SARS-CoV-2 genomics and impact on clinical care for COVID-19.

The emergence and worldwide spread of SARS-CoV-2 during the COVID-19 pandemic necessitated the adaptation and rapid deployment of viral WGS and analysis techniques that had been previously applied on a more limited basis to other viral pathogens, such as HIV and influenza viruses. The need for WGS was driven in part by the low mutation rate of SARS-CoV-2, which necessitated measuring variation along the entire genome sequence to effectively differentiate lineages and characterize viral evolution. Several WGS approaches designed to maximize throughput and accuracy were quickly adopted by surveillance labs around the world. These broad-based SARS-CoV-2 genomic sequencing efforts revealed ongoing evolution of the virus, highlighted by the successive emergence of new viral variants throughout the course of the pandemic. These genomic insights were instrumental in characterizing the effects of viral mutations on transmissibility, immune escape and viral tropism, which in turn helped guide public health policy, the use of monoclonal antibody therapeutics and vaccine development strategies. As the use of direct-acting antivirals for the treatment of COVID-19 became more widespread, the potential for emergence of antiviral resistance has driven ongoing efforts to delineate resistance mutations and to monitor global sequence databases for their emergence. Given the critical role of viral genomics in the international effort to combat the COVID-19 pandemic, coordinated efforts should be made to expand global genomic surveillance capacity and infrastructure towards the anticipation and prevention of future pandemics.

Chikungunya, Dengue, and Zika in Immunocompromised Hosts.

PURPOSE OF REVIEW: Describe the characteristics of chikungunya, dengue, and Zika in transplant recipients and immunocompromised hosts. RECENT FINDINGS: Stem cell/bone marrow grafts, organs, and blood transfusions can transmit CHIKV/DENV/ZIKV infections, which are clinically similar, resembling influenza-like illness. Laboratory confirmation is necessary. In the acute phase, RT-PCR is preferred. DENV and ZIKV serology may cross-react. Delayed engraftment and extended viruria is observed in ZIKV+/HSCT recipients, while longer viremia is observed in DENV+/HSCT patients. Arbovirus persistence in organ tissues is generally unknown. Vaccine development is in early stages for CHIKV/ZIKV. No data is available to recommend the licensed DENV vaccine in transplant recipients. In endemic areas, the assessment of epidemiological risk is mandatory. Donor deferral for 120 days in suspected or confirmed ZIKV+ has been recommended, while CHIKV+ donors should wait 30 days. No deferral is recommended for DENV+ donors. CHIKV/DENV/ZIKV tests should be included in the differential of febrile neutropenia and other transplant syndromes. Reassessment of DENV serology is urgently needed. Prospective studies are necessary to determine the impact of CHIKV/DENV/ZIKV in this special population.

Adolescent pre-exposure prophylaxis for HIV prevention: current perspectives.

Adolescents are a critical population that is disproportionately impacted by the HIV epidemic. More than 2 million adolescents between the age group of 10 and 19 years are living with HIV, and millions are at risk of infection. HIV risks are considerably higher among girls, especially in high-prevalence settings such as eastern and southern Africa. In addition to girls, there are other vulnerable adolescent subgroups, such as teenagers, who use intravenous (IV) drugs, gay and bisexual boys, transgender youth, male sex workers, and people who fall into more than one of these categories. Pre-exposure prophylaxis (PrEP) is a new intervention for people at high risk for acquiring HIV, with an estimated HIV incidence of >3%. Recent data from trials show evidence of the efficacy of PrEP as a powerful HIV prevention tool in high-risk populations, including men who have sex with men, HIV-1-serodiscordant heterosexual couples, and IV drug users. The reported efficacy in those trials of the daily use of oral tenofovir, alone or in combination with emtricitabine, to prevent HIV infection ranged from 44% to 75% and was heavily dependent on adherence. Despite the proven efficacy of PrEP in adult trials, concerns remain about its feasibility in real-life scenarios due to stigma, cost, and limited clinician experience with PrEP delivery. Recent studies are attempting to expand the inquiry into the efficacy of such HIV prophylaxis approaches in adolescent populations, but there are still many gaps in knowledge, and no country has yet approved it for use with adolescents. The aim of this review was to identify and summarize the evidence from studies on PrEP for adolescents. We have compiled and reviewed published studies focusing on safety, feasibility, adherence to therapeutics, self-perception, and legal issues related to PrEP in people aged between 10 and 24 years.