Clinico-epidemiological presentations and management of Nipah virus infection during the outbreak in Kozhikode district, Kerala state, India 2023

India experienced its sixth Nipah virus (NiV) outbreak in September 2023 in the Kozhikode district of Kerala state. The NiV is primarily transmitted by spillover events from infected bats followed by human-to-human transmission. The clinical specimens were screened using real-time RT-PCR, and positive specimens were further characterized using next-generation sequencing. We describe here an in-depth clinical presentation and management of NiV-confirmed cases and outbreak containment activities. The current outbreak reported a total of six cases with two deaths, with a case fatality ratio of 33.33%. The cases had a mixed presentation of acute respiratory distress syndrome and encephalitis syndrome. Fever was a persistent presentation in all the cases. The Nipah viral RNA was detected in clinical specimens until the post-onset day of illness (POD) 14, with viral load in the range of 1.7-3.3 × 104 viral RNA copies/mL. The genomic analysis showed that the sequences from the current outbreak clustered into the Indian clade similar to the 2018 and 2019 outbreaks. This study highlights the vigilance of the health system to detect and effectively manage the clustering of cases with clinical presentations similar to NiV, which led to early detection and containment activities.

Practical biomechanical considerations for spine implant testing

The author presents the basic biomechanical concepts linked with spine implant testing. The paper also contains the methodology of in vitro and in vivo spine implant testing. The physical and biological properties of various materials and devices commonly used in spine surgery are discussed in relation to their role in spine surgery. The paper clearly shows how all these parameters influence surgical strategy for the spine and more importantly how the choice of methods and devices influences the long term results of spinal surgery. The author also presents the biomechanical repercussions of a failed spine and his own concept of an "ideal" fusion.

Substitution of transpedicular screws by hook claws in a vertebrectomy model

At times one pedicle screw cannot be used in a posterior construct because of morphometric reasons or when the pedicle is fractured intraoperatively. It is not clear from the literature whether and to what extent a construct's stability is compromised by substituting a hook claw for one pedicle screw. A synthetic vertebra model using a hook claw in lieu of a pedicle screw in a compressive and torsional mechanical study is evaluated. Isola screw-based constructs varying in the number of pedicle screws and hook claws were used. To recreate a realistic clinical scenario, transverse connectors and a Harms cage were used as well. In compression, substituting screws with claws did not substantially change the stiffness, whereas substituting one or two pedicle screws with one or two hook claws significantly reduced torsional stiffness. We conclude that using one or two hook claws is a viable alternative for pedicle screws when the latter cannot be used in a clinical situation, especially as an adjunct when the anterior column is reconstructed.