The first decade of research advances in influenza D virus

From its initial isolation in the USA in 2011 to the present, influenza D virus (IDV) has been detected in cattle and swine populations worldwide. IDV has exceptional thermal and acid stability and a broad host range. The virus utilizes cattle as its natural reservoir and amplification host with periodic spillover to other mammalian species, including swine. IDV infection can cause mild to moderate respiratory illnesses in cattle and has been implicated as a contributor to bovine respiratory disease (BRD) complex, which is the most common and costly disease affecting the cattle industry. Bovine and swine IDV outbreaks continue to increase globally, and there is increasing evidence indicating that IDV may have the potential to infect humans. This review discusses recent advances in IDV biology and epidemiology, and summarizes our current understanding of IDV pathogenesis and zoonotic potential.

Citrus viroid V: Occurrence, Host Range, Diagnosis, and Identification of New Variants

The recently described Citrus viroid V (CVd-V) has been proposed as a new species of the genus Apscaviroid within the family Pospiviroidae. Analysis of 64 samples from different citrus-growing areas has shown that CVd-V is present in the United States, Spain, Nepal, and the Sultanate of Oman. CVd-V found in six sweet orange sources from the Sultanate of Oman was identical to the reference CVd-V variant, whereas three new variants with sequence identities of 98.6% (CVd-VCA), 97.3% (CVd-VST), and 94.9% (CVd-VNE) were identified in sources from California, Spain, and Nepal, respectively. These results suggest that this viroid has not emerged recently and that it is relatively widespread. Transmission assays to sweet orange, mandarin, and mandarin hybrids, clementine, satsuma, lemon, sour orange, Tahiti lime, Palestine sweet lime, calamondin, bergamot, and kumquat have shown that all these citrus species and citrus relatives are hosts for CVd-V. Several indexing approaches, including slot blot, northern blot hybridization, and reverse transcription-polymerase chain reaction, have been evaluated for detecting CVd-V, either using Etrog citron as an amplification host or directly from commercial species and cultivars.

Severe Acute Respiratory Syndrome Coronavirus as an Agent of Emerging and Reemerging Infection

SUMMARY Before the emergence of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) in 2003, only 12 other animal or human coronaviruses were known. The discovery of this virus was soon followed by the discovery of the civet and bat SARS-CoV and the human coronaviruses NL63 and HKU1. Surveillance of coronaviruses in many animal species has increased the number on the list of coronaviruses to at least 36. The explosive nature of the first SARS epidemic, the high mortality, its transient reemergence a year later, and economic disruptions led to a rush on research of the epidemiological, clinical, pathological, immunological, virological, and other basic scientific aspects of the virus and the disease. This research resulted in over 4,000 publications, only some of the most representative works of which could be reviewed in this article. The marked increase in the understanding of the virus and the disease within such a short time has allowed the development of diagnostic tests, animal models, antivirals, vaccines, and epidemiological and infection control measures, which could prove to be useful in randomized control trials if SARS should return. The findings that horseshoe bats are the natural reservoir for SARS-CoV-like virus and that civets are the amplification host highlight the importance of wildlife and biosecurity in farms and wet markets, which can serve as the source and amplification centers for emerging infections.