Evaluating Temperature Effects on Bluetongue Virus Serotype 10 and 17 Coinfection in Culicoides sonorensis.

Bluetongue virus (BTV) is a segmented, double-stranded RNA virus transmitted by Culicoides midges that infects ruminants. As global temperatures increase and geographical ranges of midges expand, there is increased potential for BTV outbreaks from incursions of novel serotypes into endemic regions. However, an understanding of the effect of temperature on reassortment is lacking. The objectives of this study were to compare how temperature affected Culicoides survival, virogenesis, and reassortment in Culicoides sonorensis coinfected with two BTV serotypes. Midges were fed blood meals containing BTV-10, BTV-17, or BTV serotype 10 and 17 and maintained at 20 °C, 25 °C, or 30 °C. Midge survival was assessed, and pools of midges were collected every other day to evaluate virogenesis of BTV via qRT-PCR. Additional pools of coinfected midges were collected for BTV plaque isolation. The genotypes of plaques were determined using next-generation sequencing. Warmer temperatures impacted traits related to vector competence in offsetting ways: BTV replicated faster in midges at warmer temperatures, but midges did not survive as long. Overall, plaques with BTV-17 genotype dominated, but BTV-10 was detected in some plaques, suggesting parental strain fitness may play a role in reassortment outcomes. Temperature adds an important dimension to host-pathogen interactions with implications for transmission and evolution.

Assessing Reassortment between Bluetongue Virus Serotypes 10 and 17 at Different Coinfection Ratios in Culicoides sonorenesis.

Bluetongue virus (BTV) is a segmented, double-stranded RNA orbivirus listed by the World Organization for Animal Health and transmitted by Culicoides biting midges. Segmented viruses can reassort, which facilitates rapid and important genotypic changes. Our study evaluated reassortment in Culicoides sonorensis midges coinfected with different ratios of BTV-10 and BTV-17. Midges were fed blood containing BTV-10, BTV-17, or a combination of both serotypes at 90:10, 75:25, 50:50, 25:75, or 10:90 ratios. Midges were collected every other day and tested for infection using pan BTV and cox1 (housekeeping gene) qRT-PCR. A curve was fit to the ∆Ct values (pan BTV Ct-cox1 Ct) for each experimental group. On day 10, the midges were processed for BTV plaque isolation. Genotypes of the plaques were determined by next-generation sequencing. Pairwise comparison of ∆Ct curves demonstrated no differences in viral RNA levels between coinfected treatment groups. Plaque genotyping indicated that most plaques fully aligned with one of the parental strains; however, reassortants were detected, and in the 75:25 pool, most plaques were reassortant. Reassortant prevalence may be maximized upon the occurrence of reassortant genotypes that can outcompete the parental genotypes. BTV reassortment and resulting biological consequences are important elements to understanding orbivirus emergence and evolution.

SARS-CoV-2 surveillance in a veterinary health system provides insight into transmission risks.

OBJECTIVE: To investigate the prevalence and seropositivity of SARS-CoV-2 in companion and exotic animals in a veterinary healthcare system. SAMPLE: A total of 341 animals were sampled by a combination of oral and nasal swabs. Serum from whole blood was collected from a subset of animals (86 canines, 25 felines, and 6 exotic animals). METHODS: After informed owner consent, convenience samples from client-owned animals and the pets of students and staff members associated with Colorado State University's Veterinary Health System were collected between May 2021 and September 2022. Study samples were collected by trained veterinarians, Veterinary Health System staff, and veterinary students. RESULTS: SARS-CoV-2 RNA was detected by reverse transcription PCR in 1.6% (95% CI, 0.5% to 4.6%) of domestic canines and 1.1% (95% CI, 0.2% to 6.1%) of domestic felines. No RNA was detected in any of the exotic animal species tested (n = 66). Plaque reduction neutralization tests indicated that 12.8% (95% CI, 7.3% to 21.5%) of canines and 12.0% (95% CI, 4.2% to 30.0%) of felines had neutralizing antibodies against SARS-CoV-2. CLINICAL RELEVANCE: This study provides insight regarding SARS-CoV-2 spillover in domestic companion and exotic animals and contributes to our understanding of transmission risk in the veterinary setting.

In Situ Hybridization (RNAscope) Detection of Bluetongue Virus Serotypes 10 and 17 in Experimentally Co-Infected Culicoides sonorensis.

