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Dive into the research topics where Osamah Hamouda is active.

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Featured researches published by Osamah Hamouda.


JAMA | 2008

Changes in the risk of death after HIV seroconversion compared with mortality in the general population

Krishnan Bhaskaran; Osamah Hamouda; Mette Sannes; Faroudy Boufassa; Anne M Johnson; Paul C. Lambert; Kholoud Porter

CONTEXT Mortality among human immunodeficiency virus (HIV)-infected individuals has decreased dramatically in countries with good access to treatment and may now be close to mortality in the general uninfected population. OBJECTIVE To evaluate changes in the mortality gap between HIV-infected individuals and the general uninfected population. DESIGN, SETTING, AND POPULATION Mortality following HIV seroconversion in a large multinational collaboration of HIV seroconverter cohorts (CASCADE) was compared with expected mortality, calculated by applying general population death rates matched on demographic factors. A Poisson-based model adjusted for duration of infection was constructed to assess changes over calendar time in the excess mortality among HIV-infected individuals. Data pooled in September 2007 were analyzed in March 2008, covering years at risk 1981-2006. MAIN OUTCOME MEASURE Excess mortality among HIV-infected individuals compared with that of the general uninfected population. RESULTS Of 16,534 individuals with median duration of follow-up of 6.3 years (range, 1 day to 23.8 years), 2571 died, compared with 235 deaths expected in an equivalent general population cohort. The excess mortality rate (per 1000 person-years) decreased from 40.8 (95% confidence interval [CI], 38.5-43.0; 1275.9 excess deaths in 31,302 person-years) before the introduction of highly active antiretroviral therapy (pre-1996) to 6.1 (95% CI, 4.8-7.4; 89.6 excess deaths in 14,703 person-years) in 2004-2006 (adjusted excess hazard ratio, 0.05 [95% CI, 0.03-0.09] for 2004-2006 vs pre-1996). By 2004-2006, no excess mortality was observed in the first 5 years following HIV seroconversion among those infected sexually, though a cumulative excess probability of death remained over the longer term (4.8% [95% CI, 2.5%-8.6%] in the first 10 years among those aged 15-24 years). CONCLUSIONS Mortality rates for HIV-infected persons have become much closer to general mortality rates since the introduction of highly active antiretroviral therapy. In industrialized countries, persons infected sexually with HIV now appear to experience mortality rates similar to those of the general population in the first 5 years following infection, though a mortality excess remains as duration of HIV infection lengthens.


The Journal of Infectious Diseases | 2005

Prevalence of Drug-Resistant HIV-1 Variants in Untreated Individuals in Europe: Implications for Clinical Management

Annemarie M. J. Wensing; David A. M. C. van de Vijver; Gioacchino Angarano; Birgitta Åsjö; Claudia Balotta; Enzo Boeri; Ricardo Jorge Camacho; Maire-Laure Chaix; Dominique Costagliola; Andrea De Luca; Inge Derdelinckx; Zehava Grossman; Osamah Hamouda; Angelos Hatzakis; Robert Hemmer; Andy I. M. Hoepelman; Andrzej Horban; Klaus Korn; Claudia Kücherer; Thomas Leitner; Clive Loveday; E MacRae; I Maljkovic; Carmen de Mendoza; Laurence Meyer; Claus Nielsen; Eline Op de Coul; Vidar Ormaasen; D Paraskevis; Luc Perrin

BACKGROUND Infection with drug-resistant human immunodeficiency virus type 1 (HIV-1) can impair the response to combination therapy. Widespread transmission of drug-resistant variants has the disturbing potential of limiting future therapy options and affecting the efficacy of postexposure prophylaxis. METHODS We determined the baseline rate of drug resistance in 2208 therapy-naive patients recently and chronically infected with HIV-1 from 19 European countries during 1996-2002. RESULTS In Europe, 1 of 10 antiretroviral-naive patients carried viruses with > or = 1 drug-resistance mutation. Recently infected patients harbored resistant variants more often than did chronically infected patients (13.5% vs. 8.7%; P=.006). Non-B viruses (30%) less frequently carried resistance mutations than did subtype B viruses (4.8% vs. 12.9%; P<.01). Baseline resistance increased over time in newly diagnosed cases of non-B infection: from 2.0% (1/49) in 1996-1998 to 8.2% (16/194) in 2000-2001. CONCLUSIONS Drug-resistant variants are frequently present in both recently and chronically infected therapy-naive patients. Drug-resistant variants are most commonly seen in patients infected with subtype B virus, probably because of longer exposure of these viruses to drugs. However, an increase in baseline resistance in non-B viruses is observed. These data argue for testing all drug-naive patients and are of relevance when guidelines for management of postexposure prophylaxis and first-line therapy are updated.


