Cost-effectiveness of early infant HIV diagnosis of HIV-exposed infants and immediate antiretroviral therapy in HIV-infected children under 24 months in Thailand

Development and evaluation of a high-sensitivity RT-PCR lateral flow assay for early detection of HIV-1 infection

Early diagnosis of HIV-1 is crucial to minimize transmission, morbidity, and mortality, particularly for neonates with developing immune systems. This study aimed to develop and evaluate a simplified, high-sensitivity assay for early HIV-1 detection before seroconversion. The assay utilizes reverse-transcription-polymerase chain reaction (RT-PCR) to amplify the HIV-1 RNA protease gene. Digoxigenin (dig)-labeled forward, and biotin-labeled universal reverse primers are used, generating digoxigenin-amplicon-biotin (DAB) products. These products are detected using a lateral flow assay (LFA) containing a conjugated pad with colloidal gold-labeled 6-histidine tag-fused maltose-binding protein-monomeric streptavidin (6HISMBP-mSA-CGC). Anti-dig monoclonal antibody (mAb) and biotinylated-BSA are immobilized in the test and control line zones, respectively. Five plasma samples with known viral load (VL) were used to simulate the efficacy of early HIV-1 detection. RNA extracted from these samples was amplified by RT-PCR using the labeled primers, and DAB products were examined on agarose gel electrophoresis and LFA. RT-PCR from diluted clinical samples yielded visible DNA bands in agarose gel electrophoresis, consistent with positive LFA results. Conversely, negative samples only displayed the control line on LFA. This assay exhibited a limit of detection (LOD) of 82.29 RNA copies/mL, comparable to other nucleic acid amplification tests (NAATs). This novel technique provides a highly sensitive assay for early HIV-1 diagnosis, even with low VL, making it suitable for resource-limited settings.

A focused multi-state model to estimate the pediatric and adolescent HIV epidemic in Thailand, 2005–2025

Background

We estimated the magnitude of the HIV epidemic among children and youth living with HIV (CYHIV) aged 0–25 years in Thailand, projecting forward from 2005 to 2025, and identified underreported input parameters that influence epidemic projections, in order to inform future public health and research priorities.

Methods

We developed a focused multi-state transition model incorporating perinatally-acquired HIV and non-perinatally-acquired HIV, stratified by population, including men who have sex with men (MSM), female sex workers (FSW), people who inject drugs (PWID), and the remainder of the population (“other”). We populated the model with published and programmatic data from the Thai national AIDS program when available. We projected the period from 2005–2025 and compared model results to programmatic data and projections from other models. In a scenario analysis, we projected the potential impact of pre-exposure prophylaxis (PrEP) for MSM from 2018–2025.

Results

The initial 2005 cohort was comprised of 66,900 CYHIV; 8% CYHIV were <5 years, 21% were 5–14 years, and 71% were 15–25 years of age. By 2020, 94% were projected to be >15 years and infections among MSM constituted 83% of all new HIV infections. The numbers of CYHIV decreased over time, projected to reach 30,760 by 2020 (-54%) and 22,640 by 2025 (-66%). The proportion of all CYHIV aged 0–25 who were diagnosed and on ART increased from 37 to 60% over the 2005–2025 period. Projections were sensitive to variations in assumptions about initial HIV prevalence and incidence among MSM, PWID, and “other” youth.

Conclusions

More data on incidence rates among sexual and gender minority youth and PWID are needed to characterize the role of specific exposures and key populations in the adolescent HIV epidemic. More accurate estimates will project shifts in population and inform more targeted interventions to prevent and care for Thai CYHIV.

Costs and cost-effectiveness of HIV early infant diagnosis in low- and middle-income countries: a scoping review

Background

Continuing progress in the global pediatric human immunodeficiency virus (HIV) response depends on timely identification and care of infants with HIV. As countries scale-out improvements to HIV early infant diagnosis (EID), economic evaluations are needed to inform program design and implementation. This scoping review aimed to summarize the available evidence and discuss practical implications of cost and cost-effectiveness analyses of HIV EID.

Methods

We systematically searched bibliographic databases (Embase, MEDLINE and EconLit) and grey literature for economic analyses of HIV EID in low- and middle-income countries published between January 2008 and June 2021. We extracted data on unit costs, cost savings, and incremental cost-effectiveness ratios as well as outcomes related to health and the HIV EID care process and summarized results in narrative and tabular formats. We converted unit costs to 2021 USD for easier comparison of costs across studies.

