Avian influenza A(H5) virus circulation in live bird markets in Vietnam, 2017-2022.

BACKGROUND: Highly pathogenic avian influenza A(H5) human infections are a global concern, with many A(H5) human cases detected in Vietnam, including a case in October 2022. Using avian influenza virus surveillance from March 2017-September 2022, we described the percent of pooled samples that were positive for avian influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses in live bird markets (LBMs) in Vietnam. METHODS: Monthly at each LBM, 30 poultry oropharyngeal swab specimens and five environmental samples were collected. Samples were pooled in groups of five and tested for influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses by real-time reverse-transcription polymerase chain reaction. Trends in the percent of pooled samples that were positive for avian influenza were summarized by LBM characteristics and time and compared with the number of passively detected avian influenza outbreaks using Spearman's rank correlation. RESULTS: A total of 25,774 pooled samples were collected through active surveillance at 167 LBMs in 24 provinces; 36.9% of pooled samples were positive for influenza A, 3.6% A(H5), 1.9% A(H5N1), 1.1% A(H5N6), and 0.2% A(H5N8). Influenza A(H5) viruses were identified January-December and at least once in 91.7% of sampled provinces. In 246 A(H5) outbreaks in poultry; 20.3% were influenza A(H5N1), 60.2% A(H5N6), and 19.5% A(H5N8); outbreaks did not correlate with active surveillance. CONCLUSIONS: In Vietnam, influenza A(H5) viruses were detected by active surveillance in LBMs year-round and in most provinces sampled. In addition to outbreak reporting, active surveillance for A(H5) viruses in settings with high potential for animal-to-human spillover can provide situational awareness.

Measuring the impact of an integrated bite case management program on the detection of canine rabies cases in Vietnam.

Introduction: Dog-mediated rabies is enzootic in Vietnam, resulting in at least 70 reported human deaths and 500,000 human rabies exposures annually. In 2016, an integrated bite cases management (IBCM) based surveillance program was developed to improve knowledge of the dog-mediated rabies burden in Phu Tho Province of Vietnam. Methods: The Vietnam Animal Rabies Surveillance Program (VARSP) was established in four stages: (1) Laboratory development, (2) Training of community One Health workers, (3) Paper-based-reporting (VARSP 1.0), and (4) Electronic case reporting (VARSP 2.0). Investigation and diagnostic data collected from March 2016 to December 2019 were compared with historical records of animal rabies cases dating back to January 2012. A risk analysis was conducted to evaluate the probability of a rabies exposure resulting in death after a dog bite, based on data collected over the course of an IBCM investigation. Results: Prior to the implementation of VARSP, between 2012 and 2015, there was an average of one rabies investigation per year, resulting in two confirmed and two probable animal rabies cases. During the 46 months that VARSP was operational (2016 - 2019), 1048 animal investigations were conducted, which identified 79 (8%) laboratory-confirmed rabies cases and 233 (22%) clinically-confirmed(probable) cases. VARSP produced a 78-fold increase in annual animal rabies case detection (one cases detected per year pre-VARSP vs 78 cases per year under VARSP). The risk of succumbing to rabies for bite victims of apparently healthy dogs available for home quarantine, was three deaths for every 10,000 untreated exposures. Discussion: A pilot IBCM model used in Phu Tho Province showed promising results for improving rabies surveillance, with a 26-fold increase in annual case detection after implementation of a One Health model. The risk for a person bitten by an apparently healthy dog to develop rabies in the absence of rabies PEP was very low, which supports the WHO recommendations to delay PEP for this category of bite victims, when trained animal assessors are available and routinely communicate with the medical sector. Recent adoption of an electronic IBCM system is likely to expedite adoption of VARSP 2.0 to other Provinces and improve accuracy of field decisions and data collection.

Exogenous cross-linking increases the stability of spinal motion segments.

