Persistent spiking fever in a child with acute myeloid leukemia and disseminated infection with enterovirus

Enterovirus infections in pediatric hematologic/oncologic patients

BACKGROUND

Enteroviruses (EV) are a large group of Picornaviruses associated with respiratory, gastrointestinal, and neurologic symptoms in the immunocompetent host. Little is known about the epidemiologic and clinical impact in pediatric hematologic/oncologic patients.

PROCEDURE

From 2001 through 2017, different clinical specimens were collected from pediatric hematologic/oncologic patients and were tested for enteroviral RNA.

RESULTS

Of 13 004 specimens collected from 761 patients, 38 (0.3%) obtained from 14 patients (1.8%) tested positive for EV RNA. Viral shedding was observed without viremia and vice versa. None of 80 cerebrospinal fluid specimens obtained from 60 patients with neurologic symptoms were positive for EV RNA. None of 14 patients positive for EV RNA showed EV-specific symptoms. In 11/14 patients, EV RNA was found to be negative in the follow-up specimen. The remaining patient with a severe primary immune deficiency showed repeated positive EV RNA results for >5 years.

CONCLUSIONS

In this pediatric hematologic/oncologic cohort, EV infection occurred rarely and without related symptoms. Specimens concurrently obtained from one patient are commonly not in accordance with each other. In the vast majority of patients, EV RNA appears to turn negative in the follow-up specimen. EV infections seem to have a low impact in this patient cohort.

Enteroviruses and Parechoviruses

Infections with enteroviruses and human parechoviruses are highly prevalent, particularly in neonates, where they may cause substantial morbidity and mortality. Individuals with B-cell-related immunodeficiencies are at risk for severe enteroviral infections, usually a chronic and fatal meningoencephalitis. In transplant recipients and patients with malignancy, enterovirus infections typically involve the respiratory tract, but cases of severe, disseminated infection have been described. The mainstay of diagnosis for enterovirus and human parechovirus infections involves the use of molecular diagnostic techniques. However, routine nucleic acid-detection methods for enteroviruses will not detect human parechoviruses. Laboratory diagnosis of these viral infections is important in determining a patient's prognosis and guiding clinical management.

Capturing norovirus transmission

Human norovirus is a leading cause of gastroenteritis and is efficiently transmitted between humans and around the globe. The burden of norovirus infections in the global community and in health-care settings warrant the availability of outbreak prevention strategies and control measures that are tailored to the pathogen, outbreak setting and population at risk. A better understanding of viral and host determinants of transmission would aid in developing and fine-tuning such efforts. Here, we describe mechanisms of transmission, available model systems for studying norovirus transmission and their strengths and weaknesses as well as future research strategies.

Sustained fecal-oral human-to-human transmission following a zoonotic event

Bacterial, viral and parasitic zoonotic pathogens that transmit via the fecal-oral route have a major impact on global health. However, the mechanisms underlying the emergence of such pathogens from the animal reservoir and their persistence in the human population are poorly understood. Here, we present a framework of human-to-human transmission of zoonotic pathogens that considers the factors relevant for fecal-oral human-to-human transmission route at the levels of host, pathogen, and environment. We discuss current data gaps and propose future research directions.

A Case of Fulminant Hepatitis due to Echovirus 9 in a Patient on Maintenance Rituximab Therapy for Follicular Lymphoma

Rituximab is a CD20 monoclonal antibody commonly used in the treatment of haematological malignancies. It causes lymphopenia with subsequent compromised humoral immunity resulting in an increased risk of infection. A number of infections and viral reactivations have been described as complicating Rituximab therapy. We report an apparently unique case of echovirus 9 (an enterovirus) infection causing an acute hepatitis and significant morbidity in an adult patient on maintenance treatment of Rituximab for follicular lymphoma. We also describe potential missed opportunities to employ more robust screening for viral infections which may have prevented delays in the appropriate treatment and thus may have altered the patient's clinical course. We also make suggestions for lowering the threshold of viral testing in similar patients in the future.