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HIV-associated neurocognitive disorders (HANDs) are prevalent in older people living with HIV (PLWH) worldwide. HAND prevalence and incidence studies of the newly emergent population of combination antiretroviral therapy (cART)-treated older PLWH in sub-Saharan Africa are currently lacking. We aimed to estimate HAND prevalence and incidence using robust measures in stable, cART-treated older adults under long-term follow-up in Tanzania and report cognitive comorbidities.
A systematic sample of consenting HIV-positive adults aged ≥50 years attending routine clinical care at an HIV Care and Treatment Centre during March–May 2016 and followed up March–May 2017.
HAND by consensus panel Frascati criteria based on detailed locally normed low-literacy neuropsychological battery, structured neuropsychiatric clinical assessment, and collateral history. Demographic and etiological factors by self-report and clinical records.
In this cohort (n = 253, 72.3% female, median age 57), HAND prevalence was 47.0% (95% CI 40.9–53.2, n = 119) despite well-managed HIV disease (Mn CD4 516 (98-1719), 95.5% on cART). Of these, 64 (25.3%) were asymptomatic neurocognitive impairment, 46 (18.2%) mild neurocognitive disorder, and 9 (3.6%) HIV-associated dementia. One-year incidence was high (37.2%, 95% CI 25.9 to 51.8), but some reversibility (17.6%, 95% CI 10.0–28.6 n = 16) was observed.
HAND appear highly prevalent in older PLWH in this setting, where demographic profile differs markedly to high-income cohorts, and comorbidities are frequent. Incidence and reversibility also appear high. Future studies should focus on etiologies and potentially reversible factors in this setting.
Background: The transmissibility of vaccine-strain viruses from immunocompromised patients, such as those with severe combined immune deficiency (SCID) is unknown. The infection control management of a patient diagnosed with SCID and infected with vaccine-strain varicella zoster virus (VZV) and measles virus is described below. A previously healthy, full-term boy was vaccinated at 14 months with measles mumps rubella varicella (MMR) vaccine. He had received prior vaccinations, including rotavirus, without adverse effects. During the 6 weeks after vaccination, the patient developed signs and symptoms clinically consistent with chicken pox and measles. An immune work-up revealed SCID. Methods: The Alberta Health Services (AHS) SCID protocol was followed to manage the patient upon admission at 17 months of age. Multiple meetings with various stakeholders were held to ensure appropriate precautions were followed to minimize the risk of pathogen transmission. Results: The patient was placed on airborne and contact precautions in a negative-pressure room. The pressure differential of the room to the corridor was continually monitored and displayed at the entry to the room. Staff known to be immune to VZV or measles were not required to wear an N95 respirator. All intrahospital movement of the patient was coordinated with the respective care teams and departments, including infection prevention and control, facilities maintenance and engineering, respiratory therapy, and diagnostic imaging. A mask was placed on the patient when movement outside the room was required. VZV testing was positive for the Oka/vaccine strain on all samples tested (ie, nasopharyngeal, skin, blood, and cerebrospinal fluid). Nasopharyngeal swabs and blood were PCR positive for measles genotype A/vaccine strain virus. Both viruses were persistently positive in spite of treatment with acyclovir, valganciclovir, varicella zoster immune globulin, and intravenous immune globulin. Conclusions: There is currently no documented transmission of measles vaccine-strain virus, and transmission of VZV vaccine-strain virus is rare. According to the AHS SCID protocol, the use of airborne and contact precautions for a patient identified with measles and/or VZV supersedes the use of a positive-pressure room for patients identified with SCID. Newborn screening for SCID was implemented in Alberta in June 2019. As a result, more SCID patients will be diagnosed earlier in their course, and therefore prior to most routine vaccinations. However, newborn screening will not pick up some types of combined immune deficiencies. Some children may still be at risk of vaccine-associated illnesses due to undiagnosed underlying immune deficiencies.
Hematology is the study of blood and bone marrow disorders. These conditions affect the structure, quantity, and/or function of the cellular and plasma components of blood and include inherited and acquired cytopenias/cytoses, coagulation/hemostatic and immune dysregulation disorders, and malignancies. Significant iatrogenic hematological effects can also result from various drug therapies commonly prescribed in the elderly.
