Spatial Distribution of TB and HIV incidences in SSA in 2018

Titilola Gbaja-Biamila; Graduate student College for Public Health and Social Justice Saint Louis University

Tara Mott; Adjunct Professor Department of Earth & Atmospheric Sciences Saint Louis University Chisom Obiezu-Umeh; Graduate student College for Public Health and Social Justice Saint Louis University Thembekile shato; Postdoc graduate,Washington University in St Louis Ucheoma Nwaozuru; Assistant Professor, Department of Implementation Science Division of Public Health Sciences Juliet Iwelunmor; Professor of Behavioral Science and Health Education, College for Public Health, and Social Justice

GIS enable the geographical representation of data to promote better public health planning, decision-making, and bridging inequalities within and across countries using geospatial technologies (WHO, 2022). It enables us to visualize and disseminate images and data about disease outbreaks, natural disasters that affect human lives, healthcare access, "hotspots" for adverse health outcomes, and environmental health threats (Kandwal, Garg, & Garg, 2009; Shrestha & Stopka, 2022). GIS has a wide range of global health and medical applications, and many countries are missing out on the benefits of using GIS to improve their health information systems, especially in Africa (WHO, 2022). GIS and spatial analysis are new tools for global health, but it is unclear how much they have been used in Tuberculosis (TB), and the human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), research in Africa (Boyda, Holzman, Berman, Kathyrn Grabowski, & Chang, 2019).

TB and HIV/AIDS have significant reciprocal interactions and global public health hazards (Qanbarnezhad et al., 2018). Much of Africa's endemic disease burden is dominated by HIV and TB (Colebunders & Mendelson,2014; Pheage, 2017). TB is the world's ninth leading cause of death, surpassing HIV/AIDS (Schluger, 2006). More than a twenty-five percent of all TB deaths occur in the African region (WHO (World Health Organization), 2020). In 2016, an estimated 417,000 individuals died in Africa (1.7 million worldwide), and 2.5 million people in Africa contracted TB, accounting for a quarter of all new TB cases worldwide (WHO (World Health Organization), 2020). In 2016, Nigeria and South Africa were notably the countries in Africa with the highest incidence of new TB cases (WHO, 2020a; World Health Organization, 2020a). These two countries coincidentally are amongst the countries in Africa most affected by HIV (HIV/AIDS). it, therefore, stands to reason that to understand the TB trends in Africa, we need to understand the trends of HIV in AfricaAt the end of 2020, there were an estimated 7.7 million [30.2–45.1 million] persons living with HIV, with almost two-thirds (25.4 million) living in the WHO African Region.(HIV/AIDS) Despite the fact that HIV is not one of the world's leading causes of mortality, it is still one of Africa's top five (John, 2021).

What is the relationship between TB and HIV?

TB is an opportunistic infection (OI) (World Health Organization, 2020c). Infections that affect persons with compromised immune systems occur more frequently or are more severe than infections that affect people with healthy immune systems (WHO, 2017). HIV impairs the immune system, increasing the risk of tuberculosis in HIV-positive individuals (CDC, 2022). So HIV-positive people are 20 to 30 times more likely to acquire active TB (World Health Organization, 2020a). HIV and TB are a deadly combo, with each speeding up the progression of the other (Dowdy, 2014). Treatment with HIV drugs is called antiretroviral therapy (ART) can reduce the chances of HIV-infected persons developing TB (CDC, 2022).  It is therefore critical to address TB and HIV jointly; reducing HIV transmission will reduce the TB epidemic (Härtl, 2002; Ugwu, Agbo, & Ezeonu,2021).

Scope

This is a descriptive study done between the 25th of April and the 6th of May 2022. It includes sub-Saharan African data from only 2018 WHO database on incidences of HIV, TB, and the Proportion of HIV-positive new and relapsed TB cases on ART during TB treatment. It is important to note that Algeria, Djibouti, Egypt, Libya, Morocco, Somalia, Sudan, and Tunisia are not listed as "sub-Saharan" countries by the UN Development Program (World Bank, 2022). This study will not include data from countries not in SSA, and it will not include data from other sources not within the WHO. Results will be presented of only the top five SSA countries in all the categories analyzed.

Project goals

This study was created to contribute to the achievement of the Sustainable Development Goals (SDGs)( Ending the TB epidemic by 2030) in Africa and to the delivery of the deliver the GPW 13 Triple Billion targets, which focuses on the triple billion targets to achieve measurable impacts on people's health at the country level (WHO, 2022; WHO (World Health Organization), 2020). This study aims to inform researchers and program implementers on the trends of incidence of TB and HIV spread in Africa, using GIS to map out the geographical distribution and analyze the trend while indicating the disease hotspots in Africa. Having a bird's eye view of trends of TB and HIV spread in Africa will give a better understanding of this area.  

Project limitation

This study has some limitations that are primarily dependent on GIS use. GIS software-assisted investigations emphasize associative links. Any suggestion based on a GIS-assisted investigation regarding a putative causal relationship would be premature. The results of GIS-assisted analysis, like the results of other research methods, provide the impetus for further investigation to identify a potential causal relationship between connected variables. Although GIS software may combine data from many geographic units, such features inevitably allow for misinterpretation. Resource limitations were a problem in this research, and the researcher was restricted to certain forms of data since health-related data are not readily available, especially for SSA. There were missing data from some countries. Hence the lack of data for some African countries is due to difficulty obtaining data in those areas. Although data accuracy is a restriction in any research, it is particularly relevant in GIS-related research since data inaccuracies are amplified in resource-poor geographic areas (Rodrigues et al., 2021).

