Artificial Intelligence for Finding Parasites in Stool

This page looks at one point from a 2026 integrative-oncology presentation: that a deep-learning computer model published in October 2025 finds parasites in stool samples better than the traditional microscope examination. It sets that point beside the published research — the October 2025 study itself, the earlier work it grew from, validations in other laboratories (including one with disappointing results), a before-and-after count from a laboratory that adopted the method, and field studies in places where parasitic worms are common. The research is about detecting parasites; none of it measures cancer.


Table of Contents

  1. What the Presentation Said
  2. How Parasites Are Found in Stool Today
  3. What a Deep-Learning Image Model Does
  4. The October 2025 Wet-Mount Study
  5. Earlier Work: Stained Slides and Portable Scanners
  6. Validations in Other Laboratories
  7. After Adoption: A Before-and-After Count
  8. How to Read the Accuracy Figures
  9. Beyond Stool: Malaria Blood Smears and Primary Care
  10. How the Claim Compares With the Research
  11. What Is Not Known
  12. Connections
  13. Key Research Papers
  14. Featured Videos

What the Presentation Said

The presentation came to artificial intelligence at the end of a section on testing. Before it, the speaker described standard stool tests as having low sensitivity, said parasites release eggs and larvae only intermittently so a single test can come back falsely negative, said antibody blood tests cannot tell a past infection from a current one, and described molecular (polymerase chain reaction (PCR)) tests as more specific but costly and available only in specialised laboratories. The speaker also said that less than 10% of parasite cases are detected by standard stool tests — a figure examined on the sibling page Stool Tests for Parasites and Their Limits.

The speaker then described a paper published in October 2025 that, in the speaker's words, states that AI outperforms traditional methods for detecting parasites in stool samples. According to the presentation:

The speaker linked better detection to the presentation's larger theme, that parasitic infection promotes inflammation and contributes to cancer. Answering an audience question later, the speaker returned to the slide, described AI as a likely quantum leap in the ability to diagnose parasites accurately, and expressed the hope that many laboratories would soon have the ability.

The presentation did not name the paper's authors, journal or laboratory. The study that matches the description — a deep convolutional neural network for parasites in stool wet mounts, published online on 21 October 2025 — is described below. It comes from a large US reference laboratory (a laboratory that tests specimens sent in by many hospitals and clinics) working with the company that makes the software.

How Parasites Are Found in Stool Today

The classic stool parasite test is the ova and parasite examination (often shortened to "O&P"; ova means eggs). A trained laboratory scientist looks through a microscope at prepared stool for the eggs and larvae of worms and the cysts and moving forms of single-celled parasites (protozoa). Two preparations are common in clinical laboratories:

In tropical control programmes the usual method is the Kato-Katz thick smear, a measured amount of stool pressed under cellophane so eggs can be counted per gram.

The authors of the October 2025 study describe stool microscopy as manual, labour-intensive work requiring highly trained staff, performed on millions of specimens a year and largely unchanged in 100 years apart from minor improvements in processing and fixation (Mathison and colleagues, 2025). A 2026 laboratory report adds that in low-prevalence settings such as the United States, the examination is "prone to error" (Anderson and colleagues, 2026). Microscopists also disagree with one another: when two reference microscopists in the Philippines labelled images of worm eggs from Kato-Katz slides for an AI training set, they agreed on 89.24% of images (a statistical agreement score, kappa, of 0.86); the eggs of Schistosoma japonicum were the hardest to agree on, and a third expert was needed to resolve most disagreements (Chua and colleagues, 2025).

These limits are the reason researchers have tried to automate the reading of slides.

What a Deep-Learning Image Model Does

The systems in these studies work in two steps. First, a slide scanner photographs the whole microscope slide at high magnification and stores it as a digital image. Second, a convolutional neural network — a type of computer program that learns to recognise patterns in pictures by being shown many labelled examples — searches the image for objects that look like parasites and labels each one with its most likely identity.

Some terms used in the studies:

A model can only recognise what it was trained on. A parasite that is absent from its training set, or a preparation it has not seen, is a known weak point, which is why several of the papers below stress validation in each laboratory that adopts it.

The October 2025 Wet-Mount Study

The paper is "Detection of protozoan and helminth parasites in concentrated wet mounts of stool using a deep convolutional neural network", published in the Journal of Clinical Microbiology (online 21 October 2025; issue of 12 November 2025). Its authors were from a large US reference laboratory and its associated university pathology department, and from the company that makes the software (Mathison and colleagues, 2025). The authors describe it as the first comprehensive wet-mount AI model development and validation.

