A trend analysis and sub-regional distribution in number of people living with HIV and dying with TB in Africa, 1991 to 2006

Cardiovascular risk and D-dimer levels in HIV-infected ART-naïve Africans

Anti-retroviral therapy (ART) has decreased morbidity and mortality in HIV-infected individuals. With the adoption of the 90-90-90 strategy prevention and control of non-communicable disease, particularly knowledge of the burden and profile of cardiovascular disease, will become increasingly important. Our study assessed cardiovascular risk among recently diagnosed HIV-infected ART-naïve patients in a first referral urban hospital in a low-income country in sub-Saharan Africa. HIV-positive ART-naïve patients were submitted to cardiovascular risk assessment, clinical history, physical examination and laboratory workout, including 12-lead electrocardiography, portable transthoracic echocardiography, glycemia, lipidemia, hemogram and D-dimers. Three years after the diagnosis their vital status and occurrence of major cardiovascular events was assessed. We recruited 70 patients, all of black ethnicity (41 females; mean age 37±10.7). CD4 levels were very low (mean 21.3 cells/mL; SD 10.4). Twenty-one (26.6%) were overweight, 13 (16.7%) were obese, 19 (20.5%) had hyperglycemia and 20 patients (25.6%) had hypercholesterolemia. The median blood pressure was 119.5/79 mmHg (IQR 107-141/67-83); 20 patients (25.6%) had hypertension. Four (5.7%) patients had signs of heart failure, and left ventricular ejection fraction was reduced in 17 (25%). High levels of circulating D-dimers were found in 44 (62.8%) patients; the mean levels were 725.9 (SD 555.1). We found high occurrence of cardiovascular risk factors, left ventricular dysfunction and evidence of a pro-coagulant state in these HIV-infected ART-naïve patients. Active cardiovascular risk screening and stratification, as well as management protocols tailored to low-income settings are needed to sustain the gains obtained with increased availability of ART in Africa.

Spatial and temporal analysis of tuberculosis in an area of social inequality in Northeast Brazil

BACKGROUND

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. It is a disease known worldwide for its vulnerability factors, magnitude and mortality. The objective of the study was to analyze the spatial and temporal dynamics of TB in the area of social inequality in northeast Brazil between the years 2001 and 2016.

METHODS

An ecological time series study with the use of spatial analysis techniques was carried out from 2001 to 2016. The units of analysis were the 75 municipalities in the state of Sergipe. Data from the Notification of Injury Information System were used. For the construction of the maps, the cartographic base of the state of Sergipe, obtained at the Instituto Brasileiro de Geografia e Estatística, was used. Georeferenced data were analysed using TerraView 4.2.2 software (Instituto Nacional de Pesquisas Espaciais) and QGis 2.18.2 (Open Source Geospatial Foundation). Spatial analyses included the empirical Bayesian model and the global and local Moran indices. The time trend analyses were performed by the software Joinpoint Regression, Version 4.5.0.1, with the variables of sex, age, cure and abandonment.

RESULTS

There was an increasing trend of tuberculosis cases in patients under 20 years old and 20-39 years old, especially in males. Cured cases showed a decreasing trend, and cases of treatment withdrawal were stationary. A spatial dependence was observed in almost all analysed territories but with different concentrations. Significant spatial correlations with the formation of clusters in the southeast and northeast of the state were observed. The probability of illness among municipalities was determined not to occur in a random way.

CONCLUSION

The identification of risk areas and priority groups can help health planning by refining the focus of attention to tuberculosis control. Understanding the epidemiological, spatial and temporal dynamics of tuberculosis can allow for improved targeting of strategies for disease prevention and control.

Spatiotemporal analysis and epidemiological characterization of the human immunodeficiency virus (HIV) in Libya within a twenty five year period: 1993-2017

Background

Infection with the human immunodeficiency virus (HIV) is an alarming problem in North African countries, but few studies have analyzed the geographical distribution of the epidemic. Libya, the second largest country in Africa and with the longest coast on the Mediterranean basin facing Europe, has experienced major outbreaks of HIV infection. Since then, no studies have followed up on the burden of HIV infections. To plan interventions and allocate resources, spatial analysis of HIV/AIDS clusters are required in order to identify epidemic foci and trends in the country. The objective of this study was to assess HIV infection clustering and trends in Libya.

Methods

Information on all recorded HIV/AIDS cases during 1993–2017 were extracted from the National Reporting System. A total of 8015 newly diagnosed HIV cases with address information were included. Spatial autocorrelation and spatial–temporal analysis were used to identify HIV clusters. Spatial correlations between cases and socio-demographic factors were determined using spatial regression.