Annals of Epidemiology | 2009

Reemergence of the HIV epidemic among men who have sex with men in North America, Western Europe, and Australia, 1996-2005.

Patrick S. Sullivan; Osamah Hamouda; Valerie Delpech; Jennifer Geduld; Joseph Prejean; Caroline Semaille; John M. Kaldor; Cinta Folch; Eline Op de Coul; Ulrich Marcus; Gwenda Hughes; Chris P. Archibald; Françoise Cazein; Ann McDonald; Jordi Casabona; Ard van Sighem; Kevin A. Fenton

PURPOSE To describe and contextualize changes in rates of human immunodeficiency virus (HIV) notifications in men who have sex with men (MSM) in eight countries (Australia, Canada, France, Germany, Netherlands, Spain, United Kingdom, and United States) from 1996-2005. METHODS We analyzed trends in HIV notification rates from 1996-2000 and 2000-2005 by generalized linear regression and estimated annual percentage change (EAPC) in rates of HIV notifications. To interpret trends, we visually examined graphs of primary and secondary syphilis reports among MSM and the prevalence of recent HIV testing. RESULTS The rate of HIV notifications among MSM declined 5.2% per year (95% confidence interval [CI]: -5.8%, -4.7%) from 1996-2000, and increased 3.3% per year (95% CI: +2.9%,+3.7%) from 2000-2005. During the period of increasing HIV diagnoses, increases in primary and secondary syphilis diagnoses occurred among MSM, but recent HIV testing among MSM did not seem to increase. CONCLUSIONS After declining in the second half of the 1990s, HIV notification rates for MSM increased beginning in 2000. Increased HIV notifications in MSM are not wholly explained by changes in HIV testing. Urgent efforts are required to develop effective HIV prevention interventions for MSM, and implement them broadly in these countries.


The Journal of Infectious Diseases | 2009

Transmission of Drug-Resistant HIV-1 Is Stabilizing in Europe

Jurgen Vercauteren; Annemarie M. J. Wensing; David A. M. C. van de Vijver; Jan Albert; Claudia Balotta; Osamah Hamouda; Claudia Kücherer; Daniel Struck; Jean-Claude Schmit; Birgitta Åsjö; Marie Bruckova; Ricardo Jorge Camacho; Bonaventura Clotet; Suzie Coughlan; Zehava Grossman; Andrzej Horban; Klaus Korn; Leondios G. Kostrikis; Claus Nielsen; Dimitrios Paraskevis; Mario Poljak; Elisabeth Puchhammer-Stöckl; Chiara Riva; Lidia Ruiz; Mika Salminen; Rob Schuurman; Anders Sönnerborg; Danica Stanekova; Maja Stanojevic; Anne-Mieke Vandamme

The SPREAD Programme investigated prospectively the time trend from September 2002 through December 2005 of transmitted drug resistance (TDR) among 2793 patients in 20 European countries and in Israel with newly diagnosed human immunodeficiency virus type 1 (HIV-1) infection. The overall prevalence of TDR was 8.4% (225 of 2687 patients; 95% confidence interval [CI], 7.4%-9.5%), the prevalence of nucleoside reverse-transcriptase inhibitor (NRTI) resistance was 4.7% (125 of 2687 patients; 95% CI, 3.9%-5.5%), the prevalence of nonucleoside reverse-transcriptase inhibitor (NNRTI) resistance was 2.3% (62 of 2687 patients; 95% CI, 1.8%-2.9%), and the prevalence of protease inhibitor (PI) resistance was 2.9% (79 of 2687 patients; 95% CI, 2.4%-3.6%). There was no time trend in the overall TDR or in NRTI resistance, but there was a statistically significant decrease in PI resistance (P = .04) and in NNRTI resistance after an initial increase (P = .02). We found that TDR appears to be stabilizing in Europe, consistent with recent reports of decreasing drug resistance and improved viral suppression in patients treated for HIV-1 infection.


AIDS | 2009

Non-AIDS-defining deaths and immunodeficiency in the era of combination antiretroviral therapy.

Benoît Marin; Rodolphe Thiébaut; Heiner C. Bucher; Virginie Rondeau; Dominique Costagliola; Maria Dorrucci; Osamah Hamouda; Maria Prins; A. Sarah Walker; Kholoud Porter; Caroline Sabin; Geneviève Chêne

