Fecal Load Research Articles

Gastrointestinal: Enterobiasis

Gastroenterologists who perform colonoscopy are likely to encounter occasional patients with small worms in the large bowel. The most common worm is Enterobius vermicularis (pinworm or threadworm). The infestation is acquired by direct person-to-person transmission, by autoinfection or by indirect spread associated with the handling of bed linen. Larvae in ingested eggs hatch in the jejunum, develop in the ileum and finally reside in the cecum and other parts of the colon. The female worm is 8–13 mm long while the male worm is only 2–5 mm long. The average lifespan of the worms is approximately 50 days. The only definite symptom attributed to enterobiasis is that of anal pruritis. This occurs when female worms actively pass out of the anus at night and lay sticky eggs over the perianal skin. Other clinical syndromes associated with enterobiasis may include vulvovaginitis in children and perhaps acute appendicitis. Enterobiasis is endemic throughout the world and particularly affects pre-school children, children in primary schools and children in institutions. Infestation rates may also increase in advanced age. Pinworms do not appear to cause inflammation in the large bowel and have not been associated with increases in blood eosinophils or serum IgE. The diagnosis can be made by the identification of worms at sigmoidoscopy or colonoscopy. However, the usual diagnostic test is the identification of eggs on a tape that is applied to the perianal area first thing in the morning. Several drugs are effective including mebendazole, albendazole and pyrantel pamoate. The patient illustrated below was a 90-year-old man who was admitted to hospital with abdominal pain and abdominal distension. Additional medical problems included hypertension, paroxysmal atrial fibrillation and chronic obstructive pulmonary disease. Blood tests revealed a mild normocytic anemia with a marked elevation of the erythrocyte sedimentation rate (108 mm/hr). A plain abdominal x-ray showed fecal loading in the colon. At colonoscopy, the only abnormality was thousands of small pinworms throughout the large bowel (Figure 1). Pinworms close to the anal canal are shown by retroflexion of the colonoscope in Figure 2. The appearance was typical of heavy infestation. His symptoms appeared to improve after treatment with albendazole.

Growing season surface water loading of fecal indicator organisms within a rural watershed

The loading of microbial contaminants was examined within the Thomas Brook watershed, a 784 ha mixed land-use catchment located in the headwaters of the Cornwallis River drainage basin (Nova Scotia, Canada). The objectives were to: (i) examine spatial and temporal characteristics of fecal bacteria loading during the growing season from five subwatersheds, and (ii) develop areal fecal indicator organism export coefficients for rural landscapes. Fecal coliform, Escherichia coli, total suspended solids (TSS) concentrations and stream flow were monitored at five locations in the watershed over six consecutive growing seasons (May–Oct, 2001–2006). A nested watershed monitoring approach was used to determine bacterial loading from distinct source types (residential vs. agricultural) during both baseflow and stormflow periods. Areal bacterial loading rates increased in each nested watershed moving downstream through the watershed and were highest in the three subcatchments dominated by agricultural activities. Upper watershed bacterial loading throughout the growing season from an agricultural subcatchment (Growing Season Avg 8.92 × 10 10 CFU ha −1) was consistently higher than a residential subcatchment (Growing Season Avg 8.43 × 10 9 CFU ha −1). As expected, annual average stormflow bacterial loads were higher than baseflow loads, however baseflow loads still comprised between 14 and 35% of the growing season bacterial loads in the five subwatersheds. Fecal bacteria loads were greater during years with higher annual precipitation. A positive linear relationship was observed between E. coli and TSS loading during the 2005 and 2006 growing seasons when both parameters were monitored, indicating that the processes of sediment transport and bacterial transport are linked. It is anticipated that computed areal microbial loading coefficients will be useful in developing watershed management plans. More intensive sampling during stormflow events is recommended for improving these coefficients.

