Geographic mapping of HIV infection among civilian applicants for United States military service

The Spatial Scale and Spread of Child Victimization

Previous research shows that large, densely populated urban areas have higher rates of child victimization that have persisted over time. However, few investigations have inquired about the processes that produce and sustain hot and cold spots of child victimization. As a result, the mechanisms that produce the observed spatial clustering of child victimization, and hence "why" harms against children tend to cluster in space, remains unknown. Does the likelihood of being a victim of violence in one location depend on a similar event happening in a nearby location within a specified timeframe? Rather, are child victims of violence more likely to reside in suboptimal neighborhood conditions? This paper aims to present an analytical and theoretical framework for distinguishing between these locational (point) processes to determine whether the empirical spatial patterns undergirding child victimization are more reflective of the "spread" via contagion (i.e., dependency) or whether they are produced by neighborhood structural inequality resulting from spatial heterogeneity. To detect spatial dependence, we applied the inhomogeneous K-function to Los Angeles Medical Examiner data on child homicide victim locations while controlling for regional differences in victimization events (i.e., heterogeneity). Our analysis found strong evidence of spatial clustering in child victimization at small spatial scales but inhibition at larger scales. We further found limited support for the spatiotemporal clustering of child victimization indicative of a contagion effect. Overall, our results support the role of neighborhood structural vulnerability in the underlying mechanisms producing patterns of child victimization across Los Angeles County. We conclude by discussing the policy implications for understanding this spatial patterning in geographical context and for developing effective and targeted preventive interventions.

Spatial analysis of HIV infection and the associated correlates among transgender persons in the United States

Identifying the geographic hotspots of HIV infection among high-risk populations such as transgender people is critical to ending the HIV epidemic in the United States (U.S.). This study examined the spatial pattern of HIV positivity rate and the associated correlates among transgender persons in the 48 contiguous states and the District of Columbia in the U.S. The data source was the 2015 U.S. Transgender Survey (n = 27,715). We conducted spatial analyses, with state as the unit of analysis. We fitted a spatial lag regression model to assess demographic, social, and behavioral risk variables associated with HIV. The HIV positivity rate ranged by state from 0.5% to 17.1%, with a mean of 2.9%. There was a significant positive global spatial autocorrelation (global Moran's I = 0.42, p = 0.001). The identified spatial clusters of high values (hot spots i.e., states with high HIV positivity rates surrounded by states with similarly high rates) included five neighboring states (Arkansas, Louisiana, Mississippi, Alabama, and Tennessee) in the Southern region. HIV positivity rate was positively associated with the percentage of transgender persons who were non-Hispanic Black, had no high school education, living in poverty, and engaged in sex work. Structural interventions are needed to address education, poverty, racial discrimination, and sex work that predispose transgender persons to HIV.

Spatiotemporal Analysis of AIDS Incidence and Its Influencing Factors on the Chinese Mainland, 2005-2017

Acquired Immune Deficiency Syndrome (AIDS) has become one of the most severe public health issues and nowadays around 38 million people are living with the human immunodeficiency virus (HIV). Ensuring healthy lives and promoting well-being is one of 17 United Nations Sustainable Development Goals. Here, we used the Markov chain matrix and geospatial clustering to comprehensively quantify the trends of the AIDS epidemic at the provincial administrate level in the mainland of China from 2005 to 2017. The Geographically Weighted Regression (GWR) model was further adopted to explore four groups of potential influencing factors (i.e., economy, traffic and transportation, medical care, and education) of the AIDS incidence rate in 2017 and their spatially distributed patterns. Results showed that the AIDS prevalence in southeastern China had been dominant and become prevalent in the past decade. The AIDS intensity level had been increasing between 2008 and 2011 but been gradually decreasing afterward. The analysis of the Markov chain matrix indicated that the AIDS epidemic has been generally in control on the Chinese mainland. The economic development was closely related to the rate of AIDS incidence on the Chinese mainland. The GWR result further suggested that medical care and the education effects on AIDS incidence rate can vary with different regions, but significant conclusions cannot be directly demonstrated. Our findings contribute an analytical framework of understanding AIDS epidemic trends and spatial variability of potential underlying factors throughout a complex extent to customize scientific prevention.

Spatial Analysis of the Human Immunodeficiency Virus Epidemic among Men Who Have Sex with Men in China, 2006-2015

Background

Studies have shown a recent upsurge in human immunodeficiency virus (HIV) burden among men who have sex with men (MSM) in China, especially in urban areas. For intervention planning and resource allocation, spatial analyses of HIV/AIDS case-clusters were required to identify epidemic foci and trends among MSM in China.

Methods

Information regarding MSM recorded as HIV/AIDS cases during 2006-2015 were extracted from the National Case Reporting System. Demographic trends were determined through Cochran-Armitage trend tests. Distribution of case-clusters was examined using spatial autocorrelation. Spatial-temporal scan was used to detect disease clustering. Spatial correlations between cases and socioenvironmental factors were determined by spatial regression.

Results

Between 2006 and 2015, in China, 120 371 HIV/AIDS cases were identified among MSM. Newly identified HIV/AIDS cases among self-reported MSM increased from 487 cases in 2006 to >30 000 cases in 2015. Among those HIV/AIDS cases recorded during 2006-2015, 47.0% were 20-29 years old and 24.9% were aged 30-39 years. Based on clusters of HIV/AIDS cases identified through spatial analysis, the epidemic was concentrated among MSM in large cities. Spatial-temporal clusters contained municipalities, provincial capitals, and main cities such as Beijing, Shanghai, Chongqing, Chengdu, and Guangzhou. Spatial regression analysis showed that sociodemographic indicators such as population density, per capita gross domestic product, and number of county-level medical institutions had statistically significant positive correlations with HIV/AIDS among MSM.

