Embracing different approaches to estimating HIV incidence, prevalence and mortality

Short-term associations of PM2.5 and PM2.5 constituents with immune biomarkers: A panel study in people living with HIV/AIDS

Studies on associations of fine particulate matter (PM_2.5) with immunity in people living with HIV/AIDS (PLWHA) were absent. We aimed to explore whether changes of immune biomarkers were associated with short-term exposure to PM_2.5 in PLWHA. Based on a panel study in Wuhan, we selected 163 PLWHA as participants with up to 4 repeated visits from March 2020 to January 2021. Immune biomarkers, including CD4⁺T cell count, CD8⁺T cell count, HIV viral load (VL) and CD4⁺T/CD8⁺T ratio were tested for all participants at each visit. Residential exposures of PM_2.5 and PM_2.5 constituents for each participant were assessed using spatial-temporal models. Linear mixed-effect models and general linear mixed models were applied to evaluate the associations between PM_2.5 and immune biomarkers. To estimate the combined effect of PM_2.5 constituents, weighted quantile sum regression and Bayesian kernel machine regression were employed. Each 10 μg/m³ increase of 7-day average PM_2.5 concentrations was associated with an 8.75 cells/mm³ (95%CI: -15.55, -1.98) decrease in CD4⁺T cell count and a 92% (OR: 1.92, 95%CI: 1.43, 2.58) increased odds ratio of detectable HIV VL. However, the odds ratio of inverted CD4⁺T/CD8⁺T was only positively associated with PM_2.5 concentrations at lag2 day (OR:1.27, 95%CI:1.02, 1.57). CD4⁺T may be a potential mediator between PM_2.5 and detectable HIV VL with 3.83% mediated proportion. Besides, the combined effect of PM_2.5 chemical constituents indicated that NO₃^- and SO₄^2- were the main constituents in reducing CD4⁺T cell count and increasing odds ratio of detectable HIV VL. Our finding revealed that short-term exposure to PM_2.5 was negatively associated with CD4⁺T cell count but positively related to the odds ratio of detectable HIV VL in PLWHA. This research may provide new evidence in associations between PM_2.5 and immune biomarkers as well as improving prognosis of PLWHA.

HIV incidence estimates by sex and age group in the population aged 15 years or over, Brazil, 1986-2018

INTRODUCTION

HIV incidence estimates are essential to monitor the progress of prevention and control interventions.

METHODS

Data collected by Brazilian surveillance systems were used to derive HIV incidence estimates by age group (15-24; 25+) and sex from 1986 to 2018. This study used a back-calculation method based on the first CD4 count among treatment-naïve cases. Incidence estimates for the population aged 15 years or over were compared to Global Burden of Disease Study (GBD) estimates from 2000 to 2018.

RESULTS

Among young men (15-24 years), HIV incidence increased from 6,400 (95% CI: 4,900-8,400), in 2000, to 12,800 (95% CI: 10,800-15,900), in 2015, reaching incidence rates higher than 70/100,000 inhabitants and an annual growth rate of 3.7%. Among young women, HIV incidence decreased from 5,000 (95% CI: 4,200-6,100) to 3,200 (95% CI: 3,000-3,700). Men aged ≥25 years and both female groups showed significant annual decreases in incidence rates from 2000 to 2018. In 2018, the estimated number of new infections was 48,500 (95% CI: 45300-57500), 34,800 (95% CI: 32800-41500) men, 13,600 (95% CI: 12,500-16,000) women. Improvements in the time from infection to diagnosis and in the proportion of cases receiving antiretroviral therapy immediately after diagnosis were found for all groups. Comparison with GBD estimates shows similar rates for men with overlapping confidence intervals. Among women, differences are higher mainly in more recent years.

CONCLUSIONS

The results indicate that efforts to control the HIV epidemic are having an impact. However, there is an urgent need to address the vulnerability of young men.