A new ultrasound scoring system for assessing the severity of constipation in children

Pelvic ultrasound (US) has been used in various different ways to assess severity of constipation. We evaluated the use of a new US scoring system to determine if there is any correlation between symptom severity and US findings. Data were collected prospectively on all children attending the constipation clinic from January 2007 to July 2008. All patients completed a standardised symptom severity score sheet (SSS) for constipation. US was done with the probe placed 2 cm above the pubic symphysis. A new US scoring system designed to assess the faecal loading and its effect on the bladder was used. Patients with severe symptoms were followed up with few patients requiring as many as four follow up visits. During each follow-up visit SSS and US scoring was completed. A total of 500 patients were studied (male 317, female 183) with a median age of 8 years (8 months, 18 years). Statistical analysis was done using SPSS software (version 15.0). Pearson's correlation was used to assess the correlation between SSS and US score. P value <0.05 was considered to represent a statistically significant correlation between symptoms and ultrasound findings. US is an easy and quick tool that can be used in the out-patient setting to assess severity of constipation. The new US scoring system is a reliable method that can be used in conjunction with clinical examination for assessing the long-term improvement of children who are undergoing treatment for chronic constipation.

Blinded comparison of faecal loading on plain radiography versus radio-opaque marker transit studies in the assessment of constipation

To compare faecal loading on plain radiography versus radio-opaque marker transit studies in the assessment of constipation. The study group was a convenience sample of patients attending the Durham Constipation Clinic. All patients underwent transit studies according to an established protocol, and severity of constipation was assessed contemporaneously using a validated questionnaire (PAC-SYM). Transit studies were performed using radio-opaque markers that were ingested over 3 consecutive days, with a radiograph taken on the fourth day. Digital images of the radiograph were digitally altered to remove all traces of the transit markers without affecting the underlying pattern of faecal loading. Four observers assessed faecal loading independently; two clinicians (C1 and C2) and two radiologists (R1 and R2). C1 and R1 used a previously described formal scoring method of assessing faecal loading, whereas C2 and R2 assessed the images as if they were in a clinic or reporting session, grading the faecal loading as mild, moderate, or severe. One hundred patients were recruited out of 186 presenting in a 2-year period. All patients completed assessments. The correlation between observers was only fair to moderate (r ranging from 0.34-0.51). There were some surprisingly marked disagreements in 10-18% of assessments. The correlation between faecal loading and transit was weak for all observers (r ranging from 0.261-0.311). Symptom severity did not correlate with faecal loading. These results suggest that there is considerable inter-observer variation in the radiological assessment of faecal loading, irrespective of the training or method used by the observer, and that there is very poor correlation with colonic transit. The diagnosis of constipation, and the assessment of severity, is best performed clinically.

Bilateral synchronous testicular torsion in a young adult

An 18-year-old man presented to accident and emergency with acute left testicular pain of 2 hours’ duration. He woke up with the pain radiating to his left hemiscrotum, left groin, left iliac fossa and left lumbar flank. Nausea and vomiting accompanied the pain. He had not opened his bowels for 48 hours. He denied any lower urinary tract symptoms or any previous history of genital trauma. His past medical history revealed that he had suffered from intermittent left testicular pain for 3 years and, 6 months before this admission, had been admitted with a similar episode of left testicular pain, which was treated as epididymitis. There was no family history of testicular torsion. On examination, he was apyrexial, distressed with pain and retching. His left scrotum was erythematous and mildly oedematous, lying relatively high. It was extremely tender at the upper pole, which made evaluation of its contents difficult, but a ‘knot-like’ structure was palpated. Cremaster reflexes were absent bilaterally. The right testis was also tender, but on palpation it felt normal and was not swollen. The left inguinal canal and left iliac fossa were also painful. A midstream urine showed no pyuria or haematuria. A kidney-urinary bladder radiograph showed faecal loading of the large bowel. Transverse testicular ultrasound scanning showed a markedly inflamed left epididymis with decreased blood flow. The left distal spermatic cord showed a whorled appearance. The right testis was normal in echotexture, size and blood flow. Bilateral hydroceles were noted. The patient underwent immediate bilateral scrotal exploration, which revealed the left testis to be cyanosed and the cord to be twisted 540° anticlockwise. The right testis was normal in colour and the cord was twisted 360° clockwise. Bilateral bell-clapper deformity was noted. Detorsion, orchidopexy and drainage of serous-coloured hydrocele was performed bilaterally. Postoperatively the patient recovered well and was discharged home 2 days later with an outpatient follow-up appointment. Serum sex hormone levels were all within the normal ranges. Semen analysis was of normal consistency and pH. The count was 38 million, but 54% were immotile and 87% displayed abnormal morphology.