Conclusions

Assorted spatial analyses revealed an increasingly concentrated HIV epidemic among young MSM in Chinese cities, calling for targeted health education and intensive interventions at an early age.

A comparative study of the spatial distribution of HIV prevalence in the metropolis of Kermanshah, Iran, in 1996-2014 using geographical information systems

OBJECTIVES

Geographical information systems (GISs) have made spatiotemporal understanding of geographical patterns possible and have contributed to the identification and analysis of factors relating to health care behaviours and outcomes. The present study is the first to examine the spatial distribution of HIV prevalence in the metropolis of Kermanshah, Iran, using GISs.

METHODS

The research methods were descriptive, analytical and comparative. Additionally, data recorded for HIV-infected patients in 1996-2014 were used and then the loci of HIV infection in the metropolis of Kermanshah were identified and analysed spatially using ArcGIS (Esri, New York, NY, USA).

RESULTS

HIV prevalence in the metropolis of Kermanshah increased from 1996 to 2014. Analysis of the spatial distribution of the prevalence of HIV using ArcGIS indicated the presence of clusters of HIV infection. The findings demonstrate that there were many clusters of high HIV prevalence throughout the city of Kermanshah and that these clusters increased in size during the study period. Furthermore, the statistics are indicative of a growing number of HIV-infected women as well as a significant reduction in the mean age of the HIV-infected female population.

CONCLUSIONS

The spatial differences in HIV prevalence across the city of Kermanshah, as well as the identification of the resulting spatial clusters in different parts of the city, suggest that measures should be put in place to prevent the growth of these clusters and to reduce the number of women being infected with HIV.

Are neighborhood sociocultural factors influencing the spatial pattern of gonorrhea in North Carolina?

PURPOSE

To determine if the spatial pattern of gonorrhea observed for North Carolina was influenced by neighborhood-level sociocultural determinants of health, including race/ethnicity.

METHODS

A generalized linear mixed model with spatially correlated random effects was fit to measure the influence of socio-cultural factors on the spatial pattern of gonorrhea reported to the North Carolina State Health Department (January 1, 2005 to March 31, 2008).

RESULTS

Neighborhood gonorrhea rates increased as the percent single mothers increased (25th to 75th neighborhood percentile Relative Rate 1.18, 95% CI 1.12, 1.25), and decreased as socioeconomic status increased (Relative Rate 0.89, 95% CI 0.84, 0.95). Increasing numbers of men in neighborhoods with more women than men did not change the gonorrhea rate, but was associated with decreased rates in neighborhoods with more men than women. Living in the mountains was protective for all race/ethnicities. Rurality was associated with decreased rates for Blacks and increased rates for Native Americans outside the mountains.

PURPOSE

Neighborhood-level sociocultural factors, primarily those indicative of neighborhood deprivation, explained a significant proportion of the spatial pattern of gonorrhea in both urban and rural communities. Race/ethnicity was an important proxy for social and cultural factors not captured by measures of socioeconomic status.

Spatial clustering of HIV prevalence in Atlanta, Georgia and population characteristics associated with case concentrations

We assessed prevalent HIV cases in Atlanta to examine case distribution trends and population characteristics at the census tract level that may be associated with clustering effects. We calculated cluster characteristics (area and internal HIV prevalence) via Kuldorff's spatial scan method. Subsequent logistic regression analyses were performed to analyze sociodemographics associated with inclusion in a cluster. Organizations offering voluntary HIV testing and counseling services were identified and we assessed average travel time to access these services. One large cluster centralized in downtown Atlanta was identified that contains 60% of prevalent HIV cases. The prevalence rate within the cluster was 1.34% compared to 0.32% outside the cluster. Clustered tracts were associated with higher levels of poverty (OR = 1.19), lower density of multi-racial residents (OR = 1.85), injection drug use (OR = 1.99), men having sex with men (OR = 3.01), and men having sex with men and IV drug use (OR = 1.6). Forty-two percent (N = 11) of identified HIV service providers in Atlanta are located in the cluster with an average travel time of 13 minutes via car to access these services (SD = 9.24). The HIV epidemic in Atlanta is concentrated in one large cluster characterized by poverty, men who have sex with men (MSM), and IV drug usage. Prevention efforts targeted to the population living in this area as well as efforts to address the specific needs of these populations may be most beneficial in curtailing the epidemic within the identified cluster.

Prevalence of markers for HIV, hepatitis B and hepatitis C infection in UK military recruits

An unlinked anonymous survey was conducted to measure the prevalence of selected markers for HIV, hepatitis B and C infection in recruits to the UK Armed Forces to inform future screening and hepatitis B vaccination policies. During 2007, nearly 14 000 left-over samples taken from new recruits for blood typing were collected, unlinked from identifiers and anonymously tested for HIV, hepatitis C and current and past cleared hepatitis B infection. Overall, serological evidence of HIV and hepatitis C was found in 0·06% and 0·06% of recruits, respectively. Evidence of past cleared and current hepatitis B infection was found in 3·63% and 0·37% of recruits, respectively. Overall, prevalence rates were broadly consistent with UK population estimates of infection. However, HIV and hepatitis B prevalence was higher in recruits of African origin than in those from the UK (P<0·0001). Screening for these infections is an option that could be considered for those entering Services from high-prevalence countries.