Objective:To assess whether immunodeficiency is associated with the most frequent non-AIDS-defining causes of death in the era of combination antiretroviral therapy (cART). Design:Observational multicentre cohorts. Methods:Twenty-three cohorts of adults with estimated dates of human immunodeficiency virus (HIV) seroconversion were considered. Patients were seroconverters followed within the cART era. Measurements were latest CD4, nadir CD4 and time spent with CD4 cell count less than 350 cells/μl. Outcomes were specific causes of death using a standardized classification. Results:Among 9858 patients (71 230 person-years follow-up), 597 died, 333 (55.7%) from non-AIDS-defining causes. Non-AIDS-defining infection, liver disease, non-AIDS-defining malignancy and cardiovascular disease accounted for 53% of non-AIDS deaths. For each 100 cells/μl increment in the latest CD4 cell count, we found a 64% (95% confidence interval 58–69%) reduction in risk of death from AIDS-defining causes and significant reductions in death from non-AIDS infections (32, 18–44%), end-stage liver disease (33, 18–46%) and non-AIDS malignancies (34, 21–45%). Non-AIDS-defining causes of death were also associated with nadir CD4 while being cART-naive or duration of exposure to immunosuppression. No relationship between risk of death from cardiovascular disease and CD4 cell count was found though there was a raised risk associated with elevated HIV RNA. Conclusion:In the cART era, the most frequent non-AIDS-defining causes of death are associated with immunodeficiency, only cardiovascular disease was associated with high viral replication. Avoiding profound and mild immunodeficiency, through earlier initiation of cART, may impact on morbidity and mortality of HIV-infected patients.


Journal of Acquired Immune Deficiency Syndromes | 2001

Frequency of genotypic and phenotypic drug-resistant HIV-1 among therapy-naive patients of the German Seroconverter Study.

Susanne Duwe; Monika Brunn; Doris Altmann; Osamah Hamouda; Barbara Schmidt; Hauke Walter; Georg Pauli; Claudia Kücherer

Summary: Genotypic and phenotypic resistance of viral reverse transcriptase (RT) and protease (PR) was determined for 64 therapy‐naive, HIV‐1‐infected seroconverters of the German Seroconverter Study coordinated by the Robert Koch‐Institut, Berlin. The date of seroconversion of patients and the laboratory, clinical, and therapeutic follow‐up data were documented. Samples were collected between 1996 and 1999. Phenotypic resistant HIV‐1 were found in 8 (13%) seroconverters; in most cases resistance was weak and mainly directed against RT inhibitors (4 nucleoside reverse transcriptase inhibitors [NRTIs], 2 nonnucleoside reverse transcriptase inhibitors [NNRTIs], 1 combination NRTI/NNRTI). Only one infection with a weak PR inhibitor resistance was identified. Transmission of multidrug‐resistant HIV‐1 has not yet been observed. Frequently at least one or more amino acid mutations associated with antiretroviral drug resistance were detected by genotypic analysis. The mean number of resistance‐associated mutations in the RT of the transmitted virus has increased significantly since 1996. Studies have shown the improved benefit of initial antiretroviral therapy if based on genotypic resistance data. In view of the considerably high level of transmission of resistant HIV‐1 in Germany, which is also seen in other studies in Europe and the United States, we suggest determining the genotypic resistance pattern before starting therapy of newly HIV‐1‐infected patients.


AIDS | 2011

The hepatitis C epidemic among HIV-positive MSM: incidence estimates from 1990 to 2007

Jannie J. van der Helm; Maria Prins; Julia del Amo; Heiner C. Bucher; Geneviève Chêne; Maria Dorrucci; John Gill; Osamah Hamouda; Mette Sannes; Kholoud Porter; Ronald B. Geskus

Background:Outbreaks of acute hepatitis C virus (HCV) infection among HIV-infected MSM have been described since 2000. However, phylogenetic analysis suggests that the spread of HCV started around 1996. We estimated the incidence of HCV in HIV-infected MSM with well estimated dates of HIV seroconversion from 1990 to 2007. Methods:Data from 12 cohorts within the Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) Collaboration were used. HCV incidence was estimated using standard incidence methods and methods for interval-censored data. We accounted for the fact that routine HCV data collection in each cohort started in different calendar years. Results:Of 4724 MSM, 3014 had an HCV test result and were included. Of these, 124 (4%) had only positive HCV test results, 2798 (93%) had only negative results and 92 (3%) had both. In 1990, HCV incidence ranged from 0.9 to 2.2 per 1000 person-years, depending on the analysis strategy used. HCV incidence increased up to 1995 when it was estimated to range between 5.5 and 8.1 per 1000 person-years. From 2002 onwards, it increased substantially to values between 16.8 and 30.0 per 1000 person-years in 2005 and between 23.4 and 51.1 per 1000 person-years in 2007. Conclusion:Our data support phylodynamic findings that HCV incidence had already increased among HIV-infected MSM from the mid-1990s. However, the main expansion of the HCV epidemic started after 2002. Incidence estimates obtained from cohort studies may help identify changes in the spread of important infections earlier and should guide routine testing policies to minimize further disease burden.


