Epidemiologic surveillance of Clostridium difficile diarrhea in a freestanding pediatric hospital and a pediatric hospital at a university medical center

Clostridium difficile infection in pediatric patients (Review)

Clostridium difficile (C. difficile) infection (CDI) is the most common cause of healthcare-associated diarrhea and among adults, the worldwide incidence rate of the infection is increasing. There is a small amount of data in the literature for pediatric patients, but most indicate an increasing trend. C. difficile is a constituent of the normal microbiota; however, under specific conditions that cause a disruption of the normal bacterial flora, colonization of C. difficile and the released toxins that cause inflammation and mucosal damage occurs. Risk factors for CDI at any age include hospitalization, exposure to antibiotics, administration of proton pump inhibitors, invasive mechanical ventilation, immunosuppression and presence of associated comorbidities. Clinical manifestations range from asymptomatic colonization to fulminant disease characterized by toxic megacolon, intestinal perforation and, rarely, death. The aim of the present review was to outline the features of CDI in pediatric patients.

Community-acquired Clostridium difficile infection in Serbian pediatric population

Carriage of Clostridium (C.) difficile in the intestinum of children, as well as its role in the disease (diarrhea) onset, is still controversial. The aim of this study is to investigate the community-acquired Clostridium difficile infection (CA-CDI) in Serbian pediatric population and to describe the basic clinical characteristics and risk factors for CA-CDI occurrence in Serbian pediatric population. The data obtained from 63 Serbian pediatric patients with CA-CDI and from control group of 126 children with community-acquired diarrhea, whose stool specimens were negative for C. difficile and toxins A/B, were mutually compared. In the current work, we found that children with CA-CDI display a significantly less severe disease clinical presentation than children with diarrheas of other origin. Lethal outcome was noted in two cases, but in children with severe underlying diseases (Crohn's disease and leukemia). By using the multivariate statistical regression model, the following statistically significant risk factors for community-acquired C. difficile-associated diarrhea development were determined: previous application of laxatives (OR = 0.199, CI 0.55-0.79, p = 0.015), general antibiotic use during the previous 2 months (OR = 0.05, CI 0.02-0.17, p < 0.001), and specifically the use of penicillins (OR = 0.112, CI 0.04-0.31, p < 0.0001) and cephalosporins (OR = 0.16, CI 40.06-0.44, p < 0.0001). Antibiotics from the groups of cephalosporins and penicillins were found to be the most important independent risk factors. Laxative application plays a significant role in the community-acquired Clostridium difficile infections in children, with mechanisms that are not completely understood.

Epidemiology and Factors Related to Clinical Severity of Acute Gastroenteritis in Hospitalized Children after the Introduction of Rotavirus Vaccination

We aimed to investigate epidemiology and host- and pathogen-related factors associated with clinical severity of acute gastroenteritis (AGE) in children after rotavirus vaccination introduction. Factors assessed included age, co-infection with more than 2 viruses, and virus-toxigenic Clostridium difficile co-detection. Fecal samples and clinical information, including modified Vesikari scores, were collected from hospitalized children with AGE. The presence of enteric viruses and bacteria, including toxigenic C. difficile, was detected by polymerase chain reaction (PCR). Among the 415 children included, virus was detected in stool of 282 (68.0%) children. Co-infection with more than 2 viruses and toxigenic C. difficile were found in 24 (8.5%) and 26 (9.2%) children with viral AGE, respectively. Norovirus (n = 130) infection, including norovirus-associated co-infection, was the most frequent infection, especially in children aged < 24 months (P < 0.001). In the severity-related analysis, age < 24 months was associated with greater diarrheal severity (P < 0.001) and modified Vesikari score (P = 0.001), after adjustment for other severity-related factors including rotavirus status. Although the age at infection with rotavirus was higher than that for other viruses (P = 0.001), rotavirus detection was the most significant risk factor for all severity parameters, including modified Vesikari score (P < 0.001). Viral co-infection and toxigenic C. difficile co-detection were not associated with any severity-related parameter. This information will be helpful in the management of childhood AGE in this era of rotavirus vaccination and availability of molecular diagnostic tests, which often lead to the simultaneous detection of multiple pathogens.

Outcomes in children with Clostridium difficile infection: results from a nationwide survey

OBJECTIVE

Hospital- and population-based studies demonstrate an increasing incidence of Clostridium difficile infection (CDI) in adults and children; although pediatric CDI outcomes are incompletely understood. We analysed United States National Hospital Discharge Survey (NHDS) data to study CDI in hospitalized children.