Stormflow-dominated loads of faecal pollution from an intensively dairy-farmed catchment

Rainstorms can flush large amounts of faecal pollution from land sources into water bodies, threatening, particularly, contact recreation and bivalve shellfish harvest. We quantified the faecal pollution loads of stormflows in the Toenepi Stream, draining a catchment in intensive dairy-farming (Waikato Region, New Zealand). In this stream, as is typical, E. coli concentration peaks well ahead of flow on storm flow hydrographs, which complicates calculation of loads. However, stormflow E. coli concentration correlates with turbidity in the Toenepi Stream, so we used a continuously-recording turbidimeter to estimate 'continuous' E. coli concentrations and thence E. coli fluxes (cfu/s) and loads (cfu). E. coli was measured on 25 out of the 30 (83%) of storm events occurring in the Toenepi Stream in a 12-month period, using an automatic sampler sampling every 2 hrs over stormflow hydrographs for microbial analysis (within 48 hr). E. coli (cfu) yield on individual events tended to increase systematically with event size. The sum of storm-flow exports (occurring 24% of total time) amounted to 95% of the total annual E. coli export from the Toenepi Catchment. The stream exported about 6% of the (expected) total E. coli production in cattle faeces within the catchment.

Predicting Enteric Virus Presence in Surface Waters Using Artificial Neural Network Models

Many researchers have successfully used multivariate logistic regression models and artificial neural networks (ANN) for modeling environmental datasets when there are sufficient data observations to support their use. Recent advances in training methods of ANN models have allowed for the use of a greater number of observations of a limited dataset for model training, enhancing the usefulness of available data. This study employs an advanced relative strength effect (RSE)-based ANN training termination procedure for developing models for the prediction of the presence or absence of viruses in raw surface waters. The presence/absence of enteric viruses was predicted using a blend of input parameters that represented fecal load, age, and source as well as parameters that indicated the degree of change in watershed conditions. A conventionally trained ANN model was compared against an RSE-based trained ANN model and a multivariate logistic regression for prediction accuracy. The RSE-based ANN modeling method...

The role of birds in dissemination of human waterborne enteropathogens

Cryptosporidiosis, giardiasis and microsporidiosis are serious human diseases of waterborne origin; their etiologic agents and a substantial fecal coliform load can enter surface, drinking and recreational water resources from aquatic birds. The aim of this article is to present interactions between waterfowl and these waters that imply a negative public health impact, reinforcing the need for either better water-quality indicators or for water monitoring specifically for Cryptosporidium, Giardia and microsporidia. Where justifiable, the presence of waterfowl should be supported; however, management of drinking and recreational water resources needs to be improved by incorporating effective protection measures for pathogens linked to these birds.

A framework for valuing the health benefits of improved bathing water quality in the River Irvine catchment

A simple model predicting bathing water concentrations of Escherichia coli from livestock in the Irvine catchment in SW Scotland has been adapted for intestinal enterococci (IE). This has been used to predict risk of bather illness by extrapolation of published data on bather IE exposure vs incidence of gastro-enteritis. Simulated reduction in the risk of illness by reduced faecal loading was multiplied by a willingness to pay for risk reduction to estimate the annual benefits of mitigation. Health benefits of reducing loading by 75% at Irvine Beach were estimated by a willingness to pay method to be about £276k pa. Estimated annualised costs of diffuse pollution mitigation measures across the catchment were higher (>£1 m), and it is very unlikely that 75% mitigation is achievable with current stocking rates. Further work should explore the influence of uncertainty of model parameters, and use emerging epidemiological information on specific zoonotic pathogens such as E. coli O157 and Cryptosporidium. Other components of the value of clean water should also be included to obtain a complete estimate of the cost:benefit of mitigation.

