A new test conducted by scientists reveals intestinal parasites are far more common than expected on Pemba Island, Tanzania, with nearly three in four people infected — highlighting the need for stronger public health measures and ongoing surveillance.

The test, called real-time Polymerase Chain Reaction (qPCR), “can accurately detect and differentiate six parasite species,” researchers say, offering a powerful new tool for disease monitoring. It is clearer and more reliable than traditional methods that rely on microscope examination.

Published in Springer Nature on April 2025, the study also tested whether the promising new worm medicine emodepside could treat protozoa infections. The results showed no clear effect, confirming that emodepside mainly works against parasitic worms in humans.

Why this matters
Tiny parasites like entamoeba histolytica and giardia duodenalis cause serious health problems such as diarrhea and malnutrition, affecting millions of people worldwide each year. But traditional tests often miss infections or can’t distinguish harmful parasites from harmless ones, making it harder to control these diseases.

This new test is faster, more sensitive (able to detect even small amounts of parasites), and cheaper than older methods. Because of this, it can help doctors and health workers better find and track infections, leading to improved care for patients.

How the study was done
Scientists collected 70 stool samples from participants before and 54 after treatment with either emodepside or a placebo. Using the qPCR test, they screened for multiple parasite species at once. Findings revealed that 74% of participants carried at least one intestinal parasite, with about one-third infected by Entamoeba histolytica or a related species. 

Notably, the test identified Chilomastix mesnili in humans for the first time—broadening knowledge of parasite diversity in the region.

What this means for the future
The qPCR test could transform how intestinal parasites are diagnosed and monitored, giving health workers a clearer picture to better control infections. Researchers emphasize the urgent need to develop alternative drugs against intestinal protozoa, coupled with stronger public health measures to reduce their impact.

Study led by global experts

The research was led by experts from the Swiss Tropical and Public Health Institute in Allschwil, Switzerland, with Christian Lotz as the lead author. Contributors included scientists from the Ifakara Health Institute, represented by Emmanuel Mrimi; and the University of Basel, represented by Ivo de Carneri.

Read the publication here.