METHODS

NHDS data for 2005-2009 (demographics, diagnoses and discharge status) were obtained; cases and comorbidities were identified using ICD-9 codes. Weighted univariate and multivariate analyses were performed to ascertain incidence of CDI; associations between CDI and outcomes [length of stay (LOS), colectomy, all-cause in-hospital mortality and discharge to a care facility (DTCF)].

RESULTS

Of an estimated 13.8 million pediatric inpatients; 46 176 had CDI; median age was 3 years; overall incidence was 33.5/10 000 hospitalizations. The annual frequency of CDI did not vary from 2005 to 2009 (0.24-0.43%; P = 0.64). On univariate analyses, children with CDI had a longer median LOS (6 vs 2 days), higher rates of colectomy [odds ratio (OR) 2.0; 95% confidence interval (CI) 1.7-2.4], mortality (OR 2.5; 95% CI 2.3-2.7), and DTCF (OR 1.6; 95% CI 1.6-1.7) (all P < 0.0001). After adjusting for age, sex and comorbidities, CDI was an independent and the strongest predictor of increased LOS (adjusted mean difference, 6.4 days; 95% CI 5.4-7.4), higher rates of colectomy (OR 2.1; 95% CI 1.8-2.5), mortality (OR 2.3; 95% CI 2.2-2.5), and DTCF (OR 1.7; 95% CI 1.6-1.8) (all P < 0.0001). On excluding infants from the analysis, children with CDI had higher rates of mortality, DTCF and longer LOS than children without CDI.

CONCLUSIONS

Despite increased awareness and advancements in management, CDI remains a significant problem and is associated with increased LOS, colectomy, in-hospital mortality and DTCF in hospitalized children.

Structural and functional changes within the gut microbiota and susceptibility to Clostridium difficile infection

Alteration of the gut microbial community structure and function through antibiotic use increases susceptibility to colonization by Clostridium difficile and other enteric pathogens. However, the mechanisms that mediate colonization resistance remain elusive. As the leading definable cause of infectious diarrhea, toxigenic C. difficile represents a burden for patients and health care systems, underscoring the need for better diagnostics and treatment strategies. Next-generation sequence data has increased our understanding of how the gut microbiota is influenced by many factors including diet, disease, aging and drugs. However, a microbial-based biomarker differentiating C. difficile infection from antibiotic-associated diarrhea has not been identified. Metabolomics profiling, which is highly responsive to changes in physiological conditions, have shown promise in differentiating subtle disease phenotypes that exhibit a nearly identical microbiome community structure, suggesting metabolite-based biomarkers may be an ideal diagnostic for identifying patients with CDI. This review focuses on the current understanding of structural and functional changes to the gut microbiota during C. difficile infection obtained from studies assessing the microbiome and metabolome of samples from patients and murine models.

Molecular Characterization of Clostridium difficile Isolates from Human Subjects and the Environment

Clostridium difficile is a spore-forming, gram-positive, anaerobic bacillus that can cause C. difficile infection (CDI). However, only a few studies on the prevalence and antibiotic resistance of C. difficile in healthy individuals in China have been reported. We employed a spore enrichment culture to screen for C. difficile in the stool samples of 3699 healthy Chinese individuals who were divided into 4 groups: infants younger than 2 years of age and living at home with their parents; children aged 1 to 8 years of age and attending three different kindergarten schools; community-dwelling healthy adult aged 23-60 years old; and healthcare workers aged 28-80 years old. The C. difficile isolates were analyzed for the presence of toxin genes and typed by PCR ribotyping and multilocus sequence typing (MLST). The minimum inhibitory concentration of 8 antimicrobial agents was determined for all of the isolates using the agar dilution method. The intestinal carriage rate in the healthy children was 13.6% and ranged from 0% to 21% depending on age. The carriage rates in the 1654 community-dwelling healthy adults and 348 healthcare workers were 5.5% and 6.3%, respectively. Among the isolates, 226 were toxigenic (225 tcdA+/tcdB+ and 1 tcdA+/tcdB+ ctdA+/ctdB+). Twenty-four ribotypes were found, with the dominant type accounting for 29.7% of the isolates. The toxigenic isolates were typed into 27 MLST genotypes. All of the strains were susceptible to vancomycin, metronidazole, fidaxomicin, and rifaximin. High resistance to levofloxacin and ciprofloxacin at rates of 39.8% and 98.3%, respectively, were observed. ST37 isolates were more resistant to levofloxacin than the other STs. The PCR ribotypes and sequence types from the healthy populations were similar to those from the adult patients.

