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Tsegaye A, Ran L, Wolday D, Petros B, Dorigo W, Piriou E, Messele T, Sanders E, Tilahun T, Eshetu D, Schuitemaker H, Coutinho RA, Miedema F, Borghans J, van Baarle D. HIV-1 Subtype C gag-specific T-cell responses in relation to human leukocyte antigens in a diverse population of HIV-infected Ethiopians. J Acquir Immune Defic Syndr 2007; 45:389-400. [PMID: 17417101 DOI: 10.1097/qai.0b013e318059beaa] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Knowledge of the most dominant T-cell epitopes in the context of the local human leukocyte antigen (HLA) background is a prerequisite for the development of an effective HIV vaccine. In 100 Ethiopian subjects, 16 different HLA-A, 23 HLA-B, and 12 HLA-C specificities were observed. Ninety-four percent of the population carried at least 1 of the 5 most common HLA-A and/or HLA-B specificities. HIV-specific T-cell responses were measured in 48 HIV-infected Ethiopian subjects representing a wide range of ethnicities in Ethiopia using the interferon (IFN)-gamma enzyme-linked immunospot (Elispot) assay and 49 clade C-specific synthetic Gag peptides. Fifty-eight percent of the HIV-positive study subjects showed T-cell responses directed to 1 or more HIV Gag peptides. Most Gag-specific responses were directed against the subset of peptides spanning Gag p24. The breadth of response ranged from 1 to 9 peptides, with most (78%) individuals showing detectable responses to <3 Gag peptides. The magnitude of HIV-specific T-cell responses was not associated with HIV viral load but correlated positively with CD4 T-cell counts. The most frequently targeted Gag peptides overlapped with those previously described for HIV-1 subtype C-infected southern Africans, and therefore can be used in a multiethnic vaccine.
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Tsegaye A, Ran L, Wolday D, Petros B, Nanlohy NM, Meles H, Girma M, Hailu E, Borghans J, Miedema F, van Baarle D. Stable pattern of HIV-1 subtype C Gag-specific T-cell responses coincides with slow rate of CD4 T-cell decline in HIV-infected Ethiopians. AIDS 2007; 21:369-72. [PMID: 17255746 DOI: 10.1097/qad.0b013e32801222e3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We studied HIV-1 clade C Gag-specific T-cell responses in five HIV-infected Ethiopians with a relatively slow (< 15 cells/microl per year) and five with a fast (> 45 cells/microl per year) CD4 T-cell decline longitudinally. Six study subjects had T-cell responses directed to one or more HIV-1 Gag peptides. The persistence of strong and broad anti-Gag cytotoxic T-lymphocyte responses was associated with a slow rate of CD4 T-cell decline and with human leukocyte antigen alleles from the B27 supertype.
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van Baarle D, Tsegaye A, Miedema F, Akbar A. Significance of senescence for virus-specific memory T cell responses: rapid ageing during chronic stimulation of the immune system. Immunol Lett 2005; 97:19-29. [PMID: 15626472 DOI: 10.1016/j.imlet.2004.10.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 10/01/2004] [Accepted: 10/01/2004] [Indexed: 12/31/2022]
Abstract
There is a generalized age-related decline in immune responses which leads to increased susceptibility of elderly to infection and, possibly, to autoimmune disease and cancer. This is associated with phenotypic changes of CD8+ T lymphocytes that include the loss of costimulatory molecules CD28 and CD27, which are important for proliferation and cell survival of CD8+ T cells. Loss of these molecules is associated with less ability to respond to recurrent infection. Functional changes within T cells during ageing include a reduction in the number of naive T cells and a progressively limited T cell repertoire. Furthermore, persistent life-long antigenic stress upon the memory pool leads to telomere erosion and concomittant loss of proliferative capacity, a phenomenon known as replicative senesence. In this review, we discuss that replicative senescence, or clonal exhaustion, may also occur in relatively young individuals, as evidenced from HIV-infected individuals and healthy Ethiopians. We discuss data suggesting that T cell defects may arise in individuals because of chronic antigen activation leading to rapid ageing of the memory CD8+ T cell pool.
