Norwalk Virus Shedding after Experimental Human Infection

Noroviruses are shed in feces up to 8 weeks after infection

Noroviruses as a Cause of Diarrhea in Immunocompromised Pediatric Hematopoietic Stem Cell and Solid Organ Transplant Recipients

Case reports describe significant norovirus gastroenteritis morbidity in immunocompromised patients. We evaluated norovirus pathogenesis in prospectively enrolled solid organ (SOT) and hematopoietic stem cell transplant (HSCT) patients with diarrhea who presented to Texas Children\u27s Hospital and submitted stool for enteric testing. Noroviruses were detected by real-time reverse transcription polymerase chain reaction. Clinical outcomes of norovirus diarrhea and non-norovirus diarrhea patients, matched by transplanted organ type, were compared. Norovirus infection was identified in 25 (22%) of 116 patients, more frequently than other enteropathogens. Fifty percent of norovirus patients experienced diarrhea lasting ≥14 days, with median duration of 12.5 days (range 1–324 days); 29% developed diarrhea recurrence. Fifty-five percent of norovirus patients were hospitalized for diarrhea, with 27% requiring intensive care unit (ICU) admission. One HSCT recipient developed pneumatosis intestinalis. Three HSCT patients expired ≤6 months of norovirus diarrhea onset. Compared to non-norovirus diarrhea patients, norovirus patients experienced significantly more frequent ICU admission (27% vs. 0%, p = 0.02), greater serum creatinine rise (median 0.3 vs. 0.2 mg/dL, p = 0.01), and more weight loss (median 1.6 vs. 0.6 kg, p \u3c 0.01). Noroviruses are an important cause of diarrhea in pediatric transplant patients and are associated with significant clinical complications

The Dynamics of Nestedness Predicts the Evolution of Industrial Ecosystems

In economic systems, the mix of products that countries make or export has been shown to be a strong leading indicator of economic growth. Hence, methods to characterize and predict the structure of the network connecting countries to the products that they export are relevant for understanding the dynamics of economic development. Here we study the presence and absence of industries at the global and national levels and show that these networks are significantly nested. This means that the less filled rows and columns of these networks' adjacency matrices tend to be subsets of the fuller rows and columns. Moreover, we show that nestedness remains relatively stable as the matrices become more filled over time and that this occurs because of a bias for industries that deviate from the networks' nestedness to disappear, and a bias for the missing industries that reduce nestedness to appear. This makes the appearance and disappearance of individual industries in each location predictable. We interpret the high level of nestedness observed in these networks in the context of the neutral model of development introduced by Hidalgo and Hausmann (2009). We show that, for the observed fills, the model can reproduce the high level of nestedness observed in these networks only when we assume a high level of heterogeneity in the distribution of capabilities available in countries and required by products. In the context of the neutral model, this implies that the high level of nestedness observed in these economic networks emerges as a combination of both, the complementarity of inputs and heterogeneity in the number of capabilities available in countries and required by products. The stability of nestedness in industrial ecosystems, and the predictability implied by it, demonstrates the importance of the study of network properties in the evolution of economic networks.Comment: 26 page

Invasive Mold Infections Following Hurricane Harvey-Houston, Texas

BACKGROUND: Characterizing invasive mold infection (IMI) epidemiology in the context of large flooding events is important for public health planning and clinical decision making. METHODS: We assessed IMI incidence (per 10 000 healthcare encounters) 1 year before and after Hurricane Harvey at 4 hospitals in Houston, Texas. Potential IMI cases were assigned as proven or probable cases using established definitions, and surveillance cases using a novel definition. We used rate ratios to describe IMI incidence and multivariable logistic regression to examine patient characteristics associated with IMI case status. RESULTS: IMI incidence was significantly higher posthurricane (3.69 cases) than prehurricane (2.50 cases) (rate ratio, 1.48 [95% confidence interval, 1.10-2.00]), largely driven by surveillance IMI cases. CONCLUSIONS: IMI incidence likely increased following Hurricane Harvey and outcomes for IMI patients were severe. Patient and clinician education on IMI prevention and identification is warranted, particularly as the frequency of extreme weather events increases due to climate change

Safety and pharmacokinetics of rimantadine small-particle aerosol.

