Case Series: Virulent hemosporidiosis infections in juvenile great horned owls (Bubo virginianus) from Louisiana and California, USA

A total of eight juvenile great horned owls (Bubo virginianus) were found lethargic and on the ground in spring 2015, 2016, and 2017, including one fledgling from Louisiana, USA and seven nestlings from California, USA. One bird survived to release after rehabilitation; seven birds died or were euthanized due to poor prognosis and were necropsied. Necropsy findings were similar and included general pallor of all tissues, particularly the subcutis and lungs, and enlarged liver and spleen. Histopathology revealed multi-organ necrosis, abundant meronts containing merozoites, and intracytoplasmic pigmented haemosporidian parasites in blood cells in one bird. Leucocytozoon lineages lSTOCC16 and BUVIR06 were identified by polymerase chain reaction and genetic sequencing. The systemic Leucocytozoon infections were likely associated with morbidity and mortality in these owls. A second parasite, Haemoproteus lineage hSTVAR01, was also identified in an owl from Louisiana. This is the first identification of Leucocytozoon lineages that have been associated with mortality in young great horned owls.

Loss of brain inter-frequency hubs in Alzheimer's disease

Alzheimer's disease (AD) causes alterations of brain network structure and function. The latter consists of connectivity changes between oscillatory processes at different frequency channels. We proposed a multi-layer network approach to analyze multiple-frequency brain networks inferred from magnetoencephalographic recordings during resting-states in AD subjects and age-matched controls. Main results showed that brain networks tend to facilitate information propagation across different frequencies, as measured by the multi-participation coefficient (MPC). However, regional connectivity in AD subjects was abnormally distributed across frequency bands as compared to controls, causing significant decreases of MPC. This effect was mainly localized in association areas and in the cingulate cortex, which acted, in the healthy group, as a true inter-frequency hub. MPC values significantly correlated with memory impairment of AD subjects, as measured by the total recall score. Most predictive regions belonged to components of the default-mode network that are typically affected by atrophy, metabolism disruption and amyloid-β deposition. We evaluated the diagnostic power of the MPC and we showed that it led to increased classification accuracy (78.39%) and sensitivity (91.11%). These findings shed new light on the brain functional alterations underlying AD and provide analytical tools for identifying multi-frequency neural mechanisms of brain diseases.

A randomized, controlled clinical trial to evaluate the immunogenicity of a PreS/S hepatitis B vaccine Sci-B-Vac™, as compared to Engerix B®, among vaccine naïve and vaccine non-responder dialysis patients

BACKGROUND

Dialysis patients have a suboptimal response to hepatitis B (HBV) vaccination. This study aimed to compare the immunogenicity of two vaccines: the third-generation Sci-B-Vac™ vs. the second-generation Engerix B^®. The cohort included two groups of dialysis patients: naïve and previously vaccinated non-responders. Primary endpoints were antibody titers ≥10 IU/L at 3 and 7 month post-vaccination. Secondary objectives were seroprotection rates in vaccine-naïve patients and in previously vaccinated non-responders.

METHODS

Eighty-six patients were assigned to vaccine (Sci-B-Vac™ or Engerix B^®) using computer-generated randomization, stratified by age, gender, diabetes, and previous HBV vaccination. Sci-B-Vac™ was administered in three doses, 10 μg, at 0, 1, and 6 months in naïve patients; or 20 μg in previously vaccinated non-responders. Engerix B^® included four doses, 40 μg at 0, 1, 2, and 6 months.

RESULTS

Each group had 43 patients. Seroconversion was 69.8% with Engerix B^® vs. 73.2% with Sci-B-Vac™. Antibody titers at 7 months were higher with Sci-B-Vac™ (266.4 ± 383.9, median 53.4) than with Engerix^® (193.2 ± 328.9, median 19). However, these differences were not significant, perhaps due to a suboptimal sample size.

CONCLUSIONS

This study suggests comparable immunogenicity for both vaccines. Thus, we cannot reject the null hypothesis that there is no difference in seroconversion by vaccine type. It is noteworthy that naïve patients were vaccinated with a standard dose of Sci-B-Vac™, while Engerix B^® was administered at a double dose. Similarly, although mean antibody titer levels in the Sci-B-Vac™ group were higher than in the Engerix^® group, this difference did not reach significance. Consequently, a future clinical trial should recruit a larger cohort of patients, using a standard double-dose protocol in both groups.

Time to Detection with BacT/Alert FA Plus Compared to BacT/Alert FA Blood Culture Media

Rapid identification of the causative pathogen in patients with bacteremia allows adjustment of antibiotic therapy and improves patient outcomes. We compared in vitro and real-life time to detection (TTD) of two blood culture media, BacT/Alert FA (FA) and BacT/Alert FA Plus (FA Plus), for the nine most common species of bacterial pathogens recovered from blood samples. Experimental data from simulated cultures was compared with microbiology records of TTD for both culture media with growth of the species of interest in clinical blood cultures. In the experimental conditions, median TTD was 3.8 hours (23.9 %) shorter using FA Plus media. The magnitude of reduction differed between species. Similarly, in real life data, FA Plus had shorter TTD than FA media; however, the difference between culture media was smaller, and median TTD was only 1 hour (8.5 %) less. We found shorter TTD with BacT/Alert FA Plus culture media, both experimentally and in real-life conditions and unrelated to antibiotic neutralization, highlighting the importance of appropriate blood culture media selection.

Congenital tuberculosis and management of exposure in neonatal and pediatric intensive care units

SETTING

This report describes the management and outcome of neonatal intensive care unit (NICU) and paediatric ICU (PICU) exposure to a 26-day-old premature infant with congenital tuberculosis (TB).

DESIGN

The infant's mother underwent chest X-ray (CXR) and sputum culture. Contacts of the infant were identified. Tuberculin skin tests (TSTs) were performed on 97 infants and children, 156 NICU and PICU visitors and 115 health care workers.

RESULTS

The mother's sputum culture was positive for Mycobacterium tuberculosis. No TST conversion occurred in the exposed NICU infants. All neonates received prophylactic isoniazid (INH). One exposed child in the PICU had TST conversion with normal CXR and completed 9 months of INH without developing active disease; 22 (14%) PICU and NICU visitors and 3 NICU personnel had TST conversion without evidence of disease.

CONCLUSIONS

The sequence of events described here demonstrates the difficulty in diagnosis and management of TB in this age group. Transmission of TB in NICU and PICUs is unusual but can occur, and calls for a systematic approach to investigation of the exposed infants, family members and health care providers.