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Abuye C, Tsegaye A, West CE, Versloot P, Sanders EJ, Wolday D, Hamann D, De Wit TFR, Fontanet AL. Determinants of CD4 Counts Among HIV-Negative Ethiopians: Role of Body Mass Index, Gender, Cigarette Smoking, Khat (Catha Edulis) Chewing, and Possibly Altitude? J Clin Immunol 2005; 25:127-33. [PMID: 15821889 DOI: 10.1007/s10875-005-2818-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2004] [Indexed: 10/25/2022]
Abstract
To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including determination of HIV serological status and T-cell subsets, were performed during follow-up visits every six months. In addition, micronutrients (retinol, carotenoids, tocopherol, transferrin receptor, and selenium) plasma concentrations were determined in a subset of 38 HIV-positive and 121 HIV-negative participants. HIV-negative participants with at least one CD4 count measurement were 157 females in Akaki, 203 males in Akaki, and 712 males in Wonji. CD4 counts were independently and positively associated with body mass index (through an increase in lymphocyte counts), female gender (through an increase in CD4%), cigarette smoking (through an increase in CD4%), khat chewing (through an increase in both lymphocyte counts and CD4%), and Akaki study site (through a large increase in lymphocyte counts compensating a decrease in CD4%). Intestinal parasitic infections were not associated with CD4% or CD4 counts. Retinol, carotenoids, and alpha-tocopherol plasma concentrations decreased with HIV infection and advancing immunosuppression, but were not associated with CD4 counts among HIV-negative subjects. Low body mass index among Ethiopians may have contributed to their overall low CD4 counts. Other factors remain to be elucidated.
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Tsegaye A, Wolday D, Otto S, Petros B, Assefa T, Alebachew T, Hailu E, Adugna F, Measho W, Dorigo W, Fontanet AL, van Baarle D, Miedema F. Immunophenotyping of blood lymphocytes at birth, during childhood, and during adulthood in HIV-1-uninfected Ethiopians. Clin Immunol 2003; 109:338-46. [PMID: 14697749 DOI: 10.1016/j.clim.2003.08.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
To obtain more insight into blood lymphocyte subpopulations of Ethiopians, we studied the immunologic profile of children and neonates and compared these data with those obtained from adults. Peripheral blood mononuclear cells (PBMCs) and cord blood mononuclear cells (CBMCs) were collected from 137 HIV-1-uninfected subjects aged 0 (cord blood) up to 40 years. Lymphocyte subsets (T, B, and NK cells, CD4+ and CD8+ T cells) were determined and T cell activation (CD38 and HLA-DR) and differentiation (CD45RO and CD27) markers were measured on CD4+ and CD8+ T cells. The absolute number and percentage values of most lymphocyte subpopulations differed substantially with age. Neonates and children were found to have significantly higher CD4+ T cell counts compared to adults. The median absolute CD4 count at birth was comparable to those reported for Caucasians. At birth 97% of the CD4+ T cells were naîve and this proportion significantly declined to 14.2% during adulthood. In addition, activation of both CD4+ and CD8+ T cells, as determined by the double expression of HLA-DR and CD38, was observed in children under the age of 16 and adults, but not in neonates. A more differentiated phenotype (CD27-) was observed in adults compared to children for both CD4+ and CD8+ T cells. The immune alterations including the remarkably low CD4 count with highly depleted naîve phenotype and a persistently activated immune system seen in adult Ethiopians are not apparent at birth, but rather develop over time.
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Tsegaye A, Rinke de Wit TF, Mekonnen Y, Beyene A, Aklilu M, Messele T, Abebe A, Coutinho R, Sanders E, Fontanet AL. Decline in prevalence of HIV-1 infection and syphilis among young women attending antenatal care clinics in Addis Ababa, Ethiopia: results from sentinel surveillance, 1995-2001. ETHIOPIAN MEDICAL JOURNAL 2003; 41 Suppl 1:31-4. [PMID: 15227878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
From 1995 to 2001, five rounds of sentinel surveillance were carried out for young women attending antenatal care clinics at four health centers in Addis Ababa, the capital city of Ethiopia, to monitor trends in the prevalence of HIV infection and syphilis. Serum samples were tested for antibodies to HIV (enzyme-linked immunosorbent assay and Western blotting) and antibodies to Treponema pallidum (T. pallidum hemagglutination assay and rapid plasma reagin test). Prevalence ratios for an increase in one calendar year were estimated using log-binomial models. Between 1995 and 2001, the prevalence of HIV infection among young women (age range, 15-24 years) attending antenatal care clinics in inner city health centers declined from 24.2% to 15.1% (prevalence ratio for an increase in one calendar year, 0.91; 95% confidence interval, 0.87-0.95). No change was observed for older age groups or in outer city health centers. The decline in the prevalence of active syphilis (T. pallidum hemagglutination assay and rapid plasma reagin testing positive for antibodies to T. pallidum) was more pronounced among and also restricted to the young age groups (age range, 15-24 years) in the inner city (from 7.6% in 1995 to 1.3% in 2001; prevalence ratio, 0.69; 95% confidence interval, 0.59-0.80). The declining trends in the prevalence of HIV infection and syphilis among young women attending antenatal care clinics in the inner city are encouraging, but these findings require confirmation in future years and for other population groups.
