International Epidemiology Databases To Evaluate AIDS Research Articles

Brief Report: Pediatric Cancer Burden and Treatment Resources Within the Pediatric IeDEA Consortium.

The incidence and treatment of cancer in HIV-infected children from resource-limited settings has not been extensively studied. Develop and implement a cross-sectional survey to evaluate pediatric cancer burden, diagnostic modalities in use, and treatment availability as perceived by HIV clinic staff at regional International Epidemiology Databases to Evaluate AIDS (IeDEA) sites. IeDEA regional investigators developed a cross-sectional clinical site survey which included questions on the numbers and types of pediatric cancers observed, modalities used to treat identified cancers, and treatment options available at individual sites in the Asia-Pacific, Latin America, Central Africa, East Africa, West Africa, and Southern Africa regions. Kaposi sarcoma, non-Hodgkin lymphoma, and Burkitt lymphoma were reported by site personnel to be the most prevalent types of cancer in the pediatric HIV population. Survey results indicate that access to comprehensive cancer treatment modalities is very limited for children in these regions despite HIV care and treatment sites reporting that they diagnose pediatric cancers. Responses also showed that evaluating cancer in the pediatric HIV population is a challenge due to a lack of resources and varying treatment availability within regions. Further study is needed to increase our understanding of the changing epidemiology of cancer in HIV-infected pediatric populations. Increased financial and technical resources are critical to aid in the advancement of health services to support treatment of these children in resource-constrained settings.

Tuberculosis Treatment Outcomes Among HIV/TB-Coinfected Children in the International Epidemiology Databases to Evaluate AIDS (IeDEA) Network.

Management of tuberculosis (TB) is challenging in HIV/TB-coinfected children. The World Health Organization recommends nucleic acid amplification tests for TB diagnosis, a 4-drug regimen including ethambutol during intensive phase (IP) of treatment, and initiation of antiretroviral therapy (ART) within 8 weeks of TB diagnosis. We investigated TB treatment outcomes by diagnostic modality, IP regimen, and ART status. We conducted a retrospective cohort study among HIV/TB-coinfected children enrolled at the International Epidemiology Databases to Evaluate AIDS treatment sites from 2012 to 2014. We modeled TB outcome using multivariable logistic regression including diagnostic modality, IP regimen, and ART status. Among the 386 HIV-infected children diagnosed with TB, 20% had microbiologic confirmation of TB, and 20% had unfavorable TB outcomes. During IP, 78% were treated with a 4-drug regimen. Thirty-one percent were receiving ART at the time of TB diagnosis, and 32% were started on ART within 8 weeks of TB diagnosis. Incidence of ART initiation within 8 weeks of TB diagnosis was higher for those with favorable TB outcomes (64%) compared with those with unfavorable outcomes (40%) (P = 0.04). Neither diagnostic modality (odds ratio 1.77; 95% confidence interval: 0.86 to 3.65) nor IP regimen (odds ratio 0.88; 95% confidence interval: 0.43 to 1.80) was associated with TB outcome. In this multinational study of HIV/TB-coinfected children, many were not managed as per World Health Organization guidelines. Children with favorable TB outcomes initiated ART sooner than children with unfavorable outcomes. These findings highlight the importance of early ART for children with HIV/TB coinfection, and reinforce the need for implementation research to improve pediatric TB management.

Low implementation of Xpert MTB/RIF among HIV/TB co-infected adults in the International epidemiologic Databases to Evaluate AIDS (IeDEA) program.

