Volume 05 · Issue 02 · 2023

Infections by nonpolio enteroviruses (EVs) are highly prevalent, particularly among children and neonates, where they may cause substantial morbidity and mortality. Laboratory diagnosis of these viral infections is important in patient prognosis and guidance of clinical management. Although the laboratory diagnosis of non-polio EVs is mainly based on molecular techniques, classical virus-isolation techniques are still used in reference laboratories. Other techniques, such as antigen detection and serology, are becoming obsolete and rarely used in diagnosis. An important part of diagnosis and surveillance of EV infections is viral typing by VP1 gene sequencing using conventional Sanger technique and more recently, full-genome next-generation sequencing. The latter allows the typing of all EVs, better investigation of EV outbreaks, detection of coinfection, and identification of severity markers in the EV genome.

Human astrovirus (HAstV) is one of the main pathogens that cause sporadic cases of acute gastroenteritis, sometimes leading to outbreaks. This study aimed to elucidate the epidemiological and etiological characteristics of HAstV outbreaks worldwide. Literature on HAstV outbreaks published before January 2022 was retrieved from the China National Knowledge Infrastructure, WanFang, WeiPu, PubMed, and Web of Science databases. Date, region, population, settings, transmission modes, clinical symptoms, and etiological characteristics of the outbreaks were collected and analyzed. Thirty-one articles on 32 HAstV outbreaks reported between November 1978 and October 2018 were included. The outbreaks mainly occurred in autumn (14/32, 43.75%), and more of them were reported in 1996, 2004, and 2017. Outbreaks were primarily distributed in the Northern Hemisphere and mainly occurred in nursery centers and kindergartens (9/29, 31.03%), hospitals (5/29, 17.24%), and schools (4/29, 13.79%). Viral genotypes were identified during 19 outbreaks, and HAstV-1 was predominant (8/19, 42.10%). Eleven outbreaks were caused by mixed infection, and norovirus (9/11, 81.82%) and rotavirus (5/11, 45.45%) were the most common mixed pathogens. The transmission routes were reported in 9 outbreaks of mixed infection, and most (7/9) were related to waterborne and foodborne transmission. Although HAstV outbreaks are infrequently reported, it is necessary to consider HAstV in norovirus-negative gastroenteritis outbreaks. In addition, local Centers for Disease Control and Prevention should have the capacity to handle HAstV outbreaks and identify pathogens.

Mosquito-borne diseases, particularly dengue and chikungunya have become global threats, infecting millions of people worldwide, including developing countries of Southeast Asia and Latin America. Bangladesh, like many other developing countries, is experiencing frequent dengue outbreaks. This article, therefore, critically discussed the current status of dengue disease, vector control approaches, and the need for Wolbachia-mediated intervention in Bangladesh and other dengue-endemic developing countries. In this narrative review study, relevant literature was searched from major databases and search engines such as PubMed, BanglaJol, World Health Organization (WHO)/European Centre for Disease Prevention and Control (ECDC) and Google Scholar. Considering the selection criteria, our search strategies finally involved 55 related literature for further investigation. Findings showed that current vector control strategies could not render protection for an extended period, and the disease burden of arboviruses is increasing. The impoverished outbreak preparedness, urbanization, climate change, and less efficacy of existing control methods have made people susceptible to vector-borne diseases. Hence, Wolbachia, a naturally occurring endosymbiont of many mosquito species that can potentially limit virus transmission through several host genetic alterations, would be a potential alternative for dengue prevention. We also critically discussed the challenges and prospects of Wolbachia-based dengue control in developing countries. The evidence supporting the efficacy and safety of this intervention and its mechanism have also been elucidated. Empirical evidence suggests that this introgression method could be an eco-friendly and long-lasting dengue control method. This review would help the policymakers and health experts devise a scheme of Wolbachia-based dengue control that can control mosquito-borne diseases, particularly dengue in Bangladesh and other developing countries.