Importance of the new radiographic sign of fecal loading in the cecum in the presence of acute appendicitis in comparison with other inflammatory diseases of the right abdomen

Background The value of plain abdominal radiography in acute appendicitis has not been completely studied. Therefore, the purpose of this investigation was to verify a new radiographic sign: the presence of fecal loading in the cecum for the diagnosis of acute appendicitis in comparison with other diseases of the right abdomen. Methods A total of 470 consecutive patients of both sexes admitted to the hospital due to acute abdominal pain were prospectively studied. Group 1 ( n = 170), the acute appendicitis group, included patients subjected to an abdominal radiographic study a few hours before surgical treatment; group 2 ( n = 100) had right nephrolithiasis; group 3 ( n = 100) had right acute inflammatory pelvic disease; and group 4 ( n = 100) had acute cholecystitis. Results The sign of fecal loading in the cecum was present in 165 patients in group 1, in 19% of those in group 2, in 12% of those in group 3, and in 13% in group 4. The sensitivity of the radiographic sign for acute appendicitis was 97.05% and its specificity was 85.33%. The positive predictive value of this sign for acute appendicitis was 78.94% and its negative predictive value was 98.08%. This sign disappeared in 66 (94.28%) of the 70 patients who had plain abdominal radiographs on the first postoperative day. Conclusions The radiographic image of fecal loading in the cecum is associated with acute appendicitis and disappears after appendectomy. This sign is uncommon in other acute inflammatory diseases of the right side of the abdomen.

Efficacy of Bacteroides Measurements for Reducing the Statistical Uncertainty Associated with Hydrologic Flow and Fecal Loads in a Mixed Use Watershed

This paper presents an analysis of the occurrence and uncertainty of source-specific Bacteroides and Escherichia coli in a stream in a mixed land-use watershed with human, cattle, and wildlife fecal inputs located in a karstic geologic region during baseflow conditions. The objectives of the study were to evaluate the occurrence, hydrologic significance, and source of fecal mass in the stream using assays for total Bacteroides (AllBac) and bovine-specific Bacteroides (BoBac), and then to compare these measurements with E. coli densities and loads. Samples were collected during baseflow conditions over several months at seven different main channel sites in the Stock Creek watershed, a 49.3 km2 basin located in Knoxville, TN (USA). We determined instantaneous loads for total fecal loads, bovine fecal loads, and E. coli from measured flow rates and the representative Bacteroides fecal masses and/or E. coli densities. The study indicated a strong correlation between total fecal load (kg d(-1)), bovine fecal load (kg d(-1)), E. coli load rate (CFU d(-1)), 7-d antecedent precipitation, and turbidity. The various datasets were used to establish parameter correlations and spatial dependencies throughout the watershed. The data analysis demonstrated two prevalent patterns throughout the watershed: (i) a runoff-dominated transport and occurrence; and (ii) potential groundwater-dominated transport and occurrence.

Imagem radiográfica de acúmulo fecal no ceco, como sinal diagnóstico de apendicite aguda

OBJETIVO: Apesar de os achados radiográficos de apendicite aguda serem bem documentados, o valor da radiografia simples ainda não foi completamente determinado. O objetivo do presente estudo foi estabelecer a freqüência da associação de apendicite aguda a um sinal radiográfico caracterizado por imagem de acúmulo fecal ocupando todo o ceco. MATERIAIS E MÉTODOS: Foram realizadas radiografias simples de abdome de 100 pacientes consecutivos com apendicite aguda, comprovada por operação e exame anatomopatológico. Pesquisou-se, nas radiografias, a presença de imagem de acúmulo fecal no ceco, caracterizada por hipotransparência ocupando todo o ceco e, eventualmente, também o cólon ascendente. RESULTADOS: A imagem de acúmulo fecal no ceco foi encontrada em 97% dos doentes, independentemente de idade, sexo, cor da pele ou estádio da apendicite. CONCLUSÃO: Este estudo sugere que a presença de imagem radiográfica de acúmulo fecal no ceco pode ser um sinal útil no diagnóstico de apendicite aguda.

Post-Katrina fecal contamination in Violet Marsh near New Orleans.