Results

After title and abstract screening of 1278 records and full-text review of 99 records, we included 29 studies: 17 cost analyses and 12 model-based cost-effectiveness analyses. Unit costs were 21.46–51.80 USD for point-of-care EID tests and 16.21–42.73 USD for laboratory-based EID tests. All cost-effectiveness analyses stated at least one of the interventions evaluated to be cost-effective. Most studies reported costs of EID testing strategies; however, few studies assessed the same intervention or reported costs in the same way, making comparison of costs across studies challenging. Limited data availability of context-appropriate costs and outcomes of children with HIV as well as structural heterogeneity of cost-effectiveness modelling studies limits generalizability of economic analyses of HIV EID.

Conclusions

The available cost and cost-effectiveness evidence for EID of HIV, while not directly comparable across studies, covers a broad range of interventions and suggests most interventions designed to improve EID are cost-effective or cost-saving. Further studies capturing costs and benefits of EID services as they are delivered in real-world settings are needed.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-01006-7.

Barriers to early infant diagnosis of HIV in the Wa Municipality and Lawra District of Upper West Region, Ghana

Objective

We identified socio-demographic, health system and psycho-social barriers to Early Infant Diagnosis (EID) of HIV in the Upper West Region of Ghana.

Design

An unmatched case control study of 96 cases and 96 controls was conducted in the ART centers in Lawra district and Wa Municipality between December 2014 and April 2015.

Setting

A public health facility

Participants

We defined a case as an HIV positive mother with an exposed infant who received EID service between January 2011 and December 2014. A control was defined as HIV Positive Mother with an exposed infant who did not receive EID services between January 2011 and December 2014.

Main outcome

EID by dry blood spot Deoxyribonucleic acid Polymerase chain reaction.

Results

A total of 192 mother-infant pairs were assessed. The mean age of infants at testing for cases was 17.3±14.9 weeks. Mother-to-child-transmission-rate was 2.3%. Factors associated with EID testing included: mother being formally employed (cOR=2.0: 95%CI:1.1–3.8), maternal formal education (cOR=2.0, 95%CI: 1.1–3.6) and maternal independent source of income (cOR 2.2, 95%CI 1.2–4.1). After adjusting for confounders, maternal independent income source was associated with EID testing (aOR 2.2, 95%CI 1.2–4.1). Median turn-around time of EID result was 11 weeks (IQR 4–27 weeks).

Conclusion

Women need to be empowered to gain an independent source of income. This can help maximize the benefits of e-MTCT and increase EID in the Upper West Region of Ghana.

Funding

This work was funded by the authors

Cost-Effectiveness of antiretroviral therapy: A systematic review

Background

The mobilization of resources to prevent and treat human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) is unparalleled in the history of public health. The uptake of antiretroviral therapy (ART) has been rapid and unprecedented and made possible by the availability of funding - external and domestic. To justify continuous funding of ART in resource-scarce settings, a spate of cost-effectiveness studies has been undertaken in a number of countries. This paper is based on a systematic review of global studies on cost-effectiveness analysis of ART.

Objectives

The major objective was to review the existing literature on cost-effectiveness of ART to determine whether ART has been cost-effective (CE) in different settings.

Methods

We searched PubMed and Google Scholar for articles published between 2008 and 2017. We included studies that measured costs as well as effectiveness of HIV treatment - specifically ART - using incremental cost-effectiveness ratio as one of the outcomes.

Results

We identified 15 studies that met the search criteria for inclusion in the systematic review. The review confirms that ART programs have been CE across different settings, contexts, and strategies.

Conclusion

The review would be useful for countries that are straining to raise funds for the health sector, generally, and for AIDS prevention and control program, specifically. This would also be beneficial for carrying out similar studies, if necessary, and as an advocacy tool for garnering additional funding.

Associations of Sociodemographic and Clinical Factors with Late Presentation for Early Infant HIV Diagnosis (EID) Services in Kenya

BACKGROUND

Understanding the missed opportunities in early infant HIV testing within the PMTCT program is essential to address any gaps. The study set out to describe the clinical and sociodemographic characteristics of the infants presenting late for early infant diagnosis in Kenya.

METHODS

We abstracted routinely collected clinical and sociodemographic characteristics, in a cross-sectional study, on all HIV-infected infants with a positive polymerase chain reaction (PCR) test from 1,346 President's Emergency Plan for AIDS Relief (PEPFAR) supported health facilities for the period October 2016 to September 2018. We used multivariate logistic regression to examine the association of sociodemographic and clinical characteristics with late (>2 months after birth) presentation for infant HIV testing.