ObjectiveXpert MTB/RIF is recommended by the World Health Organization (WHO) as the initial tuberculosis (TB) diagnostic test in individuals suspected of HIV-associated TB. We sought to evaluate field implementation of Xpert among a cohort of HIV/TB co-infected individuals, including availability, utilization and outcomes.DesignObservational cohort study (patient-level data) and cross-sectional study (site-level Xpert availability data).MethodsData were collected at 30 participating International epidemiologic Databases to Evaluate AIDS (IeDEA) sites in 18 countries from January 2012-January 2016. All patients were HIV-infected and diagnosed with TB, either bacteriologically or clinically, and followed until a determination of TB treatment outcome. We used multivariable modified Poisson regression to estimate adjusted relative risk (RR) and 95% confidence intervals for unfavorable TB treatment outcomes.ResultsMost sites (63%) had access to Xpert, either in the clinic (13%), in the same facility (20%) or offsite (30%). Among 2722 HIV/TB patients included, median age was 35.4 years and 41% were female; BMI and CD4 count were low. Overall, most patients (76%) received at least one TB test; 45% were positive. Only 4% of all patients were tested using Xpert: 64% were Xpert-positive, 13% showed rifampicin (RIF) resistance and 30% were extrapulmonary (EPTB) or both pulmonary-EPTB. Treatment outcomes were mostly favorable (77%) and we found little association between Xpert use and an unfavorable TB treatment outcome (RR 1.25, 95%CI: 0.83, 1.90).ConclusionsIn this cohort, Xpert utilization was low even though the majority of sites had access to the test. Our findings show the need for expanded implementation and further research exploring barriers to use in low-resource settings.

Targeted Spontaneous Reporting: Assessing Opportunities to Conduct Routine Pharmacovigilance for Antiretroviral Treatment on an International Scale.

IntroductionTargeted spontaneous reporting (TSR) is a pharmacovigilance method that can enhance reporting of adverse drug reactions related to antiretroviral therapy (ART). Minimal data exist on the needs or capacity of facilities to conduct TSR.ObjectivesUsing data from the International epidemiologic Databases to Evaluate AIDS (IeDEA) Consortium, the present study had two objectives: (1) to develop a list of facility characteristics that could constitute key assets in the conduct of TSR; (2) to use this list as a starting point to describe the existing capacity of IeDEA-participating facilities to conduct pharmacovigilance through TSR.MethodsWe generated our facility characteristics list using an iterative approach, through a review of relevant World Health Organization (WHO) and Uppsala Monitoring Centre documents focused on pharmacovigilance activities related to HIV and ART and consultation with expert stakeholders. IeDEA facility data were drawn from a 2009/2010 IeDEA site assessment that included reported characteristics of adult and pediatric HIV care programs, including outreach, staffing, laboratory capacity, adverse event monitoring, and non-HIV care.ResultsA total of 137 facilities were included: East Africa (43); Asia–Pacific (28); West Africa (21); Southern Africa (19); Central Africa (12); Caribbean, Central, and South America (7); and North America (7). Key facility characteristics were grouped as follows: outcome ascertainment and follow-up; laboratory monitoring; documentation—sources and management of data; and human resources. Facility characteristics ranged by facility and region. The majority of facilities reported that patients were assigned a unique identification number (n = 114; 83.2 %) and most sites recorded adverse drug reactions (n = 101; 73.7 %), while 82 facilities (59.9 %) reported having an electronic database on site.ConclusionWe found minimal information is available about facility characteristics that may contribute to pharmacovigilance activities. Our findings, therefore, are a first step that can potentially assist implementers and facility staff to identify opportunities and leverage their existing capacities to incorporate TSR into their routine clinical programs.

Pregnancy incidence and associated factors among HIV-infected female adolescents in HIV care in urban Côte d'Ivoire, 2009–2013

ObjectiveAdolescents living with HIV are sexually active and engaged in risky sexual behaviors. Knowledge on how and to what extent adolescents in HIV care are affected by pregnancy is needed so as to adopt better preventive services. We estimated 4-year pregnancy incidence and correlates among HIV-infected female adolescents in HIV care in urban Côte d'Ivoire.DesignWe conducted retrospective analysis of a pediatric prospective cohort of the International epidemiological Databases to Evaluate AIDS (IeDEA) West Africa Collaboration. Female patients with confirmed HIV infection aged 10–19 years, having at least one clinical visit in 2009 to health facilities participating in the pediatric IeDEA West African cohort in Abidjan, Côte d'Ivoire, were included. Data on incident pregnancies were obtained through medical records and interviews with health professionals. Pregnancy incidence rate was estimated per 100 person-years (PY). Poisson regression models were used to identify factors associated with the first pregnancy and provided incidence rate ratios (IRR) with 95% confidence intervals (CI).ResultsIn 2009, 266 female adolescents were included, with a median age of 12.8 years (interquartile range, IQR: 10.0–15.0), CD4 cell counts of 506 cells/mm3 (IQR: 302–737), and 80% on antiretroviral treatment. At the 48th month, 17 new pregnancies were reported after 938 PY of follow-up: 13 girls had one pregnancy while 2 had two pregnancies. Overall incidence rate of pregnancy was 1.8/100 PY (95% CI: 1.1–2.9). High incidence was observed among those aged 15–19 years: 3.6/100 PY (95% CI: 2.2–5.9). Role of maternal death in the risk of pregnancy was at the limit of statistical significance (adjusted IRR: 3.1, 95% CI: 0.9–11.0; ref. non-maternal orphans).ConclusionsIncidence of pregnancy among HIV-infected adolescents in care aged 15–19 years reached a level observed in adult cohorts in Sub-Saharan Africa. Health personnel in pediatric care have to intensify their efforts to provide more realistic and age-adapted reproductive health services to meet the needs of adolescent patients already confronting issues of sexuality. Vulnerability of maternal orphans merits further investigation.