Bluetongue virus (BTV) is a segmented, double-stranded RNA virus transmitted by Culicoides biting midges. Infection of domestic and wild ruminants with BTV can result in a devastating disease and significant economic losses. As a virus with a segmented genome, reassortment among the BTV serotypes that have co-infected a host may increase genetic diversity, which can alter BTV transmission dynamics and generate epizootic events. The objective of this study was to determine the extent of dissemination and characterize the tropism of BTV serotypes 10 and 17 in co-infected Culicoides sonorensis. Midges were exposed to both BTV serotypes via blood meal and processed for histologic slides 10 days after infection. An in situ hybridization approach was employed using the RNAscope platform to detect the nucleic acid segment 2 of both serotypes. Observations of the mosaic patterns in which serotypes did not often overlap suggest that co-infection at the cellular level may not be abundant with these two serotypes in C. sonorensis. This could be a consequence of superinfection exclusion. Understanding BTV co-infection and its biological consequences will add an important dimension to the modeling of viral evolution and emergence.

Monitoring longitudinal immunological responses to bluetongue virus 17 in experimentally infected sheep.

Bluetongue virus (BTV) is an economically important pathogen of ruminant species with worldwide prevalence. While many BTV infections are asymptomatic, animals with symptomatic presentation deteriorate quickly with the sickest succumbing to disease within one week. Animals that survive the infection often require months to recover. The immune response to BTV infection is thought to play a central role in controlling the disease. Key to understanding BTV disease is profiling vertebrate host immunological cellular and cytokine responses. Studies to characterize immune responses in ruminants have been limited by a lack of species-specific reagents and assay technology. Here we assess the longitudinal immunological response to experimental BTV-17-California (CA) infection in sheep using the most up to date assays. We infected a cohort of sheep with BTV-17-CA and longitudinally monitored each animal for clinical disease, viremia and specific immunological parameters (B cells, T cells, monocytes) by RT-qPCR, traditional flow cytometry and/or fluorescent based antibody arrays. BTV-inoculated sheep exhibited clinical signs characteristic of bluetongue virus disease. Circulating virus was demonstrated after 8 days post inoculation (DPI) and remained detectable for the remainder of the time course (24 DPI). A distinct lymphopenia was observed between 7 and 14 DPI that rebounded to mock-inoculated control levels at 17 DPI. In addition, we observed increased expression of pro-inflammatory cytokines after 8 DPI. Taken together, we have established a model of BTV infection in sheep and have successfully monitored the longitudinal vertebrate host immunological response and viral infection progression using a combination of traditional methods and cutting-edge technology.

Receipt of First and Second Doses of JYNNEOS Vaccine for Prevention of Monkeypox - United States, May 22-October 10, 2022.

Vaccination with JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) to prevent monkeypox commenced shortly after confirmation of the first monkeypox case in the current outbreak in the United States on May 17, 2022 (1). To date, more than 27,000 cases have been reported across all 50 states, the District of Columbia (DC), and Puerto Rico.* JYNNEOS vaccine is licensed by the Food and Drug Administration (FDA) as a 0.5-mL 2-dose series administered subcutaneously 28 days apart to prevent smallpox and monkeypox infections (2) and has been found to provide protection against monkeypox infection during the current outbreak (3). The U.S. Department of Health and Human Services (HHS) allocated 1.1 million vials of JYNNEOS vaccine from the Strategic National Stockpile, with doses allocated to jurisdictions based on case counts and estimated size of population at risk (4). However, initial vaccine supplies were severely constrained relative to vaccine demand during the expanding outbreak. Some jurisdictions with highest incidence responded by prioritizing first dose administration during May-July (5,6). The FDA emergency use authorization (EUA) of 0.1 mL dosing for intradermal administration of JYNNEOS for persons aged ≥18 years on August 9, 2022, substantially expanded available vaccine supply† (7). The U.S. vaccination strategy focuses primarily on persons with known or presumed exposures to monkeypox (8) or those at high risk for occupational exposure (9). Data on monkeypox vaccine doses administered and reported to CDC by U.S. jurisdictions were analyzed to assess vaccine administration and completion of the 2-dose series. A total of 931,155 doses of JYNNEOS vaccine were administered and reported to the CDC by 55 U.S. jurisdictions during May 22-October 10, 2022. Among persons who received ≥1 dose, 51.4% were non-Hispanic White (White), 22.5% were Hispanic or Latino (Hispanic), and 12.6% were non-Hispanic Black or African American (Black). The percentages of vaccine recipients who were Black (5.6%) and Hispanic (15.5%) during May 22-June 25 increased to 13.3% and 22.7%, respectively, during July 31-October 10. Among 496,888 persons who received a first dose and were eligible for a second dose during the study period, 57.6% received their second dose. Second dose receipt was highest among older adults, White persons, and those residing in the South U.S. Census Bureau Region. Tracking and addressing disparities in vaccination can reduce inequities, and equitable access to and acceptance of vaccine should be an essential factor in planning vaccination programs, events, and strategies. Receipt of both first and second doses is necessary for optimal protection against Monkeypox virus infection.