The Brechin Lagerstätte of southern Ontario contains an exceptionally diverse and well-preserved Late Ordovician (Katian) crinoid fauna. We describe four genera and eight species of camerate crinoids from the Brechin Lagerstätte, including six new species. Consequently, the total diversity of the fauna now stands at 27 genera and 39 nominal species, thereby making it the most taxonomically diverse Ordovician crinoid fauna known. Taxa described include the diplobathrid Pararchaeocrinus kiddi new species and the monobathrids Glyptocrinus ramulosus Billings, 1856, Periglyptocrinus priscus (Billings, 1857a), Periglyptocrinus astricus new species, Periglyptocrinus kevinbretti new species, Periglyptocrinus mcdonaldi new species, Periglyptocrinus silvosus new species, and Abludoglyptocrinus steinheimerae new species. We summarize the taxonomic composition, diversity, and abundance distribution of all known crinoids from the Brechin Lagerstätte to better characterize the paleoecological structure and complexity of the community. We establish that the fauna is dominated by the subclass Pentacrinoidea, both in terms of abundance and species richness. In addition, we analyze species-level abundance data using Relative Abundance Distribution (RAD) models to evaluate the ecological complexity of the paleocommunity. We found that community structure of the Brechin Lagerstätte is best explained by an ecologically ‘complex’ RAD model, which suggests that species partitioned niches along multiple resource axes and/or the presence of multiple ecological ways of life. These results indicate that the Brechin Lagerstätte is significant not only for being the most taxonomically diverse Katian crinoid assemblage, but also for being an early ecologically complex fauna that developed in the wake of the Great Ordovician Biodiversification Event.
Research on autocratic regimes in comparative politics and international relations often uses categorical typologies of autocratic regimes to distinguish among different forms of autocracy. This paper introduces historical data on dozens of features of dictatorships to estimate latent dimensions of autocratic rule. We identify three time-varying dimensions of autocracy that correspond to ideal types proposed in the literature: party dominance, military rule, and personalism. We show that dimensions of autocratic rule are orthogonal to commonly-used measures of democracy–autocracy, and compare these dimensions to existing typologies of autocracies, showing that time-varying information on personalism is unique. We discuss a measurement model of personalism and illustrate the time-varying features of this measure in applied research on conflict initiation and regime collapse.
Because personalist dictators wreak havoc in their own countries, threaten neighbors, and set the stage for renewed dictatorship after they fall, the principal policy recommendation implied by our research is that international policy makers should avoid contributing to the personalization of dictatorial rule, even if security concerns suggest support. Dictators with unlimited policy discretion can switch sides easily and unpredictably, using the very weapons provided by their allies to turn against them. Decisions about economic and military intervention aimed at ending dangerous or abhorrent dictatorships should be informed by realistic assessments of whether the intervention is likely to succeed and what will happen if the dictator falls. After foreign intervention to oust a personalist dictator, the likelihood of democratization is not high. The more arbitrary, violent, and paranoid the personalist dictator, the more likely his overthrow will result in another autocracy, civil war, or a failed state. We suggest that personalist dictators who rely on narrow ethnic, clan, or religious groups for support are especially likely to experience bloody transitions and violent, unstable futures.
This chapter provides some basic facts about how dictatorships begin and who leads them. It also describes the immediate aftermath of different kinds of seizures of power. Most dictatorships replace earlier autocracies. The regimes they oust are often incompetent, dishonest, or both, as well as repressive. Since World War II, military coups have established more dictatorships than other means of seizing power. “Authoritarianization” by a democratically elected incumbent, insurgency, and foreign imposition are the other common ways of establishing dictatorship. Because of the difficulty and risk of trying to force out an incumbent government, groups that seek to do so focus their efforts on organizing the details of the physical overthrow, often at the expense of planning what to do post-seizure. The lack of detailed planning about what to do post-seizure tends to make the first months after forcible impositions of dictatorship chaotic. Power struggles occur between supporters of different policies and different potential leaders. It may take time for observers and even participants to figure out what kind of regime is being created.
Dictators who achieve power through force of arms face special difficulties in consolidating their rule because many of their supporters control sufficient weapons to oust them. Because of the ease of ouster, the dictator’s promises to share are credible, but his supporters’ promises of support if he shares may not be. When factions divide the seizure group, those included in the dictator’s inner circle cannot credibly commit their subordinates to support the dictator even if he shares power and spoils. Dissident factions may stage rogue coups. Consequently, power-sharing bargains between the dictator and his armed supporters cannot be maintained. Dictators in this situation often try to counterbalance their armed supporters with unarmed ones. To do this, they organize civilian support networks – parties. We show that factionalism within armed seizure groups increases the likelihood of post-seizure party creation. We also provide evidence that post-seizure party creation helps dictators to survive. Party creation protects dictators from coups, as would be expected if it were a strategy for reducing the dictator’s vulnerability to ousters launched by an unreliable military support base. It is associated with both longer dictator tenure and longer regime survival.