Poor concordance between interferon-γ release assays and tuberculin skin tests in diagnosis of latent tuberculosis infection among HIV-infected individuals

<p>Abstract</p> <p>Background</p> <p>A new generation of diagnostic tests, the interferon-γ release assays (IGRAs), have been developed for the detection of latent tuberculosis infection (LTBI). Limited data are available on their use in HIV-infected persons.</p> <p>Methods</p> <p>A cross-sectional study was carried out at 2 HIV clinics in Atlanta to assess the utility of two IGRA tests (T-SPOT.TB [TSPOT] and QuantiFERON-TB Gold in Tube [QFT-3G]) compared to the tuberculin skin test (TST).</p> <p>Results</p> <p>336 HIV-infected persons were enrolled. Median CD4 count was 335 cells/μl and median HIV viral load was 400 copies/ml. Overall, 27 patients (8.0%) had at least 1 positive diagnostic test for LTBI: 7 (2.1%) had a positive TST; 9 (2.7%) a positive QFT-3G; and 14 (4.2%) a positive TSPOT. Agreement between the 3 diagnostic tests was poor: TST and TSPOT, [κ = 0.16, 95% CI (-0.06, 0.39)], TST and QFT-3G [κ = 0.23, 95% CI (-0.05, 0.51)], QFT-3G and TSPOT [κ = 0.06, 95% CI (-0.1, 0.2)]. An indeterminate test result occurred among 6 (1.8%) of QFT-3G and 47 (14%) of TSPOT tests. In multivariate analysis, patients with a CD4 ≤ 200 cells/μl were significantly more likely to have an indeterminate result [OR = 3.6, 95% CI (1.9, 6.8)].</p> <p>Conclusion</p> <p>We found a low prevalence of LTBI and poor concordance between all 3 diagnostic tests. Indeterminate test results were more likely at CD4 counts ≤ 200 cells/μl. Additional studies among HIV-infected populations with a high prevalence of TB are needed to further assess the utility of IGRAs in this patient population.</p

Cultural practices and exposure to particulate pollution from indoor biomass cooking: Effects on respiratory health and nutritional status among the Aymara Indians of the Bolivian highlands.

The traditional focus of air pollution studies has been the urban outdoor environment of industrialized countries. This fails to consider the use of biomass fuels by roughly half the world's population for indoor cooking. In order to address the problem of air pollution from indoor biomass cooking, this research examined the relationship among health, cultural practices associated with cooking, and exposure to indoor biomass cooking by comparing two Bolivian Aymara Indian villages that were the same in every respect except for their cooking practices: in one of the villages biomass cooking was done exclusively indoors while in the other village biomass cooking was done exclusively outdoors. The quantification of total human exposure to pollution showed that cultural patterns, especially those related to cooking practices and human activity patterns, are important determinants of pollution exposure. While kitchen concentrations in the indoor cooking village were significantly higher (p $<$ 0.0001) than those in the outdoor cooking village, differences in exposure were relatively small, but still statistically significant, because the home in the outdoor cooking village was unexpectedly an important source of particulate pollution. The results of the health component of the study showed a significantly higher incidence of acute respiratory infections in the indoor cooking village compared to the outdoor cooking village for all tests (p $<$ 0.05). Differences in the prevalence of chronic bronchitis, while not always significant, were systematically higher in the indoor cooking village compared to the outdoor cooking village. In addition, adolescent and adult females from the indoor cooking village exhibited a greater delay in growth and reduction in fat reserves than their counterparts in the outdoor cooking village. The present study shows that indoor cooking and the cultural factors associated with indoor cooking lead to high pollutant exposures which in turn adversely affect respiratory health and nutritional status. From an anthropological perspective this shows clearly the intimate relationship that exists between the culture and the biology of a population. As such, research in human biology and air pollution epidemiology must consider cultural practices in order to gain better insight into the health status of a population.Ph.D.Cultural anthropologyEnvironmental scienceHealth and Environmental SciencesNutritionPhysical anthropologyPublic healthSocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/130187/2/9721934.pd

Costs of providing HIV care and optimal allocation of HIV resources in Guyana.

IntroductionGreat strides in responding to the HIV epidemic have led to improved access to and uptake of HIV services in Guyana, a lower-middle-income country with a generalized HIV epidemic. Despite efforts to scale up HIV treatment and adopt the test and start strategy, little is known about costs of HIV services across the care cascade.MethodsWe collected cost data from the national laboratory and nine selected treatment facilities in five of the country's ten Regions, and estimated the costs associated with HIV testing and services (HTS) and antiretroviral therapy (ART) from a provider perspective from January 1, 2016 to December 31, 2016. We then used the unit costs to construct four resource allocation scenarios. In the first two scenarios, we calculated how close Guyana would currently be to its 2020 targets if the allocation of funding across programs and regions over 2017-2020 had (a) remained unchanged from latest-reported levels, or (b) been optimally distributed to minimize incidence and deaths. In the next two, we estimated the resources that would have been required to meet the 2020 targets if those resources had been distributed (a) according to latest-reported patterns, or (b) optimally to minimize incidence and deaths.ResultsThe mean cost per test was US$15 and the mean cost per person tested positive was US$796. The mean annual cost per of maintaining established adult and pediatric patients on ART were US$428 and US$410, respectively. The mean annual cost of maintaining virally suppressed patients was US$648. Cost variation across sites may suggest opportunities for improvements in efficiency, or may reflect variation in facility type and patient volume. There may also be scope for improvements in allocative efficiency; we estimated a 28% reduction in the total resources required to meet Guyana's 2020 targets if funds had been optimally distributed to minimize infections and deaths.ConclusionsWe provide the first estimates of costs along the HIV cascade in the Caribbean and assessed efficiencies using novel context-specific data on the costs associated with diagnostic, treatment, and viral suppression. The findings call for better targeting of services, and efficient service delivery models and resource allocation, while scaling up HIV services to maximize investment impact