The Prevalence of Post-Traumatic Stress Disorder among People Living with HIV/AIDS: a Systematic Review and Meta-Analysis

Numerous studies have reported that the prevalence estimates of post-traumatic stress disorder (PTSD) might be substantially high among people with HIV/AIDS (PLWHA) when compared to the general population. However, there are no previous systematic reviews and meta-analysis studies that reported the pooled prevalence of PTSD among PLWHA. To fill this gap in research, this study aims to analyze data from observational studies concerning the prevalence of PTSD among PLWHA and formulate a recommendation for future research and clinical practice. Three electronic databases (PubMed, EMBASE, and SCOPUS) were searched to identify relevant studies that reported the prevalence of PTSD among PLWHA. A comprehensive meta-analysis software was used to conduct the meta-analysis. Subgroup and sensitivity analysis was conducted the I² test was utilized to evaluate heterogeneity. Publication bias was assessed by using Egger's test and visual inspection of the symmetry in funnel plots. Nineteen-studies with 9094 participants were included in this systematic review and meta-analysis. The pooled prevalence estimate of PTSD among PLWHA was found to be 32.67% (95% CI; 25.29-41.01). The prevalence of PTSD was 25.17% (95% CI; 19.72-31.55) for studies that used diagnostic instrument to assess PTSD and it was 34.68% (95% CI; 25.42-45.26) for studies that used screening instruments. Furthermore, the prevalence of PTSD among PLWHA was comparable between high-income (31.19%) and low, and middle-income countries (34.87%). We also found that the pooled prevalence of PTSD was remarkably higher for moderate and low-quality studies (42.64%) than for high-quality studies (24.84%). The prevalence of PTSD among PLWHA in the current study showed a significant variation by the location of the studies, the instruments used to measure PTSD as well as the quality of the included studies. The present review demonstrated that the prevalence estimates of PTSD among PLWHA (32.67%) was notably high and requires clinical attention. The estimated prevalence of PTSD was found to be comparable between high income and low, and middle-income countries. In addition, we found that the prevalence of PTSD was notably lower when measured by the diagnostic instrument than the screening instrument, although the variation was not statistically significant. Early screening and treatment of PTSD among PLWHA is needed to alleviate suffering.

Global variations in mortality in adults after initiating antiretroviral treatment: an updated analysis of the International epidemiology Databases to Evaluate AIDS cohort collaboration

BACKGROUND

UNAIDS models use data from the International epidemiology Databases to Evaluate AIDS (IeDEA) collaboration in setting assumptions about mortality rates after antiretroviral treatment (ART) initiation. This study aims to update these assumptions with new data, to quantify the extent of regional variation in ART mortality and to assess trends in ART mortality.

METHODS

Adult ART patients from Africa, Asia and the Americas were included if they had a known date of ART initiation during 2001-2017 and a baseline CD4 cell count. In cohorts that relied only on passive follow-up (no patient tracing or linkage to vital registration systems), mortality outcomes were imputed in patients lost to follow-up based on a meta-analysis of tracing study data. Poisson regression models were fitted to the mortality data.

RESULTS

464 048 ART patients were included. In multivariable analysis, mortality rates were lowest in Asia and highest in Africa, with no significant differences between African regions. Adjusted mortality rates varied significantly between programmes within regions. Mortality rates in the first 12 months after ART initiation were significantly higher during 2001-2006 than during 2010-2014, although the difference was more substantial in Asia and the Americas [adjusted incidence rate ratio (aIRR) 1.43, 95% CI: 1.22-1.66] than in Africa (aIRR 1.07, 95% CI: 1.04-1.11).

CONCLUSION

There is substantial variation in ART mortality between and within regions, even after controlling for differences in mortality by age, sex, baseline CD4 category and calendar period. ART mortality rates have declined substantially over time, although declines have been slower in Africa.

