Diagnostic determination of Norovirus infection as one of the major causes of infectious diarrhea in HIV patients using a multiplex polymerase chain reaction assay

Evaluation of chronic diarrhea in patients newly diagnosed with HIV infection through the FilmArray® gastrointestinal panel

INTRODUCTION

The treatment and diagnosis of chronic diarrhea in the immunocompromised patient depends on the ability to rapidly detect the etiologic agents.

AIMS

Our aim was to evaluate the results of the FilmArray® gastrointestinal panel in patients newly diagnosed with HIV infection that presented with chronic diarrhea.

MATERIAL AND METHODS

Utilizing nonprobability consecutive convenience sampling, 24 patients were included that underwent molecular testing for the simultaneous detection of 22 pathogens.

RESULTS

In 24 HIV-infected patients with chronic diarrhea, enteropathogen bacteria were detected in 69% of the cases, parasites in 18%, and viruses in 13%. Enteropathogenic Escherichia coli and enteroaggregative Escherichia coli were the main bacteria identified, Giardia lamblia was found in 25%, and norovirus was the most frequent viral agent. The median number of infectious agents per patient was three (range of 0 to 7). The biologic agents not identified through the FilmArray® method were tuberculosis and fungi.

CONCLUSIONS

Several infectious agents were simultaneously detected through the FilmArray® gastrointestinal panel in patients with HIV infection and chronic diarrhea.

Norovirus infection among HIV-infected patients in Abuja, Nigeria: impact of combination antiretroviral therapy status

BACKGROUND

Norovirus is now recognized to be major cause of gastroenteritis worldwide, with significantly higher disease burden among immunocompromised patients. This study aimed to determine the prevalence of Norovirus among HIV-infected patients and to evaluate the impact of combination antiretroviral therapy (cART) status on Norovirus prevalence in a sub-urban area of Abuja, Nigeria.

METHODS

This study included a total of Two hundred and fifteen subjects (85 cART-naïve and 130 cART-exposed) HIV-infected patients. Age range of study participants was 18 to 60 years. Faecal specimens where collected in screw capped containers and analyzed for Norovirus using Accupower Norovirus real-time PCR Test kit. CD4 + cell count was determined using flow cytometry.

RESULTS

The prevalence of Norovirus among cART-naïve HIV-infected patients was 10.6%. Age and gender was not associated with norovirus infection. cART -naïve HIV-infected patients with CD4 + cell count < 200 was significantly more infected with Norovirus as compared to those with CD4 + count ≥ 200 (OR: 28.000, 95% CI 3.2237, 243.2007, P = 0.0025). Norovirus was also found to be significantly higher in cART-naïve HIV-infected patients than amongst cART-exposed counterparts (OR: 6.882, 95% CI: 1.4514, 32.6343, P = 0.015).

CONCLUSIONS

The prevalence of Norovirus among cART-naïve HIV-infected patients was high; and was significantly higher in subjects with low CD4 + counts. Screening for Norovirus among cART-naïve HIV-infected patients is however emphasized to allow for effective Norovirus disease management.

The influence of hospitalization and HIV severity on gastrointestinal PCR panel evaluation of HIV-related acute diarrhea in New York City: a retrospective, cross-sectional study

INTRODUCTION

Diarrhea is common in persons living with HIV (PLWH)/AIDS. With the increasing utilization of multiplex gastrointestinal PCR panel (GI panel) testing, we aimed to characterize the roles of CD4 count and hospitalization in GI panel assessments of PLWH with acute diarrhea.

METHODS

We performed a cross-sectional study of adult PLWH with acute diarrhea who underwent GI panel testing at two urban academic centers. Demographic, HIV disease, GI panel result, and hospitalization data were collected, and patients were cohorted by CD4 count (CD4 < 200, CD4 200-499, CD4 > = 500). The primary outcome was enteric infection as detected by GI panel, and hospitalization.

RESULTS

Of 298 PLWH, 119 (39.9%) had a CD4 count below 200, 195 (65.4%) were hospitalized, and 137 (46.0%) had enteric infection. Bacterial infection correlated with higher CD4 count (41.9% (CD4 > = 500) vs 31.2% (CD4 200-499) vs 25.2% (CD4 < 200), p = 0.041). Hospitalization correlated with poorly controlled HIV and fewer enteric infections (34.4% vs 68.0%, p < 0.001). After adjusting for HIV disease severity, a negative GI panel remained independently associated with hospitalization (adjusted odds ratio (aOR) 5.32, 95% confidence interval (CI) 2.72-10.9), even in patients tested within 72 hours of hospitalization. Despite better HIV control, men who have sex with men (MSM) had more frequent infectious diarrhea, including from E. coli, giardiasis, and multiple pathogens. MSM status independently predicted enteric infection (aOR 1.93, 95% CI: 1.02-3.67).

CONCLUSIONS

GI panel results vary by HIV disease severity and hospitalization in PLWH. Clinicians - especially in the inpatient setting - should carefully consider these factors when interpreting GI panel results. Further characterization of diarrheal etiology in PLWH with a negative GI panel is needed.

