The E119D neuraminidase mutation identified in a multidrug-resistant influenza A(H1N1)pdm09 isolate severely alters viral fitness in vitro and in animal models.

We recently isolated an influenza A(H1N1)pdm09 E119D/H275Y neuraminidase (NA) variant from an immunocompromised patient who received oseltamivir and zanamivir therapies. This variant demonstrated cross resistance to zanamivir, oseltamivir, peramivir and laninamivir. In this study, the viral fitness of the recombinant wild-type (WT), E119D and E119D/H275Y A(H1N1)pdm09 viruses was evaluated in vitro and in experimentally-infected C57BL/6 mice and guinea pigs. In replication kinetics experiments, viral titers obtained with the E119D and E119D/H275Y recombinants were up to 2- and 4-log lower compared to the WT virus in MDCK and ST6GalI-MDCK cells, respectively. Enzymatic studies revealed that the E119D mutation significantly decreased the surface NA activity. In experimentally-infected mice, a 50% mortality rate was recorded in the group infected with the WT recombinant virus whereas no mortality was observed in the E119D and E119D/H275Y groups. Mean lung viral titers on day 5 post-inoculation for the WT (1.2 ± 0.57 × 10(8) PFU/ml) were significantly higher than those of the E119D (9.75 ± 0.41 × 10(5) PFU/ml, P < 0.01) and the E119D/H275Y (1.47 ± 0.61 × 10(6) PFU/ml, P < 0.01) groups. In guinea pigs, comparable seroconversion rates and viral titers in nasal washes (NW) were obtained for the WT and mutant index and contact groups. However, the D119E reversion was observed in most NW samples of the E119D and E119D/H275Y animals. In conclusion, the E119D NA mutation that could emerge in A(H1N1)pdm09 viruses during zanamivir therapy has a significant impact on viral fitness and such mutant is unlikely to be highly transmissible.

Impact of a large deletion in the neuraminidase protein identified in a laninamivir-selected influenza A/Brisbane/10/2007 (H3N2) variant on viral fitness in vitro and in ferrets.

Viral fitness of a laninamivir-selected influenza A/Brisbane/10/2007-like (H3N2) isolate (LRVp9) containing a 237-amino acid neuraminidase deletion and a P194L hemagglutinin mutation was evaluated in vitro and in ferrets. LRVp9 and the wild-type (WT) virus showed comparable replication kinetics in MDCK-ST6GalI cells. Cultured virus was recovered between days 2 and 5 post-infection in nasal washes (NW) from the 4 WT-infected ferrets whereas no virus was recovered from the LRVp9-infected animals. There was a ≥1 log reduction in viral RNA copies/µl of NW for LRVp9 compared to WT at most time points. The large neuraminidase deletion compromises viral infectivity in vivo.

Symptom Experience and Quality of Life in Children after Sport-Related Head Injuries: A Cross-Sectional Study.

BACKGROUND: Sports are a major cause of concussions, and little is known about the symptom experience and health-related quality of life (HRQL) in children who remain symptomatic for over 3 months following such head injuries. METHODS: A cross-sectional study of children aged 10-18 years was performed who were referred to the Neurosurgery Clinic at our centre following a head injury. Symptom experience was measured using the modified Concussion Symptom Scale, and HRQL was measured using the Pediatric Quality of Life Inventory (PedsQL). The Immediate Postconcussion Assessment and Cognitive Test (ImPACT) was administered to assess neurocognitive and neurobehavioural sequelae. RESULTS: Symptoms with the highest mean symptom scores on a Likert scale of 0-6 in 35 children at the time of assessment included headaches (3.1), poor concentration (2.7), memory problems (2.1), fatigue (2.1) and sensitivity to noise (2.0). Compared with normative data, children in this study had ImPACT summary scores between the 28th and 38th percentiles and a comparably low Cognitive Efficiency Index score. Mean scores for females were consistently statistically significantly lower (p < 0.05) than for males across all of the HRQL domains. Trouble falling asleep and memory problems explained 62% of the variance in the PedsQL total scores. CONCLUSIONS: Children continue to experience many symptoms at least 3 months following sport-related head injuries that significantly impact their HRQL and neurocognitive abilities.

Reduced airborne transmission of oseltamivir-resistant pandemic A/H1N1 virus in ferrets.

BACKGROUND: The H275Y neuraminidase mutation conferring oseltamivir resistance has been reported in several pandemic A/H1N1 (pH1N1) isolates. We sought to evaluate transmission of this mutant virus through the direct contact and the airborne (aerosol and droplet) routes in the ferret model. METHODS: Groups of four ferrets were infected with either wild-type (WT) or oseltamivir-resistant pH1N1 (H275Y) strains. At 24 h following viral infection, a receptive ferret was introduced in the same cage as the infected animal to assess direct contact transmission. For the airborne transmission, naive ferrets were placed in a modified separate cage adjacent to that of their respective index ferret. RESULTS: The H275Y mutant virus was as efficiently transmitted as the WT strain by direct contact, as 100% (4/4) of contact ferrets in both groups seroconverted and shed virus. Mean peak viral titres were similar in both groups (4 × 10(4) and 2.63 × 10(4) plaque-forming units/ml after WT or H275Y mutant virus transmission, respectively). Peak viral shedding occurred on day 2 post-contact for the WT group and on day 4 post-contact for the H275Y mutant group. By contrast, airborne transmission of the mutant strain was less efficient, as only 25% (1/4) of contact ferrets seroconverted and shed virus, whereas 100% (4/4) of the WT ferrets did. Peak of viral replication was delayed compared to direct contact transmission and occurred on day 4 post-contact. CONCLUSIONS: Transmission of the H275Y pH1N1 mutant strain by the airborne route is somewhat compromised, which may limit its widespread dissemination.

Implementing best practice pain management in a pediatric hospital.

PURPOSE: This study aims to evaluate the implementation of a comprehensive program to improve pain management practices in a pediatric hospital. METHODS: The pretest posttest design used questionnaires, patient record audits, and postimplementation focus groups with 366 nurses and 8 physicians. RESULTS: Positive changes occurred in the use of pain scales and in valuing good pain management. The program was less effective in improving procedural pain management and pain documentation. PRACTICE IMPLICATIONS: Important program strengths were the "local champions" (Pain Resource Nurses) and the ongoing support and expertise of the pain committee. Systematic evaluation was important to document successes as well as areas requiring further focus.