[Epidemiology of infectious acute diarrhoea in France and Europe]

Clinical impact of a gastrointestinal PCR panel in children with infectious diarrhoea

OBJECTIVES

Multiplex gastrointestinal PCR (GI-PCR) allows fast and simultaneous detection of 22 enteric pathogens (including Campylobacter, Salmonella, Shigella/enteroinvasive Escherichia coli (EIEC), among other bacteria, parasites and viruses). However, its impact on the management of children with infectious diarrhoea remains unknown.

PATIENTS/DESIGN

All children eligible for stool culture from May to October 2018 were prospectively included in a monocentric study at Robert-Debré University-Hospital.

INTERVENTION

A GI-PCR (BioFire FilmArray) was performed on each stool sample.

MAIN MEASURES

Data on the children's healthcare management before and after GI-PCR results were collected. Stool culture results were also reported.

RESULTS

172 children were included. The main criteria for performing stool analysis were mucous/bloody diarrhoea and/or traveller's diarrhoea (n=130). GI-PCR's were positive for 120 patients (70%). The main pathogens were enteroaggregative E. coli (n=39; 23%), enteropathogenic E. coli (n=34; 20%), Shigella/EIEC (n=27; 16%) and Campylobacter (n=21; 12%). Compared with stool cultures, GI-PCR enabled the detection of 21 vs 19 Campylobacter, 12 vs 10 Salmonella, 27 Shigella/EIEC vs 13 Shigella, 2 vs 2 Yersinia enterocolitica, 1 vs 1 Plesiomonas shigelloides, respectively. Considering the GI-PCR results and before stool culture results, the medical management was revised for 40 patients (23%): 28 initiations, 2 changes and 1 discontinuation of antibiotics, 1 hospitalisation, 2 specific room isolations related to Clostridioides difficile infections, 4 additional test prescriptions and 2 test cancellations.

CONCLUSION

The GI-PCR's results impacted the medical management of gastroenteritis for almostone-fourth of the children, and especially the prescription of appropriate antibiotic treatment before stool culture results.

SARS-CoV-2 as Enteric Virus in Wastewater: Which Risk on the Environment and Human Behavior?

Microorganisms such as viruses, bacteria, and protozoa are the cause of many waterborne human infections. These microbes are either naturally present in aquatic environments or transferred within them by fecal sources. They remain in these environments for varying lengths of time before contaminating a new host. With the emergence of the COVID-19 pandemic, some studies have reported the presence of viral nucleic acids in stool samples from COVID-19 patients, suggesting the possibility of fecal-oral transmission. The SARS-CoV-2 RNA was thereby detected in the wastewater of symptomatic and asymptomatic people with a risk to human and environmental health. In this work, we try to discuss the different potential sources of this contamination, the forms of persistence in the environment, the techniques of partial elimination, and the possibility of creating new reservoirs.

Etiology and Risk Factors of Acute Gastroenteritis in a Taipei Emergency Department: Clinical Features for Bacterial Gastroenteritis

BACKGROUND

The causative pathogen is rarely identified in the emergency department (ED), since the results of cultures are usually unavailable. As a result, antimicrobial treatment may be overused. The aim of our study was to investigate the pathogens, risk factors of acute gastroenteritis, and predictors of acute bacterial gastroenteritis in the ED.

METHODS

We conducted a matched case-control study of 627 stool samples and 612 matched pairs.