Acid-Suppressing Agents and Risk for Clostridium difficile Infection in Pediatric Patients

BACKGROUND

Acid-suppressing agents have been associated with increased Clostridium difficile infection (CDI) in adults. The objective of this study was to evaluate the association of acid-suppressing therapy with the development of CDI in the pediatric population.

METHODS

This was a retrospective case-control study. Children aged 1 through 17 years with a positive C difficile polymerase chain reaction (PCR) result obtained between June 1, 2008, and June 1, 2012, were randomly matched to a control population selected from patients with negative PCR.

RESULTS

A total of 458 children were included. No difference was observed in acid-suppressive therapy prior to PCR in CDI-positive versus -negative patients (n = 131 [57.2%] vs n = 121 [52.8%], P = .348). Among patients receiving acid-suppressing therapy prior to obtaining a PCR, no difference was observed in proton pump inhibitor use (45% vs 46.3%, P = .843), but histamine-2 receptor antagonist (H2RA) use was greater in the CDI-positive patients (32.8% vs 14.9%, P = .001). Logistic regression analysis demonstrated that H2RA therapy at home (odds ratio = 4.6; 95% confidence interval = 1.5-14.5) was an independent CDI predictor.

CONCLUSION

In this pediatric population, CDI risk in children receiving home acid-suppressive therapy with H2RAs is nearly 4.5 times greater than that of children not receiving H2RA therapy. These results suggest the need for continued monitoring and study of H2RA therapy in children.

Co-infection as a confounder for the role of Clostridium difficile infection in children with diarrhoea: a summary of the literature

Although Clostridium difficile is a major cause of antibiotic-associated diarrhoea in adults, the incidence and severity of C. difficile infection (CDI) in children is unclear. One complicating factor in assessing the role of CDI in children is the possibility of co-infection with other gastrointestinal pathogens. In this review, we summarise the literature concerning C. difficile co-infections in young children, in an attempt to discuss the rate of co-infections and their potential role in the severity of CDI clinical presentation. We identified 31 studies where co-infections were analysed, comprising 1,718 patients with positive C. difficile tests. The pooled percentage of reported co-infections was 20.7% (range 0-100%). Viral co-infections were most commonly reported (46%), with bacteria and parasites accounting for 14.9% and 0.01% of cases, respectively. However, the panel of co-infections tested for varied considerably among studies and 38% of stated co-infections did not have a pathogen reported. Substantial variation in how and when tests for gastrointestinal co-infections are carried out, small sample sizes and a lack of clear CDI case definitions preclude meaningful conclusions on the true rate of co-infections in this patient population. This review suggests that co-infections may be common in children with diarrhoea who tested positive for C. difficile. Given a lack of CDI case definitions, especially in young children under the age of 5 years, a broad panel of pathogens should be tested for to exclude other microbiological causes. However, the summarised poor quality of the available literature on this subject highlights a need for further studies.

Clostridium difficile infection in the hospitalized pediatric population: increasing trend in disease incidence

To determine whether the incidence of Clostridium difficile infection continues to increase in hospitalized pediatric patients, we evaluated data from a United States national inpatient database. For the period of 2003 to 2009, we found an increasing trend in the incidence of C. difficile infection. These data suggest greater effort be given to prevent and treat this infection in children.

Trends in Clostridium difficile infection and risk factors for hospital acquisition of Clostridium difficile among children with cancer

OBJECTIVES

To study the trend of Clostridium difficile infection (CDI) and risk factors for hospital acquired CDI (HA-CDI) among children with cancer.

STUDY DESIGN

We analyzed 33 095 first pediatric hospitalizations for malignancy among 43 pediatric hospitals between 1999 and 2011. The effect of demographics, disease characteristics, and weekly drug exposure (antibiotics, antacids, and chemotherapy) on HA-CDI was assessed with multivariate Cox regression. CDI was defined by the combination of International Classification of Diseases, 9th edition-Clinical Modification (ICD-9CM), CDI diagnostic assay billing code, and concurrent administration of a CDI-active antibiotic. HA-CDI was defined as CDI with assay occurring after the sixth hospital day.