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Mekonnen Y, Sanders E, Aklilu M, Tsegaye A, Rinke de Wit TF, Schaap A, Wolday D, Geskus R, Coutinho RA, Fontanet AL. Evidence of changes in sexual behaviours among male factory workers in Ethiopia. ETHIOPIAN MEDICAL JOURNAL 2003; 41 Suppl 1:51-9. [PMID: 15227881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
OBJECTIVE To assess changes in sexual behaviours among male factory workers in Ethiopia. DESIGN Open cohort studies in two factories near Addis Ababa. DATA AND METHODS At intake and biannual follow-up visits, data were collected on sexual behaviours including casual sex, sex with commercial sex workers (CSW), condom use, and history of sexually transmitted diseases (STDs) as indicated by genital discharge and genital ulcer. Health education, HIV testing, and counselling were offered to all participants. RESULTS Between February 1997 and December 1999, 1124 males were enrolled in the two cohort studies. At intake, the prevalence of casual sex in the past year, sex with CSWs, condom use with the last casual partner, history of genital discharge in the past 5 years, and history of genital ulcer in the past 5 years were 9.7, 43.4, 38.8 (Akaki site only), 10.6 and 2.1%, respectively. At the Wonji site, the intake prevalence of casual sex, sex with CSW, and history of genital discharge decreased significantly by calendar year between 1997 and 1999. At both sites combined, between the first and the fourth follow-up visits, there was a decline in the proportion of males reporting recent causal sex (from 17.5 to 3.5%, P < 0.001), sex with CSWs (from 11.2 to 0.75%, P < 0.001), and genital discharge (from 2.1 to 0.6%, P = 0.004). CONCLUSION There was a decline over time in risky sexual behaviours reported by cohort participants. Part of this decline occurred independently of cohort interventions.
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Kassu A, Tsegaye A, Wolday D, Petros B, Aklilu M, Sanders EJ, Fontanet AL, Van Baarle D, Hamann D, De Wit TFR. Role of incidental and/or cured intestinal parasitic infections on profile of CD4+ and CD8+ T cell subsets and activation status in HIV-1 infected and uninfected adult Ethiopians. Clin Exp Immunol 2003; 132:113-9. [PMID: 12653845 PMCID: PMC1808681 DOI: 10.1046/j.1365-2249.2003.02106.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2003] [Indexed: 11/20/2022] Open
Abstract
Intestinal parasitic infections have been suggested to cause persistent immune activation leading to an unbalanced immune state. Such a state has been proposed to be a major factor in the pathogenesis of AIDS in an African context. The present study investigated the effect of incidental parasitic infection and treatment on the profile of T cell differentiation and activation markers on CD4+ and CD8+ T cells from HIV-1 infected and uninfected adult Ethiopians. Cryopreserved PBMCs from 64 subjects (41 HIV-negative and 23 HIV-positive) with follow-up visits at 6-monthly intervals were used to compare the effect of incidental intestinal parasites and their treatment upon T cell subset profiles and activation status. The samples were stained with antibodies to various T cell differentiation and activation markers allowing naive, memory, effector, memory/effector, activated and resting CD4+ and CD8+ T cell subsets to be quantified by triple-colour FACScan. Incidental intestinal parasitic infections resulted in a significant increase in memory CD4+ T cell numbers both in HIV-negative and HIV-positive subjects (P < 0.05). There was also a significant increase in the percentage of CD8+ HLA-DR+ T cells (P < 0.05) in HIV-positive subjects co-infected with parasites. In HIV-negative subjects, a significant decline in activated cells and a significant increase in resting CD8+ T cells (P < 0.05) was observed after treatment for parasites. These data suggest that intestinal parasitic infections could result in the alteration of T cell subset counts and also in the up-regulation of T cell activation markers in peripheral blood. Treatment of parasitic infections showed a tendency to reduce the activation suggesting that, together with other community based intervention strategies, such treatment could be used to down-regulate immune activation and hence protect the host from being easily attacked by HIV.