GIS Data

All data were processed using ArcGIS Pro 2.9 patch 3(2.9.2). The data were downloaded as text, and cleaning and spatial analysis were done where data was joined (using geoprocessing tools) to the geodatabase of the African map (ICPAC geoportal, 2020). Data for all populations in Africa, both male, and female, were obtained from the WHO/Global health observatory. The data consists of the following with the definition of the data:

Item details

·         A shapefile for African countries was obtained at A shapefile for African countries was obtained at  http://geoportal.icpac.net/layers/geonode%3Aafr_g2014_2013_   (ICPAC geoportal, 2020).

·         TB incidence is defined as the TB incidence per 100,000 population that is the assessed number of new and relapse TB cases that occur in a given year, expressed as a rate per 100 000 population. Data site:  https://aho.afro.who.int/ind/af?ind=333&cc=af&ci=1&dim=74&dom=Tuberculosis%20incidence  (World Health Organization, 020b).

·         HIV incidence, defined as the Number of new HIV per 1000 uninfected populations data site is  https://aho.afro.who.int/ind/af?ind=104&cc=af&ci=1&dim=93&dom=HIV/AIDS%20UHC%20across%20communicable%20diseases  (WHO, 2020b).

·         Proportion of HIV-positive new and relapsed TB cases on ART during TB treatment is defined as This metric will assess how well programs connect HIV-positive TB patients to appropriate HIV treatment. TB patients' HIV status is commonly established at TB clinics (and will be captured with TB STAT), but the HIV program frequently provides ART for TB cases (Indicator Registry, 2020). registry) https://aho.afro.who.int/ind/af?ind=169&cc=af&ci=1&dim=94& om=Tuberculosis%20UHC%20across%20communicable%20diseases  (WHO, 2020b).

TB case detection rate: The case detection rate is the number of reported cases per 100,000 persons per year divided by the estimated incidence rate per 100,000 per year. ( The World Health Organization's (WHO) aim for tuberculosis (TB) control is to detect 70% of new smear-positive TB cases and cure 85% of them.) (Indicator Registry, 2020).

Analysis

Spatial analysis was used to process, model, examine and interpret the model results.

Hypothesis:

·         TB and HIV incidences will be equally distributed in all the SSA countries in 2018.

·         SSA Countries with a high incidence of HIV will also have a high Proportion of HIV-positive new and relapsed TB cases on ART in 2018.

Research Questions

·         What countries in SSA had the highest incidence of HIV in 2018?

·         What countries in SSA had the highest incidence of TB in 2018?

·         What countries in SSA had High HIV and TB incidences in 2018?

·         What is the trend of TB and HIV in SSA in 2018?

·         Is there any association between SSA countries with HIV-positive new cases with relapsed TB cases on ART and the incidence of HIV positive cases in 2018?

Method

Downloaded text data was converted to a comma-delimited file on Microsoft excel, and then it was cleaned. A new field 'ID' was created to join the shapefile's attribute table. Performing this would enable using the geoprocessing tool to join data to this shapefile and create a choropleth map. Data was also manually uploaded to the newly created attribute table—data visualization using Symbology to visualize the data by creating comparative maps. The researcher utilized a variety of symbology approaches  (color and size)  to understand spatial variations. Primary Symbology used in four maps was graduated colors, while one had graduated symbols. The method used was Natural breaks in five classes. The Colour schemes are as follows.

·         HIV incidence map: Yellow-orange-red

·         TB detection map: Blues  (Continous ) and Yellow(graduated symbols)

·         TB incidence map: Blue-green (5 Class)

·         TB Relapse: White to black

This thematic mapping of the values will show the variations in colors, the highs and lows, and their distribution. Association may be assessed using this form of analysis. The attribute tables will be sorted in ascending and descending values to assess the values noted in the maps. The pop-up will also be configured to indicate the variations noted. A bar chart was created on Excel to show trend of HIV incidence. Three Map layouts for thematic maps were created, two were created through the ArcGIS experience builder.

Results

The results show that three(60%) out of five of the top countries have both high incidences of HIV and TB. These countries are Lesotho, Mozambique, and Botswana. While Comoros was the only country with low TB and HIV incidences in the results presented. Two(40%) out of five SSA countries presented were seen to have high incidence rates of HIV and  HIV-positive new and relapse TB patient cases. These countries are South Africa and Mozambique. In comparison, low rates of these indicators are seen in three(60%) SSA countries, namely Mauritania, Comoros, and são Tomé and Principe. Comoros was the only country that showed it had low rates of TB detection and incidence of TB. No country showed that they had high rates of TB detection and incidence of TB. Mauritius Mauritius is the only country with a high TB detection rate but has a low incidence of TB

This study showed variation in the distribution of HIV and TB in SSA countries, which is contrary to the first Hypothesis. However, the study is consistent with the second Hypothesis; it shows an association between HIV and TB. Also noted was that there is no association between the TB detection rates and incidence rates of TB in SSA countries. The study confirms the associations between HIV and TB trends in SSA countries. Countries in the southern part of SSA have a high incidence of both HIV and TB. West Africa appears to have lower rates of HIV and TB in comparison. This study shows that GIS can be used to assess data in resource-limited settings.