Articles tagged as "Ethiopia"

Identifying hotspots of HIV infection in sub-Saharan Africa

Mapping HIV clustering: a strategy for identifying populations at high risk of HIV infection in sub-Saharan Africa.

Cuadros DF, Awad SF, Abu-Raddad LJ. Int J Health Geogr. 2013 May 22;12:28.

Background: The geographical structure of an epidemic is ultimately a consequence of the drivers of the epidemic and the population susceptible to the infection. The know your epidemicconcept recognizes this geographical feature as a key element for identifying populations at higher risk of HIV infection where prevention interventions should be targeted. In an effort to clarify specific drivers of HIV transmission and identify priority populations for HIV prevention interventions, we conducted a comprehensive mapping of the spatial distribution of HIV infection across sub-Saharan Africa (SSA).

Methods: The main source of data for our study was the Demographic and Health Survey conducted in 20 countries from SSA. We identified and compared spatial clusters with high and low numbers of HIV infections in each country using Kulldorff spatial scan test. The test locates areas with higher and lower numbers of HIV infections than expected under spatial randomness. For each identified cluster, a likelihood ratio test was computed. A P-value was determined through Monte Carlo simulations to evaluate the statistical significance of each cluster.

Results: Our results suggest stark geographic variations in HIV transmission patterns within and across countries of SSA. About 14% of the population in SSA is located in areas of intense HIV epidemics. Meanwhile, another 16% of the population is located in areas of low HIV prevalence, where some behavioral or biological protective factors appear to have slowed HIV transmission.

Conclusions: Our study provides direct evidence for strong geographic clustering of HIV infection across SSA. This striking pattern of heterogeneity at the micro-geographical scale might reflect the fact that most HIV epidemics in the general population in SSA are not far from their epidemic threshold. Our findings identify priority geographic areas for HIV programming, and support the need for spatially targeted interventions in order to maximize the impact on the epidemic in SSA.

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Editor’s notes: This novel study used DHS data to map the clustering of HIV at a local level in 20 sub-Saharan African countries. The method identifies ‘hotspots’ and ‘cool spots’ of HIV infection within each country, mapping the results in a visually striking way.  The data show marked geographical variation within countries. For example, in Senegal, where overall prevalence is 0.75%, a hotspot with general population prevalence of 4.35% was identified. Conversely, within some countries with substantial HIV epidemics (Tanzania, Kenya, Malawi), the study identified settings with very low HIV prevalence. The authors present a ‘relative risk’ (ratio of HIV prevalence within the cluster to that outside the cluster) and, not surprisingly, find that this was higher in low prevalence countries.  It may also be interesting to see an absolute risk, and estimated excess number of cases. The authors hypothesize that the spatial variation may be less to do with variation in behavioural and biological factors than to the fact that HIV infection transmission in SSA is close to the epidemic (or sustainability) threshold – which means that small changes in risk factors can generate substantial changes in HIV prevalence. The implication of this is that, by focusing on the HIV ‘hotspots’, even modest intervention-driven changes in risk behaviour may have considerable impact in reducing HIV prevalence.

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Generalized HIV epidemics require generalized prevention efforts

Extra-couple HIV transmission in sub-Saharan Africa: a mathematical modelling study of survey data.

Bellan SE, Fiorella KJ, Melesse DY, Getz WM, Williams BG, Dushoff J. Lancet. 2013 Feb 4. pii: S0140-6736(12)61960-6. doi: 10.1016/S0140-6736(12)61960-6. [Epub ahead of print]

The proportion of heterosexual HIV transmission in sub-Saharan Africa that occurs within cohabiting partnerships, compared with that in single people or extra-couple relationships, is widely debated. The proportional contribution of different routes of transmission to new HIV infections was estimated. As plans to use antiretroviral drugs as a strategy for population-level prevention progress, understanding the importance of different transmission routes is crucial to target intervention efforts. A mechanistic model of HIV transmission was built with data from Demographic and Health Surveys (DHS) for 2003-2011, of 27 201 cohabiting couples (men aged 15-59 years and women aged 15-49 years) from 18 sub-Saharan African countries with information about relationship duration, age at sexual debut, and HIV serostatus. This model was combined with estimates of HIV survival times and country-specific estimates of HIV prevalence and coverage of antiretroviral therapy (ART). The proportion of recorded infections in surveyed cohabiting couples that occurred before couple formation was estimated, between couple members, and because of extra-couple intercourse. In surveyed couples, we estimated that extra-couple transmission accounted for 27-61% of all HIV infections in men and 21-51% of all those in women, with ranges showing intercountry variation. It was estimated that in 2011, extra-couple transmission accounted for 32-65% of new incident HIV infections in men in cohabiting couples, and 10-47% of new infections in women in such couples. These findings suggest that transmission within couples occurs largely from men to women; however, the latter sex have a very high-risk period before couple formation. Because of the large contribution of extra-couple transmission to new HIV infections, interventions for HIV prevention should target the general sexually active population and not only serodiscordant couples.

