IMAGE COURTESY OF PLOS NEGLECTED TROPICAL DISEASESDon’t let the title fool you. “An In-Depth Analysis of a Piece of Shit: Distribution of Schistosoma mansoni and Hookworm Eggs in Human Stool,” a paper published last month in PLOS Neglected Tropical Diseases, is a serious scientific study aiming to help health practitioners more accurately diagnose parasitic worm infections by studying patient stool samples.
The paper describes an experiment using stool samples from more than 200 residents of Côte d'Ivoire, or the Ivory Coast, an African country whose population suffers from schistosomiasis and soil-transmitted helminthiasis, two parasitic diseases that affect hundreds of millions of people around the world and account for more than 40 percent of the global neglected tropical disease burden.
Study participants defecated into containers designed to prevent contamination, and researchers from the Ivory Coast and Switzerland examined their feces for the distribution of worm eggs within individual turds. They also compared egg counts in homogenized stool samples to intact samples, and tested the effects of different storage methods—keeping stool on ice, draping it with damp tissues, and keeping samples in the shade.
The takeaway from the study was that parasitic worm eggs are distributed fairly evenly in across a stool sample—with little variation from the front to the back or the outer surface to the inner core. But the researchers did find that homogenization decreased counts of Schistosoma mansoni eggs, and hookworm egg decay could be slowed by storing stool sample in cool, damp places.
This information can potentially be used by heath practitioners in Africa and elsewhere to more accurately diagnose patients with parasitic worm infections, to better design and conduct epidemiological surveys of the diseases, and to improve tracking and evaluation of control programs aimed at reducing levels of infection.
In addition to their contributions to science, the authors of this paper should be commended for giving the scientific literature one of the most colorful titles this reporter has seen in a long time.