.61%), Strongyloides stercoralis (2.00%), Trichuris trichiura (1.80%), Ancylostoma duodenale (1.42%), Giardia intestinalis (1.40%), Cryptosporidium spp (1.00%), Entamoeba histolytica (0.201%), and Necator americanus (0.200%). Overall parasite contamination rates varied significantly between communities: Western Mississippi (46.88%); Southwestern Alabama (39.62%); Northeastern Louisiana (28.24%); Southwestern South Carolina (27.03%); and South Texas (6.93%) (p < 0.0001). Furthermore, Toxocara spp. contamination rates were correlated with community poverty rates (rs = 0.7000; p = 0.2333). Toxocara cati DNA burdens were greater in communities with higher poverty rates, including Northeastern Louisiana (50.57%) and Western Mississippi (49.60%) compared to Southwestern Alabama (30.05%) (p = 0.0011). This study demonstrates the environmental contamination of parasites and their relationship with high poverty rates in communities in the Southern United States.

Evidence and potential drivers of neglected parasitic helminth and protist infections among a small preliminary sample of children from rural Mississippi

“…Pinworm, for instance, is common in young children everywhere with few known long-term consequences (Bogitsh et al, 2018). However, recent soil analyses from public parks and private residences in the same Mississippi county sampled here found evidence of several more concerning nematode species, including Strongyloides stercoralis and both hookworm species (Blackburn et al, 2023), suggesting these are likely candidates for the nematode infections seen here (Blackburn et al, 2023); The study did not analyze potential platyhelminth presence. We also cannot speak to infection intensity, though very few parasite eggs were observed microscopically, suggesting low-intensity infections (Cepon-Robins et al, 2022).…”

“…(Hotez, 2008; Sunkes & Sellers, 1937). One of the nematode infections was able to be more specifically identified as being from the order Rhabditida, which includes Strongyloides, hookworm, and pinworm; all three of which are present in the United States (Blackburn et al, 2023). Problematically, analytical methods did not provide species‐specific identification so nematode infections may be caused by more (i.e., hookworm, strongyloidiasis) or less (i.e., pinworm) deleterious species.…”

“…Estimates and recent surveys suggest that millions of people in the United States may still be infected (Hotez, 2008; McKenna et al, 2017; Starr & Montgomery, 2011). Importantly, recent analysis of soil samples from public parks and private residences in the rural Mississippi Delta found evidence of several protist and helminth species, including Cryptosporidium spp., Trichuris trichiura , Strongyloides stercoralis , and hookworm (Blackburn et al, 2023).…”