Abstract access 

Editor’s notes: Understanding the individual and population level risks for HIV transmission and acquisition is essential for designing HIV transmission prevention programmes that can lead to an AIDS-free generation. The frequency of pre-marital or extra-marital sexual activity is not necessarily different in high prevalence countries than in lower prevalence settings, a number of theories have been suggested, including frequency of multiple concurrent partnerships. Newer data has indicated that a significant percentage of people living with HIV are in serodiscordant couples with HIV-negative partners – hence a focus on identification of such serodiscordancy and promotion of condom use within cohabitating serodiscordant couples. While these interventions remain important, this article highlights that quite significant proportions of HIV transmission in couples occurs outside of the framework of the cohabitating couple. HIV prevention campaigns, for persons in couples as well as single individuals must remain focused on the general sexually active population.  

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Addressing barriers to universal access: focus on the pre-ART phase

Quantifying and addressing losses along the continuum of care for people living with HIV infection in sub-Saharan Africa: a systematic review.

Kranzer K, Govindasamy D, Ford N, Johnston V, Lawn SD. J Int AIDS Soc. 2012 Nov 19;15(2):17383.

Introduction: Recent years have seen an increasing recognition of the need to improve access and retention in care for people living with HIV/AIDS. This review aims to quantify patients along the continuum of care in sub-Saharan Africa and review possible interventions.

Methods: We defined the different steps making up the care pathway and quantified losses at each step between acquisition of HIV infection and retention in care on antiretroviral therapy (ART). We conducted a systematic review of data from studies conducted in sub-Saharan Africa and published between 2000 and June 2011 for four of these steps and performed a meta-analysis when indicated; existing data syntheses were used for the remaining two steps.

Results: The World Health Organization estimates that only 39% of HIV-positive individuals are aware of their status. Among patients who know their HIV-positive status, just 57% (95% CI, 48 to 66%) completed assessment of ART eligibility. Of eight studies using an ART eligibility threshold of≤200 cells/µL, 41% of patients (95% CI, 27% to 55%) were eligible for treatment, while of six studies using an ART eligibility threshold of≤350 cells/µL, 57% of patients (95% CI, 50 to 63%) were eligible. Of those not yet eligible for ART, the median proportion remaining in pre-ART care was 45%. Of eligible individuals, just 66% (95% CI, 58 to 73%) started ART and the proportion remaining on therapy after three years has previously been estimated as 65%. However, recent studies highlight that this is not a simple linear pathway, as patients cycle in and out of care. Published studies of interventions have mainly focused on reducing losses at HIV testing and during ART care, whereas few have addressed linkage and retention during the pre-ART period.

Conclusions: Losses occur throughout the care pathway, especially prior to ART initiation, and for some patients this is a transient event, as they may re-engage in care at a later time. However, data regarding interventions to address this issue are scarce. Research is urgently needed to identify effective solutions so that a far greater proportion of infected individuals can benefit from long-term ART.

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Who Starts? Factors Associated with Starting Antiretroviral Therapy among Eligible Patients in Two, Public HIV Clinics in Lilongwe, Malawi. 

Feldacker C, Johnson D, Hosseinipour M, Phiri S, Tweya H. PLoS One. 2012;7(11):e50871. Epub 2012 Nov 30.

Background: Lighthouse Trust operates two, public, integrated HIV clinics, Lighthouse (LH) and Martin Preuss Center (MPC), in Lilongwe, Malawi. Approximately 20% of patients eligible for antiretroviral therapy (ART) do not start ART. We explore individual and geographic factors that influence whether ART-eligible patients initiate ART.

Methods: Adult patients eligible for ART between 2008-2011 were included. Analysis was stratified by clinic. Using logistic regression, we evaluated factors associated with initiating ART including gender, age, body mass index (BMI), employment, tuberculosis (TB), eligible at initial registration, WHO stage, CD4, months in pre-ART care (from initial registration to eligibility date), and patient neighborhood distance to clinic.

Results: Of 14,216 study patients, 4841 were from LH; 9285 were from MPC. At LH and MPC, respectively, median age was 34.2 and 33.8 years; median BMI was 22.0 and 20.6; and median distance was 5.6 and 4.9 Km. In multivariate models, odds of starting ART was highest among those older than 35 years and those eligible for ART based on WHO stages 3-4 vs. those in WHO stages 1-2 with CD4<250. Patients with 1-12 months in pre-ART were at least 11 times more likely to start ART than peers with less pre-ART time. At LH, living 2.5-5 Km from the clinic increased the likelihood of starting ART over patients living closer.