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Mekonnen Y, Sanders E, Aklilu M, Tsegaye A, Rinke de Wit TF, Schaap A, Wolday D, Geskus R, Coutinho RA, Fontanet AL. Evidence of changes in sexual behaviours among male factory workers in Ethiopia. AIDS 2003; 17:223-31. [PMID: 12545083 DOI: 10.1097/00002030-200301240-00013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To assess changes in sexual behaviours among male factory workers in Ethiopia. DESIGN Open cohort studies in two factories near Addis Ababa. DATA AND METHODS At intake and biannual follow-up visits, data were collected on sexual behaviours including casual sex, sex with commercial sex workers (CSW), condom use, and history of sexually transmitted diseases (STDs) as indicated by genital discharge and genital ulcer. Health education, HIV testing, and counselling were offered to all participants. RESULTS Between February 1997 and December 1999, 1124 males were enrolled in the two cohort studies. At intake, the prevalence of casual sex in the past year, sex with CSWs, condom use with the last casual partner, history of genital discharge in the past 5 years, and history of genital ulcer in the past 5 years were 9.7, 43.4, 38.8 (Akaki site only), 10.6 and 2.1%, respectively. At the Wonji site, the intake prevalence of casual sex, sex with CSW, and history of genital discharge decreased significantly by calendar year between 1997 and 1999. At both sites combined, between the first and the fourth follow-up visits, there was a decline in the proportion of males reporting recent casual sex (from 17.5 to 3.5%, < 0.001), sex with CSWs (from 11.2 to 0.75%, < 0.001), and genital discharge (from 2.1 to 0.6%, = 0.004). CONCLUSION There was a decline over time in risky sexual behaviours reported by cohort participants. Part of this decline occurred independently of cohort interventions.
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Rinke de Wit TF, Tsegaye A, Wolday D, Hailu B, Aklilu M, Sanders E, Hagos M, Kliphuis A, Pollakis G, Krol A, Geskus R, Miedema F, Goudsmit J, Coutinho R, Fontanet AL. Primary HIV-1 subtype C infection in Ethiopia. J Acquir Immune Defic Syndr 2002; 30:463-70. [PMID: 12154336 DOI: 10.1097/00126334-200208150-00001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Between 1997 and 2001, 1624 Ethiopian factory workers were enrolled in prospective HIV-1 cohorts in Ethiopia, at Akaki and Wonji towns. HIV-1 seroprevalence at intake was 11.8% (Akaki) and 7.1% (Wonji). HIV-1 incidence was .75 per 100 person-years (Akaki) and .35 per 100 person-years (Wonji). During follow up, CD4 T-cell counts remained significantly lower and CD8 T-cell counts significantly higher in Ethiopian seroconverters compared with Dutch seroconverters. Viral loads were lower in Ethiopian seroconverters versus Dutch seroconverters in the first months after seroconversion, subsequently increasing to similar levels. All 20 Ethiopian seroconverters were infected with HIV-1 subtype C (15 with sub-cluster C' and 5 with sub-cluster C). Viral loads were higher in sub-cluster C'-infected Ethiopian seroconverters. One subject demonstrated a window period of at least 204 days, combined with a high preseroconversion viral load and no decline of CD4 T cells over a follow-up period of at least 3 years.
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Tsegaye A, Rinke De Wit TF, Mekonnen Y, Beyene A, Aklilu M, Messele T, Abebe A, Coutinho R, Sanders E, Fontanet AL. Decline in prevalence of HIV-1 infection and syphilis among young women attending antenatal care clinics in Addis Ababa, Ethiopia: results from sentinel surveillance, 1995-2001. J Acquir Immune Defic Syndr 2002; 30:359-62. [PMID: 12131574 DOI: 10.1097/00126334-200207010-00013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
From 1995 to 2001, five rounds of sentinel surveillance were carried out for young women attending antenatal care clinics at four health centers in Addis Ababa, the capital city of Ethiopia, to monitor trends in the prevalence of HIV infection and syphilis. Serum samples were tested for antibodies to HIV (enzyme-linked immunosorbent assay and Western blotting) and antibodies to Treponema pallidum (T. pallidum hemagglutination assay and rapid plasma reagin test). Prevalence ratios for an increase in one calendar year were estimated using log-binomial models. Between 1995 and 2001, the prevalence of HIV infection among young women (age range, 15-24 years) attending antenatal care clinics in inner city health centers declined from 24.2% to 15.1% (prevalence ratio for an increase in one calendar year, 0.91; 95% confidence interval, 0.87-0.95). No change was observed for older age groups or in outer city health centers. The decline in the prevalence of active syphilis (T. pallidum hemagglutination assay and rapid plasma reagin testing positive for antibodies to T. pallidum) was more pronounced among and also restricted to the young age groups (age range, 15-24 years) in the inner city (from 7.6% in 1995 to 1.3% in 2001; prevalence ratio, 0.69; 95% confidence interval, 0.59-0.80). The declining trends in the prevalence of HIV infection and syphilis among young women attending antenatal care clinics in the inner city are encouraging, but these findings require confirmation in future years and for other population groups.