Fecal material entrained in New Orleans flood waters was pumped into the local environment. Violet Marsh received water pumped from St. Bernard Parish and the Lower Ninth Ward. Sediment core samples were collected from canals conducting water from these areas to pump stations and from locations within Violet Marsh. Viable indicator bacteria and fecal sterols were used to assess the levels of fecal material in sediment deposited after the levee failures and deeper sediments deposited before. Most of the cores had fecal coliform levels that exceed the biosolids criterion. All of the cores had fecal sterols that exceeded the suggested environmental quality criterion. Our data show both a long history of fecal contamination in Violet Marsh and an increase in fecal loading corresponding to the failure of the levee system. The work was performed as part of the Interagency Performance Evaluation Task Force investigation into the consequences of the failures of the New Orleans levee system.

Importance of the radiographic sign of fecal loading in the cecum for the differential diagnosis of acute appendicitis

Although the radiographic characteristics of acute appendicitis have been well documented, the value of plain abdominal radiography has not been completely studied. Therefore, the purpose of this investigation was to verify a new radiographic sign: the presence of fecal loading in the cecum. 470 consecutive patients of both sexes were admitted to the hospital due to acute abdomen and pain localized in the right flank were studied prospectively. The patients were divided into four groups: Group 1 (n = 170) - diagnosed with acute appendicitis and subdivided into two subgroups: Subgroup 1A - (n = 100) - patients submitted to an abdominal radiographic study a few hours before surgical treatment, Subgroup 1B - (n = 70) - patients submitted to two abdominal radiographic studies, one before the surgical procedure and the other the following day; Group 2 (n = 100) -patients of both sexes with right nephrolithiasis submitted to an abdominal radiography during the episode of pain caused by the lithiasis; Group 3 (n = 100) - women diagnosed with right acute inflammatory pelvic disease that underwent an abdominal radiographic study during the pain incident; Group 4 (n = 100) - patients of both sexes operated upon to treat acute cholecystitis submitted to abdominal radiography during the pain episode that preceded the surgical procedure. All of the radiographs were plain with an anteroposterior view of the abdomen. The sign of fecal loading in the cecum was present in 97 patients of Subgroup 1A, in 68 patients of Subgroup 1B, in 19 patients of Group 2, in 12 patients of Group 3 and in 13 patients of Group 4. During the postoperative period the radiographic sign disappeared in 66 of the 68 cases that had presented with the sign. The sensitivity of the radiographic sign for acute appendicitis was 97,05% and its specificity was 85,33%. The positive predictive value for acute appendicitis was 78,94% and its negative predictive value was 98,08%. The radiographic image of fecal loading in the cecum is associated with acute appendicitis. The image usually disappears soon after the appendix is removed. This sign is uncommon in other acute inflammatory diseases of the right side of the abdomen. When a diagnosis of acute appendicitis is suspected, the absence of this sign indicates great possibility of a different diagnosis.

Multivariate Logistic Regression for Predicting Total Culturable Virus Presence at the Intake of a Potable-Water Treatment Plant: Novel Application of the Atypical Coliform/Total Coliform Ratio

Predicting the presence of enteric viruses in surface waters is a complex modeling problem. Multiple water quality parameters that indicate the presence of human fecal material, the load of fecal material, and the amount of time fecal material has been in the environment are needed. This paper presents the results of a multiyear study of raw-water quality at the inlet of a potable-water plant that related 17 physical, chemical, and biological indices to the presence of enteric viruses as indicated by cytopathic changes in cell cultures. It was found that several simple, multivariate logistic regression models that could reliably identify observations of the presence or absence of total culturable virus could be fitted. The best models developed combined a fecal age indicator (the atypical coliform [AC]/total coliform [TC] ratio), the detectable presence of a human-associated sterol (epicoprostanol) to indicate the fecal source, and one of several fecal load indicators (the levels of Giardia species cysts, coliform bacteria, and coprostanol). The best fit to the data was found when the AC/TC ratio, the presence of epicoprostanol, and the density of fecal coliform bacteria were input into a simple, multivariate logistic regression equation, resulting in 84.5% and 78.6% accuracies for the identification of the presence and absence of total culturable virus, respectively. The AC/TC ratio was the most influential input variable in all of the models generated, but producing the best prediction required additional input related to the fecal source and the fecal load. The potential for replacing microbial indicators of fecal load with levels of coprostanol was proposed and evaluated by multivariate logistic regression modeling for the presence and absence of virus.

