Immunological Mechanisms Mediating Hantavirus Persistence in Rodent Reservoirs

Hantaviruses, similar to several emerging zoonotic viruses, persistently infect their natural reservoir hosts, without causing overt signs of disease. Spillover to incidental human hosts results in morbidity and mortality mediated by excessive proinflammatory and cellular immune responses. The mechanisms mediating the persistence of hantaviruses and the absence of clinical symptoms in rodent reservoirs are only starting to be uncovered. Recent studies indicate that during hantavirus infection, proinflammatory and antiviral responses are reduced and regulatory responses are elevated at sites of increased virus replication in rodents. The recent discovery of structural and non-structural proteins that suppress type I interferon responses in humans suggests that immune responses in rodent hosts could be mediated directly by the virus. Alternatively, several host factors, including sex steroids, glucocorticoids, and genetic factors, are reported to alter host susceptibility and may contribute to persistence of hantaviruses in rodents. Humans and reservoir hosts differ in infection outcomes and in immune responses to hantavirus infection; thus, understanding the mechanisms mediating viral persistence and the absence of disease in rodents may provide insight into the prevention and treatment of disease in humans. Consideration of the coevolutionary mechanisms mediating hantaviral persistence and rodent host survival is providing insight into the mechanisms by which zoonotic viruses have remained in the environment for millions of years and continue to be transmitted to humans

Craving predicts opioid use in opioid-dependent patients initiating buprenorphine treatment: A longitudinal study

BackgroundFew studies have assessed associations between craving and subsequent opioid use. We prospectively evaluated the relative utility of two craving questionnaires to predict opioid use among opioid-dependent patients in outpatient treatment.MethodOpioid-dependent patients (n = 147) initiating buprenorphine treatment were assessed every two weeks for 3 months. Craving was measured using the: (1) Desires for Drug Questionnaire (DDQ) and (2) Penn Alcohol-Craving Scale adapted for opioid craving (PCS). Multi-level logistic regression models estimated the effects of craving on the likelihood of opioid use. Craving assessed at time t was entered as a time-varying predictor of opioid use at time t + 1.ResultsCraving scores plateaued at approximately 2 weeks after initiation of buprenorphine. In adjusted regression models, a 1-point increase in PCS scores (on a 7-point scale) was associated with a significant increase in the odds of opioid use at the subsequent assessment (OR = 1.27, 95% CI 1.08; 1.49, p < 0.01). The odds of opioid use at the subsequent follow-up assessment increased significantly as DDQ desire and intention scores increased (OR = 1.25, 95%CI 1.03; 1.51, p < 0.05), but was not significantly associated with DDQ negative reinforcement (OR = 1.01, 95%CI 0.88; 1.17, p > 0.05) or DDQ control (OR = 0.97, 95%CI 0.85; 1.11, p > 0.05) scores.ConclusionSelf-reported craving for opioids was modestly associated with subsequent relapse to opioid use among a cohort of patients treated with buprenorphine. Assessment of craving may provide clinical utility in predicting relapse among treated opioid-dependent patients

Welfare Receipt Trajectories of African-American Women Followed for 30 Years

Although there has been much discussion about the persistence of poverty and welfare receipt among child-rearing women in the US, little is known about long-term patterns of poverty and welfare receipt or what differentiates those who remain on welfare from those who do not. Furthermore, are there distinctions between child-rearing women who are poor but not on welfare from those who do receive welfare? This study examined trajectories of welfare receipt and poverty among African-American women (n = 680) followed from 1966 to 1997. A semiparametric group-based approach revealed four trajectories of welfare receipt: no welfare (64.2%), early leavers (12.7%), late leavers (10.1%), and persistent welfare recipients (10.1%). The “no welfare” group was further divided into a poverty group and a not poverty group to distinguish predictors of welfare from predictors of poverty. Multivariate analyses revealed differences in predictors of trajectory groups in terms of education, physical and psychological health, and social integration. In addition, earlier chronic illness and social integration were important predictors to differentiate between long-term users (i.e., late leavers, persistent recipients) and short-term users (i.e., early leavers). Trajectories did not differ in teenage motherhood, substance use, or family history of welfare receipt. Implications for public policy are discussed