ABSTRACT
Varicella zoster is found exclusively in humans. Infected people with this virus result in chickenpox followed by dormant virus within neural ganglia. This dormant virus, once activated, may affect any ganglia or nerves of the body but most commonly involves the thoracic, cervical and trigeminal nerves in decreasing order of frequency. We review three such cases in which manipulation of the trigeminal ganglion resulted in reactivation of varicella at homologous operative sites. Each patient underwent surgeries in which the trigeminal ganglion was manipulated for the resection of trigeminal schwannoma under a microscope through various approaches. All three patients developed reactivation of varicella at homologous operative sites. A thorough history of chickenpox infection should be taken in patients who are undergoing surgeries for trigeminal pathology. Early diagnosis should be made once any vesicular lesions are seen with prompt treatment. Reassurance and counselling are necessary in these patients. If possible, prophylaxis may be started in all such patients. Further studies are warranted to determine the exact cause of reactivation.
ABSTRACT
A major bottleneck in scaling-up COVID-19 testing is the need for sophisticated instruments and well-trained healthcare professionals, which are already overwhelmed due to the pandemic. Moreover, the high-sensitive SARS-CoV-2 diagnostics are contingent on an RNA extraction step, which, in turn, is restricted by constraints in the supply chain. Here, we present CASSPIT (Cas13 Assisted Saliva-based & Smartphone Integrated Testing), which will allow direct use of saliva samples without the need for an extra RNA extraction step for SARS-CoV-2 detection. CASSPIT utilizes CRISPR-Cas13a based SARS-CoV-2 RNA detection, and lateral-flow assay (LFA) readout of the test results. The sample preparation workflow includes an optimized chemical treatment and heat inactivation method, which, when applied to COVID-19 clinical samples, showed a 97% positive agreement with the RNA extraction method. With CASSPIT, LFA based visual limit of detection (LoD) for a given SARS-CoV-2 RNA spiked into the saliva samples was ~200 copies; image analysis-based quantification further improved the analytical sensitivity to ~100 copies. Upon validation of clinical sensitivity on RNA extraction-free saliva samples (n = 76), a 98% agreement between the lateral-flow readout and RT-qPCR data was found (Ct<35). To enable user-friendly test results with provision for data storage and online consultation, we subsequently integrated lateral-flow strips with a smartphone application. We believe CASSPIT will eliminate our reliance on RT-qPCR by providing comparable sensitivity and will be a step toward establishing nucleic acid-based point-of-care (POC) testing for COVID-19.