RESULTS

Of the 4,011 HIV-infected infants identified, the median infant age at HIV diagnosis was 3 months [interquartile range (IQR), 1-16 months], and two-thirds [2,669 (66.5%)] presented late for infant HIV testing. Factors that were associated with late presentation for infant testing were: maternal ANC non-attendance, adjusted odds ratio (aOR) 1.41 (95% confidence interval (CI) 1.18 -1.69); new maternal HIV diagnosis, aOR 1.45, (95%CI 1.24 -1.7); and lack of maternal antiretroviral therapy(ART), aOR 1.94, (95% CI 1.64 - 2.30). There was a high likelihood of identifying HIV-infected infants among infants who presented for medical services in the outpatient setting (aOR 18.9; 95% CI 10.2 - 34.9) and inpatient setting (aOR 12.2; 95% CI 6.23-23.9) compared to the infants who presented late in maternity.

CONCLUSION AND GLOBAL HEALTH IMPLICATIONS

Gaps in early infant HIV testing suggest the need to increase maternal pre-pregnancy HIV diagnosis, timely antenatal care, early infant diagnosis services, early identification of mothers who seroconvert during pregnancy or breastfeeding and improved HIV screening in outpatient and inpatient settings. Early referral from the community and access to health facilities should be strengthened by the implementation of national PMTCT guidelines.

The potential for quality assurance systems to save costs and lives: the case of early infant diagnosis of HIV

OBJECTIVES

Scaling up of point-of-care testing (POCT) for early infant diagnosis of HIV (EID) could reduce the large gap in infant testing. However, suboptimal POCT EID could have limited impact and potentially high avoidable costs. This study models the cost-effectiveness of a quality assurance system to address testing performance and screening interruptions, due to, for example, supply stockouts, in Kenya, Senegal, South Africa, Uganda and Zimbabwe, with varying HIV epidemics and different health systems.

METHODS

We modelled a quality assurance system-raised EID quality from suboptimal levels: that is, from misdiagnosis rates of 5%, 10% and 20% and EID testing interruptions in months, to uninterrupted optimal performance (98.5% sensitivity, 99.9% specificity). For each country, we estimated the 1-year impact and cost-effectiveness (US$/DALY averted) of improved scenarios in averting missed HIV infections and unneeded HIV treatment costs for false-positive diagnoses.

RESULTS

The modelled 1-year costs of a national POCT quality assurance system range from US$ 69 359 in South Africa to US$ 334 341 in Zimbabwe. At the country level, quality assurance systems could potentially avert between 36 and 711 missed infections (i.e. false negatives) per year and unneeded treatment costs between US$ 5808 and US$ 739 030.

CONCLUSIONS

The model estimates adding effective quality assurance systems are cost-saving in four of the five countries within the first year. Starting EQA requires an initial investment but will provide a positive return on investment within five years by averting the costs of misdiagnoses and would be even more efficient if implemented across multiple applications of POCT.

Simulation Modeling and Metamodeling to Inform National and International HIV Policies for Children and Adolescents

Objective and Approach:

Computer-based simulation models serve an important purpose in informing HIV care for children and adolescents. We review current model-based approaches to informing pediatric and adolescent HIV estimates and guidelines.

Findings:

Clinical disease simulation models and epidemiologic models are used to inform global and regional estimates of numbers of children and adolescents living with HIV and in need of antiretroviral therapy, to develop normative guidelines addressing strategies for diagnosis and treatment of HIV in children, and to forecast future need for pediatric and adolescent antiretroviral therapy formulations and commodities. To improve current model-generated estimates and policy recommendations, better country-level and regional-level data are needed about children living with HIV, as are improved data about survival and treatment outcomes for children with perinatal HIV infection as they age into adolescence and adulthood. In addition, novel metamodeling and value of information methods are being developed to improve the transparency of model methods and results, as well as to allow users to more easily tailor model-based analyses to their own settings.

Conclusions:

Substantial progress has been made in using models to estimate the size of the pediatric and adolescent HIV epidemic, to inform the development of guidelines for children and adolescents affected by HIV, and to support targeted implementation of policy recommendations to maximize impact. Ongoing work will address key limitations and further improve these model-based projections.

