COVID-19 is a disease caused by SARS-CoV-2 capable of causing mild to severe infections in humans. Since its first appearance in China in December 2019, the pandemic has spread rapidly throughout the world. Despite considerable efforts made to contain the disease, the virus has continued its prevalence in many countries with varying degrees of clinical manifestations. To contain this pandemic, collaborative approach involving accurate diagnosis, epidemiology, surveillance, and prophylaxis is essential. However, proper diagnosis using rapid technologies plays a crucial role. With increasing incidence of COVID-19 cases, the accurate and early detection of the SARS-CoV-2 is need of the hour for effective prevention and management of COVID-19 cases as well as to curb its spread. RT-qPCR assay is considered to be the gold standard for the early detection of virus, but this protocol has limited application to use as bedside test because of its technical complexity. To address these challenges, several POC assays have been developed to facilitate the COVID-19 diagnosis outside the centralized testing laboratories as well to accelerate the clinical decision making with a least turnaround time. Hence, in this report, we review different nucleic acid-based and serological techniques available for the diagnosis and effective prevention of COVID-19. Key points • Provides comprehensive information on the different diagnostic tools available for COVID-19 • Nucleic acid based tests or antigen detection tests are used for diagnostic purpose • Accurate diagnosis is essential for the efficient management of COVID-19

Vibrio parahaemolyticus has caused widespread mortality in Indian shrimp aquaculture in recent years. However, there are insufficient genome data for the isolates from Indian shrimp vibriosis to analyze genetic diversity and track the acquisition of genetic features that could be involved in virulence and fitness. In this study, we have performed genome analysis of V. parahaemolyticus isolated from moribund shrimps collected from shrimp farms along coastal Karnataka, India, for better understanding of their diversity and virulence. Five newly sequenced genomes of V. parahaemolyticus along with 40 genomes retrieved from NCBI were subjected to comparative genome analysis. The sequenced genomes had an overall genome size of 5.2 Mb. MLST analysis and core genome phylogenomic analysis revealed considerable genetic diversity among the isolates obtained from the moribund shrimps. Interestingly, none of the V. parahaemolyticus isolates possessed the classical features (PirAB) of the strains associated with Acute Hepatopancreatic Necrosis Disease (AHPND). This study also revealed the presence of multiple virulence attributes, including ZOT, ACE and RTX toxins, secretion systems, and mobile genetic elements. The findings of this study provide insights into the possible transition of an environmental V. parahaemolyticus to emerge as pathogens of aquaculture species by increasing its virulence and host adaptation. Future studies focusing on continuous genomic surveillance of V. parahaemolyticus are required to study the evolution and transmission of new variants in shrimp aquaculture, as well as to design and implement biosecurity programs to prevent disease outbreaks.

Summary: The coronavirus disease 2019 (COVID‐19) is a global pandemic caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). To date, the virus has been detected in 219 countries of the world. Therefore, managing the disease becomes the priority, in which detecting the presence of the virus is a crucial step. Presently, real‐time RT polymerase chain reaction (RT‐qPCR) is considered a gold standard nucleic acid amplification test (NAAT). The test protocol of RT‐qPCR is complicated, places high demands on equipment, testing reagents, research personnel skills and is expensive. Therefore, simpler point‐of‐care (POC) tests are needed to accelerate clinical decision‐making and take some of the workload from centralized test laboratories. Various isothermal amplification‐based assays have been developed for the sensitive detection of different microorganisms, and recently some of them have been applied for detection of SARS‐CoV‐2. These do not require any programable thermocycler, can produce the results in a single temperature, and therefore, are considered simple. Unlike RT‐qPCR, these methods are highly sensitive, specific, less time‐consuming, simple and affordable, and can be used as POC diagnostic kit for COVID‐19. In this review, we have discussed the potential of isothermal amplification‐based assays as an alternative to RT‐qPCR for the detection of SARS‐CoV‐2.