Pitfalls of practicing cancer epidemiology in resource-limited settings: the case of survival and loss to follow-up after a diagnosis of Kaposi's sarcoma in five countries across sub-Saharan Africa.

BackgroundSurvival after diagnosis is a fundamental concern in cancer epidemiology. In resource-rich settings, ambient clinical databases, municipal data and cancer registries make survival estimation in real-world populations relatively straightforward. In resource-poor settings, given the deficiencies in a variety of health-related data systems, it is less clear how well we can determine cancer survival from ambient data.MethodsWe addressed this issue in sub-Saharan Africa for Kaposi’s sarcoma (KS), a cancer for which incidence has exploded with the HIV epidemic but for which survival in the region may be changing with the recent advent of antiretroviral therapy (ART). From 33 primary care HIV Clinics in Kenya, Uganda, Malawi, Nigeria and Cameroon participating in the International Epidemiologic Databases to Evaluate AIDS (IeDEA) Consortia in 2009–2012, we identified 1328 adults with newly diagnosed KS. Patients were evaluated from KS diagnosis until death, transfer to another facility or database closure.ResultsNominally, 22 % of patients were estimated to be dead by 2 years, but this estimate was clouded by 45 % cumulative lost to follow-up with unknown vital status by 2 years. After adjustment for site and CD4 count, age <30 years and male sex were independently associated with becoming lost.ConclusionsIn this community-based sample of patients diagnosed with KS in sub-Saharan Africa, almost half became lost to follow-up by 2 years. This precluded accurate estimation of survival. Until we either generally strengthen data systems or implement cancer-specific enhancements (e.g., tracking of the lost) in the region, insights from cancer epidemiology will be limited.

A prospective ascertainment of cancer incidence in sub‐Saharan Africa: The case of Kaposi sarcoma

In resource‐limited areas, such as sub‐Saharan Africa, problems in accurate cancer case ascertainment and enumeration of the at‐risk population make it difficult to estimate cancer incidence. We took advantage of a large well‐enumerated healthcare system to estimate the incidence of Kaposi sarcoma (KS), a cancer which has become prominent in the HIV era and whose incidence may be changing with the rollout of antiretroviral therapy (ART). To achieve this, we evaluated HIV‐infected adults receiving care between 2007 and 2012 at any of three medical centers in Kenya and Uganda that participate in the East Africa International Epidemiologic Databases to Evaluate AIDS (IeDEA) Consortium. Through IeDEA, clinicians received training in KS recognition and biopsy equipment. We found that the overall prevalence of KS among 102,945 HIV‐infected adults upon clinic enrollment was 1.4%; it declined over time at the largest site. Among 140,552 patients followed for 319,632 person‐years, the age‐standardized incidence rate was 334/100,000 person‐years (95% CI: 314–354/100,000 person‐years). Incidence decreased over time and was lower in women, persons on ART, and those with higher CD4 counts. The incidence rate among patients on ART with a CD4 count >350 cells/mm3 was 32/100,000 person‐years (95% CI: 14–70/100,000 person‐years). Despite reductions over time coincident with the expansion of ART, KS incidence among HIV‐infected adults in East Africa equals or exceeds the most common cancers in resource‐replete settings. In resource‐limited settings, strategic efforts to improve cancer diagnosis in combination with already well‐enumerated at‐risk denominators can make healthcare systems attractive platforms for estimating cancer incidence.