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Wolday D, Tsegaye A, Messele T. Low absolute CD4 counts in Ethiopians. ETHIOPIAN MEDICAL JOURNAL 2002; 40 Suppl 1:11-6. [PMID: 12802827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
The CD4+ T-lymphocyte count is a widely used marker of HIV disease progression. The marker also plays a crucial role in determining therapeutic interventions in HIV infections, especially with the initiation and monitoring of antiretroviral therapy and prophylactic treatment for opportunistic infections. In general, immunological studies done thus far on adult Ethiopians revealed that, healthy HIV-negative Ethiopians exhibit significantly decreased values for absolute CD4 counts than other populations. However, it remains to be illucidated whether Ethiopian AIDS patients develop opportunistic infections at much lower CD4 values than AIDS patients from Western countries, and whether Ethiopian HIV infected patients progress to AIDS more rapidly. Thus, establishing locally appropriate standard CD4 values is important in order to implement certain prophylactic or therapeutic interventions in our setting. Most of these studies are reported on international journals, which are hardly accessible to the Ethiopian medical/scientific community. The aim of this mini-review is, therefore, to provide the local scientific community and clinicians with the available information.
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Sahlu T, de Wit TR, Tsegaye A, Mekonnen Y, Beyene A, Hailu B, Coutinho RA, Fontanet A. Low incidence of syphilis among factory workers in Ethiopia: effect of an intervention based on education and counselling. Sex Transm Infect 2002; 78:123-6. [PMID: 12081173 PMCID: PMC1744445 DOI: 10.1136/sti.78.2.123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The prevalence and incidence of syphilis infection were examined in a cohort study of factory workers in Ethiopia. METHOD Between February 1997 and March 1999, 409 men and 348 women were enrolled and followed in the cohort study. RESULTS The prevalence (95% CI) of past/current syphilis (positive TPPA serology) was 28.9% (25.7% to 32.3%), and factors associated with past/current syphilis were markers of risky sexual behaviours including HIV infection. In this cohort of factory workers subject to public information/education meetings, testing for HIV antibodies, and individual counselling, the incidence (97.5% one sided CI) of new syphilis infections was 0/691 = 0 (0 to 0.5) per 100 person years. CONCLUSION This study has documented a reduction in risky sexual behaviours and a low syphilis incidence among factory workers participating in a cohort study on HIV infection progression in Addis Ababa.
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Mihret W, Rinke de Wit TF, Petros B, Mekonnen Y, Tsegaye A, Wolday D, Beyene A, Aklilu M, Sanders E, Fontanet AL. Herpes simplex virus type 2 seropositivity among urban adults in Africa: results from two cross-sectional surveys in Addis Ababa, Ethiopia. Sex Transm Dis 2002; 29:175-81. [PMID: 11875379 DOI: 10.1097/00007435-200203000-00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although several surveys investigating the epidemiology of herpes simplex virus type 2 (HSV-2) infection using type-specific immunologic assays have been carried out in Africa, none has examined the risk factors for HSV-2 infection in a representative sample from an urban adult population. GOALS To estimate the prevalence of HSV-2 infection in the adult population of Addis Ababa, Ethiopia, and to identify risk factors for HSV-2 infection. STUDY DESIGN Two cross-sectional surveys, one community-based (June to September 1996, n = 506) and one factory-based (February to November 1997, n = 657), were conducted. Samples were tested for HSV-2 immunoglobulin G antibodies using type-specific enzyme-linked immunoassays (ELISA). RESULTS In the community-based survey, HSV-2 prevalence increased with age until 25 years, then leveled off at 50% in both genders. The same independent predictors of HSV-2 infection were identified in both genders: older age, higher lifetime number of sexual partners, positive HIV serology, and positive Treponema pallidum hemagglutination serology. CONCLUSIONS This study confirmed the high prevalence of HSV-2 infection among adults in an African urban population and its association with HIV infection. Prevention of HSV-2 and other sexually transmitted infections through partner reduction and condom use should be encouraged.