RESULTS

Viruses (41.3%) were the leading cause of gastroenteritis, with noroviruses (32.2%) being the most prevalent, followed by bacteria (26.8%) and Giardia lamblia (12.4%). Taking antacids (adjusted odds ratio [aOR] 4.10; 95% confidence interval [CI], 2.57-6.53), household members/classmates with gastroenteritis (aOR 4.69; 95% CI, 2.76-7.96), attending a banquet (aOR 2.29; 95% CI, 1.64-3.20), dining out (aOR 1.70; 95% CI, 1.13-2.54), and eating raw oysters (aOR 3.10; 95% CI, 1.61-5.94) were highly associated with gastroenteritis. Elders (aOR 1.04; 05% CI, 1.02-1.05), those with CRP >10 mg/L (aOR 2.04; 95% CI, 1.15-3.62), or those who were positive for fecal leukocytes (aOR 2.04; 95% CI, 1.15-3.62) or fecal occult blood (aOR 1.97; 95% CI, 1.03-3.77) were more likely to be hospitalized in ED. In addition, presence of fecal leukocytes (time ratio [TR] 1.22; 95% CI, 1.06-1.41), abdominal pain (TR 1.20; 95% CI, 1.07-1.41), and frequency of vomiting (TR 0.79; 95% CI, 0.64-0.98) were significantly associated with the duration of acute gastroenteritis. Presence of fecal leukocytes (aOR 2.08; 95% CI, 1.42-3.05), winter season (aOR 0.45; 95% CI, 0.28-0.74), frequency of diarrhea (aOR 1.69; 95% CI, 1.01-2.83), and eating shrimp or crab (aOR 1.53; 95% CI, 1.05-2.23) were highly associated with bacterial gastroenteritis. The area under the receiver operating characteristic curve of the final model was 0.68 (95% CI, 0.55-0.63).

CONCLUSIONS

Acute bacterial gastroenteritis was highly associated with season, frequency of diarrhea, frequency of vomiting, and eating shrimp or crab.

[Epidemiological and clinical study of rotavirus acute diarrhea in infants at the hospital Jason Sendwe Lubumbashi, Democratic Republic of Congo]

Introduction

Le rotavirus est un problème de santé publique, non seulement dans les pays en développement où tous les enfants sont infectés avant l’âge de deux à trois ans mais aussi dans les pays développés où les conditions d'hygiène sont bonnes. La présente étude est la première à fournir des informations sur la prévalence de l'infection à rotavirus dans les diarrhées aiguës des nourrissons dans la ville de Lubumbashi. Elle s'est fixée comme objectifs de déterminer la fréquence hospitalière ainsi que la saisonnalité, les caractéristiques sociodémographiques, cliniques et évolutives de l'infection à Rotavirus chez les nourrissons admis à l'hôpital Jason Sendwe de Lubumbashi pour une diarrhée aiguë.

Méthodes

Il s'agit d'une étude descriptive et transversale menée pendant la période allant du 1^er janvier au 31 décembre 2012. Les paramètres épidémio-cliniques et évolutifs (âge, sexe, saison, signes cliniques, nombre journalier de selles et évolution) des enfants diagnostiqués positifs au rotavirus ont été comparés à ceux des enfants dont le test au rotavirus était négatif. Le degré de signification était de 5%.

Résultats

Nous avons récolté 193 cas de diarrhées aiguës dont 104 nourrissons étaient infectés par le rotavirus soit 53,8%. Des taux élevés des diarrhées à rotavirus sont enregistrés au cours de la saison sèche comparativement à la saison des pluies (p0,05). Par ailleurs, les enfants infectés par le rotavirus étaient 6 fois plus susceptibles de présenter une déshydratation modérée/sévère (p0,05).

Conclusion

Le rotavirus est confirmé dans la ville de Lubumbashi et touche souvent les enfants d’âge ≤12 mois, pendant la saison sèche sans distinction de sexe et conduit rapidement à une déshydratation modérée/sévère. Une prise en charge adaptée et précoce permet d’éviter les décès et l'assainissement du milieu, le lavage des mains, la prise d'eau potable et la vaccination contre le rotavirus sont les mesures préventives les plus efficaces contre les rotavirus et à conseiller dans notre communauté.

A DNA microarray for the versatile diagnosis of infectious diarrhea

Several bacteria, viruses, and parasites cause diarrhea as coinfecting pathogens. We designed a DNA microarray comprising 60‐bp probes spotted 194 times for the multiplex detection of 33 enteropathogenic bacteria and seven enteropathogenic viruses, and the archaeon Methanobrevibacter smithii was used as an internal positive control. Nine pathogen‐free stool specimens were used as negative controls. One of these control specimens was further spiked with Salmonella enterica as a positive control. The microarray was then tested with 40 pathological stool specimens, comprising S. enterica (n = 30), Campylobacter jejuni (n = 4), pathogenic Escherichia coli (n = 2), and adenovirus (n = 4). M. smithii was detected in 47/49 (95.9%) specimens, no pathogen was detected in negative controls and S. enterica was identified in the S. enterica‐spiked positive control. The overall specificity was 100% and the overall sensitivity was 97.5% because one S. enterica sample was missed by the microarray. The multiplexed detection of C. jejuni spiked into an adenovirus‐positive stool sample gave positive results, with fluorescence values of 14.3 and 9.1, respectively. These data indicate that using the protocol developed in this article, the DNA array allows for the multiplexed detection of some enteropathogens in stool samples.