Conclusions: Length of the pre-ART period is the most significant predictor of starting ART among eligible patients. Better understanding of motivation for retention in pre-ART care may reduce attrition along the treatment cascade.

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Attrition from HIV Testing to Antiretroviral Therapy Initiation among Patients Newly Diagnosed with HIV in Haiti.

Noel E, Esperance M, McLaughlin M, Bertrand R, Devieux J, Severe P, Marcelin A, Nicotera J, Delcher C, Griswold M, Meredith G, Pape JW, Koenig SP. J Acquir Immune Defic Syndr. 2012 Dec 18. [Epub ahead of print]

Objective: We report rates and risk factors for attrition in the first cohort of patients followed through all stages from HIV testing to ART initiation.

Design: Cohort study of all patients diagnosed with HIV between January and June, 2009.

Methods: We calculated the proportion of patients who completed CD4 cell counts and initiated ART or remained in pre-ART care during two years of follow-up, and assessed predictors of attrition.

Results: Of 1,427 patients newly diagnosed with HIV, 680 (48%) either initiated ART or were retained in pre-ART care for the subsequent two years. One thousand eighty-three patients (76%) received a CD4 cell count and 973 (90%) returned for result; 297 (31%) had CD4 cell count <200 cells/µl and of these, 256 (86%) initiated ART. Among 429 patients with CD4 >350 cells/µl, 215 (50%) started ART or were retained in pre-ART care. Active TB was associated with lower odds of attrition prior to CD4 cell count (OR: 0.08; 95% CI: 0.03-0.25) but also higher odds of attrition prior to ART initiation (OR: 2.46; 95% CI: 1.29-4.71). Lower annual income (≤$US125) was associated with higher odds of attrition prior to CD4 cell count (OR 1.65; 95% CI: 1.25-2.19), and prior to ART initiation among those with CD4 cell count >350 cells/µl (OR: 1.74; 95% CI: 1.20-2.52).After tracking patients through a national database, the retention rate increased to only 57%.

Conclusion: Fewer than half of patients newly diagnosed with HIV initiate ART or remain in pre-ART care for two years in a clinic providing comprehensive services. Additional efforts to improve retention in pre-ART are critically needed.

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Editor’s notes: The first of three papers presents a systematic review of the published data addressing the entire HIV care pathway, including HIV testing, pre-ART care comprising assessment of ART eligibility, retention in pre-ART care prior to ART eligibility, initiation of ART and retention in ART care. The second paper describes factors associated with ART initiation in a large cohort of patients in Malawi.The third paper presents the results of a prospective cohort study conducted at the GHESKIO clinic, the oldest and largest HIV testing facility in Haiti. GHESKIO tests nearly 30 000 patients per year for HIV, and follows patients from HIV testing through pre-ART care, ART initiation and follow-up. Their results show high rates of attrition at every step from HIV testing to ART initiation, losses occurring mainly prior to ART initiation with fewer than half of patients newly diagnosed with HIV initiating ART or remaining in pre-ART care. This is a vital study because it confirms the results of other relevant studies conducted in Africa, and highlights how the care pathway, especially prior to ART initiation is a global challenge. All research conducted in different parts of the world concur with the urgent need to address operational questions to improve the retention in pre-ART care (prior to ART eligibility and initiation).

All three papers raise a very sensitive issue, which has been poorly explored, the pre-ART care phase. Indeed, the current inclination towards earlier initiation of ART requires earlier diagnosis and regular monitoring until treatment eligibility. Poor pre-ART retention in care, or the failure to link patients from HIV testing to HIV care and retain them until they are eligible for ART, is a problem that has recently surfaced in the research literature. Without effective retention in pre-ART care – beginning with HIV testing and continuing until the first antiretrovirals are dispensed – even patients who have long been aware of their HIV status will access care only when seriously ill, which is often well after treatment eligibility. Unfortunately, only a handful of quantitative studies reporting on rates of pre-ART linkage and loss in sub-Saharan Africa have been published, and many of these are limited in the time periods and outcomes they consider. More operational research addressing the retention in care of individuals not yet eligible for ART is therefore essential. There appear to be several reasons for the poor showing of pre-ART care. Most patients during this stage are asymptomatic and may not perceive themselves to require medical care. Since little therapeutic care is offered during the pre-ART period, patients must take on faith that making the effort to come to the clinic for monitoring is worth the costs of doing so. Current approaches to providing care often require multiple clinic visits, e.g., to first provide a blood sample for a CD4 count and then return a week later to receive the results. Choosing to "wait and see what happens" may well be a preferred strategy for patients who lack resources for transport, risk losing employment by taking time off work, or fear being recognized as a client of an HIV clinic.  A number of interventions are being tried to improve retention in pre-ART care, though very few have been rigorously evaluated. Most interventions aim either to reduce the costs that patients perceive in seeking pre-ART care or increasing the perceived benefits of care. Interventions to reduce costs are more common and focus on structural changes in the delivery of care (fewer visits, more convenient locations, shorter waiting times, etc.). Interventions to increase benefits may offer more services at each visit (e.g., provision of cotrimoxazole or food parcels). There is little evidence so far as to whether these interventions will be effective. A possible way forward might also be the involvement of the local personnel such as community-based workers. Community may provide tangible support in increasing knowledge of HIV, obtain information about any changes or movements in patients’ lives, continue to follow patients in the social environment where they live, and support them to make periodic clinic visits.