How it was built

The accuracy figures, exactly as published

The comparison with people

In a limit-of-detection study, the authors compared the AI with three laboratory scientists of varying experience, using serial dilutions of specimens containing Entamoeba (an amoeba), Ascaris (the giant roundworm), Trichuris (whipworm) and hookworm. The AI "consistently detected more organisms and at lower dilutions of parasites than humans, regardless of the technologist's experience."

What the authors concluded

The abstract states that AI for wet-mount analysis is highly sensitive, "detects considerably more organisms than traditional microscopy alone", simplifies the parasitology workflow and reduces the reliance on traditional microscopy. It describes the work as bringing parasite screening "into the technological age".

Disclosures and commentary

The study measured how well a computer reads slides compared with people reading the same kind of slides. It did not test patients' outcomes, and it did not measure or discuss cancer.

Earlier Work: Stained Slides and Portable Scanners

Trichrome-stained protozoa, 2020

The same laboratory group first built a model for permanent trichrome-stained slides, aimed at screening out negative slides and flagging possible parasites for a human to confirm. Clinical validation used 10 unique positive slides per class of protozoa and 125 negative slides, with accuracy measured as slide-level agreement with microscopy. Positive agreement was 98.88% (95% confidence interval 93.76% to 99.98%) and negative agreement 98.11% (93.35% to 99.77%). With serially diluted stool, the model and scanner were 5-fold more sensitive than manual examination by multiple parasitologists (Mathison and colleagues, 2020). The 2025 wet-mount study is described by its commentators as Part II of this work.

Mobile microscopes and schoolchildren in Kenya

A separate line of research comes from Finnish and Swedish groups working with low-cost portable digital microscopes. A 2017 proof-of-concept study digitised 13 iodine-stained stool samples and 4 urine samples with a miniature scanner; a deep-learning algorithm detected Ascaris, whipworm and hookworm eggs with a sensitivity of 83.3% to 100% in a test set of 217 manually labelled eggs (Holmström and colleagues, 2017). That was egg-level testing on a handful of samples, not a diagnosis of patients.

The group's 2024 study was much larger. Stool from 1,335 schoolchildren in Kwale County, Kenya, was prepared by the Kato-Katz method at a local primary-care laboratory, scanned with a portable whole-slide scanner and uploaded over mobile networks; 1,180 samples were of adequate quality, split into training (388) and test (792) sets (Lundin and colleagues, 2024). With expert manual microscopy as the reference:

Two of the authors declared that they founded and co-own an image-analysis company, and patents for the mobile microscope were reported as pending.

Spiked slides in China

A small Chinese study added known numbers of Schistosoma japonicum eggs to stool from uninfected residents to make 80 Kato-Katz slides. An AI imaging system was correct on 97.50% of slides for presence or absence, against 81.25% for manual microscopy, and counted eggs accurately on 91.67% of infected slides, against 31.67%. It missed 3.33% of infected slides (manual: 13.33%) and made no false detections on the 20 negative slides (manual: 35.00%). It was slightly slower on average — 16.70 against 15.78 minutes per slide (Chen and colleagues, 2025). Laboratory-spiked slides are easier to score than real patient samples, because the true answer is known.

Validations in Other Laboratories

A result from the laboratory that built a system is the first step; how it performs elsewhere is the test that matters for routine use. Published validations from other laboratories give a mixed picture.

A Swiss university laboratory, 2025

The Swiss group tested the same company's wet-mount algorithm with a compact slide scanner in routine clinical work (Büschlen and colleagues, 2025).

A Spanish hospital laboratory, 2026

A university hospital in Barcelona retrospectively tested an iodine wet-mount version of the same company's software on 178 stool specimens: 116 with one parasite, 31 with mixed infections and 31 negatives (Rubio Maturana and colleagues, 2026).

A different automated analyser in Belgium, 2026

Not every system has performed well. Six Belgian hospital laboratories, including two national reference centres, evaluated a commercial automated feces analyser that combines automated microscopy with deep learning, on 267 clinical stool samples with light microscopy as the reference (Aupaix and colleagues, 2026).