RESULTS

A total of 1736 admissions with CDI were identified, of which 380 were HA-CDI. CDI incidence increased from 1999-2006 (P = .01); however, CDI testing frequency and disease decreased from 2006-2010 (P < .05). Admissions with HA-CDI had longer lengths of stay compared with those without HA-CDI (35 days vs 12 days, P < .01) and greater risk of inpatient mortality (relative risk 2.3, P < .01). Increased risk of HA-CDI (hazard ratio [95% CI]) was seen after exposure to the following drugs: aminoglycoside (1.357 [1.053-1.749]), third generation cephalosporin (1.518 [1.177-1.959]), cefepime (2.383 [1.839-3.089]), and proton pump inhibiting agent (1.398 [1.096-1.784]) in the prior week, and chemotherapy (1.942 [1.491-2.529]) in the 8-14 days prior to HA-CDI onset. Histamine-2 receptor antagonist exposure in the prior week was associated with decreased risk of HA-CDI (0.730 [0.584-0.912]).

CONCLUSIONS

Despite an apparent decrease in CDI incidence from 2006-2010, HA-CDI remains prevalent and morbid among children with cancer. Recent exposure to chemotherapy, proton pump inhibitor, and certain antibiotics were independent risk factors for HA-CDI.

The epidemiology of Clostridium difficile infection in children: a population-based study

BACKGROUND

The incidence of Clostridium difficile infection (CDI) is increasing, even in populations previously thought to be at low risk, including children. Most incidence studies have included only hospitalized patients and are thus potentially influenced by referral or hospitalization biases.

METHODS

We performed a population-based study of CDI in pediatric residents (aged 0-18 years) of Olmsted County, Minnesota, from 1991 through 2009 to assess the incidence, severity, treatment response, and outcomes of CDI.

RESULTS

We identified 92 patients with CDI, with a median age of 2.3 years (range, 1 month-17.6 years). The majority of cases (75%) were community-acquired. The overall age- and sex-adjusted CDI incidence was 13.8 per 100 000 persons, which increased 12.5-fold, from 2.6 (1991-1997) to 32.6 per 100 000 (2004-2009), over the study period (P < .0001). The incidence of community-acquired CDI was 10.3 per 100 000 persons and increased 10.5-fold, from 2.2 (1991-1997) to 23.4 per 100 000 (2004-2009) (P < .0001). Severe, severe-complicated, and recurrent CDI occurred in 9%, 3%, and 20% of patients, respectively. The initial treatment in 82% of patients was metronidazole, and 18% experienced treatment failure. In contrast, the initial treatment in 8% of patients was vancomycin and none of them failed therapy.

CONCLUSIONS

In this population-based cohort, CDI incidence in children increased significantly from 1991 through 2009. Given that the majority of cases were community-acquired, estimates of the incidence of CDI that include only hospitalized children may significantly underestimate the burden of disease in children.

Recent trends in the epidemiology and treatment of C. difficile infection in children

PURPOSE OF REVIEW

Clostridium difficile is the most common cause of healthcare-associated diarrhea among adults in Western countries, and is increasingly recognized as an important pathogen in children. This review provides an update on the changing epidemiology of C. difficile infection (CDI) for pediatric providers and summarizes current knowledge regarding available therapies.

RECENT FINDINGS

The incidence of CDI has more than doubled among adults over the past decade, with a particular rise in incidence among patients presenting from the community. CDI has also increased among children in both inpatient and outpatient settings and there is growing evidence that specific populations of children may be at highest risk. Antibiotic-based therapies remain the mainstay of treatment for CDI, but new therapies have been developed with potential future applications in children. Use of nonantibiotic-based therapies is limited in children, but their use has been studied among adults with intractable or recurrent disease.

SUMMARY

The rise in incidence of CDI over the past decade warrants increased recognition by pediatric providers. Knowledge of the pediatric populations at highest risk for infection as well as the options for therapy will improve understanding of this changing disease.

Clostridium difficile carriage in healthy infants in the community: a potential reservoir for pathogenic strains

BACKGROUND

Clostridium difficile has long been considered to be a nosocomial pathogen but has emerged in the community in recent years. During infancy, asymptomatic C. difficile colonization is common. However, knowledge of colonization determinants and strain characteristics is limited. We studied the dynamics of C. difficile colonization in healthy infants from the community. Determinants of colonization and strain genotypes were also determined in a cohort of infants attending day nurseries.

