Trichuriasis diagnosed by colonoscopy: case report and review of the literature spanning 22 years in mainland China

An Unpleasant Souvenir: Whipworm as an Incidental Finding During a Screening Colonoscopy

Trichuriasis is a neglected tropical disease caused by Trichuris trichiura that spreads through the ingestion of embryonated eggs in contaminated soil, water, or food. In nonendemic areas, T trichiura infestation is very rare and sporadic and is often diagnosed in immigrants from endemic countries such as the Philippines. Whipworms feed on human blood and also erode the colonic mucosa, thereby evoking an inflammatory response. In milder forms, trichuriasis can be asymptomatic and often an incidental diagnosis on screening colonoscopy. Heavily infested patients usually present with abdominal pain, nausea, vomiting, tenesmus, chronic diarrhea, iron deficiency anemia, or stunted growth. T trichiura worms can be removed with biopsy forceps during a colonoscopy; however, most patients require a course of albendazole, mebendazole, or ivermectin. We describe a unique case of T trichiura as an incidental finding during a screening colonoscopy. The whipworms were retrieved using biopsy forceps and the patient was treated with albendazole. At the time of the colonoscopy, the patient did not exhibit any specific symptoms related to the worm infestation.

Near-infrared spectroscopy and machine learning algorithms for rapid and non-invasive detection of Trichuris

BACKGROUND

Trichuris trichiura (whipworm) is one of the most prevalent soil transmitted helminths (STH) affecting 604-795 million people worldwide. Diagnostic tools that are affordable and rapid are required for detecting STH. Here, we assessed the performance of the near-infrared spectroscopy (NIRS) technique coupled with machine learning algorithms to detect Trichuris muris in faecal, blood, serum samples and non-invasively through the skin of mice.

METHODOLOGY

We orally infected 10 mice with 30 T. muris eggs (low dose group), 10 mice with 200 eggs (high dose group) and 10 mice were used as the control group. Using the NIRS technique, we scanned faecal, serum, whole blood samples and mice non-invasively through their skin over a period of 6 weeks post infection. Using artificial neural networks (ANN) and spectra of faecal, serum, blood and non-invasive scans from one experiment, we developed 4 algorithms to differentiate infected from uninfected mice. These models were validated on mice from a second independent experiment.

PRINCIPAL FINDINGS

NIRS and ANN differentiated mice into the three groups as early as 2 weeks post infection regardless of the sample used. These results correlated with those from concomitant serological and parasitological investigations.

SIGNIFICANCE

To our knowledge, this is the first study to demonstrate the potential of NIRS as a diagnostic tool for human STH infections. The technique could be further developed for large scale surveillance of soil transmitted helminths in human populations.

Trichuris trichiura Incidentally Detected by Colonoscopy and Identified by a Genetic Analysis

Although trichuriasis, a zoonotic disease, has recently become rare in Japan due to improved environmental hygiene, we herein report a 79-year-old man in whom a worm was incidentally found in the ascending colon during colonoscopy for positive fecal occult blood and was endoscopically removed. A genetic analysis identified the worm as Trichuris trichiura possessing mixed sequences from non-human primate and human origins. Despite controversy regarding Trichuris trichiura infection originating from Japanese macaques, according to some studies, it originates primarily from humans. This report suggests the efficacy of a genetic analysis for identifying infection sources.

An unpleasant souvenir: Endoscopic finding of Trichuris trichiura (Nematoda: Trichuridae)

Whipworms are responsible for up to 500 million cases of trichuriasis worldwide, with higher endemicity in tropical and sub-tropical countries. In non-endemic countries, trichuriasis can be accidentally diagnosed upon colonoscopy, often in the presence of negative microscopy. Here, we describe an incidental diagnosis of trichuriasis in an HIV patient residing in a non-endemic area (i.e., Turin, Italy), six months after his return from Antigua. The species-level diagnosis was made thanks to PCR-based molecular identification of Trichuris sp. following optical microscopy detection. Overall, this case highlights the importance of improving parasitic diseases diagnosis through cutting-edge clinical and laboratory diagnostic tools alongside advanced training of specialists in the area of parasitology.