Immunodeficiency at Start of Antiretroviral Therapy: The Persistent Problem of Late Presentation to Care

Immunodeficiency at Start of Antiretroviral Therapy: The Persistent Problem of Late Presentation to Care

Characteristics and comprehensiveness of adult HIV care and treatment programmes in Asia-Pacific, sub-Saharan Africa and the Americas: results of a site assessment conducted by the International epidemiologic Databases to Evaluate AIDS (IeDEA) Collaboration.

IntroductionHIV care and treatment programmes worldwide are transforming as they push to deliver universal access to essential prevention, care and treatment services to persons living with HIV and their communities. The characteristics and capacity of these HIV programmes affect patient outcomes and quality of care. Despite the importance of ensuring optimal outcomes, few studies have addressed the capacity of HIV programmes to deliver comprehensive care. We sought to describe such capacity in HIV programmes in seven regions worldwide.MethodsStaff from 128 sites in 41 countries participating in the International epidemiologic Databases to Evaluate AIDS completed a site survey from 2009 to 2010, including sites in the Asia-Pacific region (n=20), Latin America and the Caribbean (n=7), North America (n=7), Central Africa (n=12), East Africa (n=51), Southern Africa (n=16) and West Africa (n=15). We computed a measure of the comprehensiveness of care based on seven World Health Organization-recommended essential HIV services.ResultsMost sites reported serving urban (61%; region range (rr): 33–100%) and both adult and paediatric populations (77%; rr: 29–96%). Only 45% of HIV clinics that reported treating children had paediatricians on staff. As for the seven essential services, survey respondents reported that CD4+ cell count testing was available to all but one site, while tuberculosis (TB) screening and community outreach services were available in 80 and 72%, respectively. The remaining four essential services – nutritional support (82%), combination antiretroviral therapy adherence support (88%), prevention of mother-to-child transmission (PMTCT) (94%) and other prevention and clinical management services (97%) – were uniformly available. Approximately half (46%) of sites reported offering all seven services. Newer sites and sites in settings with low rankings on the UN Human Development Index (HDI), especially those in the President's Emergency Plan for AIDS Relief focus countries, tended to offer a more comprehensive array of essential services. HIV care programme characteristics and comprehensiveness varied according to the number of years the site had been in operation and the HDI of the site setting, with more recently established clinics in low-HDI settings reporting a more comprehensive array of available services. Survey respondents frequently identified contact tracing of patients, patient outreach, nutritional counselling, onsite viral load testing, universal TB screening and the provision of isoniazid preventive therapy as unavailable services.ConclusionsThis study serves as a baseline for on-going monitoring of the evolution of care delivery over time and lays the groundwork for evaluating HIV treatment outcomes in relation to site capacity for comprehensive care.

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study

BackgroundHIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART) for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA).MethodsWe collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART) and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d’Ivoire, Mali, and Senegal, in the West Africa region.ResultsData was merged for 1,754 patients (56% female), including 1,021 HIV-2 infected patients (551 on ART) and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART). At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3–51.7) and 42.4 years, IQR (37.0–47.3) for dually seropositive patients (p = 0.048). Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C). The median CD4 count at the ART initiation is 166 cells/mm3, IQR (83–247) among HIV-2 infected patients and 146 cells/mm3, IQR (55–249) among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm3 after 24 months on ART for HIV-2 patients and 169 cells/mm3 for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7–4.3).ConclusionsThis large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population.

A survey of paediatric HIV programmatic and clinical management practices in Asia and sub‐Saharan Africa—the International epidemiologic Databases to Evaluate AIDS (IeDEA)

