Microscopic Effects of Predator Digestion on the Surfaces of Bones and Teeth

Concentrations of small fossil mammals are frequently encountered in Cenozoic deposits, but the causes for such accumulations have seldom been determined. In many cases the tooth, jaw, and limb fragments appear to be well-preserved under light microscopy, and it is difficult to differentiate damage due to predator digestion from breakage and abrasion due to physical agents. In order to find more specific evidence of predator digestion, we used a scanning electron microscope (SEM) to examine the surface microstructure of bones and teeth consumed by Bubo virginianus (great horned owl) and Canis latrans (coyote), which prey upon similar species. Effects of digestion were found on all the digested bones and teeth examined. The effects on bone include distinctive sets of pits and fissures, dissolution, and physical polishing. The pits and fissures are apparently caused by solution that commences in canals beneath the surf ace of the bone. The most conspicuous effects on teeth are island-like pillars of dentin surrounded by deep solution fissures. The effects of digestion by coyote and owl are fundamentally the same but differ in degree of development. Bone digested by the owl shows a greater degree of polishing and rounding of edges but has less extensive fissuring. Wide variation in the degree of surface damage occurs in bones digested by the coyote, even within a single fecal pellet

The Direct Medical Costs of Late Presentation (<350/mm3) of HIV Infection over a 15-Year Period

We describe the immediate- and longer-term direct medical costs of care for individuals diagnosed with HIV at CD4 counts <350/mm3 (“late presenters”). We collected and stratified by initial CD4 count all inpatient, outpatient, and drug costs for all newly diagnosed patients accessing HIV care within Southern Alberta from 1/1/1995 to 1/1/2010. 59% of new patients were late presenters. We found significantly higher costs for late presenters, especially inpatient costs, during the first year after accessing care. Direct medical costs remained almost twice as high for late presenters in subsequent years compared to patients presenting with CD4 counts >350/mm3 despite significantly their improved CD4 counts. The sustained high cost for late presenters has implications for recent recommendations for wider routine HIV testing and the earlier initiation of cART. Earlier diagnosis and treatment, while increasing the immediate expenditures within a population, may produce both direct and indirect cost savings in the longer term

Impact of Practice Changes on an Antiretroviral Budget in an HIV Care Program

Background: Antiretroviral (ARV) drugs account for >70% of the direct costs of HIV care. Changing practices in the use of ARV drugs may have major cost implications for the care budget within a regional population. Objective: To characterize and quantify the precise changes in the use of ARV within an entire HIV-infected population and to develop an approach to monitor the cost impact of future changes on the ARV budget. Design, Setting, and Participants: Socio-demographic, clinical, and primary-costing data were obtained from all 1218 HIV-positive patients receiving HIV care and living within southern Alberta, Canada between 1995 and 2003. Main Outcome Measures: Mean per patient per month (PPPM) costs in $Can (2003 values) were used for the basis of comparison. Actual and predicted changes in costs are presented as percentage changes. Results: After increasing 226% between 1996 and 1998, total PPPM ARV costs climbed only 6.7% from 1998 and 2003. Four counterbalancing forces contributed to this relative stabilization in costs: (i) the increased use of four or more ARV drugs to treat resistant HIV; (ii) the use of newer, more expensive ARV drugs (both [i] and [ii] increased total ARV costs by 22%); (iii) a delay in initiating ARV therapy to a lower CD4 count threshold; and (iv) the increased use of treatment interruptions (both [iii] and [iv] decreased total ARV costs by 15.3%). Increased or decreased use of these practices differentially affected mean ARV costs by 5-25% or more. Conclusions: Changing medical practices in terms of ARV use may have a major impact on the ARV budget. Detailed knowledge of both the entire HIV population being served, along with comprehensive information on current and planned changes in ARV use are essential for projecting both immediate and longer term funding.Antiretrovirals, General-practice, HIV-infections, Non-nucleoside-reverse-transcriptase-inhibitors, Peptide-hydrolase-inhibitors

Increasing incidence of syphilis among patients engaged in HIV care in Alberta, Canada: a retrospective clinic-based cohort study