Soil-transmitted helminth infections

More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consider the possibility of infection in individuals living in, or returning from, endemic regions. Although safe and effective drugs are donated free to endemic countries, only half of at-risk children received treatment in 2016. This Seminar describes the epidemiology, lifecycles, pathophysiology, clinical diagnosis, management, and public health control of soil-transmitted helminths. Previous work has questioned the effect of population-level deworming; however, it remains beyond doubt that treatment reduces the severe consequences of soil-transmitted helminthiasis. We highlight the need for refined diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and management of these infections.

Clinical correlates of trichuriasis diagnosed at colonoscopy

Diagnosis of Trichuris trichiura infestations is usually based on identification of barrel-shaped ova in stool, but is frequently missed on stool microscopy. We describe the clinical profile of patients in whom Trichuris infection was incidentally diagnosed at colonoscopy. In a cross-sectional study, patients with colonoscopic diagnosis of trichuriasis were enrolled from the endoscopy unit in a tertiary care center. Blood and stool samples were collected from all those who were willing to participate and provide samples. Sixty-two patients participated, with mean (SD) age of 50.5 (13.6) years and male to female ratio of 40:22. Abdominal pain (61.2%) and/or altered bowel habits (32.2%) were the most common indication for colonoscopy. Most (66.6%) of the Trichuris were located in the cecum and ascending colon. Majority of the patients had live worms, either motile or adhering to the colonic mucosa. The number of worms was single or a few (<15) in 74.2% of patients. Out of 62 patients, 16 (25.8%) had relatively heavy load of parasites. Most patients had normal colonoscopic findings (80.6%). Periappendicular and/or cecal ulcerations/erosions were the most common (16.1%) abnormalities noted. Stool examination showed parasite ova only in four (6.4%) patients. In conclusion, colonoscopy was better than stool microscopy for the diagnosis of trichuriasis in our study.

Identifying Helminth Infections via Routine Fecal Parasitological Examinations in Korea

We conducted this study to explore the extent of occult helminth infection identified by fecal parasitological examinations or organ-specific examinations such as colonoscopy and abdominal ultrasonography (US) during health checkups. We analyzed 197,422 fecal samples from 99,451 subjects who received health checkups at a single center over 10 years. We found that 3,472 (1.8%) samples from 3,342 (3.4%) subjects tested positive for parasitic ova, including clonorchiasis, metagonimiasis, trichuriasis, ascariasis, trichostrongylosis, taeniasis, and enterobiasis. The detection rate for clonorchiasis was higher in those who were taking their first examination than in those who had been examined previously. The detection rate for clonorchiasis decreased gradually over the 10 years. Only 2.5% of the patients with clonorchiasis showed US or computed tomography (CT) images that were compatible with the disease. Clonorchiasis patients who had abdominal US or CT images that suggested clonorchiasis were older and had lower body mass indices and higher eosinophil counts than did those whose US or CT images did not suggest the disease. We observed worms in 9% of the patients with trichuriasis who had received a colonoscopy. Colonoscopy also uncovered adult worms in 0.03% of subjects who were not identified as having Trichuris trichiura ova in their fecal helminth examinations. In summary, our study shows that occult helminth infection is fairly frequently identified by a variety of methods during health checkups, which suggests that doctors need to make greater effort to identify and treat occult helminth infections in Korea.

Soil-transmitted helminths and plasmodium falciparum malaria among individuals living in different agroecosystems in two rural communities in the mount Cameroon area: a cross-sectional study

Background

Soil-transmitted helminths (STHs) and Plasmodium falciparum infections remain public health problems in Cameroon. A cross-sectional study was carried out in the Mount Cameroon area to determine the prevalence and intensity of STHs and P. falciparum infections in individuals living in different agroecosystems; to assess the influence of these infections on haematological parameters; and to identify the risk factors associated with STH infections.