Predicting the Antiretroviral Medication Adherence and CD4 Measure in Patients with HIV/AIDS Based on the Post Traumatic Stress Disorder and Depression

BACKGROUND

Antiretroviral therapy has significantly reduced the prevalence of diseases and mortality rate caused by HIV; therefore, recognition of the factors affecting the antiretroviral therapy is of great importance. We aimed to investigate the relationship between antiretroviral medication adherence and CD4 with posttraumatic stress disorder (PTSD) and depression in patients with HIV.

METHODS

This was a descriptive, cross-sectional, quantitative, and correlational study. The statistical population included all of the patients with HIV in Shiraz, Fars Province, southwest of Iran in 2013, of whom 220 were selected from the Behavioral Diseases Consultation Center using the convenience sampling method. The measures included Mississippi Post Traumatic Stress Disorder Questionnaire, Beck-II Depression, and ACTG Adherence (ACTG). The results were analyzed using the Pearson correlation method and stepwise hierarchical multivariate regression.

RESULTS

Regression analysis showed that of two mediating variables (age & educational level), only age could predict 5% (P<0.001) and of two predictive variables (depression & PTSD) only PTSD could predict 53% (P<0.001) of medication adherence's variance. Moreover, of two mediating variables (age & disease duration), only age could predict 3% (P<0.004) and of two predictive variables (depression & PTSD) only PTSD could predict 4% (P<0.001) of CD4 variance.

CONCLUSION

The posttraumatic stress disorder symptoms could predict the medication non-adherence and lower CD4 levels.

Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

Non-fatal outcomes of disease and injury increasingly detract from the ability of the world's population to live in full health, a trend largely attributable to an epidemiological transition in many countries from causes affecting children, to non-communicable diseases (NCDs) more common in adults. For the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015), we estimated the incidence, prevalence, and years lived with disability for diseases and injuries at the global, regional, and national scale over the period of 1990 to 2015.

METHODS

We estimated incidence and prevalence by age, sex, cause, year, and geography with a wide range of updated and standardised analytical procedures. Improvements from GBD 2013 included the addition of new data sources, updates to literature reviews for 85 causes, and the identification and inclusion of additional studies published up to November, 2015, to expand the database used for estimation of non-fatal outcomes to 60 900 unique data sources. Prevalence and incidence by cause and sequelae were determined with DisMod-MR 2.1, an improved version of the DisMod-MR Bayesian meta-regression tool first developed for GBD 2010 and GBD 2013. For some causes, we used alternative modelling strategies where the complexity of the disease was not suited to DisMod-MR 2.1 or where incidence and prevalence needed to be determined from other data. For GBD 2015 we created a summary indicator that combines measures of income per capita, educational attainment, and fertility (the Socio-demographic Index [SDI]) and used it to compare observed patterns of health loss to the expected pattern for countries or locations with similar SDI scores.

FINDINGS

We generated 9·3 billion estimates from the various combinations of prevalence, incidence, and YLDs for causes, sequelae, and impairments by age, sex, geography, and year. In 2015, two causes had acute incidences in excess of 1 billion: upper respiratory infections (17·2 billion, 95% uncertainty interval [UI] 15·4-19·2 billion) and diarrhoeal diseases (2·39 billion, 2·30-2·50 billion). Eight causes of chronic disease and injury each affected more than 10% of the world's population in 2015: permanent caries, tension-type headache, iron-deficiency anaemia, age-related and other hearing loss, migraine, genital herpes, refraction and accommodation disorders, and ascariasis. The impairment that affected the greatest number of people in 2015 was anaemia, with 2·36 billion (2·35-2·37 billion) individuals affected. The second and third leading impairments by number of individuals affected were hearing loss and vision loss, respectively. Between 2005 and 2015, there was little change in the leading causes of years lived with disability (YLDs) on a global basis. NCDs accounted for 18 of the leading 20 causes of age-standardised YLDs on a global scale. Where rates were decreasing, the rate of decrease for YLDs was slower than that of years of life lost (YLLs) for nearly every cause included in our analysis. For low SDI geographies, Group 1 causes typically accounted for 20-30% of total disability, largely attributable to nutritional deficiencies, malaria, neglected tropical diseases, HIV/AIDS, and tuberculosis. Lower back and neck pain was the leading global cause of disability in 2015 in most countries. The leading cause was sense organ disorders in 22 countries in Asia and Africa and one in central Latin America; diabetes in four countries in Oceania; HIV/AIDS in three southern sub-Saharan African countries; collective violence and legal intervention in two north African and Middle Eastern countries; iron-deficiency anaemia in Somalia and Venezuela; depression in Uganda; onchoceriasis in Liberia; and other neglected tropical diseases in the Democratic Republic of the Congo.

