Assessing the spatial heterogeneity of tuberculosis in a population with internal migration in China: a retrospective population-based study

BackgroundInternal migrants pose a critical threat to eliminating Tuberculosis (TB) in many high-burden countries. Understanding the influential pattern of the internal migrant population in the incidence of tuberculosis is crucial for controlling and preventing the disease. We used epidemiological and spatial data to analyze the spatial distribution of tuberculosis and identify potential risk factors for spatial heterogeneity.MethodsWe conducted a population-based, retrospective study and identified all incident bacterially-positive TB cases between January 1st, 2009, and December 31st, 2016, in Shanghai, China. We used Getis-Ord Gi* statistics and spatial relative risk methods to explore spatial heterogeneity and identify regions with spatial clusters of TB cases, and then used logistic regression method to estimate individual-level risk factors for notified migrant TB and spatial clusters. A hierarchical Bayesian spatial model was used to identify the attributable location-specific factors.ResultsOverall, 27,383 bacterially-positive tuberculosis patients were notified for analysis, with 42.54% (11,649) of them being migrants. The age-adjusted notification rate of TB among migrants was much higher than among residents. Migrants (aOR, 1.85; 95%CI, 1.65-2.08) and active screening (aOR, 3.13; 95%CI, 2.60-3.77) contributed significantly to the formation of TB high-spatial clusters. With the hierarchical Bayesian modeling, the presence of industrial parks (RR, 1.420; 95%CI, 1.023-1.974) and migrants (RR, 1.121; 95%CI, 1.007-1.247) were the risk factors for increased TB disease at the county level.ConclusionWe identified a significant spatial heterogeneity of tuberculosis in Shanghai, one of the typical megacities with massive migration. Internal migrants play an essential role in the disease burden and the spatial heterogeneity of TB in urban settings. Optimized disease control and prevention strategies, including targeted interventions based on the current epidemiological heterogeneity, warrant further evaluation to fuel the TB eradication process in urban China

Spotting the old foe-revisiting the case definition for TB.

Disease case definitions are important instruments for clinical care, interventional research, and surveillance. Therefore, it is concerning that the current case definitions for tuberculosis remain underscored by the classic paradigm of binary states of latent infection and active disease, with a stepwise, linear transition under which symptoms, bacteriological positivity, and disease pathology are assumed to emerge broadly together (figure, A).1 This assumption has resulted in a reliance on symptom screening to distinguish these two states. However, in recent prevalence surveys, 40–79% of bacteriologically positive tuberculosis occurs in the absence of patient-recognised tuberculosis symptoms.2 Rather than explicitly addressing this discordance, tuberculosis case definitions are often ambiguous regarding tuberculosis symptoms, or internally inconsistent

Metabolic risk factors of cognitive impairment in young women with major psychiatric disorder

BackgroundCognitive performance improves clinical outcomes of patients with major psychiatric disorder (MPD), but is impaired by hyperglycemia. Psychotropic agents often induce metabolism syndrome (MetS). The identification of modifiable metabolic risk factors of cognitive impairment may enable targeted improvements of patient care.ObjectiveTo investigate the relationship between MetS and cognitive impairment in young women with MPD, and to explore risk factors.MethodsWe retrospectively studied women of 18–34 years of age receiving psychotropic medications for first-onset schizophrenia (SCH), bipolar disorder (BP), or major depressive disorder (MDD). Data were obtained at four time points: presentation but before psychotropic medication; 4–8 and 8–12 weeks of psychotropic therapy; and enrollment. MATRICS Consensus Cognitive Battery, (MCCB)—based Global Deficit Scores were used to assess cognitive impairment. Multiple logistic analysis was used to calculate risk factors. Multivariate models were used to investigate factors associated with cognitive impairment.ResultsWe evaluated 2,864 participants. Cognitive impairment was observed in 61.94% of study participants, and was most prevalent among patients with BP (69.38%). HbA1c within the 8–12 week-treatment interval was the most significant risk factor and highest in BP. Factors in SCH included pre-treatment waist circumference and elevated triglycerides during the 8–12 weeks treatment interval. Cumulative dosages of antipsychotics, antidepressants, and valproate were associated with cognitive impairment in all MPD subgroups, although lithium demonstrated a protect effect (all P < 0.001).ConclusionsCognitive impairment was associated with elevated HbA1c and cumulative medication dosages. Pre-treatment waist circumference and triglyceride level at 8–12 weeks were risk factors in SCH. Monitoring these indices may inform treatment revisions to improve clinical outcomes

Induced Maps on Matrices over Fields

Suppose that is a field and m,n≥3 are integers. Denote by Mmn() the set of all m×n matrices over and by Mn() the set Mnn(). Let fij (i∈[1,m],j∈[1,n]) be functions on , where [1,n] stands for the set {1,…,n}. We say that a map f:Mmn()→Mmn() is induced by {fij} if f is defined by f:[aij]↦[fij(aij)]. We say that a map f on Mn() preserves similarity if A~B⇒f(A)~f(B), where A~B represents that A and B are similar. A map f on Mn() preserving inverses of matrices means f(A)f(A-1)=In for every invertible A∈Mn(). In this paper, we characterize induced maps preserving similarity and inverses of matrices, respectively

Determination of low bromine (Br) and iodine (I) in water with low-to high-salinity content using ICP-MS

