USA - Human Intestinal Parasite Burden and Poor Sanitation in Rural Alabama - Hookworm

[Gert van der Hoek]

05 september 2017

Hookworm infection affects 430 million people worldwide, causing iron deficiency, impaired cognitive development, and stunting in children. Because of the environmental conditions needed for the hookworm life-cycle, this parasite is endemic to resource-limited countries. Necator americanus was endemic in the southern United States before improvement of sewage disposal systems and eradication programs.

With continued poverty, poor sanitation, and an environment suitable for the hookworm life-cycle in some regions of the southern United States, a current prevalence study using modern molecular diagnostics is warranted. Lowndes County, Alabama, was chosen as the study site given previous high hookworm burdens, degree of poverty, and use of open-sewage systems. Participants were interviewed, and stool, serum, and soil samples were tested for nine intestinal parasites using a multiparallel quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assays .

We found that, among 24 households, 42.4% reported exposure to raw sewage within their home, and from 55 stool samples, 19 (34.5%) tested positive for N. americanus, four (7.3%) for Strongyloides stercoralis, and one (1.8%) for Entamoeba histolytica. Stool tested positive for N. americanus contained low levels of parasite DNA (geometric mean 0.0302 fg/?L). Soil studies detected one (2.9%) Cryptosporidium species, and Toxocara serology assay detected one (5.2%) positive in this population. Individuals living in this high-risk environment within the United States continue to have stool samples positive for N. americanus. Gastrointestinal parasites known to be endemic to developing countries are identifiable in American poverty regions, and areas with lower disease burden are more likely to be identified by using qPCR.

[Gert van der Hoek]

Hookworm, a disease of extreme poverty, is is thriving in the US south. Why?

sept 5, 2017

Children playing feet away from open pools of raw sewage; drinking water pumped beside cracked pipes of untreated waste; human faeces flushed back into kitchen sinks and bathtubs whenever the rains come; people testing positive for hookworm, an intestinal parasite that thrives on extreme poverty.

These are the findings of a new study into endemic tropical diseases, not in places usually associated with them in the developing world of sub-Saharan Africa and Asia, but in a corner of the richest nation on earth: Alabama.

Scientists in Houston, Texas, have lifted the lid on one of America?s darkest and deepest secrets: that hidden beneath fabulous wealth, the US tolerates poverty-related illness at levels comparable to the world?s poorest countries. More than one in three people sampled in a poor area of Alabama tested positive for traces of hookworm, a gastrointestinal parasite that was thought to have been eradicated from the US decades ago.

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