Geographic Information System-based Screening for TB, HIV, and Syphilis (GIS-THIS): A Cross-Sectional Study

Abstract

ObjectiveTo determine the feasibility and case detection rate of a geographic information systems (GIS)-based integrated community screening strategy for tuberculosis, syphilis, and human immunodeficiency virus (HIV).DesignProspective cross-sectional study of all participants presenting to geographic hot spot screenings in Wake County, North Carolina.MethodsThe residences of tuberculosis, HIV, and syphilis cases incident between 1/1/05–12/31/07 were mapped. Areas with high densities of all 3 diseases were designated “hot spots.” Combined screening for tuberculosis, HIV, and syphilis were conducted at the hot spots; participants with positive tests were referred to the health department.Results and ConclusionsParticipants (N = 247) reported high-risk characteristics: 67% previously incarcerated, 40% had lived in a homeless shelter, and 29% had a history of crack cocaine use. However, 34% reported never having been tested for HIV, and 41% did not recall prior tuberculin skin testing. Screening identified 3% (8/240) of participants with HIV infection, 1% (3/239) with untreated syphilis, and 15% (36/234) with latent tuberculosis infection. Of the eight persons with HIV, one was newly diagnosed and co-infected with latent tuberculosis; he was treated for latent TB and linked to an HIV provider. Two other HIV-positive persons had fallen out of care, and as a result of the study were linked back into HIV clinics. Of 27 persons with latent tuberculosis offered therapy, nine initiated and three completed treatment. GIS-based screening can effectively penetrate populations with high disease burden and poor healthcare access. Linkage to care remains challenging and will require creative interventions to impact morbidity.

Finding HIV in Hard to Reach Populations: Mobile HIV Testing and Geospatial Mapping in Umlazi Township, Durban, South Africa

“…Increasing the frequency of mobile unit visits to high infection rate areas may saturate the number of new HIV testers and yield the maximum number of new cases in the community. However, until linkage to care improves, the impact of any testing initiative will be limited (4, 7). Linkage to care interventions may be particularly important for mobile testers, who may be less symptomatic and not accessing a formal health care site at the time of testing.…”

“…Geospatial analyses and geographic information systems (GIS) have been used to determine “hot spots” of infectious disease and their spatial variation (7–10). Having a better understanding of disease distribution in the community can help optimize deployment of mobile testing units; previous studies have shown the advantages of using GIS to determine factors impacting access to and use of healthcare services (11–13) and in healthcare intervention planning (9).…”

Worldwide Spatial and Temporal Distribution of Tuberculosis (TB)

“…A study indicated that spatial and temporal information may be useful for targeting testing when access is limited [36] as in a cross sectional geographic information system-based screening for TB, HIV, and Syphilis (GIS-THIS) participants reported high-risk characteristics [18]. And the information that prevalence of infection among household contacts of people with tuberculosis is will guides active case finding [37].…”

“…A cross-sectional study indicated that GIS-based screening can effectively penetrate populations with high disease burden and poor healthcare access. Linkage to care remains challenging and will require creative interventions to impact morbidity [18]. And as TB is known to cluster in hyperendemic "hotspots" often characterized by crowding [16,19], HIV infection [20], and other social determinants [21], new approaches, such as mapping and spatial analysis, may be of value in contributing to basic elements of TB control [22].…”

Understanding Local Spatial Variation Along the Care Continuum

“…8 Sociocontextual factors influence the well-being of a person and include factors such as discrimination, local policies, and access to healthcare, food, and transportation. 9 Features of local neighborhood environments have been increasingly recognized as a key determinant of an HIV-infected person’s success in achieving viral suppression.…”