Factors contributing to fecal incontinence in older people and outcome of routine management in home, hospital and nursing home settings

Fecal loading, cognitive impairment, loose stools, functional disability, comorbidity and anorectal incontinence are recognized as factors contributing to loss of fecal continence in older adults. The objective of this project was to assess the relative distribution of these factors in a variety of settings along with the outcome of usual management. One hundred and twenty adults aged 65 years and over with fecal incontinence recruited by convenience sampling from four different settings were studied. They were either living at home or in a nursing home or receiving care on an acute or rehabilitation elderly care ward. A structured questionnaire was used to elicit which factors associated with fecal incontinence were present from subjects who had given written informed consent or for whom assent for inclusion in the study had been obtained. Fecal loading (Homes 6 [20%]; Acute care wards 17 [57%]; Rehabilitation wards 19 [63%]; Nursing homes 21 [70%]) and functional disability (Homes 5 [17%]; Acute care wards 25 [83%]; Rehabilitation wards 25 [83%]; Nursing homes 20 [67%]) were significantly more prevalent in the hospital and nursing home settings than in those living at home (P < 0.01). Loose stools were more prevalent in the hospital setting than in the other settings (Homes 11 [37%]; Acute care wards 20 [67%]; Rehabilitation wards 17 [57%]; Nursing homes 6 [20%]) (P < 0.01). Cognitive impairment was significantly more common in the nursing home than in the other settings (Nursing homes 26 [87%], Homes 5 [17%], Acute care wards 13 [43%], Rehabilitation wards 14 [47%]) (P < 0.01). Loose stools were the most prevalent factor present at baseline in 13 of the 19 (68%) subjects whose fecal incontinence had resolved at 3 months. The distribution of the factors contributing to fecal incontinence in older people living at home differs from those cared for in nursing home and hospital wards settings. These differences need to be borne in mind when assessing people in different settings. Management appears to result in a cure for those who are not significantly disabled with loose stools as a cause for their fecal incontinence, but this would need to be confirmed by further research.

Origin of Acute Appendicitis: Fecal Retention in Colonic Reservoirs: A Case Control Study

Appendicitis is encountered predominantly in Western, industrialized countries. Animal experiments and clinical studies have suggested an obstructive fecalith as a cause of acute appendicitis. It was hypothesized that patients with acute appendicitis would have a longer colonic transit time and more fecal retention reservoirs (coprostasis) than healthy control persons, thus favoring the occurrence of a fecalith in the appendix. Sixty-eight patients scheduled for appendectomy were included in this approved study. Before surgery, a plain abdominal radiograph was taken; at surgery, the degree of inflammation of the appendix was recorded, along with the presence or absence of a fecalith. Six weeks postoperatively, the patients underwent a colonic transit study. A cohort of 44 control persons over 18 years of age was selected at random to undergo the same marker study as the patients. The parameters studied were the number of radiopaque markers (h), the fecal retention or load (score 0-3) in the right, left, and distal colonic segments, and the number of fecaliths. Twelve patients were excluded; i.e., 56 patients and 44 controls were eligible for most analyses. In the patient group, statistically significant correlations were found between fecal loading scores and the number of markers (transit time) both overall and within the left and distal colonic segments (all p < 0.05). In the control subjects, there was significance with regard to the distal segment. The median colon transit time was 25.0 h (range 1-107 h) in patients with appendicitis compared with 19.0 h (range 0-71 h) in controls (p = NS). The transit time was longer in the right, left, and distal colon in patients than in control subjects, although not to a statistically significant extent. The total and segmental fecal loads in the colon did not differ significantly between patients and controls. A fecalith occurred in 49.0% of the patients and was in most cases associated with a gangrenous or perforated appendix. If a fecalith was not found, this correlated to a significant extent with a high fecal loading score in the left colon (p = 0.04). An obstructive fecalith occurred in one-half of the patients with acute appendicitis. The appendicitis patients had a colonic transit time similar to that in healthy controls. Furthermore, there was no difference in colonic fecal loading between patients and controls. In consequence, the occurrence of a fecalith could not be attributed to delayed colonic transit or fecal loading. However, we discovered greater amounts of feces in the colon of both patients and controls than would have been expected physiologically, and the role of these fecal reservoirs has yet to be understood.