A newly developed method for the determination of bromine (Br) and iodine (I) in low- to high-salinity aqueous samples by ICP-MS was established. Matrix related isobaric interferences ((ArK)-Ar-40-K-39 and (ArArH)-Ar-40-Ar-38-H-1 on Br-79) have been quantitatively estimated in the kinetic energy discrimination (KED) operation mode and the standard (STD) mode; it was shown that such interferences can be efficiently eliminated using the KED mode with He as a collision reaction gas. In addition, samples with high salt concentrations were analysed after pre-treatment using H-form cation-exchange resin with low dilution factors (10 or 20), rather than the high dilution factors (>200) reported in previous studies. The values for the total procedure blank of Br and I from this process were 0.784 and 0.015 mu gL(-1), respectively. The Br and I limits of detection (LOD) and spiked recoveries for this ICP-MS method were 0.1104 and 0.0013 mu g L-1 and 98.9-100.9% and 98.0-102.9%, respectively. The present method was successfully applied for the rapid and direct determination of Br and I in seawater and other aqueous samples. (C) 2018 Elsevier B.V. All rights reserved

Assessing heterogeneity of patient and health system delay among TB in a population with internal migrants in China

BackgroundsThe diagnostic delay of tuberculosis (TB) contributes to further transmission and impedes the implementation of the End TB Strategy. Therefore, we aimed to describe the characteristics of patient delay, health system delay, and total delay among TB patients in Shanghai, identify areas at high risk for delay, and explore the potential factors of long delay at individual and spatial levels.MethodThe study included TB patients among migrants and residents in Shanghai between January 2010 and December 2018. Patient and health system delays exceeding 14 days and total delays exceeding 28 days were defined as long delays. Time trends of long delays were evaluated by Joinpoint regression. Multivariable logistic regression analysis was employed to analyze influencing factors of long delays. Spatial analysis of delays was conducted using ArcGIS, and the hierarchical Bayesian spatial model was utilized to explore associated spatial factors.ResultsOverall, 61,050 TB patients were notified during the study period. Median patient, health system, and total delays were 12 days (IQR: 3–26), 9 days (IQR: 4–18), and 27 days (IQR: 15–43), respectively. Migrants, females, older adults, symptomatic visits to TB-designated facilities, and pathogen-positive were associated with longer patient delays, while pathogen-negative, active case findings and symptomatic visits to non-TB-designated facilities were associated with long health system delays (LHD). Spatial analysis revealed Chongming Island was a hotspot for patient delay, while western areas of Shanghai, with a high proportion of internal migrants and industrial parks, were at high risk for LHD. The application of rapid molecular diagnostic methods was associated with reduced health system delays.ConclusionDespite a relatively shorter diagnostic delay of TB than in the other regions in China, there was vital social-demographic and spatial heterogeneity in the occurrence of long delays in Shanghai. While the active case finding and rapid molecular diagnosis reduced the delay, novel targeted interventions are still required to address the challenges of TB diagnosis among both migrants and residents in this urban setting

Catastrophic costs of tuberculosis care in a population with internal migrants in China

BackgroundThe internal rural-to-urban migration is one of the major challenges for tuberculosis (TB) control in China. Patient costs incurred during TB diagnosis and treatment could cause access and adherence barriers, particularly among migrants. Here, we estimated the prevalence of catastrophic costs of TB patients and its associated factors in an urban population with internal migrants in China.MethodsA cross-sectional survey was conducted to enroll culture-confirmed pulmonary TB patients in Songjiang district, Shanghai, between December 1, 2014, and December 31, 2015. Consenting participants completed a questionnaire, which collected direct and indirect costs before and after the diagnosis of TB. The catastrophic cost was defined as the annual expenses of TB care that exceeds 20% of total household disposable income. We used logistic regression to identify factors associated with catastrophic costs.ResultsOverall, 248 drug-susceptible TB patients were enrolled, 70% (174/248) of them were from migrants. Migrant patients were significantly younger compared to resident patients. The total costs were 25,824 ($3689) and 13,816 ($1974) Chinese Yuan (RMB) in average for resident and migrant patients, respectively. The direct medical cost comprised about 70% of the total costs among both migrant and resident patients. Overall, 55% (132 of 248) of patients experienced high expenses (>10% of total household income), and 22% (55 of 248) experienced defined catastrophic costs. The reimbursement for TB care only reduced the prevalence of catastrophic costs to 20% (49 of 248). Meanwhile, 52% (90 of 174) of the internal migrants had no available local health insurance. Hospitalizations, no available insurance, and older age (> 45-year-old) contributed significantly to the occurrence of catastrophic costs.ConclusionsThe catastrophic cost of TB service cannot be overlooked, despite the free policy. Migrants have difficulties benefiting from health insurance in urban cities. Interventions, including expanded medical financial assistance, are needed to secure universal TB care

Deep Whole-Genome Sequencing to Detect Mixed Infection of <i>Mycobacterium tuberculosis</i>

<div><p>Mixed infection by multiple <i>Mycobacterium tuberculosis</i> (MTB) strains is associated with poor treatment outcome of tuberculosis (TB). Traditional genotyping methods have been used to detect mixed infections of MTB, however, their sensitivity and resolution are limited. Deep whole-genome sequencing (WGS) has been proved highly sensitive and discriminative for studying population heterogeneity of MTB. Here, we developed a phylogenetic-based method to detect MTB mixed infections using WGS data. We collected published WGS data of 782 global MTB strains from public database. We called homogeneous and heterogeneous single nucleotide variations (SNVs) of individual strains by mapping short reads to the ancestral MTB reference genome. We constructed a phylogenomic database based on 68,639 homogeneous SNVs of 652 MTB strains. Mixed infections were determined if multiple evolutionary paths were identified by mapping the SNVs of individual samples to the phylogenomic database. By simulation, our method could specifically detect mixed infections when the sequencing depth of minor strains was as low as 1× coverage, and when the genomic distance of two mixed strains was as small as 16 SNVs. By applying our methods to all 782 samples, we detected 47 mixed infections and 45 of them were caused by locally endemic strains. The results indicate that our method is highly sensitive and discriminative for identifying mixed infections from deep WGS data of MTB isolates.</p></div