The coronavirus disease 2019 (COVID-19) pandemic had a devastating impact on human society. Beginning with genome surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the development of omics technologies brought a clearer understanding of the complex SARS-CoV-2 and COVID-19. Here, we reviewed how omics, including genomics, proteomics, single-cell multi-omics, and clinical phenomics, play roles in answering biological and clinical questions about COVID-19. Large-scale sequencing and advanced analysis methods facilitate COVID-19 discovery from virus evolution and severity risk prediction to potential treatment identification. Omics would indicate precise and globalized prevention and medicine for the COVID-19 pandemic under the utilization of big data capability and phenotypes refinement. Furthermore, decoding the evolution rule of SARS-CoV-2 by deep learning models is promising to forecast new variants and achieve more precise data to predict future pandemics and prevent them on time.

The recent outbreak of the coronavirus disease 2019 (COVID-19) pandemic and the continuous evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have highlighted the significance of new detection methods for global monitoring and prevention. Although quantitative reverse transcription PCR (RT-qPCR), the current gold standard for diagnosis, performs excellently in genetic testing, its multiplexing capability is limited because of the signal crosstalk of various fluorophores. Herein, we present a highly efficient platform which combines 17-plex assays with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), enabling the targeting of 14 different mutation sites of the spike gene. Diagnosis using a set of 324 nasopharyngeal swabs or sputum clinical samples with SARS-CoV-2 MS method was identical to that with the RT-qPCR. The detection consistency of mutation sites was 97.9% (47/48) compared to Sanger sequencing without cross-reaction with other respiratory-related pathogens. Therefore, the MS method is highly potent to track and assess SARS-CoV-2 changes in a timely manner, thereby aiding the continuous response to viral variation and prevention of further transmission.

Human enteroviruses (HEVs) include many different types that cause a wide range of diseases, and an effective method of genus-level identification has therefore significant clinical implications. However, quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), the gold-standard method, still has shortfalls in diagnostic sensitivity and timeliness. Here we established a one-step real-time reverse-transcription recombinase-aided PCR assay (RT-RAP) to detect HEV fragment within an hour. The RT-RAP assay showed a detection limit of 5 copies/μL using recombinant plasmids and was extensively verified using 15 HEV strains. Among 15 types of HEV (species A-C), the sensitivity of RT-RAP was approximately 2-8 folds lower than that of the qRT-PCR in 9 types, and no-cross reaction with other viruses was observed. RT-RAP was further applied to analyze CSF and fecal specimens; the clinical performance demonstrated that the RT-RAP and the commercial qRT-PCR kit provided consistent results. These results indicated that RT-RAP assay may be a promising approach for rapid and sensitive detection of HEV.

With continuous mutations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the severe immune escape of Omicron sub-variants urges the development of next-generation broad-spectrum vaccines, especially as booster jabs after high-level vaccination coverage of inactivated vaccines in China and many other countries. Previously, we developed a coronavirus disease 2019 (COVID-19) protein subunit vaccine ZF2001® based on the tandem homo-prototype receptor-binding domain (RBD)-dimer of the SARS-CoV-2 spike protein. We upgraded the antigen into a hetero-chimeric prototype (PT)-Beta or Delta-BA.1 RBD-dimer to broaden the cross-protection efficacy and prove its efficiency with protein subunit and mRNA vaccine platforms. Herein, we further explored the hetero-chimeric RBD-dimer mRNA vaccines and evaluated their broad-spectrum activities as booster jabs following two doses of inactivated vaccine (IV) in mice. Our data demonstrated that the chimeric vaccines significantly boosted neutralizing antibody levels and specific T-cell responses against the variants, and PT-Beta was superior to Delta-BA.1 RBD as a booster in mice, shedding light on the antigen design for the next-generation COVID-19 vaccines.

The vulnerability of healthcare and laboratory to potential infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has thus far been analyzed through the lens of the acute phase of the pandemic, including remote-based work, as well as emergency settings that are different from routine healthcare operations. However, as lockdowns ease and activities return to an identifiable pre-pandemic routine, the safety considerations also require to shift accordingly. As laboratory workers are likely to continue being exposed to unidentified SARS-CoV-2 positive samples through routine blood collection and processing operations, coronavirus disease 2019 (COVID-19) might have to be re-considered as an occupational disease within this context. Additionally, as per many such occupational diseases, a surveillance system is implemented for the medium- and long-term. This manuscript presents the views on the possible surveillance scenarios for laboratory staff, viewed from an immunological and biosafety perspective.

作者感到遗憾的是，附属机构“中华抗结核杂志”的邮政编码拼写错误。应更正为“100035”。