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Meles H, Wolday D, Fontanet A, Tsegaye A, Tilahun T, Aklilu M, Sanders E, De Wit TFR. Indeterminate human immunodeficiency virus Western blot profiles in ethiopians with discordant screening-assay results. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2002; 9:160-3. [PMID: 11777847 PMCID: PMC119890 DOI: 10.1128/cdli.9.1.160-163.2002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2001] [Revised: 08/05/2001] [Accepted: 10/09/2001] [Indexed: 11/20/2022]
Abstract
The Western blot (WB) assay is the most widely accepted confirmatory assay for the detection of antibodies to human immunodeficiency virus type 1 (HIV-1). However, indeterminate WB reactivity to HIV-1 proteins may occur in individuals who do not appear to be infected with HIV. The profiles of WB reactivity among Ethiopians are hardly known. Here, we describe the profiles of indeterminate WB reactivity in Ethiopians with discordant screening assays. Between 1996 and 2000, a total of 12,124 specimens were tested for HIV-1 antibodies. Overall, 1,437 (11.9%) were positive for HIV-1 antibody. Ninety-one ( approximately 0.8%) gave equivocal results because of discordant results among the various screening assays and indeterminate WB profiles by the American Red Cross (ARC) criteria. Most (30.4%) of these indeterminate WB results were due to p24 reactivity. However, 12 samples (13.2%) displayed reactivity to p24 and gp41 or to p24 and gp120/160 proteins (positive by Centers for Disease Control and Prevention [CDC] criteria). Only two samples (2.2%) were reactive to both env glycoproteins gp41 and gp120/160 (positive by the World Health Organization [WHO] criteria). Of 31 WB assays initially indeterminate by the ARC criteria and with follow-up samples, 29 (93.5%) became negative when retested subsequently while 2 (6.5%) remained indeterminate for more than a year and were thus considered negative. Using CDC and WHO criteria, 6 (19.4%) and 2 (6.5%), respectively, of these WB assays would have been considered falsely positive. In addition, 17 indeterminate samples were negative when assessed by a nucleic acid-based amplification assay for HIV-1 viremia. In general, there was 97.8% concordance between the ARC and WHO criteria and 85.7% concordance between the ARC and CDC criteria for an indeterminate WB result. The ARC criteria best met the specified objectives for diagnosis in our setting.
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Kassu A, Tsegaye A, Petros B, Wolday D, Hailu E, Tilahun T, Hailu B, Roos MT, Fontanet AL, Hamann D, De Wit TF. Distribution of lymphocyte subsets in healthy human immunodeficiency virus-negative adult Ethiopians from two geographic locales. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2001; 8:1171-6. [PMID: 11687459 PMCID: PMC96245 DOI: 10.1128/cdli.8.6.1171-1176.2001] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2001] [Accepted: 09/13/2001] [Indexed: 11/20/2022]
Abstract
Immunological values for 562 factory workers from Wonji, Ethiopia, a sugar estate 114 km southeast of the capital city, Addis Ababa, Ethiopia, were compared to values for 218 subjects from Akaki, Ethiopia, a suburb of Addis Ababa, for whom partial data were previously published. The following markers were measured: lymphocytes, T cells, B cells, NK cells, CD4(+) T cells, and CD8(+) T cells. A more in depth comparison was also made between Akaki and Wonji subjects. For this purpose, various differentiation and activation marker (CD45RA, CD27, HLA-DR, and CD38) expressions on CD4(+) and CD8(+) T cells were studied in 60 male, human immunodeficiency virus-negative subjects (30 from each site). Data were also compared with Dutch blood donor control values. The results confirmed that Ethiopians have significantly decreased CD4(+) T-cell counts and highly activated immune status, independent of the geographic locale studied. They also showed that male subjects from Akaki have significantly higher CD8(+) T-cell counts, resulting in a proportional increase in each of the CD8(+) T-cell compartments studied: naïve (CD45RA(+)CD27(+)), memory (CD45RA(-)CD27(+)), cytotoxic effector (CD45RA(+)CD27(-)), memory/effector (CD45RA(-)CD27(-)), activated (HLA-DR(+)CD38(+)), and resting (HLA-DR(-)CD38(-)). No expansion of a specific functional subset was observed. Endemic infection or higher immune activation is thus not a likely cause of the higher CD8 counts in the Akaki subjects. The data confirm and extend earlier observations and suggest that, although most lymphocyte subsets are comparable between the two geographical locales, there are also differences. Thus, care should be taken in extrapolating immunological reference values from one population group to another.