Bluetongue Research at a Crossroads: Modern Genomics Tools Can Pave the Way to New Insights.

Bluetongue virus (BTV) is an arthropod-borne, segmented double-stranded RNA virus that can cause severe disease in both wild and domestic ruminants. BTV evolves via several key mechanisms, including the accumulation of mutations over time and the reassortment of genome segments.Additionally, BTV must maintain fitness in two disparate hosts, the insect vector and the ruminant. The specific features of viral adaptation in each host that permit host-switching are poorly characterized. Limited field studies and experimental work have alluded to the presence of these phenomena at work, but our understanding of the factors that drive or constrain BTV's genetic diversification remains incomplete. Current research leveraging novel approaches and whole genome sequencing applications promises to improve our understanding of BTV's evolution, ultimately contributing to the development of better predictive models and management strategies to reduce future impacts of bluetongue epizootics.

COVID-19 Vaccination Coverage Among Adolescents Aged 12-17 Years - United States, December 14, 2020-July 31, 2021.

Although severe COVID-19 illness and hospitalization are more common among adults, these outcomes can occur in adolescents (1). Nearly one third of adolescents aged 12-17 years hospitalized with COVID-19 during March 2020-April 2021 required intensive care, and 5% of those hospitalized required endotracheal intubation and mechanical ventilation (2). On December 11, 2020, the Food and Drug Administration (FDA) issued Emergency Use Authorization (EUA) of the Pfizer-BioNTech COVID-19 vaccine for adolescents aged 16-17 years; on May 10, 2021, the EUA was expanded to include adolescents aged 12-15 years; and on August 23, 2021, FDA granted approval of the vaccine for persons aged ≥16 years. To assess progress in adolescent COVID-19 vaccination in the United States, CDC assessed coverage with ≥1 dose* and completion of the 2-dose vaccination series† among adolescents aged 12-17 years using vaccine administration data for 49 U.S. states (all except Idaho) and the District of Columbia (DC) during December 14, 2020-July 31, 2021. As of July 31, 2021, COVID-19 vaccination coverage among U.S. adolescents aged 12-17 years was 42.4% for ≥1 dose and 31.9% for series completion. Vaccination coverage with ≥1 dose varied by state (range = 20.2% [Mississippi] to 70.1% [Vermont]) and for series completion (range = 10.7% [Mississippi] to 60.3% [Vermont]). By age group, 36.0%, 40.9%, and 50.6% of adolescents aged 12-13, 14-15, and 16-17 years, respectively, received ≥1 dose; 25.4%, 30.5%, and 40.3%, respectively, completed the vaccine series. Improving vaccination coverage and implementing COVID-19 prevention strategies are crucial to reduce COVID-19-associated morbidity and mortality among adolescents and to facilitate safer reopening of schools for in-person learning.

Ecological Dynamics Impacting Bluetongue Virus Transmission in North America.

Bluetongue virus (BTV) is an arbovirus transmitted to domestic and wild ruminants by certain species of Culicoides midges. The disease resulting from infection with BTV is economically important and can influence international trade and movement of livestock, the economics of livestock production, and animal welfare. Recent changes in the epidemiology of Culicoides-transmitted viruses, notably the emergence of exotic BTV genotypes in Europe, have demonstrated the devastating economic consequences of BTV epizootics and the complex nature of transmission across host-vector landscapes. Incursions of novel BTV serotypes into historically enzootic countries or regions, including the southeastern United States (US), Israel, Australia, and South America, have also occurred, suggesting diverse pathways for the transmission of these viruses. The abundance of BTV strains and multiple reassortant viruses circulating in Europe and the US in recent years demonstrates considerable genetic diversity of BTV strains and implies a history of reassortment events within the respective regions. While a great deal of emphasis is rightly placed on understanding the epidemiology and emergence of BTV beyond its natural ecosystem, the ecological contexts in which BTV maintains an enzootic cycle may also be of great significance. This review focuses on describing our current knowledge of ecological factors driving BTV transmission in North America. Information presented in this review can help inform future studies that may elucidate factors that are relevant to longstanding and emerging challenges associated with prevention of this disease.

Restaurant Characteristics Associated With the Use of Specific Food-Cooling Methods.

