Newer approaches in diagnosis of diarrhea in immunocompromised patients

Norovirus and sapovirus infections after allogeneic hematopoietic stem cell transplantation: is it worth it to look for them?

Norovirus (NoV) and Sapovirus (SaV) are potential causative agents of diarrhea after allogeneic HSCT but little is known in this population. We performed a retrospective analysis by RT-PCR of calicivirus (NoV and SaV), Human adenovirus (HAdV), rotavirus (RV), Aichi virus (AiV), enterovirus (EV), human parechovirus (HPeV) and Human bocavirus (HBoV) in the diarrheal stools of patients after allogeneic HSCT. 49/162 patients had positive viral assays: HAdV (17%), EV (7%), NoV (4.3%), RV and HBoV (3.1% each), SaV (1.9%), AiV (1.2%), HPeV (0.6%). Seven patients were positive for NoV and 3 for SaV. Among viruses-positive samples, the frequency of caliciviruses cases was 7% in the 6 months post-HSCT compared to 40% after (p < 0.0001). The median duration of symptom was 0.7 months but 2 cases, occurring more than one year after HSCT, were chronic, undiagnosed and strongly contributed to morbidity. Systematic testing of caliciviruses appears especially useful in late chronic diarrhea.

Is the Medium Still the Message? Culture-Independent Diagnosis of Gastrointestinal Infections

Infectious diarrhea is caused by a variety of pathogens, including viruses, bacteria, and parasitic organisms. Though the causative agent of diarrhea has historically been evaluated via stool cultures, recently, culture-independent diagnostic tests (CIDT) have been developed and utilized with increasing frequency. Current practice guidelines recommend their use as adjuncts to stool cultures for diagnosing acute and chronic diarrhea. The three principal CIDT are microscopy, enzyme-based immunoassays (EIAs), and molecular based polymerase chain reaction (PCR). This review explores the common causes of infectious diarrhea, the basics of stool culture, the diagnostic utility of these three culture-independent modalities, and the strengths and weaknesses of all currently available clinical techniques. It also outlines considerations for specific populations including returning travelers and those with inflammatory bowel disease.

Identification of two potential aetiological agents of chronic diarrhoea in an immunocompromised patient in Cuba using conventional and molecular diagnostic techniques

The aetiology of diarrhoea in a patient in Cuba with HIV was investigated. Although molecular diagnostics are still not used in many under-resourced settings, here traditional methods were supported by use of PCR. This approach enabled detection of a dual infection (Cystoisospora belli and Enterocytozoon bieneusi), the latter of which was not identified by microscopy with Didier's trichromic staining.

Global prevalence of norovirus in cases of acute gastroenteritis from 1997 to 2021: An updated systematic review and meta-analysis

BACKGROUND

The worldwide response towards the acute gastroenteritis epidemic was well known, but the absence of an updated systematic review of global norovirus epidemiology in cases of gastroenteritis existed. We aimed to conduct and update a systematic review and meta-analysis of studies assessing norovirus prevalence among gastroenteritis patients worldwide.

METHODS

Four databases (PubMed, EMBASE, Cochrane Library, and Web of Science) were searched for epidemiological papers from 2014 to 2021 which applied the PCR method to access the prevalence of norovirus in acute gastroenteritis patients more than a full year. Statistical analysis was conducted using R-4.0.0 software.

RESULTS

A total of 405 records with 842, 926 cases were included. The pooled prevalence of norovirus was 16% (95%CI 15, 17). Children under 5 years old were at a higher risk with norovirus. A higher prevalence was seen in South America (22%, 95% CI 18, 27), while other continents showed a similar result with the overall prevalence of norovirus. No association was found between national income level and norovirus prevalence. A gradient of decreasing prevalence was noticed from community (20%, 95% CI 16, 24) to outpatients (18%, 95% CI 16, 20) to hospital setting (included both in- and outpatients, 17%, 95% CI 16, 19) to inpatients (15%, 95% CI 13, 17).

CONCLUSION

Norovirus were associated with 16% acute gastroenteritis globally. To fully understand the prevalence of norovirus worldwide, the continual surveillance of norovirus epidemics was required.

Infectious Gastroenteritis in Transplant Patients

Infectious gastroenteritis is common after transplantation and can lead to increased morbidity and mortality. A wide range of organisms can lead to gastroenteritis in this patient population. Clostridioides difficile, cytomegalovirus, and norovirus are the most common pathogens. Newer diagnostic methods, especially multiplex polymerase chain reaction, have increased the diagnostic yield of infectious etiologies. In this review, we describe the epidemiology and risk factors for common infectious pathogens leading to gastroenteritis.

Incidence and Causes of Late Hospital Readmissions After Living Donor Renal Transplant: A Retrospective Study

OBJECTIVES

Our primary aim was to find the incidence, causes, and factors responsible for late hospital readmissions.

MATERIALS AND METHODS

There were 185 patients included in the study. The patients were divided into 2 groups: those with late readmission after discharge and those with no late readmission. Inpatient records and charts were assessed for the medical status of the patients, cause of chronic kidney disease, comorbidities, vintage and modality of dialysis, and hospital admissions 3 months before transplant. Collected patient data included recipient age, sex, height, weight, body mass index, hepatitis C status, donor age, methods of immunosuppression and induction, duration of hospital stay, postoperative complications and secondary procedures, number, duration, and causes of hospital readmission after transplant, and methods of evaluation and management during readmission.

RESULTS

There were 80 patients who received 127 late hospital readmissions. The most common cause of late hospital readmission was infection, which led to 45 admissions (35.43%). Of 45 admissions for infections, 18 were caused by urinary tract infections. Other reasons for admission were pneumonia (10 admissions), cytomegalovirus infection (11 admissions), and tuberculosis (6 admissions). The second most common cause of readmission was infectious or noninfectious diarrhea, which led to 29 admissions (22.88%). There were 28 late hospital readmissions (22.4%) for the evaluation or management of graft dysfunction. Newonset diabetes after transplant and febrile illness were causes of late hospital readmission in 8 cases each (6.9%), with 9 late hospital readmissions (7.08%) the result of other causes.

CONCLUSIONS

Incidence of late hospital readmission is high (43.2%), and the most common cause is infection, particularly urinary tract infections. Age of the recipient and early hospital readmission are predictive factors for late hospital readmission.