Abstract Background Syphilis is a global health concern disproportionately affecting HIV-infected populations. In Alberta, Canada, the incidence of syphilis in the general population has recently doubled with 25% of these infections occurring in HIV-infected patients. The Southern Alberta HIV Clinic (SAC) and Calgary STI Program (CSTI) analyzed the epidemiologic characteristics of incident syphilis infections in our well-defined, HIV-infected population over 11 years. Methods Since 2006, as routine practice of both the Southern Alberta Clinic (SAC) and Calgary STI Programs (CSTI), syphilis screening has accompanied HIV viral load measures every four months. All records of patients who, while in HIV care, either converted from being syphilis seronegative to a confirmed seropositive or were re-infected as evidenced by a four-fold increase in rapid plasma reagin (RPR) after past successful treatment, were reviewed. Results Incident syphilis was identified 249 times in 194 HIV-infected individuals. There were 36 individuals with repeated infections (28.5% of episodes). Following a prior decline in annual incident syphilis rates, the rates have tripled from 8.08/1000 patient-years (95% confidence interval (CI): 4.14–14.75) in 2011, to 27.04 per 1000 person-years (95% CI: 19.45–36.76) in 2016. Half of the syphilis episodes were asymptomatic. Patients diagnosed with syphilis were twice as likely not to be taking ART and had a higher likelihood of having plasma HIV RNA viral loads > 1000 copies/mL (19%). Incident syphilis was seen predominantly in Caucasians (72%, P < 0.001), males (94%, P < 0.001) and men who have sex with men (MSM) as their HIV risk activity (75%, P < 0.001). Conclusions We have highlighted the importance of a regular syphilis screening program in HIV-infected individuals demonstrated by increasing rates of incident syphilis in our region. Targeted preventative strategies should be directed towards HIV-infected populations identified at highest risk, including; MSM, prior alcohol abuse, prior recreational drug use and those with prior syphilis diagnoses

Additional file 1: of Increasing incidence of syphilis among patients engaged in HIV care in Alberta, Canada: a retrospective clinic-based cohort study

Table S1. Characteristics of HIV+ patients regularly followed at the Southern Alberta Clinic between 1/1/2006 and 12/31/2016 comparing patients in four groups: syphilis positive (reference group), repeat syphilis positive, syphilis positive not on ART, syphilis positive not HIV Virologically suppressed (VL > 40 copies/mL). 1Indigenous includes Aboriginal, Metis and Inuit; ACB includes African, Caribbean, Black; Other includes IndoAsian, Hispanic, East Asian, and other. 2MSM = self-reported men who have sex with men identification; HET = self-reported heterosexual identification; PWID = self-reported intravenous drug use identification; Other HIV Risk factor behavior includes: blood transfusions, hemophiliac, neonatal, postnatal infection, unknown or not reported. 3History of Cigarette Smoking-Current or Past; History of Alcohol Abuse- > 14 drinks/week or binge drinking; History of Recreational Drug Use –Current or Past; History of Intimate Partner Violence-Current or Past. (DOCX 24 kb

COVID-19 vaccine uptake among people with HIV: identifying characteristics associated with vaccine hesitancy

Abstract People with HIV (PWH) are at increased risk of COVID-19 infection. Both Canadian (NACI) and US (CDC) guidelines recommend that all PWH receive at least 2 doses of COVID-19 vaccine, and a booster. We examined vaccination uptake among PWH in Southern Alberta, Canada. Among adult PWH, we evaluated COVID-19 vaccination uptake between December 2020 and August 2022. Poisson regression models with robust variance (approximating log binomial models) estimated crude and adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) for receiving (1) any vs. no vaccine, and (2) primary series with booster (≥ 3 vaccines) versus primary series without booster. Among 1885 PWH, 10% received no COVID-19 vaccinations, 37%  200 copies/mL), and using illegal substances. Factors associated with decreased booster uptake included being younger, Black (vs. White) ethnicity, substance use, lower educational attainment, and having an unsuppressed HIV viral load. COVID-19 booster uptake among PWH does not meet vaccine guidelines, and receipt of vaccines is unevenly distributed. Booster uptake is lowest among young females and marginalized individuals. Focused outreach is necessary to close this gap