Microbial source tracking: a forensic technique for microbial source identification?

As the requirements of the Water Framework Directive (WFD) and the US Clean Water Act (USCWA) for the maintenance of microbiological water quality in 'protected areas' highlight, there is a growing recognition that integrated management of point and diffuse sources of microbial pollution is essential. New information on catchment microbial dynamics and, in particular, the sources of faecal indicator bacteria found in bathing and shellfish harvesting waters is a pre-requisite for the design of any 'programme of measures' at the drainage basin scale to secure and maintain compliance with existing and new health-based microbiological standards. This paper reports on a catchment-scale microbial source tracking (MST) study in the Leven Estuary drainage basin, northwest England, an area for which quantitative faecal indicator source apportionment empirical data and land use information were also collected. Since previous MST studies have been based on laboratory trials using 'manufactured' samples or analyses of spot environmental samples without the contextual microbial flux data (under high and low flow conditions) and source information, such background data are needed to evaluate the utility of MST in USCWA total maximum daily load (TMDL) assessments or WFD 'Programmes of Measures'. Thus, the operational utility of MST remains in some doubt. The results of this investigation, using genotyping of Bacteroidetes using polymerase chain reaction (PCR) and male-specific ribonucleic acid coliphage (F + RNA coliphage) using hybridisation, suggest some discrimination is possible between livestock- and human-derived faecal indicator concentrations but, in inter-grade areas, the degree to which the tracer picture reflected the land use pattern and probable faecal indicator loading were less distinct. Interestingly, the MST data was more reliable on high flow samples when much of the faecal indicator flux from catchment systems occurs. Whilst a useful supplementary tool, the MST information did not provide quantitative source apportionment for the study catchment. Thus, it could not replace detailed empirical measurement of microbial flux at key catchment outlets to underpin faecal indicator source apportionment. Therefore, the MST techniques reported herein currently may not meet the standards required to be a useful forensic tool, although continued development of the methods and further catchment scale studies could increase confidence in such methods for future application.

Hirschsprung's disease in a young adult: report of a case and review of the literature

Hirschsprung's disease (HD) in adults is rare and often undiagnosed or misdiagnosed. We report a case of HD in a 26-year-old woman who had a history of chronic constipation that required laxatives and enemas since early childhood. She developed severe intestinal obstruction and presented to the emergency department with significant abdominal distension. A computed tomographic scan confirmed significant fecal loading of the entire colon and rectum. An anal manometry revealed lack of normal rectoanal inhibitory reflex. A rectal biopsy showed hypoganglionic anorectum, suspicious for HD. Because of the severe fecal retention that was refractory to conservative management, total proctocolectomy with ileal pouch-anal anastomosis was performed. The entire colon showed massive dilatation and marked wall thickening. Histologic examination showed absence of ganglion cells in submucosal (Meissner's) and myenteric (Auerbach's) plexuses in the distal rectum. A diagnosis of adult HD was made. Her postoperative course was uneventful with complete resolution of the symptoms. Hirschsprung's disease should be considered in adults who have long-standing and refractory constipation.

A rapid reverse transcription-PCR assay for F + RNA coliphages to trace fecal pollution in Table Rock Lake on the Arkansas–Missouri border

Source determination of fecal contamination is imperative to efficiently reduce the fecal material load to environmental waters. This study developed primer pairs targeting three F + RNA bacteriophages and a simple filtration sampling method to enumerate and identify coliphages in environmental waters. Water samples were collected seasonally for one year from the watershed of Table Rock Lake on the Arkansas–Missouri border in areas predisposed to fecal contamination. Collected samples were analyzed quantitatively with most probable number and plaque assays and qualitatively with reverse transcription-PCR. We demonstrated the usefulness of F + RNA coliphages as an indicator of fecal contamination, but were unable to distinguish between human and non-human sources. F + coliphage numbers in Table Rock Lake showed seasonal variation with the highest level of coliphage presence during the January sampling event.