INTERPRETATION

Ageing of the world's population is increasing the number of people living with sequelae of diseases and injuries. Shifts in the epidemiological profile driven by socioeconomic change also contribute to the continued increase in years lived with disability (YLDs) as well as the rate of increase in YLDs. Despite limitations imposed by gaps in data availability and the variable quality of the data available, the standardised and comprehensive approach of the GBD study provides opportunities to examine broad trends, compare those trends between countries or subnational geographies, benchmark against locations at similar stages of development, and gauge the strength or weakness of the estimates available.

FUNDING

Bill & Melinda Gates Foundation.

PTSD co-morbid with HIV: Separate but equal, or two parts of a whole?

Approximately 30 million people currently live with HIV worldwide and the incidence of stress-related disorders, such as post-traumatic stress disorder (PTSD), is elevated among people living with HIV as compared to those living without the virus. PTSD is a severely debilitating, stress-related psychiatric illness associated with trauma exposure. Patients with PTSD experience intrusive and fearful memories as well as flashbacks and nightmares of the traumatic event(s) for much of their lives, may avoid other people, and may be constantly on guard for new negative experiences. This review will delineate the information available to date regarding the comorbidity of PTSD and HIV and discuss the biological mechanisms which may contribute to the co-existence, and potential interaction of, these two disorders. Both HIV and PTSD are linked to altered neurobiology within areas of the brain involved in the startle response and altered function of the hypothalamic-pituitary-adrenal axis. Collectively, the data highlighted suggest that PTSD and HIV are more likely to actively interact than to simply co-exist within the same individual. Multi-faceted interactions between PTSD and HIV have the potential to alter response to treatment for either independent disorder. Therefore, it is of great importance to advance the understanding of the neurobiological substrates that are altered in comorbid PTSD and HIV such that the most efficacious treatments can be administered to improve both mental and physical health and reduce the spread of HIV.

Untangling the Gordian knot of HIV, stress, and cognitive impairment

As individuals live longer with HIV, this "graying of the HIV epidemic" has introduced a new set of challenges including a growing number of age and inflammation-related diseases such as cardiovascular disease, type II diabetes, cancer, and dementia. The biological underpinnings of these complex and co-morbid diseases are not fully understood and become very difficult to disentangle in the context of HIV and aging. In the current review we examine the contributions and interactions of HIV, stress, and cognitive impairment and query the extent to which inflammation is the linchpin in these dynamic interactions. Given the inter-relatedness of stress, inflammatory mechanisms, HIV, and cognitive impairment, future work will either need to address multiple dimensions simultaneously or embrace the philosophy that breaking the aberrant cycle at any one point will subsequently remedy the other related systems and processes. Such a single-point intervention may be effective in early disease states, but after perpetuation of an aberrant cycle, adaptations in an attempt to internally resolve the issue will likely lead to the need for multifaceted interventions. Acknowledging that HIV, inflammation, and stress may interact with one another and collectively impact cognitive ability is an important step in fully understanding an individual's complete clinical picture and moving towards personalized medicine.

Estimating mother-to-child HIV transmission rates in Cameroon in 2011: a computer simulation approach

BACKGROUND

Despite the progress in the Prevention of the Mother-to-Child Transmission of HIV (PMTCT), the paediatric HIV epidemic remains worrying in Cameroon. HIV prevalence rate for the population of pregnant women was 7.6% in 2010 in Cameroon. The extent of the paediatric HIV epidemic is needed to inform policymakers. We developed a stochastic simulation model to estimate the number of new paediatric HIV infections through MTCT based on the observed uptake of services during the different steps of the PMTCT cascade in Cameroon in 2011. Different levels of PMTCT uptake was also assessed.