An Indian teaching hospital, 2026

In New Delhi, wet-mount microscopy found parasites in 204 of 7,267 stool samples (2.8%) over three years. In 275 samples run on both microscopy and another AI-assisted feces analyser, the analyser agreed with microscopy in 83.3% and with an expert audit in 84.7%; the audit found 35 misidentified cases and 6 missed detections, while the analyser found 10 cases that microscopy had overlooked. Against a composite reference standard, its sensitivity was 66.7% and specificity 86.2%. The authors wrote that with expert review its performance was excellent and that cost-effectiveness still has to be weighed (Aggarwal and colleagues, 2026).

Taken together: systems that pair a scanner with a well-trained network and human review have matched or exceeded microscopy in several laboratories, while a different analyser on the market performed well below that standard. "AI" is not one test; each system, scanner and laboratory set-up has its own figures.

After Adoption: A Before-and-After Count

In 2026 the US reference laboratory that published the October 2025 study reported what happened in routine work. It compared two six-month periods, before and after it began using AI to pre-screen concentrated wet mounts (Anderson and colleagues, 2026):

The authors describe the data as observational. A before-and-after comparison cannot fully separate the effect of the new method from changes in who was tested in each period, and the paper reports detections, not whether patients were treated differently or did better. One author disclosed being a collaborator of the software company.

How to Read the Accuracy Figures

Agreement is not the same as sensitivity

Most of these studies report positive and negative percent agreement — how often the AI's answer matched a reference method, usually human microscopy. If the reference itself misses parasites, a test that finds them will look like it is producing "false positives". Lundin and colleagues (2024) and the October 2025 study both found organisms that the human reading had missed, which means microscopy is an imperfect yardstick.

Discrepant resolution

The October 2025 study reports two sets of figures: 94.3% and 94.0% before discrepant results were resolved, and 98.6% positive agreement after. The second figure comes from re-examining only the specimens where the AI and the original reading disagreed. This method, called discrepant analysis, has been criticised in the diagnostic-statistics literature: a 1996 analysis in The Lancet by a U.S. Centers for Disease Control and Prevention (CDC) statistician showed that sensitivity and specificity estimated this way are biased upward, even when a perfect test is used to resolve the disagreements (Hadgu, 1996). This does not mean the newly found organisms are not real — the study reports they were confirmed by scan review and microscopy — but the pre-resolution figures are the more conservative ones.

How the reference standard was built

Other things that change the numbers

Beyond Stool: Malaria Blood Smears and Primary Care

The same kind of image analysis has been studied for malaria, where parasites are seen inside red blood cells on a stained blood smear. One research group built a deep-learning method that runs on a smartphone to find malaria parasites in thick blood smears, and released a dataset of 1,819 images from 150 patients. In patient-level five-fold cross-evaluation (repeatedly training on part of the data and testing on the rest), its accuracy at telling parasite from background image patches was 93.46%, with sensitivity 92.59% and specificity 94.33% (Yang and colleagues, 2020). These are figures for image patches in a research dataset, not for diagnosing patients in a clinic.

A 2026 scoping review looked for studies of AI-supported digital microscopy performed in primary health-care laboratories and compared with a standard diagnostic method. Of 3,403 papers screened, 22 qualified: 12 on blood (blood counts and malaria), 4 on urine, 3 on cervical or oral cells, 1 on sputum, and only 2 on stool parasites. The review reported accuracy comparable to the reference standard across these uses, and higher sensitivity than manual microscopy in 6 of the 7 studies whose design allowed that comparison. It named scalability and cost-effectiveness as unresolved questions (von Bahr and colleagues, 2026). One of its authors, also an author of the Kenyan stool studies, declared fees from and co-ownership of an image-analysis company.

How the Claim Compares With the Research

Supported

Supported only in part

Not found in the research

Decisions about parasite testing, and about cancer treatment, belong with a clinician.