IntroductionThere are limited data on paediatric HIV care and treatment programmes in low-resource settings.MethodsA standardized survey was completed by International epidemiologic Databases to Evaluate AIDS paediatric cohort sites in the regions of Asia-Pacific (AP), Central Africa (CA), East Africa (EA), Southern Africa (SA) and West Africa (WA) to understand operational resource availability and paediatric management practices. Data were collected through January 2010 using a secure, web-based software program (REDCap).ResultsA total of 64,552 children were under care at 63 clinics (AP, N=10; CA, N=4; EA, N=29; SA, N=10; WA, N=10). Most were in urban settings (N=41, 65%) and received funding from governments (N=51, 81%), PEPFAR (N=34, 54%), and/or the Global Fund (N=15, 24%). The majority were combined adult–paediatric clinics (N=36, 57%). Prevention of mother-to-child transmission was integrated at 35 (56%) sites; 89% (N=56) had access to DNA PCR for infant diagnosis. African (N=40/53) but not Asian sites recommended exclusive breastfeeding up until 4–6 months. Regular laboratory monitoring included CD4 (N=60, 95%), and viral load (N=24, 38%). Although 42 (67%) sites had the ability to conduct acid-fast bacilli (AFB) smears, 23 (37%) sites could conduct AFB cultures and 18 (29%) sites could conduct tuberculosis drug susceptibility testing. Loss to follow-up was defined as >3 months of lost contact for 25 (40%) sites, >6 months for 27 sites (43%) and >12 months for 6 sites (10%). Telephone calls (N=52, 83%) and outreach worker home visits to trace children lost to follow-up (N=45, 71%) were common.ConclusionsIn general, there was a high level of patient and laboratory monitoring within this multiregional paediatric cohort consortium that will facilitate detailed observational research studies. Practices will continue to be monitored as the WHO/UNAIDS Treatment 2.0 framework is implemented.

Prospective evaluation of the impact of potent antiretroviral therapy on the incidence of Kaposi’s Sarcoma in East Africa: findings from the International Epidemiologic Databases to Evaluate AIDS (IeDEA) Consortium

Author(s): Martin, Jeffrey; Wenger, Megan; Busakhala, Naftali; Buziba, Nathan; Bwana, Mwebesa; Muyindike, Winnie; Mbabazi, Ruth; Amerson, Erin; Yiannoutsos, Constantin; Musick, Beverly; LeBoit, Philip; McCalmont, Timothy; Ruben, Beth; Maurer, Toby; Wools-Kaloustian, Kara

Short‐term risk of anaemia following initiation of combination antiretroviral treatment in HIV‐infected patients in countries in sub‐Saharan Africa, Asia‐Pacific, and central and South America

BackgroundThe objective was to examine the short-term risk and predictors of anaemia following initiation of combination antiretroviral therapy (cART) in HIV-infected patients from the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian-Pacific, and Caribbean and Central and South America regions of the International Epidemiologic Databases to Evaluate AIDS (IeDEA) collaboration.MethodsAnaemia was defined as haemoglobin of < 10 g/dL. Patients were included if they started cART with three or more drugs, had prior haemoglobin of > = 10 g/dL, and had one or more follow-up haemoglobin tests. Factors associated with anaemia up to 12 months were examined using Cox proportional hazards models and stratified by IeDEA region.ResultsBetween 1998 and 2008, 19,947 patients initiated cART with baseline and follow-up haemoglobin tests (7358, 7289, 2853, 471, 1550 and 426 in the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian-Pacific, and Caribbean and Central and South America regions, respectively). At initiation, anaemia was found in 45% of Western Africa patients, 29% of Eastern Africa patients, 21% of Southern Africa patients, 36% of Central Africa patients, 15% of patients in Asian-Pacific and 14% of patients in Caribbean and Central and South America. Among patients with haemoglobin of > = 10 g/dL at baseline (13,445), the risks of anaemia were 18.2, 6.6, 9.7, 22.9, 11.8 and 19.5 per 100 person-years in the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian, and Caribbean and Central and South America regions, respectively. Factors associated with anaemia were female sex, low baseline haemoglobin level, low baseline CD4 count, more advanced disease stage, and initial cART containing zidovudine.ConclusionsIn data from 34 cohorts of HIV-infected patients from sub-Saharan Africa, Central and South America, and Asia, the risk of anaemia within 12 months of initiating cART was moderate. Routine haemoglobin monitoring was recommended in patients at risk of developing anaemia following cART initiation.