Microbiological diagnosis of severe diarrhea in kidney transplant recipients by use of multiplex PCR assays

Diarrhea is a frequent complication after kidney transplantation, ascribed to adverse effects of the immunosuppressive therapy in case of negative microbiological examination of the stools. The aim of this study was to improve the microbiological diagnosis by implementing molecular tests. Fifty-four severe diarrhea events that occurred in 49 adult kidney transplant recipients from September 2010 to November 2011 were investigated. One or several enteric pathogens were detected in 13 (23%) stool samples using classical microbiological methods versus 39 (72%) for the seven commercially available multiplex PCR assays used retrospectively (P = 0.006). Interestingly, molecular diagnosis identified 15 multiple infections compared to none using classical techniques. The primary pathogens detected were enteropathogenic Escherichia coli (EPEC) (n = 15; 38%), Campylobacter spp. (n = 15; 38%), and Norovirus (n = 14; 36%). Specificities for Campylobacter and Norovirus infection diagnosis were 75 and 100%, respectively, by comparison to reference methods. Based on molecular findings, a cyclosporine-mycophenolate mofetil combination was identified as a risk factor for developing Norovirus-induced diarrhea. Norovirus infections were also responsible for higher weight loss than all the other causes of diarrhea. In samples from asymptomatic immunocompromised and immunocompetent patients, EPEC but not Norovirus and Campylobacter infections were detected at a frequency similar to that observed in symptomatic kidney transplant recipients. In conclusion, molecular tools significantly improved the detection of single and multiple enteric infections by comparison to classical techniques and could quickly become the key element in the management of severe acute diarrhea in transplant recipients.

Optimized microbial DNA extraction from diarrheic stools

BACKGROUND

The detection of enteropathogens in stool specimens increasingly relies on the detection of specific nucleic acid sequences. We observed that such detection was hampered in diarrheic stool specimens and we set-up an improved protocol combining lyophilization of stools prior to a semi-automated DNA extraction.

FINDINGS

A total of 41 human diarrheic stool specimens comprising of 35 specimens negative for enteropathogens and six specimens positive for Salmonella enterica in culture, were prospectively studied. One 1-mL aliquot of each specimen was lyophilised and total DNA was extracted from lyophilised and non-lyophilised aliquots by combining automatic and phenol-chloroform DNA extraction. DNA was incorporated into real-time PCRs targeting the 16S rRNA gene of Bacteria and the archaea Methanobrevibacter smithii and the chorismate synthase gene of S. enterica. Whereas negative controls consisting in DNA-free water remained negative, M. smithii was detected in 26/41 (63.4%) non-lyophilised (Ct value 28.78 ± 9.1) versus 39/41 (95.1%) lyophilised aliquots (Ct value 22.04 ± 5.5); bacterial 16S rRNA was detected in 33/41 (80.5%) non-lyophilised (Ct value 28.11 ± 5.9) versus 40/41 (97.6%) lyophilised aliquots (Ct value 24.94 ± 6.6); and S. enterica was detected in 6/6 (100%) non-lyophilized and lyophilized aliquots (Ct value 26.98 ± 4.55 and 26.16 ± 4.97, respectively). S. enterica was not detected in the 35 remaining diarrheal-stool specimens. The proportion of positive specimens was significantly higher after lyophilization for the detection of M. smithii (p = 0.00043) and Bacteria (p = 0.015).

CONCLUSION

Lyophilization of diarrheic stool specimens significantly increases the PCR-based detection of microorganisms. The semi-automated protocol described here could be routinely used for the molecular diagnosis of infectious diarrhea.