METHODS

A 1-year follow-up study involving 10 healthy infants was performed to determine the incidence and kinetics of intestinal C. difficile colonization. In addition, a 1-point study involving 85 healthy infants (age, 0-3 years) from 2 day nurseries was performed. C. difficile isolates were typed by polymerase chain reaction-ribotyping and analyzed for the presence of toxin genes.

RESULTS

During the follow-up study, all infants acquired C. difficile and were colonized for several months. An early (neonatal) and a late (4-6 months of age) acquisition period were identified. In day nurseries, 38 infants (45%) carried C. difficile, with 11 (13%) carrying a toxigenic isolate. Age and several environmental factors were associated with the C. difficile carrier state. Strains causing disease in adults were identified in infants. Interestingly, no infant carried the common epidemic 027 or 078 strains.

CONCLUSIONS

This study provides information on the dynamics of colonization in infants in the community and on the genotype of involved strains. C. difficile colonization appears mainly as an age-dependent process. Pathogenic strains circulate in asymptomatic infants from the community, who represent a potential reservoir of pathogenic strains.

Risk factors and outcomes associated with severe clostridium difficile infection in children

BACKGROUND

The incidence and severity of Clostridium difficile infection (CDI) is increasing among adults; however, little is known about the epidemiology of CDI among children.

METHODS

We conducted a nested case-control study to identify the risk factors for and a prospective cohort study to determine the outcomes associated with severe CDI at 2 children's hospitals. Severe CDI was defined as CDI and at least 1 complication or ≥2 laboratory or clinical indicators consistent with severe disease. Studied outcomes included relapse, treatment failure, and CDI-related complications. Isolates were tested to determine North American pulsed-field gel electrophoresis type 1 lineage.

RESULTS

We analyzed 82 patients with CDI, of whom 48 had severe disease. Median age in years was 5.93 (1.78-12.16) and 1.83 (0.67-8.1) in subjects with severe and nonsevere CDI, respectively (P = 0.012). All patients with malignancy and CDI had severe disease. Nine subjects (11%) had North American pulsed-field gel electrophoresis type 1 isolates. Risk factors for severe disease included age (adjusted odds ratio [95% confidence interval]: 1.12 [1.02, 1.24]) and receipt of 3 antibiotic classes in the 30 days before infection (3.95 [1.19, 13.11]). If infants less than 1 year of age were excluded, only receipt of 3 antibiotic classes remained significantly associated with severe disease. Neither the rate of relapse nor treatment failure differed significantly between patients with severe and nonsevere CDI. There was 1 death.

CONCLUSIONS

Increasing age and exposure to multiple antibiotic classes were risk factors for severe CDI. Although most patients studied had severe disease, complications were infrequent. Relapse rates were similar to those reported in adults.

Prevalence and diversity of Clostridium difficile strains in infants

During early infancy asymptomatic intestinal colonization by Clostridium difficile is frequent. To update information on infant colonization prevalence and to characterize infant strains, in terms of their virulence factors and their phylogenetic diversity, a prospective screening of C. difficile in the stools of infants 0 to 2 years old was conducted at Jean Verdier Hospital (Hôpital Jean Verdier) over an 18 month period. C. difficile was screened by toxigenic culture, and molecular characterization was performed by PCR-ribotyping and multilocus sequence typing (MLST). The overall C. difficile colonization prevalence was 33.7 % (99/294). The colonization rate by a toxigenic strain was 7.1 % (21/294). Community-acquired C. difficile accounted for 66.7 % (66/99) of cases. Molecular typing was performed on 90 isolates from Jean Verdier Hospital and 8 additional isolates from another hospital in Versailles (Centre Hospitalier de Versailles). Among these isolates, 23 were toxigenic (21 tcdA(+)/tcdB(+) and 2 tcdA(-)/tcdB(+)). All the isolates were negative for the binary toxin genes. Seventeen PCR ribotypes (PRs) were identified, with five PRs accounting for 82.7 % (81/98) of the isolates. MLST generated 15 different sequence types (STs). The predominant genotype, PRJV11-ST38 (33.7 %), included only non-toxigenic strains. Toxigenic strains were distributed in eight genotypes. Neither PR027-ST3, nor PR078/126-ST49 were identified but some PRs/STs corresponded to well-known adult infectious strains. These results indicate that infants are widely colonized by non-toxigenic strains. However, toxigenic adult infectious strains circulate in asymptomatic infants even in the community; thus, infants may be a reservoir for adult infectious strains.