Cohort Profile: The international epidemiological databases to evaluate AIDS (IeDEA) in sub-Saharan Africa

In response to the HIV/AIDS pandemic in sub-Saharan Africa the African networks of IeDEA (International epidemiologic databases to Evaluate AIDS) aim to inform the scale-up of ART in the region through clinical and epidemiologic research. Funded by the National Institutes of Allergy and Infectious Diseases (NIAID) the objectives across the four African IeDEA regions (West Africa Central Africa East Africa and Southern Africa) are similar and cover all populations including pregnant women infants children adolescents and adult patients. They can be summarized as follows: (1) To prove robust evaluation of the delivery of ART in children adolescents and adults in sub-Saharan Africa with a focus on long-term program effectiveness and outcomes; (2) to describe the long-term temporal trends in regimen durability and tolerability and to examine monitoring strategies; (3) to describe important comorbidities and co-infections of HIV infection including malaria tuberculosis and cancer; (4) to examine the pregnancy- and HIV-related outcomes of women initiating ART during pregnancy and of infants exposed to HIV or ART in utero; (5) to develop and apply novel statistical methods to deal with missing data loss to follow-up competing risks and time-dependent confounding; (6) to establish procedures to link the HIV cohort data with other databases at local or national level. The present report provides an indicative summary of some of the major research themes and key findings as well as a discussion of the program’s strengths and weaknesses.

ART in low-resource settings: how to do more with less

In The Lancet today, Margaret May and colleagues 1 May M Boulle A Phiri S et al. for IeDEA Southern Africa and West AfricaPrognosis of patients with HIV-1 infection starting antiretroviral therapy in sub-Saharan Africa: a collaborative analysis of scale-up programmes. Lancet. 2010; (published online July 16.)https://doi.org/10.1016/S0140-6736(10)60666-6 Summary Full Text Full Text PDF Scopus (185) Google Scholar report prognostic models for patients starting antiretroviral therapy in sub-Saharan Africa. The group analysed data from four large scale-up cohorts in the Southern and West African regions that participate in the International epidemiologic Databases to Evaluate AIDS (IeDEA). On the basis of identified risk factors for death, May and colleagues constructed two prognostic models: one with CD4 cell count, clinical stage, bodyweight, age, and sex; and one that replaced CD4 cell count with total lymphocyte count and haemoglobin concentration in the blood. The group concluded that both models provide similarly strong discrimination for prediction of early mortality in patients starting antiretrovirals in sub-Saharan Africa. Prognosis of patients with HIV-1 infection starting antiretroviral therapy in sub-Saharan Africa: a collaborative analysis of scale-up programmesPrognostic models should be used to counsel patients, plan health services, and predict outcomes for patients with HIV-1 infection in sub-Saharan Africa. Full-Text PDF

Low retention of HIV-infected patients on antiretroviral therapy in 11 clinical centres in West Africa.

To study factors associated with the probability of retention in antiretroviral therapy (ART) programmes in West Africa. The International epidemiologic Databases to Evaluate AIDS (IeDEA) in West Africa is a prospective, operational, observational cohort study based on collaboration between 11 cohorts of HIV-infected adult patients in Benin, Côte d'Ivoire, Gambia, Mali and Senegal. All patients aged 16 and older at ART initiation, with documented gender and date of ART initiation, were included. For those with at least 1 day of follow-up, Kaplan-Meier method and Weibull regression model were used to estimate the 12-month probability of retention in care and the associated factors. In this data merger, 14 352 patients (61% female) on ART were included. Median age was 37 (interquartile range (IQR): 31-44 years) and median CD4 count at baseline was 131 cells/mm(3) (IQR: 48-221 cells/mm(3)). The first-line regimen was NNRTI-based for 78% of patients, protease inhibitor-based for 17%, and three NRTIs for 3%. The probability of retention was 0.90 [95% confidence interval (CI): 0.89-0.90] at 3 months, 0.84 (95% CI: 0.83-0.85) at 6 months and 0.76 (95% CI: 0.75-0.77) at 12 months. The probability of retention in care was lower in patients with baseline CD4 count <50 cells/mm(3) [adjusted hazard ratio (aHR) = 1.37; 95% CI: 1.27-1.49; P < 0.0001] (reference CD4 > 200 cells/mm(3), in men (aHR = 1.17; 95% CI: 1.10-1.24; P = 0.0002), in younger patients (<30 years) (aHR = 1.10; 95% CI: 1.03-1.19; P = 0.01) and in patients with low haemoglobinaemia <8 g/dl (aHR = 1.33; 95% CI: 1.21-1.45; P < 0.0001). Availability of funds for systematic tracing was associated with better retention (aHR = 0.29; 95% CI: 0.16-0.55; P = 0.001). Close follow-up, promoting early access to care and ART and a decentralized system of care may improve the retention in care of HIV-infected patients on ART.