What Is Not Known

Connections

Key Research Papers

  1. Mathison BA, Knight K, Potts J, Black B, Walker JF, Markow F, Wood A, Bess D, Dixon K, Cahoon B, Hymas W, Couturier MR. Detection of protozoan and helminth parasites in concentrated wet mounts of stool using a deep convolutional neural network. J Clin Microbiol. 2025;63(11):e0106225. PubMed PMID: 41117595
  2. Kirby JE, Arnaout R. What's not to learn? AI meets parasitology. J Clin Microbiol. 2026;64(1):e0145125. PubMed PMID: 41358779
  3. Mathison BA, Kohan JL, Walker JF, Smith RB, Ardon O, Couturier MR. Detection of Intestinal Protozoa in Trichrome-Stained Stool Specimens by Use of a Deep Convolutional Neural Network. J Clin Microbiol. 2020;58(6):e02053-19. PubMed PMID: 32295888
  4. Anderson CP, Couturier MR, DeMaranville M, Jensen R, Sant M, Barker A, Mathison BA. Diagnosing helminth infections in a large reference laboratory in the United States: a 6-month pre- and post-implementation analysis of AI-augmented screening of concentrated fecal wet mounts. J Clin Microbiol. 2026;64(7):e0016526. PubMed PMID: 42283511
  5. Büschlen C, Rotzer D, Sidler N, Nguyen HTT, Oberli A. Validation of Digital Slide Scanning and a Convolutional Neural Network for the Detection of Intestinal Parasites in Human Stool Samples. Diagnostics (Basel). 2025;15(23):2974. PubMed PMID: 41374355
  6. Rubio Maturana C, Sulleiro E, Zarzuela F, Martínez-Vallejo P, Mediavilla A, Silgado A, Turró C, Balladares M, Gracia A, Paz C, García-Vega D, José-Villar SMS, Blanco-Grau A, Moreno F, Larrosa N, Goterris L. Performance of an [product name omitted] AI-based image analysis system for coproparasitological diagnosis in clinical stool specimens: a retrospective evaluation study. J Clin Microbiol. 2026;64(8):e0043126. PubMed PMID: 42324608
  7. Aupaix A, Filippin L, Jaumot J, Cannoot S, Chemais M, Martiny D, Miendje Deyi VY, Deffontaine M, Deckers C, Verbelen V, Potters I, Drieghe C, Mzougui S, Soleimani R, Philippart P, Brauner J. Evaluation of [product name omitted] automated microscope for parasitology: when artificial intelligence meets old school microscopy. J Clin Microbiol. 2026;64(3):e0074325. PubMed PMID: 41665376
  8. Aggarwal P, Choudhary J, Pallavi, Saxena S, Dey S. Prevalence of intestinal parasites in a tertiary care hospital and utility of AI-assisted fecal analyzer for their detection. Exp Parasitol. 2026;282:109110. PubMed PMID: 41628712
  9. Lundin J, Suutala A, Holmström O, Henriksson S, Valkamo S, Kaingu H, Kinyua F, Muinde M, Lundin M, Diwan V, Mårtensson A, Linder N. Diagnosis of soil-transmitted helminth infections with digital mobile microscopy and artificial intelligence in a resource-limited setting. PLoS Negl Trop Dis. 2024;18(4):e0012041. PubMed PMID: 38602896
  10. Holmström O, Linder N, Ngasala B, Mårtensson A, Linder E, Lundin M, Moilanen H, Suutala A, Diwan V, Lundin J. Point-of-care mobile digital microscopy and deep learning for the detection of soil-transmitted helminths and Schistosoma haematobium. Glob Health Action. 2017;10(sup3):1337325. PubMed PMID: 28838305
  11. Chen L, Luo H, Wu C, Wan J, Wu J, Liu H, Li B, Yang S. [Effectiveness of an artificial intelligence-enabled microscopic imaging recognition system for detection of Schistosoma japonicum eggs]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2025;37(4):415-419. PubMed PMID: 41167950
  12. Chua RSCS, Henderson KA, de Guzman LMC, Foss V, Schub N, Bell C, Medina JRC, Siao TG, Mistica MS, Belleza MLB, Modequillo MCR, Torres NJC, Belizario VY Jr. Variability of interobserver interpretation of selected helminth ova in the development of a training image set. Int Health. 2025;17(5):836-842. PubMed PMID: 39782878
  13. Hadgu A. The discrepancy in discrepant analysis. Lancet. 1996;348(9027):592-3. PubMed PMID: 8774575
  14. Yang F, Poostchi M, Yu H, Zhou Z, Silamut K, Yu J, Maude RJ, Jaeger S, Antani S. Deep Learning for Smartphone-Based Malaria Parasite Detection in Thick Blood Smears. IEEE J Biomed Health Inform. 2020;24(5):1427-1438. PubMed PMID: 31545747
  15. von Bahr J, Suutala A, Diwan V, Mårtensson A, Lundin J, Linder N. AI-Supported Digital Microscopy Diagnostics in Primary Health Care Laboratories: Scoping Review. J Med Internet Res. 2026;28:e78500. PubMed PMID: 41490467

PubMed Topic Searches

  1. Convolutional neural networks and stool parasites
  2. Artificial intelligence and the ova and parasite examination
  3. Deep learning and Kato-Katz helminth egg detection
  4. Digital microscopy and AI for malaria blood smears