Rapid stool-based diagnosis of Clostridium difficile infection by real-time PCR in a children's hospital

Clostridium difficile is a major cause of nosocomial antibiotic-associated infectious diarrhea and pseudomembranous colitis. Detection of C. difficile by anaerobic bacterial culture and/or cytotoxicity assays has been largely replaced by rapid enzyme immunoassays (EIA). However, due to the lack of sensitivity of stool EIA, we developed a multiplex real-time PCR assay targeting the C. difficile toxin genes tcdA and tcdB. Stool samples from hospitalized pediatric patients suspected of having C. difficile-associated disease were prospectively cultured on cycloserine-cefoxitin-fructose agar following alcohol shock. Six testing modalities were evaluated, including stool EIA, culture EIA, and real-time PCR (tcdA and tcdB) of cultured isolates and stool samples. Real-time PCR detection was performed with tcdA and tcdB gene-specific primers and hydrolysis probes using the LightCycler platforms (Roche Diagnostics, Indianapolis, IN). A total of 157 samples from 96 pediatric patients were analyzed. The sensitivities of stool real-time PCR and stool EIA were 95% and 35%, respectively, with a specificity of 100% for both methods. The lower limit of detection of the stool real-time PCR was 30 CFU/ml of stool sample per reaction for tcdA and tcdB. This study highlights the poor performance of stool toxin EIAs in pediatric settings. Direct detection of C. difficile toxin genes in stool samples by real-time PCR showed sensitivity superior to that of stool and culture EIAs and performance comparable to that of real-time PCR assay of cultured isolates. Real-time PCR of DNA from stool samples is a rapid and cost-effective diagnostic modality for children that should facilitate appropriate patient management and halt the practice of serial testing by EIA.

The changing epidemiology of Clostridium difficile infections

The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI. These changes have been driven to a major degree by the emergence and epidemic spread of a novel strain, known as PCR ribotype 027 (sometimes referred to as BI/NAP1/027). We review the evidence for the changing epidemiology, clinical virulence and outcome of treatment of CDI, and the similarities and differences between data from various countries and continents. Community-acquired CDI has also emerged, although the evidence for this as a distinct new entity is less clear. There are new data on the etiology of and potential risk factors for CDI; controversial issues include specific antimicrobial agents, gastric acid suppressants, potential animal and food sources of C. difficile, and the effect of the use of alcohol-based hand hygiene agents.

A possible role for Clostridium difficile in the etiology of calf enteritis

Clostridium difficile was investigated as a possible cause of enteritis in calves. The organism and its toxins (TcdA and TcdB), respectively, were found in 25.3% and 22.9% of stool samples from diarrheic calves. Culture positive samples were more likely than culture negative samples to be toxin positive. However, toxin positive stools were more common among nondiarrheic calves, but diarrheic calves were nearly twice as likely to be culture positive. Ribotype 078 was dominant among isolates. Salmonella sp. was isolated from both diarrheic and nondiarrheic calves, but large numbers of E. coli were found more commonly in diarrheic calves than in nondiarrheic animals. Prevalence rates for coronavirus and Cryptosporidium sp. were substantially higher in nondiarrheic calves than in diarrheic, but rates of detection of rotavirus and Giardia sp. were more nearly equal between groups. Lesions in naturally infected calves included superficial mucosal erosion with associated fibrinous exudates. Neutrophils and eosinophils infiltrated lamina propria. Large Gram-positive rods morphologically compatible with C. difficile were abundant in the colonic lumen and the organism was isolated by bacteriologic culture. Toxins were found throughout the colon. Purified toxins A and B (individually and conjointly) caused comparable lesions, as well as fluid accumulation, in ligated intestinal loops. Our findings are in substantial agreement with those of others [Rodriguez-Palacios, A., Stampfli, H.R., Duffield, T., Peregrine, A.S., Trotz-Williams, L.A., Arroyo, L.G., Brazier, J.S., Weese, J.S., 2006. Clostridium difficile PCR ribotypes in calves, Canada. Emerg. Infect. Dis. 12, 1730–1736; Porter, M.C., Reggiardo, C., Bueschel, D.M., Keel, M.K., Songer, J.G., 2002. Association of Clostridium difficile with bovine neonatal diarrhea. Proc. 45th Ann. Mtg. Amer. Assoc. Vet. Lab. Diagn., St. Louis, MO, U.S.A.] and add strength to a working hypothesis that C. difficile infection and the accompanying intoxication can manifest as diarrhea in calves. It seems clear that calves serve as multiplying hosts for this organism.