Results

HIV cases steadily increased within the Libyan population, particularly among those aged < 27 years. Spatiotemporal analysis showed marked geographic and temporal variation of HIV infection, particularly during 2005–2012. The risk factors varied from one region to another, and the contribution of injection drug use to infection increased with time. Four clusters in three time periods were identified, three on the Mediterranean coast and one in the south.

Conclusion

HIV is an emerging problem in Libya, particularly among young adults. The infection rate varies greatly among the regions and districts, particularly within certain definable geographical areas. Effective intervention strategies are needed to contain HIV infections, especially within the endemic areas.

Electronic supplementary material

The online version of this article (10.1186/s12981-019-0228-0) contains supplementary material, which is available to authorized users.

Methods used in the spatial analysis of tuberculosis epidemiology: a systematic review

BACKGROUND

Tuberculosis (TB) transmission often occurs within a household or community, leading to heterogeneous spatial patterns. However, apparent spatial clustering of TB could reflect ongoing transmission or co-location of risk factors and can vary considerably depending on the type of data available, the analysis methods employed and the dynamics of the underlying population. Thus, we aimed to review methodological approaches used in the spatial analysis of TB burden.

METHODS

We conducted a systematic literature search of spatial studies of TB published in English using Medline, Embase, PsycInfo, Scopus and Web of Science databases with no date restriction from inception to 15 February 2017. The protocol for this systematic review was prospectively registered with PROSPERO ( CRD42016036655 ).

RESULTS

We identified 168 eligible studies with spatial methods used to describe the spatial distribution (n = 154), spatial clusters (n = 73), predictors of spatial patterns (n = 64), the role of congregate settings (n = 3) and the household (n = 2) on TB transmission. Molecular techniques combined with geospatial methods were used by 25 studies to compare the role of transmission to reactivation as a driver of TB spatial distribution, finding that geospatial hotspots are not necessarily areas of recent transmission. Almost all studies used notification data for spatial analysis (161 of 168), although none accounted for undetected cases. The most common data visualisation technique was notification rate mapping, and the use of smoothing techniques was uncommon. Spatial clusters were identified using a range of methods, with the most commonly employed being Kulldorff's spatial scan statistic followed by local Moran's I and Getis and Ord's local Gi(d) tests. In the 11 papers that compared two such methods using a single dataset, the clustering patterns identified were often inconsistent. Classical regression models that did not account for spatial dependence were commonly used to predict spatial TB risk. In all included studies, TB showed a heterogeneous spatial pattern at each geographic resolution level examined.

CONCLUSIONS

A range of spatial analysis methodologies has been employed in divergent contexts, with all studies demonstrating significant heterogeneity in spatial TB distribution. Future studies are needed to define the optimal method for each context and should account for unreported cases when using notification data where possible. Future studies combining genotypic and geospatial techniques with epidemiologically linked cases have the potential to provide further insights and improve TB control.

The Characteristics of TB Epidemic and TB/HIV Co-Infection Epidemic: A 2007-2013 Retrospective Study in Urumqi, Xinjiang Province, China

Objective

This study was aimed to find out epidemiologic characteristic of tuberculosis (TB) cases, and Human Immunodeficiency Virus (HIV) positive cases among TB patients (TB/HIV co-infection) through demographic, temporal, and spatial study in Urumqi.

Methods

Descriptive statistics and multivariate logistic regression were applied to identify the epidemiologic characteristics and risk factors of TB epidemic and TB/HIV co-infection epidemic. All addresses of each TB case, TB/HIV co-infection case, and administrative street were transformed into geographical coordinate. Subsequently, the geocoded address for 82 streets was transformed into a dot map used as the basis of spatial datasets. In addition, the paper also used quantile map and the spatial scan statistic in order to identify the spatial distribution and spatial clusters of TB epidemic and TB/HIV co-infection epidemic.

Result

There was a declining trend of the notification rates of TB epidemic from 2007 to 2009, as well as a rising trend from 2010 to 2013. However, the notification rates of TB/HIV co-infection epidemic showed a rising trend from 2007 to 2010, and a declining trend from 2011 to 2013. Moreover, a significant share of TB epidemic and TB/HIV co-infection epidemic happened between the age of 15 to 45 years old, indicating an increase in risk of TB and TB/HIV infection. It is worth noting that the risk of HIV infection for male TB patients was 2.947 times (95% CI [2.178, 3.988]) than that of female patients. Han ethnicity and Uygur ethnicity in urban region accounted for a large proportion of total TB and TB/HIV co-infection cases. Most of the TB cases of minorities in Urumqi showed a statistically significant increase in risk of HIV infection than Han ethnicity in Urumqi. In addition, the spatial distribution of TB epidemic and TB/HIV co-infection epidemic was highly skewed. Most of the local clusters were located in urban area and rural-urban continuum where showed an increase in risk of TB and TB/HIV infection.