Trends and Patterns of Differences in Infectious Disease Mortality Among US Counties, 1980-2014

IMPORTANCE

Infectious diseases are mostly preventable but still pose a public health threat in the United States, where estimates of infectious diseases mortality are not available at the county level.

OBJECTIVE

To estimate age-standardized mortality rates and trends by county from 1980 to 2014 from lower respiratory infections, diarrheal diseases, HIV/AIDS, meningitis, hepatitis, and tuberculosis.

DESIGN AND SETTING

This study used deidentified death records from the National Center for Health Statistics (NCHS) and population counts from the US Census Bureau, NCHS, and the Human Mortality Database. Validated small-area estimation models were applied to these data to estimate county-level infectious disease mortality rates.

EXPOSURES

County of residence.

MAIN OUTCOMES AND MEASURES

Age-standardized mortality rates of lower respiratory infections, diarrheal diseases, HIV/AIDS, meningitis, hepatitis, and tuberculosis by county, year, and sex.

RESULTS

Between 1980 and 2014, there were 4 081 546 deaths due to infectious diseases recorded in the United States. In 2014, a total of 113 650 (95% uncertainty interval [UI], 108 764-117 942) deaths or a rate of 34.10 (95% UI, 32.63-35.38) deaths per 100 000 persons were due to infectious diseases in the United States compared to a total of 72 220 (95% UI, 69 887-74 712) deaths or a rate of 41.95 (95% UI, 40.52-43.42) deaths per 100 000 persons in 1980, an overall decrease of 18.73% (95% UI, 14.95%-23.33%). Lower respiratory infections were the leading cause of infectious diseases mortality in 2014 accounting for 26.87 (95% UI, 25.79-28.05) deaths per 100 000 persons (78.80% of total infectious diseases deaths). There were substantial differences among counties in death rates from all infectious diseases. Lower respiratory infection had the largest absolute mortality inequality among counties (difference between the 10th and 90th percentile of the distribution, 24.5 deaths per 100 000 persons). However, HIV/AIDS had the highest relative mortality inequality between counties (10.0 as the ratio of mortality rate in the 90th and 10th percentile of the distribution). Mortality from meningitis and tuberculosis decreased over the study period in all US counties. However, diarrheal diseases were the only cause of infectious diseases mortality to increase from 2000 to 2014, reaching a rate of 2.41 (95% UI, 0.86-2.67) deaths per 100 000 persons, with many counties of high mortality extending from Missouri to the northeastern region of the United States.

CONCLUSIONS AND RELEVANCE

Between 1980 and 2014, there were declines in mortality from most categories of infectious diseases, with large differences among US counties. However, over this time there was an increase in mortality for diarrheal diseases.

Survival of HIV-1 vertically infected children

PURPOSE OF REVIEW

It is 20 years since the start of the combination antiretroviral therapy (cART) era and more than 10 years since cART scale-up began in resource-limited settings. We examined survival of vertically HIV-infected infants and children in the cART era.

RECENT FINDINGS

Good survival has been achieved on cART in all settings with up to 10-fold mortality reductions compared with before cART availability. Although mortality risk remains high in the first few months after cART initiation in young children with severe disease, it drops rapidly thereafter even for those who started with advanced disease, and longer term mortality risk is low. However, suboptimal retention on cART in routine programs threatens good survival outcomes and even on treatment children continue to experience high comorbidity risk; infections remain the major cause of death. Interventions to address infection risk include a cotrimoxazole prophylaxis, isoniazid preventive therapy, routine childhood and influenza immunization, and improving maternal survival.

SUMMARY

Pediatric survival has improved substantially with cART and HIV-infected children are aging into adulthood. It is important to ensure access to diagnosis and early cART, good program retention as well as optimal comorbidity prophylaxis and treatment to achieve the best possible long-term survival and health outcomes for vertically infected children.

Elimination of mother-to-child transmission of HIV: lessons learned from success in Thailand

In 1988, the generalised HIV/AIDS epidemic in Thailand began and in the same year the first HIV-exposed infant in Thailand was born at King Chulalongkorn Memorial Hospital, Bangkok. From the early to mid-1990s, an epidemic wave of HIV-infected women and infants occurred. Heterosexual HIV transmission, as described in the Asian Epidemic Model, was the major mode of spread in Thailand, causing an increasing number of HIV-infected pregnant women. The early and concerted multi-sectoral response of Thai society reduced the prevalence of HIV infection in pregnant women from 2% in the mid-1990s to 0.6% in 2015 and mother-to-child transmission of HIV (MTCT) from an estimated 20-40% to 1.9%. Thus, Thailand became the first Asian country to achieve the World Health Organization's (WHO) targets for the elimination of MTCT. In this narrative review, the key historic evolutions of the science and policy of prevention of mother-to-child transmission of HIV (PMTCT) in Thailand that addressed the four prongs of the recommended WHO PMTCT strategy are described, and the lessons learned are discussed.