METHODS

A discrete events computer simulation-based approach with stochastic structure was proposed to generate a cohort of pregnant women followed-up until 6 weeks post-partum, and optionally until complete breastfeeding cessation in both prevalent and incident lactating HIV-infected women. The different parameters of the simulation model were fixed using data sources available from the 2011 national registry surveys, and from external cohorts in Cameroon. Different PMTCT coverages were simulated to assess their impact on MTCT. Available data show a low coverage of PMTCT services in Cameroon in 2011.

RESULTS

Based on a simulation approach on a population of 995, 533 pregnant women, the overall residual MTCT rate in 2011 was estimated to be 22.1% (95 % CI: 18.6%-25.2%), the 6-week perinatal MTCT rate among prevalent HIV-infected mothers at delivery is estimated at 12.1% (95% CI: 8.1%-15.1%), with an additional postnatal MTCT rate estimated at 13.3% (95% CI: 9.3%-17.8%). The MTCT rate among children whose mothers seroconverted during breastfeeding was estimated at 20.8% (95% CI: 14.1%-26.9%). Overall, we estimated the number of new HIV infections in children in Cameroon to be 10, 403 (95% CI: 9, 054-13, 345) in 2011. When PMTCT uptake have been fixed at 100%, 90% and 80%, global MTCT rate failed to 0.9% (9% CI: 0.5%-1.7%), 2.0% (95% CI: 0.9%-3.2%) and 4.3% (95% CI: 2.4%-6.7%) respectively.

CONCLUSIONS

This model is helpful to provide MTCT estimates to guide the national HIV policy in Cameroon. Increasing supply and uptake of PMTCT services among prevalent HIV infected pregnant women, as well as HIV-prevention interventions including the offer and acceptance of HIV testing and counselling in lactating women could reduce significantly the residual HIV MTCT in Cameroon. A public health effort should be made to encourage health care workers and pregnant women to use PMTCT services until complete breastfeeding cessation.

HIV Incidence and Spatial Clustering in a Rural Area of Southern Mozambique

Background

Monitoring the HIV epidemic in a defined population is critical for planning treatment and preventive strategies. This is especially important in sub-Saharan Africa, which harbours the highest burden of the disease.

Objective

To estimate HIV incidence in adults aged 18-47 years old and to investigate spatial variations of HIV prevalence in Manhiça, a semi-rural area of southern Mozambique.

Methods

Two cross-sectional community-based surveys were conducted in 2010 and 2012 to determine HIV prevalence. Individual participants were randomly selected from the demographic surveillance system in place in the area and voluntary HIV counselling and testing was offered at the household level. HIV incidence was calculated using prevalence estimates from the two sero-surveys. Each participant’s household was geocoded using a global information system. The Spatial Scan Statistics programme was used to identify areas with disproportionate excess in HIV prevalence.

Results

A total of 1511 adults were tested. The estimated HIV prevalence in the community was 39.9% in 2010 and 39.7% in 2012. The overall HIV incidence was 3.6 new infections per 100 person-years at risk (PYAR) [95CI 1.56; 7.88], assuming stable epidemic conditions, and tended to be higher in women (4.9/100 PYAR [95CI 1.74; 11.85]) than in men (3.2/PYAR [95CI 1.36; 9.92]). One cluster with significant excess HIV prevalence was identified at the same geographic location in both surveys. This cluster had an HIV prevalence of 79.0% in 2010 and 52.3% in 2012.

Conclusions

The findings of these first individually-randomised community-HIV sero-surveys conducted in Mozambique reinforce the need to combine HIV incidence estimates and research on micro geographical infection patterns to guide and consolidate effective prevention strategies.