HIV testing, HIV Treatment
Africa, Latin America
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Integration of HIV and TB services: a model to shift from "vertical to horizontal"

Integrating tuberculosis and HIV services in low- and middle-income countries: a systematic review.

Legido-Quigley H, Montgomery CM, Khan P, Atun R, Fakoya A, Getahun H, Grant AD. Trop Med Int Health. 2012 Dec 10. [Epub ahead of print]

Objectives: Given the imperative to scale up integrated tuberculosis (TB) and HIV services in settings where both are of major public health importance, we aimed to synthesise knowledge concerning implementation of TB/HIV service integration.

Methods: Systematic review of studies describing a strategy to facilitate TB and HIV service integration, searching 15 bibliographic databases including Medline, Embase and the Cochrane library; and relevant conference abstracts.

Results: Sixty-three of 1936 peer-reviewed articles and 70 of 170 abstracts met our inclusion criteria. We identified five models: entry via TB service, with referral for HIV testing and care; entry via TB service, on-site HIV testing, and referral for HIV care; entry via HIV service with referral for TB screening and treatment; entry via HIV service, on-site TB screening, and referral for TB diagnosis and treatment; and TB and HIV services provided at a single facility. Referral-based models are most easily implemented, but referral failure is a key risk. Closer integration requires more staff training and additional infrastructure (e.g. private space for HIV counselling; integrated records). Infection control is a major concern. More integrated models hold potential efficiencies from both provider and user perspective. Most papers report 'outcomes' (e.g. proportion of TB patients tested for HIV); few report downstream 'impacts' such as outcomes of TB treatment or antiretroviral therapy. Very few studies address the perspectives of service users or staff, or costs or cost-effectiveness.

Conclusions: While scaling up integrated services, robust comparisons of the impacts of different models are needed using standardised outcome measures.

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Editor’s notes:This study emphasizes the need to implement the most effective integrated services for the prevention and cure of HIV and TB.  TB remains one of the most deadly infectious diseases that dramatically impacts on people in sub-Saharan Africa and represent the major cause of death in those living with HIV in the region. In fact, the progressive weakening of the immune system in HIV-positive people increases the likelihood of contracting/reactivating tuberculosis. Already in 2004, the WHO published "A Interim Policy on TBV/HIV Collaborative Activities" with the purpose of providing a guide to establish integration of TB and HIV services, and to reduce the TB load in people living with HIV. An updated document "WHO policy on collaborative TB/HIV activities: guidelines for national programmes and other stakeholders" is now available. The document provides guidance for integrating care activities between TB and HIV health services. However, to put this paper into perspective, a consensus can be reached by saying that integration shall not just be about HIV and TB. Indeed, the old debate between "vertical approaches (e.g. disease focused)" and horizontal approaches (e.g. health systems focused) shall now be concluded and integration of services shall expand to care of other diseases, particularly when, at the horizon, an epidemic of chronic non-communicable diseases is slowly but surely rising in Africa. In summary, HIV is a chronic infection impacting the lifecycle; with periods of illness and wellness, with multiple clinical and psychosocial needs, requiring lifelong care and treatment with a secure supply of medicines and laboratory tests.

It is evident that HIV care may inform appropriate responses to other health threats which share the same demand for services, training of health care workers, support for adherence, infrastructure and equipment, programme management, drug and laboratory supplies, linkage to care and community involvement. In other words, there is a wide recognition of the spillover effect of HIV interventions towards health systems strengthening, not only to the benefit of other communicable diseases, but also of child and maternal health and of chronic non-communicable diseases (like diabetes, hypertension and cancer).

Africa, Asia, Europe, Latin America
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