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Aklilu M, Messele T, Tsegaye A, Biru T, Mariam DH, van Benthem B, Coutinho R, Rinke de Wit T, Fontanet A. Factors associated with HIV-1 infection among sex workers of Addis Ababa, Ethiopia. AIDS 2001; 15:87-96. [PMID: 11192872 DOI: 10.1097/00002030-200101050-00013] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To study the prevalence and risk factors for HIV infection among sex workers of Addis Ababa, Ethiopia. DESIGN AND METHODS Cross-sectional survey on socio-demographic characteristics, behaviours, and HIV serological status of sex workers attending two health centres of Addis Ababa. RESULTS HIV prevalence among sex workers was 274 of 372 (73.7%). Several factors were significantly associated with an increased risk of being HIV-infected [among others, working in 'shared rooms', high number of clients, use of injectable hormones, and positive Treponema pallidum particle agglutination (TPPA) serology], and others with a decreased risk (being born in Addis Ababa, high level of education, peer education on sex work, condom use, use of oral pill, and use of condoms for contraception). Of interest, sex workers who were using condoms for contraception were, compared with others, more likely to use condoms consistently (65 versus 24%, respectively; P < 0.001), and less likely to be HIV-infected (55 versus 86%, respectively; P < 0.001). In multivariate analysis [log-binomial model, giving estimates of the prevalence ratio (PR)], being born in Addis Ababa (PR = 0.74; 95% confidence interval (CI), 0.61-0.91), using condoms for contraception (PR = 0.73; 95% CI, 0.64-0.85), and a positive TPPA serology (PR = 1.21; 95% CI, 1.09-1.36), remained significantly associated with HIV infection. CONCLUSIONS HIV prevalence was remarkably high among sex workers of Addis Ababa. Condom use was higher, and HIV prevalence lower, in sex workers using condoms not only for prevention of HIV and sexually transmitted diseases, but also for contraceptive purpose. This finding is of particular interest for its implications for prevention strategies among sex workers in the developing world.
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Hazenberg MD, Otto SA, Cohen Stuart JW, Verschuren MC, Borleffs JC, Boucher CA, Coutinho RA, Lange JM, Rinke de Wit TF, Tsegaye A, van Dongen JJ, Hamann D, de Boer RJ, Miedema F. Increased cell division but not thymic dysfunction rapidly affects the T-cell receptor excision circle content of the naive T cell population in HIV-1 infection. Nat Med 2000; 6:1036-42. [PMID: 10973325 DOI: 10.1038/79549] [Citation(s) in RCA: 312] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Recent thymic emigrants can be identified by T cell receptor excision circles (TRECs) formed during T-cell receptor rearrangement. Decreasing numbers of TRECs have been observed with aging and in human immunodeficiency virus (HIV)-1 infected individuals, suggesting thymic impairment. Here, we show that in healthy individuals, declining thymic output will affect the TREC content only when accompanied by naive T-cell division. The rapid decline in TRECs observed during HIV-1 infection and the increase following HAART are better explained not by thymic impairment, but by changes in peripheral T-cell division rates. Our data indicate that TREC content in healthy individuals is only indirectly related to thymic output, and in HIV-1 infection is mainly affected by immune activation.
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Sahlu T, Kassa E, Agonafer T, Tsegaye A, Rinke de Wit T, Gebremariam H, Doorly R, Spijkerman I, Yeneneh H, Coutinho RA, Fontanet AL. Sexual behaviours, perception of risk of HIV infection, and factors associated with attending HIV post-test counselling in Ethiopia. AIDS 1999; 13:1263-72. [PMID: 10416532 DOI: 10.1097/00002030-199907090-00017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To describe sexual behaviours, perception of risk of HIV infection, and factors associated with attending HIV post-test counselling (PTC) among Ethiopian adults. METHODS Data on socio-demographic characteristics, knowledge of HIV infection, sexual history, medical examination, and HIV and syphilis serological status were compared, through uni- and multivariate analysis, in relation to attending PTC within 60 days of HIV testing. RESULTS Between February 1997 and June 1998, 751 factory workers were enrolled in a cohort study of HIV infection progression. Despite reporting high-risk sexual behaviours, mainly for males (64% of males and 6% of females had more than five sexual partners in their lifetime, 16% of males and 2% of females reported having had recent casual partners), and knowing that HIV is commonly transmitted heterosexually in Ethiopia (97% of answers being correct, both genders combined), only 17% of males and 2% of females acknowledged having had activities which had put them at risk of HIV infection. HIV prevalence was 12%, and did not differ by gender. Of all study participants, 327 (43.5%) returned for PTC within 60 days of HIV testing. PTC attendance did not differ by age, gender, or HIV serological status. Factors independently associated with PTC attendance in males were: good knowledge of HIV infection, [odds ratio (OR) = 1.661, belief that medical follow-up improves the course of HIV infection (OR = 2.02), history of genital symptoms (OR = 2.83), positive syphilis serology (OR = 2.62), recent weight loss (OR = 1.89), and, with a negative association, being a manual worker (OR = 0.40), and history of recent casual sexual relationships (OR = 0.35). In women, belief that HIV/AIDS can be cured (OR = 3.16), never having been married (OR = 5.02), having five or less children (OR = 2.16), having been raped (OR = 3.42), and having used health facilities in the past year (OR = 1.73) were all positively and independently associated with PTC attendance. CONCLUSION Study participants reported high-risk sexual behaviours, yet had a low perception of individual risk. Men attended for PTC because of their knowledge of HIV infection, their past sexual history or their current health status. Women attended for PTC because of their plans for the future, marriage and/or children, rather than their past sexual exposure. Only in cases of rape were they willing to learn of their HIV status.