Accuracy of WHO CD4 cell count criteria for virological failure of antiretroviral therapy

To examine the accuracy of the World Health Organization immunological criteria for virological failure of antiretroviral treatment. Analysis of 10 treatment programmes in Africa and South America that monitor both CD4 cell counts and HIV-1 viral load. Adult patients with at least two CD4 counts and viral load measurements between month 6 and 18 after starting a non-nucleoside reverse transcriptase inhibitor-based regimen were included. WHO immunological criteria include CD4 counts persistently <100 cells/microl, a fall below the baseline CD4 count, or a fall of >50% from the peak value. Virological failure was defined as two measurements > or =10 0000 copies/ml (higher threshold) or > or =500 copies/ml (lower threshold). Measures of accuracy with exact binomial 95% confidence intervals (CI) were calculated. A total of 2009 patients were included. During 1856 person-years of follow up 63 patients met the immunological criteria and 35 patients (higher threshold) and 95 patients (lower threshold) met the virological criteria. Sensitivity [95% confidence interval (CI)] was 17.1% (6.6-33.6%) for the higher and 12.6% (6.7-21.0%) for the lower threshold. Corresponding results for specificity were 97.1% (96.3-97.8%) and 97.3% (96.5-98.0%), for positive predictive value 9.5% (3.6-19.6%) and 19.0% (10.2-30.9%) and for negative predictive value 98.5% (97.9-99.0%) and 95.7% (94.7-96.6%). The positive predictive value of the WHO immunological criteria for virological failure of antiretroviral treatment in resource-limited settings is poor, but the negative predictive value is high. Immunological criteria are more appropriate for ruling out than for ruling in virological failure in resource-limited settings.

Determination of the Incidence of Tuberculosis in Low‐Income Countries

To the Editor—We read with interest the report by The Antiretroviral Therapy in Low-Income Countries Collaboration of the International epidemiological Databases to Evaluate AIDS (IeDEA) andThe ART Cohort Collaboration on tuberculosis (TB) after initiation of antiretroviral therapy in low-income and high-income countries [1]. The authors do notmention the number of patients who were already receiving treatment for TB when the antiretroviral therapy was started (were the data not available?). However, they do mention that programs in lower-income countries routinely screened patients for TB before they commenced HAART. It is unclear to us whether patients being given treatment for TB at the start of HAART were included in the analysis. We propose that they should have been excluded from the study population if the aim of the study was to determine the incidence of TB and to compare the incidence rateratios for new TB infections. Indeed, in contrast to in high-income countries, in low-income countries, TB is one of the main reasons to initiate HAART. In Malawi, for example, from July through September 2005, 12% of the patients who started HAART did so because of TB [2]. During treatment for TB, by definition these patients cannot develop a new TB infection. We suppose that, if this approach were taken, the conclusions of the report would remain the same, but the calulations may change slightly. If the number of patients not receiving treatment for TB who started HAART is used as the denominator, the real incidence of TB in low-income countries will be even higher, particularly soon after the initiation of HAART.

Cohort Profile: Caribbean, Central and South America Network for HIV research (CCASAnet) collaboration within the International Epidemiologic Databases to Evaluate AIDS (IeDEA) programme

The HIV/AIDS epidemic has evolved in its third decade to be an unprecedented human catastrophe of global scale and importance. Although an historic response for change and intervention has led to decreased rates of new infections and HIV-associated mortality in many communities the enormity of the pandemic continues to overwhelm already constrained resources everywhere. Improved understanding of antiretroviral therapy (ART) responses and viral and host characteristics both within and between diverse settings and populations is needed to guide initiatives in HIV prevention and treatment worldwide. The merging of existing clinical and research data related to HIV infection and its associated disorders answers questions that currently cannot be addressed using randomized trials or single sources of data. Cohorts such as MACS WIHS HIVRN EuroSida and the Swiss HIV Cohort have produced important observations regarding the epidemiology and long-term outcomes of HIV-infected individuals residing in North America and Europe both before and after the era of highly active antiretroviral therapy (HAART). Assessments of short-term response to HAART in recently expanded single-site programmes have been reported globally. Collaborations such as TAHOD and ART-LINC have allowed short-term evaluation of antiretroviral programmes in resource-limited settings from several continents and recently comparisons of outcomes in the first year of ART between low- and high-income countries have been reported. (excerpt)