[Management of acute diarrhea in children]

Diarrhea in childhood is very frequent (two episodes/year/children less of 5 years), rarely fatale (mostly mild) and not requiring additional exploration. But it can justify a hospitalization in case of dehydration (delay of care) or risk of dehydration. It is mainly of viral origin (rotavirus +++) and it has for main complication dehydration. Diagnosis and evaluation of the dehydration, in percentage of loss of weight, must be fast and lead (drive) to a premature correction of hypovolumic shock (or to an accurate fluid management). Main treatment is oral rehydration solutions (ORS), which considerably upset the morbi-mortality, associated with a premature refeeding. Breast-feeding must not be interrupted. Symptomatic treatments and especially antibiotics are not recommended. In case of failure of the rehydration by ORS, alternative is nasogastric tube or intraveinous infusion. Prevention includes essentially the respect of hygienic rules and antirotavirus vaccine.

Norovirus as a foodborne disease hazard

Norovirus (NoV) is the most common cause of infectious gastroenteritis in the world. Gastroenteritis caused by bacterial and parasitic pathogens is commonly linked to food sources, but the link between NoV and contaminated foods has been more difficult to establish. Even when epidemiological information indicates that an outbreak originated with food, the presence of NoV in the suspect product may not be confirmed. If food is found to contain a common strain of NoV that circulates widely in the community, it is not possible to use strain typing to link the contamination to patient cases. Although food is certainly implicated in NoV spread, there are additional person-to-person and fomite transmission routes that have been shown to be important. NoV has an extremely low infectious dose, is stable in the environment, and resists disinfection. Cell culture methods are not available, so viability cannot be determined. Finally, many NoV outbreaks originate with when an infected food handler contaminates ready-to-eat food, which can be interpreted as foodborne or person-to-person transmission. This review will discuss both the physical characteristics of NoVs and the available epidemiological information with particular reference to the role of foods in NoV transmission.

Outbreak of acute gastroenteritis caused by adenovirus type 41 in a kindergarten

In response to an alert due to epidemic gastroenteritis in children in a kindergarten, an outbreak investigation was carried out in a Portuguese municipality. The objectives were to establish an aetiological diagnosis, assess vaccine efficacy if possible, and to take corrective measures if necessary. The warden at the kindergarten was interviewed, and we visited the premises. The overall attack rate was 11·4% and most cases were mild. Stool samples from three symptomatic children were collected and screened for the presence of noroviruses, rotaviruses and adenoviruses. High vaccination coverage against rotaviruses was recorded in children aged <2 years. We initially thought that noroviruses and rotaviruses were more likely to have been the aetiological cause of the disease, but the outbreak was caused by infection with adenovirus 41. These viruses should not be overlooked in the laboratory protocol in the study of acute gastroenteritis outbreaks.

[Clinical aspects and management of adult patients with acute gastroenteritis in primary care]

AIM

In patients with acute gastroenteritis, general behaviour of patients as well as medical care remain poorly documented. The aim of this work was to determine clinical and demographic characteristics, reason for visiting a doctor, and medical care in adult patients with acute gastroenteritis.

METHODS

During the winter epidemic peak of acute diarrhea, 2,217 general practitioners filled in standardized clinical observations of 17,273 patients (mean age 40 yrs) with acute gastroenteritis.

RESULTS

There were abdominal pain, nausea, and vomiting in respectively 72%, 53% and 43% of patients. Thirty one percent of patients had fever. Nausea and vomiting were more frequently observed in younger patients (15-25 yrs) than in older ones. More severe diarrhea more frequent nausea, vomiting and abdominal pain (p<0.0001). Time for consulting was less than 24 and 48h in respectively 42% and 87% of patients, and was different according to professional classes. Predominant reason for consulting was the physical consequences of the disease (78%). Self medication was reported in 42% of patients and was different according to age and professional classes. Prescription of antidiarrheal drugs was reported by 91% of patients, sometimes in association with antiemetic (43%) and/or antispasmodic agents (35%). Additional explorations (mainly biological work-up) were rare but they were more frequently considered in older and female patients as well as in patients with severe and prolonged diarrhea. Stoppage of work was different among professional classes. It was reported in one third of patients, and was more frequent in patients with severe diarrhea.

CONCLUSIONS

This study describes the behaviour of patients and doctors facing acute gastroenteritis and illustrates important fluctuations according age and professional classes. It shows high discomfort and repercussions of acute gastroenteritis especially regarding stoppage of work.