STUDY DESIGN: The mechanical stability of cross-linked and control spinal motion segments was evaluated using neutral zone, range of motion (ROM), and instability score metrics. OBJECTIVE: To determine if exogenous cross-linking could increase the stability of spinal motion segments. SUMMARY OF BACKGROUND DATA: The microstructure of the anulus fibrosus extracellular matrix can affect the stability of the intervertebral joint. Parallel testing in our laboratory has shown that exogenous cross-linking can improve the fatigue resistance of anulus fibrosus. METHODS: There were 3 separate experimental protocols conducted. The first study used calf lumbar intervertebral joints randomly divided into a genipin cross-linked group and phosphate buffered saline-soaked controls. After 2 days of soaking, flexion-extension ramp cycles were applied to the specimens. The second study repeated the test protocol using 22 moderately and severely degenerated human lumbar intervertebral joints. The third experiment compared the effect of cross-linking treatment on human discs with known degrees of preexisting mechanical instability. Each data set was used to assess joint instability by 3 calculations: ROM, neutral zone, and an instability score. Joint instability for each data set was evaluated using 3 calculations: ROM, neutral zone, and a novel instability score. RESULTS: These results show that cross-link augmentation can effectively reduce instability of intervertebral discs. The stabilizing effect was observed to be higher in the more mechanically unstable discs. However, cross-linking did not appear to affect the total range of sagittal motion. CONCLUSIONS: By reducing the neutral zone, exogenous cross-linking may help combat the progression of instability in degenerative disc disease.

Stability provided by the sternum and rib cage in the thoracic spine.

STUDY DESIGN: Multidirectional flexibility tests were conducted on 10 human thoracic spines with intact rib cage. OBJECTIVES: To determine the amount of stability the rib cage imparts to the thoracic spine and to show the amount of stability lost by a sternal fracture. SUMMARY OF BACKGROUND DATA: There is no published study of biomechanical testing of human cadaveric specimens with the rib cage intact. METHODS: In this study, 10 human cadaveric thoracic spines with the rib cage intact were tested using a biaxial material testing machine and an opto-electronic three-dimensional motion measuring device (Opto-trak 3020). The specimens were tested in axial compression, axial rotation, lateral bending, and flexion/extension. First, the specimens were tested through all four loading types with the sternum and rib cage intact. Next, the sternum was fractured at the sternomanubrial junction displacing the proximal fragment posteriorly. Lastly, the entire rib cage was removed. RESULTS: The rib cage increased the stability of the thoracic spine by 40% in flexion/extension (P = 0.012), 35% in lateral bending (P = 0.008), and 31% in axial rotation (P = 0.008). An indirect flexion-compression type of sternal fracture decreased the stability of the thoracic spine by 42% in flexion/extension (P = 0.036), 22% in lateral bending (P = 0.038), and 15% in axial rotation (P = 0.011). CONCLUSION: The rib cage significantly increases the stability of the thoracic spine in flexion/extension, lateral bending, and axial rotation. A sternal fracture significantly decreases the stability of the thorax.

Changes in abduction and rotation range of motion in response to simulated dorsal and ventral translational mobilization of the glenohumeral joint.

BACKGROUND AND PURPOSE: Translational mobilization techniques are frequently used by physical therapists as an intervention for patients with limited ranges of motion (ROMs). However, concrete experimental support for such practice is lacking. The purpose of the study was to evaluate the effect of simulated dorsal and ventral translational mobilization (DTM and VTM) of the glenohumeral joint on abduction and rotational ROMs. METHODS: Fourteen fresh frozen shoulder specimens from 5 men and 3 women (mean age=77.3 years, SD=10.1, range=62-91) were used for this study. Each specimen underwent 5 repetitions of DTM and VTM in the plane of scapula simulated by a material testing system (MTS) in the resting position (40 of abduction in neutral rotation) and at the end range of abduction with 100 N of force. Abduction and rotation were assessed as the main outcome measures before and after each mobilization procedure performed and monitored by the MTS (abduction, 4 N m) and by a servomotor attached to the piston of the actuator of the MTS (medial and lateral rotation, 2 N m). RESULTS: There were increases in abduction ROM for both DTM (mean=2.10 , SD=1.76 ) and VTM (mean=2.06 , SD=1.96 ) at the end-range position. No changes were found in the resting position following the same procedure. Small increases were also found in lateral rotation ROM after VTM in the resting position (mean=0.90 , SD=0.92 , t=3.65, P=.003) and in medial rotation ROM after DTM (mean=0.97 , SD=1.45 , t=2.51, P=.026) at the end range of abduction. DISCUSSION AND CONCLUSION: The results indicate that both DTM and VTM procedures applied at the end range of abduction improved glenohumeral abduction range of motion. Whether these changes would result in improved function could not be determined because of the use of a cadaver model.