Conclusion

The epidemiologic and spatial-temporal analysis of TB epidemic and TB/HIV co-infection epidemic demonstrates a potential connection between TB and HIV in Urumqi. Demographic, temporal, geographic factors are the reasons of causing TB and TB/HIV co-infection epidemic.

Trends and Predictors of Mortality Among HIV Positive Patients in the Era of Highly Active Antiretroviral Therapy in Uganda

Knowledge of mortality trends and predictors among HIV-positive patients in the era of highly active antiretroviral therapy (HAART) in resource poor settings is still limited. The aim of this study was to describe trends and predictors of mortality among HIV-positive patients in the era of HAART in Uganda. Data from 2004 to 2013 for adult HIV-positive patients (≥15 years) obtaining care and treatment from the AIDS Support Organization in Uganda were reviewed for mortality. Descriptive statistics were analyzed by frequencies and cross tabulations. Calendar period was used as a proxy measure for HAART exposure and a time plot of the proportion of HIV-positive patients reporting dead per year was used to describe the trends. Logistic regression was used to determine the predictors of mortality at bivariate and multivariate levels, respectively. We included in the analysis 95,857 HIV positive patients; 64% were female with median age of 33 years (interquartile range 27-40). Of these 36,133 (38%) were initiated on ART and a total of 4279 (4.5%) died; 19.5% (835/4279) of those who died had an opportunistic infection. Overall, mortality first increased between 2004 and 2006 and thereafter substantially declined (X²_trend=211.9, P<0.001). Mortality was relatively higher in Eastern Uganda compared to other geographical areas. Male gender, older age (>45 years), being from Eastern or Northern Uganda, having none or primary education, being unemployed, advanced immunodeficiency (CD4 count <100 cell/µL or WHO stage III or IV) and underweight (<45 kg weight) at HAART initiation and calendar period 2004-2008 were significant predictors of mortality (P<0.001). Overall, the expanding coverage of HAART is associated with a declining trend in mortality among HIV positive patients in Uganda. However, mortality trends differed significantly by geographical area and men remain potentially at higher risk of death probably because of delayed initiation on ART. There is urgent need for men targeted interventions for improved ART performance.

Analyzing spatial clustering and the spatiotemporal nature and trends of HIV/AIDS prevalence using GIS: the case of Malawi, 1994-2010

BACKGROUND

Although local spatiotemporal analysis can improve understanding of geographic variation of the HIV epidemic, its drivers, and the search for targeted interventions, it is limited in sub-Saharan Africa. Despite recent declines, Malawi's estimated 10.0% HIV prevalence (2011) remained among the highest globally. Using data on pregnant women in Malawi, this study 1) examines spatiotemporal trends in HIV prevalence 1994-2010, and 2) for 2010, identifies and maps the spatial variation/clustering of factors associated with HIV prevalence at district level.

METHODS

Inverse distance weighting was used within ArcGIS Geographic Information Systems (GIS) software to generate continuous surfaces of HIV prevalence from point data (1994, 1996, 1999, 2001, 2003, 2005, 2007, and 2010) obtained from surveillance antenatal clinics. From the surfaces prevalence estimates were extracted at district level and the results mapped nationally. Spatial dependency (autocorrelation) and clustering of HIV prevalence were also analyzed. Correlation and multiple regression analyses were used to identify factors associated with HIV prevalence for 2010 and their spatial variation/clustering mapped and compared to HIV clustering.

RESULTS

Analysis revealed wide spatial variation in HIV prevalence at regional, urban/rural, district and sub-district levels. However, prevalence was spatially leveling out within and across 'sub-epidemics' while declining significantly after 1999. Prevalence exhibited statistically significant spatial dependence nationally following initial (1995-1999) localized, patchy low/high patterns as the epidemic spread rapidly. Locally, HIV "hotspots" clustered among eleven southern districts/cities while a "coldspot" captured configurations of six central region districts. Preliminary multiple regression of 2010 HIV prevalence produced a model with four significant explanatory factors (adjusted R2 = 0.688): mean distance to main roads, mean travel time to nearest transport, percentage that had taken an HIV test ever, and percentage attaining a senior primary education. Spatial clustering linked some factors to particular subsets of high HIV-prevalence districts.

CONCLUSIONS

Spatial analysis enhanced understanding of local spatiotemporal variation in HIV prevalence, possible underlying factors, and potential for differentiated spatial targeting of interventions. Findings suggest that intervention strategies should also emphasize improved access to health/HIV services, basic education, and syphilis management, particularly in rural hotspot districts, as further research is done on drivers at finer scale.