The safety and pharmacokinetics of rimantadine administered by small-particle aerosol were assessed in healthy adults and adults with acute influenza virus infection. Aerosolized rimantadine delivered at a concentration of 40 micrograms/liter of air was associated with nasal burning and irritation in normal volunteers. A concentration of 20 micrograms/liter of air was well tolerated for up to 12 h by normal volunteers and was not associated with any changes in pulmonary function, as measured by routine spirometry, plethysmography, or diffusion capacity of carbon monoxide. Mean peak levels of drug in serum were approximately 10-fold lower after 12 h of aerosol administration than they were after oral administration of 200 mg (29.7 versus 255 ng/ml, respectively), while mean nasal wash levels were approximately 100-fold higher (6,650 versus 66.6 ng/ml, respectively). Elimination half-lives were similar after both aerosol and oral administration (24.1 and 25.2 h, respectively), and rimantadine urinary excretion was less than 1% per 24 h in both groups. Twenty micrograms of aerosolized rimantadine per liter of air given 12 h daily for 3 days to nine adults with acute influenza virus infection was well tolerated. Levels in plasma after 12 h of aerosol inhalation were similar to those in normal volunteers, but were higher at the end of the third treatment than they were at the end of the first treatment (88.3 versus 47.9 ng/ml, respectively). Thus, rimantadine delivered via small-particle aerosol at a dose of 20 micrograms/liter of air was well tolerated in normal volunteers and in those with acute influenza and was associated with high local concentrations

Effects of Child and Maternal Histo-Blood Group Antigen Status on Symptomatic and Asymptomatic Enteric Infections in Early Childhood

Funding Information: Financial support. This work was funded by the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED) is carried out as a collaborative project funded by the Bill & Melinda Gates Foundation (BMGF) (BMGF-47075), the Foundation for the National Institutes of Health, and the National Institutes of Health, Fogarty International Center, whereas additional support was obtained from BMGF for the examination of host innate factors on enteric disease risk and enteropathy (Grants OPP1066146 and OPP1152146; to M. N. K.). Additional funding was obtained from teh Sherrilyn and Ken Fisher Center for Environmental Infectious Diseases, Johns Hopkins School of Medicine (to M. N. K) and the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institues of health 1UL1TR001079. Acknowledgments. We thank the participants, their families, and the study community for their dedicated time and effort to better the understanding the transmission and more enduring impact of enteric infections in early childhood. We also thank the following: Jan Vinje (Centers for Disease Control and Prevention) for critical input and manuscript review; Dr. Leah Jager for consultation regarding the statistical analysis; Dr. Ben Jann (University of Bern, Switzerland) for guidance in generating the figures; Christine Szymanski for insight and encouragement, particularly regarding Campylobacter infection and disease patency; Chris Damman and Anita Zaidi for input on early iterations of the analysis; and Dick Guerrant for final reflections.Peer reviewe

Influence of Novel Norovirus GII.4 Variants on Gastroenteritis Outbreak Dynamics in Alberta and the Northern Territories, Canada between 2000 and 2008

BACKGROUND: Norovirus GII.4 is the predominant genotype circulating worldwide over the last decade causing 80% of all norovirus outbreaks with new GII.4 variants reported in parallel with periodic epidemic waves of norovirus outbreaks. The circulating new GII.4 variants and the epidemiology of norovirus outbreaks in Alberta, Canada have not been described. Our hypothesis is that the periodic epidemic norovirus outbreak activity in Alberta was driven by new GII.4 variants evolving by genetic drift. METHODOLOGY/PRINCIPAL FINDINGS: The Alberta Provincial Public Health Laboratory performed norovirus testing using RT-PCR for suspected norovirus outbreaks in the province and the northern Territories between 2000 and 2008. At least one norovirus strain from 707 out of 1,057 (66.9%) confirmed norovirus outbreaks were successfully sequenced. Phylogenetic analysis was performed using BioNumerics and 617 (91.1%) outbreaks were characterized as caused by GII.4 with 598 assigned as novel variants including: GII.4-1996, GII.4-2002, GII.4-2004, GII.4-2006a, GII.4-2006b, GII.4-2008a and GII.4-2008b. Defining July to June of the following year as the yearly observation period, there was clear biannual pattern of low and high outbreak activity in Alberta. Within this biannual pattern, high outbreak activity followed the emergence of novel GII.4 variants. The two variants that emerged in 2006 had wider geographic distribution and resulted in higher outbreak activity compared to other variants. The outbreak settings were analyzed. Community-based group residence was the most common for both GII.4 variants and non-GII.4 variants. GII.4 variants were more commonly associated with outbreaks in acute care hospitals while outbreaks associated non-GII.4 variants were more commonly seen in school and community social events settings (p<0.01). CONCLUSIONS/SIGNIFICANCE: The emergence of new norovirus GII.4 variants resulted in an increased norovirus outbreak activity in the following season in a unique biannual pattern in Alberta over an eight year period. The association between antigenic drift of GII.4 strains and epidemic norovirus outbreak activity could be due to changes in host immunity, viral receptor binding efficiency or virulence factors in the new variants. Early detection of novel GII.4 variants provides vital information that could be used to forecast the norovirus outbreak burden, enhance public health preparedness and allocate appropriate resources for outbreak management