R. F. W. Barnes

Estimating forest elephant numbers with dung counts and a geographic information system

Dung counts are the most practical means of estimating numbers and distribution of forest-dwelling elephants. In the forests of Gabon, which have a sparse human population, the density of elephant dung piles increased with distance from roads. Human influences (roads and density of human habitation) accounted for half the variation in dung-pile density. Ninety-five percent of the dung piles were estimated to occur in the low human density stratum that covers two-thirds of Gabon. We present a new method of estimating the dung-pile population using the gradient of dung density in relation to roads. Estimates of the gradient were combined with estimates from a geographic information system (GIS) of the area of forest in bands at different distances (e.g., 0-5, 5-10 km) from roads. This process gave an estimate of the dung-pile population for the whole forest zone; the standard error and confidence limits were found by bootstrapping. We argue that estimates of forest elephant abundance in central Africa will be both more accurate and more precise if one accounts for the gradient. Simulation showed that the optimum sample for Gabon is 40 transects, each 5 km in length.

A method for censusing the greater white-nosed monkey in northeastern Gabon using the population density gradient in relation to roads

This paper presents a method for estimating monkey numbers in a large area of forest where there is a gradient of monkey densities. The method is illustrated using data collected in the northeastern forests of Gabon during an earlier project. These forests are sparsely populated and there are few roads. The density of Cercopithecus nictitans increases with distance from the nearest road. A geographic information system (GIS) divided the forest into bands of increasing distance from the nearest road. The number of monkeys in each band is the prod- uct of the monkey density in that band and the area of the band. Summing across bands gives the population estimate; the standard error can be estimated by boots- trapping. The optimum sample size can be estimated by simulation. Combining estimates of the density gradient with a GIS is a cost-effective method of censusing primates in extensive forests.

Vascular remodeling underlies rebleeding in hemophilic arthropathy.

Hemophilic arthropathy is a debilitating condition that can develop as a consequence of frequent joint bleeding despite adequate clotting factor replacement. The mechanisms leading to repeated spontaneous bleeding are unknown. We investigated synovial, vascular, stromal, and cartilage changes in response to a single induced hemarthrosis in the FVIII‐deficient mouse. We found soft‐tissue hyperproliferation with marked induction of neoangiogenesis and evolving abnormal vascular architecture. While soft‐tissue changes were rapidly reversible, abnormal vascularity persisted for months and, surprisingly, was also seen in uninjured joints. Vascular changes in FVIII‐deficient mice involved pronounced remodeling with expression of α‐Smooth Muscle Actin (SMA), Endoglin (CD105), and vascular endothelial growth factor, as well as alterations of joint perfusion as determined by in vivo imaging. Vascular architecture changes and pronounced expression of α‐SMA appeared unique to hemophilia, as these were not found in joint tissue obtained from mouse models of rheumatoid arthritis and osteoarthritis and from patients with the same conditions. Evidence that vascular changes in hemophilia were significantly associated with bleeding and joint deterioration was obtained prospectively by dynamic in vivo imaging with musculoskeletal ultrasound and power Doppler of 156 joints (elbows, knees, and ankles) in a cohort of 26 patients with hemophilia at baseline and during painful episodes. These observations support the hypothesis that vascular remodeling contributes significantly to bleed propagation and development of hemophilic arthropathy. Based on these findings, the development of molecular targets for angiogenesis inhibition may be considered in this disease. Am. J. Hematol. 90:1027–1035, 2015.

HIV–Tuberculosis Coinfection in Southern California: Evaluating Disparities in Disease Burden

OBJECTIVES We sought to understand tuberculosis (TB) and HIV coinfection trends in San Diego County, California, and to identify associations between sociodemographic risk factors and TB and HIV coinfection. METHODS We analyzed TB surveillance data from 1993 through 2007. TB cases were grouped by HIV status: positive, negative, or unknown. We used Poisson regression to estimate trends and tested associations between TB and HIV coinfection and sociodemographic risk factors with polychotomous logistic regression. RESULTS Of 5172 TB cases, 8.8% were also infected with HIV. Incidence of coinfected cases did not change significantly over the period studied, but the proportion of cases among Hispanics increased significantly, whereas cases among non-Hispanic Whites and Blacks decreased. TB cases with HIV coinfection were significantly more likely to be Hispanic, male, injection drugs users, and aged 30 to 49 years, relative to cases with TB disease only. CONCLUSIONS The burden of TB and HIV in San Diego has shifted to Hispanics in the last decade. To address this health disparity, binational TB and HIV prevention efforts are needed.

Factors associated with genotype clustering of Mycobacterium tuberculosis isolates in an ethnically diverse region of southern California, United States