Pathogen growth caused by improper or slow cooling of hot foods was a contributing factor in 504 of restaurant- and deli-related outbreaks in the U.S. from 1998-2008. Little is known, however, about restaurant cooling practices. To fill this gap, the Centers for Disease Control and Prevention's Environmental Health Specialists Network (EHS-Net) conducted an observational study to identify and understand factors that might determine which methods restaurants follow to rapidly cool food. These methods include refrigerating food at ≤41 °F, at shallow depths, and in containers that are ventilated, unstacked, and have space around them. EHS-Net personnel collected data through manager interviews and observation of cooling processes in 420 randomly selected restaurants. Regression analyses revealed characteristics of restaurants most likely to use the cooling methods assessed. These characteristics included ownership by restaurant chains, manager food safety training and certification, few foods cooled at a time, many meals served daily, and a high ratio of workers to managers. These findings suggest that regulatory food safety programs and the retail industry might improve cooling methods-and reduce outbreaks-by providing and encouraging manager food safety training and certification, and by focusing intervention efforts on independent and smaller restaurants.

Foodborne Illness Outbreaks at Retail Establishments - National Environmental Assessment Reporting System, 16 State and Local Health Departments, 2014-2016.

PROBLEM/CONDITION: State and local public health departments report hundreds of foodborne illness outbreaks each year to CDC and are primarily responsible for investigations of these outbreaks. Typically, investigations involve epidemiology, laboratory, and environmental health components. Health departments voluntarily report epidemiologic and laboratory data from their foodborne illness outbreak investigations to CDC through the Foodborne Disease Outbreak Surveillance System (FDOSS); however, minimal environmental health data from outbreak investigations are reported to FDOSS. PERIOD COVERED: 2014-2016. DESCRIPTION OF SYSTEM: In 2014, CDC launched the National Environmental Assessment Reporting System (NEARS) to complement FDOSS surveillance and to use these data to enhance prevention efforts. State and local health departments voluntarily report data from their foodborne illness outbreak investigations of retail food establishments. These data include characteristics of foodborne illness outbreaks (e.g., agent), characteristics of establishments with outbreaks (e.g., number of meals served daily), food safety policies and practices of these establishments (e.g., glove use policies), and characteristics of outbreak investigations (e.g., timeliness of investigation activities). NEARS is the only available data source that includes characteristics of retail establishments with foodborne illness outbreaks. RESULTS: During 2014-2016, a total of 16 state and local public health departments reported data to NEARS on 404 foodborne illness outbreaks at retail establishments. The majority of outbreaks with a suspected or confirmed agent were caused by norovirus (61.1%). The majority of outbreaks with identified contributing factors had at least one factor associated with food contamination by a worker who was ill or infectious (58.6%). Almost half (47.4%) of establishments with outbreaks had a written policy excluding ill workers from handling food or working. Approximately one third (27.7%) had a written disposable glove use policy. Paid sick leave was available for at least one worker in 38.3% of establishments. For most establishments with outbreaks (68.7%), environmental health investigators initiated their component of the investigation soon after learning about the outbreak (i.e., the same day) and completed their component in one or two visits to the establishment (75.0%). However, in certain instances, contacting the establishment and completing the environmental health component of the investigation occurred much later (>8 days). INTERPRETATION: Most outbreaks reported to NEARS were caused by norovirus, and contamination of food by workers who were ill or infectious contributed to more than half of outbreaks with contributing factors; these findings are consistent with findings from other national outbreak data sets and highlight the role of workers in foodborne illness outbreaks. The relative lack of written policies for ill workers and glove use and paid sick leave for workers in establishments with outbreaks indicates gaps in food safety practices that might have a role in outbreak prevention. The environmental health component of the investigation for most outbreaks was initiated quickly, yet the longer initiation timeframe for certain outbreaks suggests the need for improvement. PUBLIC HEALTH ACTION: Retail establishments can reduce viral foodborne illness outbreaks by protecting food from contamination through proper hand hygiene and excluding workers who are ill or infectious from working. NEARS data can help prioritize training and interventions for state and local food safety programs and the retail food establishment industry by identifying gaps in food safety policies and practices and types of establishments vulnerable to outbreaks. Improvement of certain outbreak investigation practices (e.g., delayed initiation of environmental health investigations) can accelerate identification of the agent and implementation of interventions. Future analysis comparing establishments with and without outbreaks will contribute knowledge about how establishments' characteristics and food safety policies and practices relate to foodborne illness outbreaks and provide information to develop effective prevention approaches.