PLAIN LANGUAGE SUMMARY

PCR stool test results are affected by certain factors in HIV-related diarrhea Diarrhea is common in people living with HIV (PLWH) and has a variety of causes, including infections, medications, and HIV itself. Multiplex polymerase chain reaction (PCR) stool testing simultaneously evaluates for a variety of common viral, bacterial, and parasitic infections of the gastrointestinal tract, and is increasingly being used in patients with diarrhea. However, patients with HIV and diarrheal illness may have uncommon infections not typically present in those with normal immune function - and thus not routinely evaluated for in stool testing. It is not known what factors, if any, might affect the results of PCR testing in HIV-related diarrhea.In this study, we examined all PLWH who underwent stool PCR testing for diarrhea over a 4-year period. We separated the patients into groups based on HIV disease severity as measured by CD4 T-cell count, or the count of the immune cells affected by HIV. We examined whether there were differences among groups in infection rates as detected by PCR stool testing. Separately, we studied the role of hospitalization in stool PCR test results.Of 298 PLWH who underwent stool PCR testing for diarrhea, 119 had a CD4 count less than 200 (low CD4 count), 195 were hospitalized at time of testing, and 137 had a positive stool PCR test. Compared to those with a low CD4 count, subjects with less severe HIV disease were more likely to have a bacterial infection on stool PCR testing and less likely to be hospitalized. Hospitalized patients were more likely to have a negative PCR stool test, regardless of CD4 count. Many patients with a low CD4 count had diarrheal etiologies not evaluated by multiplex stool PCR. In PLWH who experience diarrhea, stool PCR testing results vary by CD4 count and hospitalization. Providers should be mindful of these factors when interpreting stool PCR test results.

Review of the role of gastrointestinal multiplex polymerase chain reaction in the management of diarrheal illness

Acute and chronic diarrheal illness secondary to gastrointestinal infection is a significant cause of morbidity and mortality around the world. A cornerstone of management includes prompt diagnosis and appropriate treatment of culprit pathogens. Timely diagnosis can improve patient care, assist in infection control, and prevent disease outbreaks. Historical methods of diagnosis include traditional culture methods and stool analysis. These are limited by long turnaround time and inability to simultaneously assess multiple pathogens. The advent of multiplexed nucleic acid amplification tests first began with the Food and Drug Administration-approved respiratory virus multiplex polymerase chain reaction (PCR) panel in 2009, followed by gastrointestinal infections in 2013, and neurological infections in 2014. We conducted a review of current literature pertaining to the clinical utility of a gastrointestinal multiplex PCR in management of acute and chronic diarrhea in patients. To date, seven platforms approved by the US Food and Drug Administration are used in detection of various bacterial, viral, and parasitic causative organisms for diagnosis of gastrointestinal infections. The sensitivity and specificity of each assay vary depending on the tested organism. Interpretation of a positive result has to be tailored to the clinical context. Further studies are required to establish the utility of gastrointestinal multiplex PCR from a cost-based perspective, whether specific enteropathogens such as Clostridioides difficile are better assessed with toxin gene detection and whether new parameters such as cycle threshold values can improve clinical application of test results.

[Value of serum procalcitonin combined with soluble triggering receptor expressed on myeloid cells-1 in the differential diagnosis of bacterial and viral diarrhea in children]

OBJECTIVE

To study the value of serum procalcitonin (PCT) combined with soluble triggering receptor expressed on myeloid cells-1 (STREM-1) in the differential diagnosis of bacterial diarrhea and viral diarrhea in children.

METHODS

A retrospective analysis was performed on the medical data of 73 children with bacterial infectious diarrhea (bacteria group) and 68 children with viral infectious diarrhea (virus group) who were treated from February 2018 to May 2019. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic efficacy of serum PCT and STREM-1 for bacterial infectious diarrhea and viral infectious diarrhea.

RESULTS

Compared with the virus group, the bacteria group had significantly higher detection rates of fecal red blood cells (79% vs 43%, P<0.05) and pus (51% vs 19%, P<0.05), as well as significantly higher serum levels of PCT and STREM-1 (P<0.05). The ROC curve analysis showed that in the differential diagnosis of bacterial infectious diarrhea and viral infectious diarrhea, serum PCT had a cut-off value of 0.97 ng/mL and an area under the ROC curve (AUC) of 0.792, and STREM-1 had a cut-off value of 15.66 ng/mL and an AUC of 0.889. Serum PCT combined with STREM-1 had an AUC of 0.955, which was significantly higher than that of each index alone (P<0.05).

CONCLUSIONS

Children with bacterial diarrhea have increased serum levels of PCT and STREM-1 than those with viral diarrhea. Both serum PCT and STREM-1 can be used as the indices for the differential diagnosis of bacterial diarrhea and viral diarrhea in children, and the combined measurement of PCT and STREM-1 can improve the efficiency of differential diagnosis.