Methods

STH and malaria parasites were detected using the Kato-Katz method and Giemsa staining of blood films, respectively. Complete blood count values were obtained using an automatic haematology analyser. Soil samples were analysed using the sucrose floatation sedimentation method. Categorical and continuous variables were compared as required and logistic regression models were used to assess the risk factors for STH infections and anaemia.

Results

Of the 450 participants examined, STHs, P. falciparum and mixed co-infections were detected in 14.0, 33.3 and 5.6% of participants, respectively. Significantly higher prevalences of Ascaris (18.8%) and Trichuris (7.9%) infections were observed in participants from tea plantation areas compared to those from banana and palm plantation areas, with similar trends in egg density. P. falciparum prevalence and parasite density were comparable between the different agroecosystems. The overall prevalence of anaemia was 64.2%. The prevalence of haematological manifestations such as moderate (48.0%) and severe (8.0%) anaemia, leucopenia (26.9%) and microcytosis (30.8%) was significantly higher among Plasmodium-STH co-infected participants. Soil samples from plantations showed the highest prevalences of STH eggs compared to soil samples from areas around pit toilets and public water taps. Living in a tea plantation area (OR = 3.07), age (AOR = 1.49) and lack of access to potable water (OR = 2.25) were identified as risk factors for STH infections, while the age groups 15–25 years (OR = 2.928) and 26–35 years (OR = 2.832), and being female (OR = 2.671) were significant risk factors for anaemia.

Conclusions

STHs, malaria and anaemia are still of public health concern in plantation communities. Co-infections negatively influence haematological parameters. The tea farming agroecosystem, age and lack of access to potable water were identified as significant risk factors for STH infections.

Trial registration

Not applicable.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0266-6) contains supplementary material, which is available to authorized users.

Complexities and Perplexities: A Critical Appraisal of the Evidence for Soil-Transmitted Helminth Infection-Related Morbidity

BACKGROUND

Soil-transmitted helminths (STH) have acute and chronic manifestations, and can result in lifetime morbidity. Disease burden is difficult to quantify, yet quantitative evidence is required to justify large-scale deworming programmes. A recent Cochrane systematic review, which influences Global Burden of Disease (GBD) estimates for STH, has again called into question the evidence for deworming benefit on morbidity due to STH. In this narrative review, we investigate in detail what the shortfalls in evidence are.

METHODOLOGY/PRINCIPAL FINDINGS

We systematically reviewed recent literature that used direct measures to investigate morbidity from STH and we critically appraised systematic reviews, particularly the most recent Cochrane systematic review investigating deworming impact on morbidity. We included six systematic reviews and meta-analyses, 36 literature reviews, 44 experimental or observational studies, and five case series. We highlight where evidence is insufficient and where research needs to be directed to strengthen morbidity evidence, ideally to prove benefits of deworming.

CONCLUSIONS/SIGNIFICANCE

Overall, the Cochrane systematic review and recent studies indicate major shortfalls in evidence for direct morbidity. However, it is questionable whether the systematic review methodology should be applied to STH due to heterogeneity of the prevalence of different species in each setting. Urgent investment in studies powered to detect direct morbidity effects due to STH is required.

Parasitic colitis

Over one billion people worldwide harbor intestinal parasites. Parasitic intestinal infections have a predilection for developing countries due to overcrowding and poor sanitation but are also found in developed nations, such as the United States, particularly in immigrants or in the setting of sporadic outbreaks. Although the majority of people are asymptomatically colonized with parasites, the clinical presentation can range from mild abdominal discomfort or diarrhea to serious complications, such as perforation or bleeding. Protozoa and helminths (worms) are the two major classes of intestinal parasites. Protozoal intestinal infections include cryptosporidiosis, cystoisosporiasis, cyclosporiasis, balantidiasis, giardiasis, amebiasis, and Chagas disease, while helminth infections include ascariasis, trichuriasis, strongyloidiasis, enterobiasis, and schistosomiasis. Intestinal parasites are predominantly small intestine pathogens but the large intestine is also frequently involved. This article highlights important aspects of parasitic infections of the colon including epidemiology, transmission, symptoms, and diagnostic methods as well as appropriate medical and surgical treatment.