The Journal of Infectious Diseases | 2009

Cumulative HIV viremia during highly active antiretroviral therapy is a strong predictor of AIDS-related lymphoma.

Alexander Zoufaly; Hans-Jürgen Stellbrink; Matthias an der Heiden; Christian Kollan; Christian Hoffmann; Jan van Lunzen; Osamah Hamouda

BACKGROUND AIDS-related lymphoma contributes to significant morbidity and mortality among human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART). We assessed the predictive role of cumulative HIV viremia and other risk factors in the development of AIDS-related non-Hodgkin lymphoma. METHODS Data from the Clinical Surveillance of HIV Disease (ClinSurv) study, an ongoing, observational, open cohort study of HIV-infected patients from different urban areas in Germany, were analyzed using a Cox proportional hazards model. RESULTS In the Cox model, which comprised 6022 patients and 27,812 patient-years of follow-up while patients were receiving HAART from 1999 through 2006, cumulative HIV viremia was found to be independently associated with the risk of lymphoma (hazard ratio, [HR], 1.67 [95% confidence interval {CI}, 1.27-2.20]) (P < .001]). This association differed markedly between lymphoma subtypes. Although the association was more pronounced for Burkitt-type lymphoma (HR, 3.45 [95% CI, 1.52-7.85]) (P = .003), there was no association between cumulative HIV viremia and the incidence of primary central nervous system lymphoma (HR, 1.00 [95% CI, 0.39-2.57]) (P = .997). Other risk factors associated with an increased risk in a multivariable analysis included the latest CD4 T cell count as well as age per 10-year increment. CONCLUSIONS Cumulative HIV viremia is an independent and strong predictor of AIDS-related lymphoma among patients receiving HAART. The influence of cumulative HIV viremia may differ between lymphoma subtypes.


Retrovirology | 2013

HIV-1 subtype distribution and its demographic determinants in newly diagnosed patients in Europe suggest highly compartmentalized epidemics

Ana B. Abecasis; Annemarie M. J. Wensing; D Paraskevis; Jurgen Vercauteren; Kristof Theys; David A. M. C. van de Vijver; Jan Albert; Birgitta Åsjö; Claudia Balotta; Danail Beshkov; Ricardo Jorge Camacho; Bonaventura Clotet; Cillian F. De Gascun; Algis Griskevicius; Zehava Grossman; Osamah Hamouda; Andrzej Horban; Tatjana Kolupajeva; Klaus Korn; Leon G. Kostrikis; Claudia Kücherer; Kirsi Liitsola; Marek Linka; Claus Nielsen; Dan Otelea; Roger Paredes; Mario Poljak; Elisabeth Puchhammer-Stöckl; Jean-Claude Schmit; Anders Sönnerborg

BackgroundUnderstanding HIV-1 subtype distribution and epidemiology can assist preventive measures and clinical decisions. Sequence variation may affect antiviral drug resistance development, disease progression, evolutionary rates and transmission routes.ResultsWe investigated the subtype distribution of HIV-1 in Europe and Israel in a representative sample of patients diagnosed between 2002 and 2005 and related it to the demographic data available. 2793 PRO-RT sequences were subtyped either with the REGA Subtyping tool or by a manual procedure that included phylogenetic tree and recombination analysis. The most prevalent subtypes/CRFs in our dataset were subtype B (66.1%), followed by sub-subtype A1 (6.9%), subtype C (6.8%) and CRF02_AG (4.7%). Substantial differences in the proportion of new diagnoses with distinct subtypes were found between European countries: the lowest proportion of subtype B was found in Israel (27.9%) and Portugal (39.2%), while the highest was observed in Poland (96.2%) and Slovenia (93.6%). Other subtypes were significantly more diagnosed in immigrant populations. Subtype B was significantly more diagnosed in men than in women and in MSM > IDUs > heterosexuals. Furthermore, the subtype distribution according to continent of origin of the patients suggests they acquired their infection there or in Europe from compatriots.ConclusionsThe association of subtype with demographic parameters suggests highly compartmentalized epidemics, determined by social and behavioural characteristics of the patients.


Emerging Infectious Diseases | 2007

Major outbreak of hepatitis A associated with orange juice among tourists, Egypt, 2004.

Christina Frank; Jan Walter; M Muehlen; Andreas Jansen; Ulrich van Treeck; Anja M. Hauri; Iris Zoellner; Magda Rakha; Marina Hoehne; Osamah Hamouda; Eckart Schreier; Klaus Stark

In 2004, a major outbreak of hepatitis A among tourists returning from Egypt involved 351 case-patients from 9 European countries who were infected with a single strain (genotype 1b). The case-control study identified orange juice as the most likely infection vehicle. Vaccination against hepatitis A virus is strongly recommended before travel to disease-endemic areas.

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