Mycobacterium tuberculosis (Mtb) isolates with identical genotypes, found in different patients, are most likely the result of recent transmission. Mtb strains with closely related genotypes, called clonal complexes, are most likely derived from one another. We examined Mtb genotypes from southern California TB patients from 2005 through 2008 to complete the first comprehensive molecular epidemiology analysis of this complicated and ethnically diverse region. Mtb genotypes were characterized with spoligotype and MIRU-12 typing. MIRU-VNTRplus was utilized to assign genotypes to global lineages and complete cluster analyses. Associations between patient characteristics and genotype clustering and clonal complexes were evaluated using logistic regression and frequency analysis. Of 832 Mtb isolates analyzed, 480 (58%) fell into 94 strain clusters. The majority of isolates were identified as being in the EA1 (31%), LAM (17%) and Haarlem (15%) lineages, but 13 different lineages were found in this region. TB patients with clustered isolates were more likely to be homeless (AOR 3.44, 95% CI 1.65, 7.18) and male (AOR 1.57, 95% CI 1.17, 2.10). Of the 480 clustered strains, 388 aggregated into six clonal complexes. Over 45% of reported TB cases were clustered and likely resulted from recent transmission events. Patients with clustered Mtb isolates that were grouped into clonal complexes had unique socio-demographic characteristics. These data suggest that TB is being transmitted in relatively insular community networks defined by race/ethnicity and country of origin. The addition of clonal complex analysis to simple cluster analysis provides important public health insights into the local transmission of TB in ethnically diverse regions with diverse Mtb genotypes.

Multidrug-resistant tuberculosis among patients in Baja California, Mexico, and Hispanic patients in California.

OBJECTIVES We sought to compare prevalence and determinants of multidrug-resistant tuberculosis (MDR-TB) between tuberculosis patients in Baja California, Mexico, and Hispanic patients in California. METHODS Using data from Mexicos National TB Drug Resistance Survey (2008-2009) and California Department of Public Health TB case registry (2004-2009), we assessed differences in MDR-TB prevalence comparing (1) Mexicans in Baja California, (2) Mexico-born Hispanics in California, (3) US-born Hispanics in California, and (4) California Hispanics born elsewhere. RESULTS MDR-TB prevalence was 2.1% in Baja California patients, 1.6% in Mexico-born California patients, 0.4% in US-born California patients, and 2.7% in Hispanic California patients born elsewhere. In multivariate analysis, previous antituberculosis treatment was associated with MDR-TB (odds ratio [OR] = 6.57; 95% confidence interval [CI] = 3.34, 12.96); Mexico-born TB patients in California (OR = 5.08; 95% CI = 1.19, 21.75) and those born elsewhere (OR = 7.69; 95% CI = 1.71, 34.67) had greater odds of MDR-TB compared with US-born patients (reference category). CONCLUSIONS Hispanic patients born outside the US or Mexico were more likely to have MDR-TB than were those born within these countries. Possible explanations include different levels of exposure to resistant strains and inadequate treatment.

Efficacy and safety of point-of-care ultrasound-guided intra-articular corticosteroid joint injections in patients with haemophilic arthropathy.

Intra‐articular corticosteroid injections are standard of care for managing joint pain secondary to osteoarthritis or rheumatoid arthritis but are rarely used in haemophilic arthropathy. We have introduced and evaluated the efficacy and safety of ultrasound‐guided corticosteroid injections for pain relief in patients with haemophilic arthropathy.

Trends in mortality of tuberculosis patients in the United States: the long-term perspective.

PURPOSE To describe long-term trends in tuberculosis (TB) mortality and to compare trends estimated from two different sources of public health surveillance data. METHODS Trends and changes in trend were estimated by joinpoint regression. Comparisons between data sets were made by fitting a Poisson regression model. RESULTS Since 1900, TB mortality rates estimated from death certificates have declined steeply, except for a period of no change in the 1980s. This decade had long-term consequences resulting in more TB deaths in later years than would have occurred had there been no flattening of the trend. Recent trends in TB mortality estimated from National Tuberculosis Surveillance System (NTSS) data, which record all-cause mortality, differed from trends based on death certificates. In particular, NTSS data showed TB mortality rates flattening since 2002. CONCLUSIONS Estimates of trends in TB mortality vary by data source, and therefore interpretation of the success of control efforts will depend on the surveillance data set used. The data sets may be subject to different biases that vary with time. One data set showed a sustained improvement in the control of TB since the early 1990s whereas the other indicated that the rate of TB mortality was no longer declining.

The hypertension of hemophilia is associated with vascular remodeling in the joint

Hemophilic arthropathy is associated with pronounced vascular joint remodeling. Also, compared to the general population, PWH have a higher prevalence of hypertension not explained by usual risk factors. As vascular remodeling in various vascular beds is a hallmark of hypertension, we hypothesized that vascular joint remodeling is associated with elevated blood pressures and hypertension.

The Hypertension of Hemophilia Is Not Explained by the Usual Cardiovascular Risk Factors: Results of a Cohort Study

Background. The etiology of the high prevalence of hypertension among patients with hemophilia (PWH) remains unknown. Methods. We compared 469 PWH in the United States with males from the National Health and Nutrition Examination Survey (NHANES) to determine whether differences in cardiovascular risk factors can account for the hypertension in hemophilia. Results. Median systolic and diastolic BP were higher in PWH than NHANES (P < 0.001) for subjects not taking antihypertensives. Those taking antihypertensives showed similar differences. Differences in both systolic and diastolic BP were especially marked among adults <30 years old. Differences between PWH and NHANES persisted after adjusting for age and risk factors (body mass index, renal function, cholesterol, smoking, diabetes, Hepatitis C, and race). Conclusions. Systolic and diastolic BP are higher in PWH than in the general male population and especially among PWH < 30 years old. The usual cardiovascular risk factors do not account for the etiology of the higher prevalence of hypertension in hemophilia. New investigations into the missing link between hemophilia and hypertension should include age of onset of hypertension and hemophilia-specific morbidities such as the role of inflammatory joint disease.