Differential Alphavirus Defective RNA Diversity between Intracellular and Extracellular Compartments Is Driven by Subgenomic Recombination Events.

Alphaviruses are positive-sense RNA arboviruses that can cause either a chronic arthritis or a potentially lethal encephalitis. Like other RNA viruses, alphaviruses produce truncated, defective viral RNAs featuring large deletions during replication. These defective RNAs (D-RNAs) have primarily been isolated from virions after high-multiplicity-of-infection passaging. Here, we aimed to characterize both intracellular and packaged viral D-RNA populations during early-passage infections under the hypothesis that D-RNAs arise de novo intracellularly that may not be packaged and thus have remained undetected. To this end, we generated next-generation sequencing libraries using RNA derived from passage 1 (P1) stock chikungunya virus (CHIKV) 181/clone 25, intracellular virus, and P2 virions and analyzed samples for D-RNA expression, followed by diversity and differential expression analyses. We found that the diversity of D-RNA species is significantly higher for intracellular D-RNA populations than P2 virions and that specific populations of D-RNAs are differentially expressed between intracellular and extracellular compartments. Importantly, these trends were likewise observed in a murine model of CHIKV AF15561 infection, as well as in vitro studies using related Mayaro, Sindbis, and Aura viruses. Additionally, we identified a novel subtype of subgenomic D-RNA that is conserved across arthritogenic alphaviruses. D-RNAs specific to intracellular populations were defined by recombination events specifically in the subgenomic region, which were confirmed by direct RNA nanopore sequencing of intracellular CHIKV RNAs. Together, these studies show that only a portion of D-RNAs generated intracellularly are packaged and D-RNAs readily arise de novo in the absence of transmitted template.IMPORTANCE Our understanding of viral defective RNAs (D-RNAs), or truncated viral genomes, comes largely from passaging studies in tissue culture under artificial conditions and/or packaged viral RNAs. Here, we show that specific populations of alphavirus D-RNAs arise de novo and that they are not packaged into virions, thus imposing a transmission bottleneck and impeding their prior detection. This raises important questions about the roles of D-RNAs, both in nature and in tissue culture, during viral infection and whether their influence is constrained by packaging requirements. Further, during the course of these studies, we found a novel type of alphavirus D-RNA that is enriched intracellularly; dubbed subgenomic D-RNAs (sgD-RNAs), they are defined by deletion boundaries between the capsid-E3 region and the E1-3' untranslated region (UTR) and are common to chikungunya, Mayaro, Sindbis, and Aura viruses. These sgD-RNAs are enriched intracellularly and do not appear to be selectively packaged, and additionally, they may exist as subgenome-derived transcripts.

Consumer-directed home care: client profiles and service challenges.

This article presents the results of a study that sought to develop a profile of potential consumer-directed clients in a countywide home care program. In order to develop this profile, clients were assessed by the telephone case manager and the in-home assessor, each of whom made an independent decision about the appropriate level of case management for the client. Of the 278 clients assessed, 16.5% were identified by both professionals as candidates for consumer-directed care; for another 42.1%, the case manager and assessor agreed that a more intense level of care was appropriate. For the remaining clients (41.4%), there was disagreement between the two assessments about the appropriate level of case management. Clients identified as consumer-directed candidates were more likely to be female, to have fewer impairments, to receive fewer services, to have low incomes, and to live alone. Case managers' and assessors' comments indicated that the consumer-directed group consisted of those more likely to have stable health and a good support system, along with an understanding of the service system and a willingness to make contacts in case of problems or status changes. The article also explores the implications for service providers.

Estimating the prevalence of long-term disability for an aging society.

Using information from two national data sets, this report provides projections of disability rates for the U.S. population age 65 and above. The research develops a series of projections based upon alternative sets of assumptions about mortality and disability. Using 1986 baseline disability data, estimates by single year of age are projected through the year 2040. The social policy implications of these projections are discussed in the final section.

Exploratory and problem-solving consumer behavior across the life span.

Different cognitive functioning, social, and personality changes appear to occur systematically during the adult life span. This article synthesizes research on life span changes in order to develop age-specific models of shopping behavior. The models are tested within a naturalistic field study of shoppers.