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95
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Tsegaye A, Messele T, Tilahun T, Hailu E, Sahlu T, Doorly R, Fontanet AL, Rinke de Wit TF. Immunohematological reference ranges for adult Ethiopians. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1999; 6:410-4. [PMID: 10225845 PMCID: PMC103732 DOI: 10.1128/cdli.6.3.410-414.1999] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/1998] [Accepted: 01/19/1999] [Indexed: 11/20/2022]
Abstract
A cross-sectional survey was carried out with 485 healthy working adult Ethiopians who are participating in a cohort study on the progression of human immunodeficiency virus type 1 (HIV-1) infection to establish hematological reference ranges for adult HIV-negative Ethiopians. In addition, enumeration of absolute numbers and percentages of leukocyte subsets was performed for 142 randomly selected HIV-negative individuals. Immunological results were compared to those of 1,356 healthy HIV-negative Dutch blood donor controls. Immunohematological mean values, medians, and 95th percentile reference ranges were established. Mean values were as follows: leukocyte (WBC) counts, 6.1 x 10(9)/liter (both genders); erythrocyte counts, 5.1 x 10(12)/liter (males) and 4.5 x 10(12)/liter (females); hemoglobin, 16.1 (male) and 14.3 (female) g/dl; hematocrit, 48.3% (male) and 42.0% (female); platelets, 205 x 10(9)/liter (both genders); monocytes, 343/microl; granulocytes, 3, 057/microl; lymphocytes, 1,857/microl; CD4 T cells, 775/microl; CD8 T cells, 747/microl; CD4/CD8 T-cell ratio, 1.2; T cells, 1, 555/microl; B cells, 191/microl; and NK cells, 250/microl. The major conclusions follow. (i) The WBC and platelet values of healthy HIV-negative Ethiopians are lower than the adopted reference values of Ethiopia. (ii) The absolute CD4 T-cell counts of healthy HIV-negative Ethiopians are considerably lower than those of the Dutch controls, while the opposite is true for the absolute CD8 T-cell counts. This results in a significantly reduced CD4/CD8 T-cell ratio for healthy Ethiopians, compared to the ratio for Dutch controls.
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Tsegaye A, Ritchey CR, Morrison RD. Hypertension II. Statistical correlation of seventy-eight diet components to blood pressure. THE JOURNAL OF THE OKLAHOMA STATE MEDICAL ASSOCIATION 1985; 78:414-9. [PMID: 4078648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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97
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Tsegaye A, Ritchey CR, Morrison RD. Hypertension. I. The relationship of hypertension to serum cholesterol, triglycerides, and sodium. THE JOURNAL OF THE OKLAHOMA STATE MEDICAL ASSOCIATION 1985; 78:375-9. [PMID: 4067696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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98
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Payne DL, Welsh JD, Manion CV, Tsegaye A, Herd LD. Effectiveness of milk products in dietary management of lactose malabsorption. Am J Clin Nutr 1981; 34:2711-5. [PMID: 6797289 DOI: 10.1093/ajcn/34.12.2711] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Eleven lactose malabsorbers were studied to compare the effectiveness of commercially available products recommended for dietary treatment of lactose malabsorption. One product, a commercial lactase preparation, is added to milk for lactose hydrolysis before consumption. The other is a commercial milk product containing lactose-hydrolyzing, nonpathogenic bacteria, Lactobacillus acidophilus. Both of these products are presently recommended for management of lactose malabsorption, although such recommendations have not been validated by controlled studies. Lactose malabsorption was determined by breath H2 analyses after subjects drank four different test doses on 4 different days. The first test dose was 480 ml of low fat milk; the second was 480 ml of milk treated with a commercial lactase preparation; the third was 480 ml of a commercial L. acidophilus-containing milk; and the fourth was 480 ml of the L. acidophilus-containing milk after 1 wk of gastrointestinal exposure to this commercial bacteria-containing milk. The mean breath H2 response to the lactase-treated milk was significantly lower (p less than 0.001) than the mean response to regular milk. However, the mean breath H2 response to either of the test doses of the L. acidophilus-containing milk were not significantly different than responses to regular milk. It is concluded that the lactase-treated milk reduces breath H2 responses and symptomatic discomfort from malabsorption while the L. acidophilus-containing milk does not.
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Payne-Bose D, Tsegaye A, Morrison RD, Waller GR. An improved method for determining breath H2 as an indicator of carbohydrate malabsorption. Anal Biochem 1978; 88:659-67. [PMID: 697035 DOI: 10.1016/0003-2697(78)90470-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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