Clinical Impact and Cost-effectiveness of Diagnosing HIV Infection During Early Infancy in South Africa: Test Timing and Frequency

BACKGROUND

 Diagnosis of human immunodeficiency virus (HIV) infection during early infancy (commonly known as "early infant HIV diagnosis" [EID]) followed by prompt initiation of antiretroviral therapy dramatically reduces mortality. EID testing is recommended at 6 weeks of age, but many infant infections are missed.

DESIGN/METHODS

 We simulated 4 EID testing strategies for HIV-exposed infants in South Africa: no EID (diagnosis only after illness; hereafter, "no EID"), testing once (at birth alone or at 6 weeks of age alone; hereafter, "birth alone" and "6 weeks alone," respectively), and testing twice (at birth and 6 weeks of age; hereafter "birth and 6 weeks"). We calculated incremental cost-effectiveness ratios (ICERs), using discounted costs and life expectancies for all HIV-exposed (infected and uninfected) infants.

RESULTS

 In the base case (guideline-concordant care), the no EID strategy produced a life expectancy of 21.1 years (in the HIV-infected group) and 61.1 years (in the HIV-exposed group); lifetime cost averaged $1430/HIV-exposed infant. The birth and 6 weeks strategy maximized life expectancy (26.5 years in the HIV-infected group and 61.4 years in the HIV-exposed group), costing $1840/infant tested. The ICER of the 6 weeks alone strategy versus the no EID strategy was $1250/year of life saved (19% of South Africa's per capita gross domestic product); the ICER for the birth and 6 weeks strategy versus the 6 weeks alone strategy was $2900/year of life saved (45% of South Africa's per capita gross domestic product). Increasing the proportion of caregivers who receive test results and the linkage of HIV-positive infants to antiretroviral therapy with the 6 weeks alone strategy improved survival more than adding a second test.

CONCLUSIONS

 EID at birth and 6 weeks improves outcomes and is cost-effective, compared with EID at 6 weeks alone. If scale-up costs are comparable, programs should add birth testing after strengthening 6-week testing programs.

Early infant HIV diagnosis and entry to HIV care cascade in Thailand: an observational study

BACKGROUND

Early infant diagnosis of HIV is crucial for timely initiation of antiretroviral therapy (ART) in infected children who are at high risk of mortality. Early infant diagnosis with dried blood spot testing was provided by the National AIDS Programme in Thailand from 2007. We report ART initiation and vital status in children with HIV after 7 years of rollout in Thailand.

METHODS

Dried blood spot samples were collected from HIV-exposed children in hospitals in Thailand and mailed to the Faculty of Associated Medical Sciences, Chiang Mai University, where HIV DNA was assessed with real-time PCR to establish HIV infection. We linked data from children with an HIV infection to the National AIDS Programme database to ascertain ART and vital status.

FINDINGS

Between April 5, 2007, and Oct 1, 2014, 16 046 dried blood spot samples were sent from 8859 children in 364 hospitals in Thailand. Median age at first dried blood spot test was 2·1 (IQR 1·8-2·5) months. Of 7174 (81%) children with two or more samples, 223 (3%) were HIV positive (including five unconfirmed). Of 1685 (19%) children with one sample, 70 (4%) were unconfirmed positive. Of 293 (3%) children who were HIV positive, 220 (75%) registered for HIV care and 170 (58%) initiated ART. Median age at ART initiation decreased from 14·2 months (IQR 10·2-25·6) in 2007 to 6·1 months (4·2-9·2) in 2013, and the number of children initiating ART aged younger than 1 year increased from five (33%) of 15 children initiating ART in 2007 to ten (83%) of 12 initiating ART in 2013. 15 (9%) of 170 children who initiated ART died and 16 (32%) of 50 who had no ART record died.

INTERPRETATION

Early infant diagnosis with dried blood spot testing had high uptake in primary care settings. Further improvement of linkage to HIV care is needed to ensure timely treatment of all children with an HIV infection.

FUNDING

None.