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Dive into the research topics where Melanie Maier is active.

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Featured researches published by Melanie Maier.


BMC Infectious Diseases | 2014

Virological efficacy and immunological recovery among Ethiopian HIV-1 infected adults and children

Andargachew Mulu; Uwe G. Liebert; Melanie Maier

BackgroundIntroduction of antiretroviral therapy (ART) in sub-Saharan Africa was a hot debate due to many concerns about adherence, logistics and resistance. Currently, it has been significantly scaled up. However as the WHO clinico-immunological approaches for initiation and monitoring of ART in the region lacks viral load determination and drug resistance monitoring, HIV infected adults and children may be at risk for “unrecognized” virologic failure and the subsequent development of antiretroviral drug resistance. This study evaluates the virological efficacy and immunological recovery of HIV/AIDS patients under ART.MethodsConsecutive HIV-1 infected adults (N = 100) and children (N = 100) who have been receiving ART for up to 6 years at Gondar University Hospital, Ethiopia were enrolled following the WHO protocol for assessment of acquired drug resistance. Magnitude of viral suppression, genotypic drug resistance mutations and patterns of CD4+ T cell recovery were determined using standard virological and immunological methods.ResultsVirological suppression (HIV RNA < 40 copies/ml) was observed in 82 and 87% of adults and children on a median time of 24 months on ART, respectively. Mutation K103N conferring resistance to non nucleoside reverse transcriptase inhibitors and thymidine analogue mutations (M41L, L210W) were found only in one adult and child patient, respectively. Median CD4+ T cell count has increased from baseline 124 to 266 (IQR: 203–306) and 345 (IQR: 17–1435) to 998 (IQR: 678–2205) cells/mm3 in adults and children respectively after 12 months of ART. Nevertheless, small but significant number of clinically asymptomatic adults (16%) and children (13%) had low level viraemia (HIV-1 RNA 41–1000 copies/ml).ConclusionsMajority of both adults (82%) and children (87%) who received ART showed high viral suppression and immunological recovery. This indicates that despite limited resources in the setting virological efficacy can be sustained for a substantial length of time and also enhance immunological recovery irrespective of age. However, the presence of drug resistance mutations and low level viraemia among clinically asymptomatic patients highlights the need for virological monitoring.


Journal of Clinical Microbiology | 2016

Multicenter Evaluation of the Xpert Norovirus Assay for Detection of Norovirus Genogroups I and II in Fecal Specimens

Mark D. Gonzalez; L. Claire Langley; Blake W. Buchan; Matthew L. Faron; Melanie Maier; Kate Templeton; Kimberly Walker; Melissa B. Miller; Arundhati Rao; Uwe G. Liebert; Nathan A. Ledeboer; Jan Vinjé; Carey-Ann D. Burnham

ABSTRACT Norovirus is the most common cause of sporadic gastroenteritis and outbreaks worldwide. The rapid identification of norovirus has important implications for infection prevention measures and may reduce the need for additional diagnostic testing. The Xpert Norovirus assay recently received FDA clearance for the detection and differentiation of norovirus genogroups I and II (GI and GII), which account for the vast majority of infections. In this study, we evaluated the performance of the Xpert Norovirus assay with both fresh, prospectively collected (n = 914) and frozen, archived (n = 489) fecal specimens. A Centers for Disease Control and Prevention (CDC) composite reference method was used as the gold standard for comparison. For both prospective and frozen specimens, the Xpert Norovirus assay showed positive percent agreement (PPA) and negative percent agreement (NPA) values of 98.3% and 98.1% for GI and of 99.4% and 98.2% for GII, respectively. Norovirus prevalence in the prospective specimens (collected from March to May of 2014) was 9.9% (n = 90), with the majority of positives caused by genogroup II (82%, n = 74). The positive predictive value (PPV) of the Xpert Norovirus assay was 75% for GI-positive specimens, whereas it was 86.5% for GII-positive specimens. The negative predictive values (NPV) for GI and GII were 100% and 99.9%, respectively.


BMC Infectious Diseases | 2016

Hepatitis viruses in Ethiopia: a systematic review and meta-analysis

Yeshambel Belyhun; Melanie Maier; Andargachew Mulu; Ermias Diro; Uwe G. Liebert

BackgroundThe existing seroepidemiological data on viral hepatitis in Ethiopia showed a wide variation in prevalence pattern and the clinical and public health burden have been underestimated. The aim of this systematic review and meta-analysis was to provide a clear and comprehensive estimation of viral hepatitis epidemiology and the potential clinical burdens in Ethiopia.MethodsA comprehensive literature search was carried out from five decades (1968–2015) published studies from biomedical databases; PubMed, Google scholar, Medline and Web of Science.ResultsThe overall pooled prevalence of hepatitis B virus (HBV) was 7.4% (95%CI: 6.5–8.4). The pooled prevalence among subgroups showed 5.2% (95%CI: 3.7–7.4) in human immunodeficiency virus (HIV) infected individuals, 8.0% (95%CI: 5.9–10.7) in community based studies, 8.4% (95%CI: 5.4–12.7) in blood donors, 11.0% (95%CI: 7.5–15.9) in immigrants and 6.9% (95%CI: 5.6–8.5) in other groups. Among study parameters considered during meta-regression analysis, only study years were associated with a decreasing HBV prevalence rate over time. The overall pooled prevalence of anti-hepatitis C virus antibody (anti-HCV) was 3.1% (95%CI: 2.2–4.4). Unlike HBV, the anti-HCV prevalence in HIV infected individuals was higher (5.5%, 95%CI: 3.8–7.8%, p = 0.01) than the prevalence observed in the other subgroup of study population. Although relatively few data were available, hepatitis virus A (HAV), D (HDV) and E (HEV) were also circulated in Ethiopia.ConclusionsThis review indicates that all types of viral hepatitis origins are endemic in Ethiopia. Adapting a recommended diagnostic and treatment algorithm of viral hepatitis in the routine healthcare systems and implementing prevention and control policies in the general population needs an urgent attention.


International Journal of Infectious Diseases | 2013

Deworming of intestinal helminths reduces HIV-1 subtype C viremia in chronically co-infected individuals

Andargachew Mulu; Melanie Maier; Uwe G. Liebert

OBJECTIVE To define the impact of helminthic infestations and their treatment on viral load and T cell subsets in chronic HIV-1-infected patients. METHODS Two hundred twenty chronic HIV-1-infected Ethiopian patients with (N = 87) and without (N = 133) helminthic infestations were included. To determine the impact of deworming on viral load and T cell subsets, a subset of these patients with (n = 23) and without (n = 20) helminthic infestations were followed longitudinally. Helminth egg loads, plasma HIV RNA levels, and peripheral blood CD4(+) and CD8(+) T cells were determined at baseline and at 12 weeks after antihelminthic treatment. RESULTS At baseline, plasma viral load was significantly higher in individuals with (n = 87) than without (n = 133) a helminthic infestation (5.01 log10 vs. 3.41 log10, p < 0.001). Twelve weeks after antihelminthic treatment, plasma HIV RNA levels were reduced in the successfully treated group (p < 0.001). Twelve weeks after antihelminthic treatment, helminth infestations and their treatment had no significant effect on CD4(+) T cell counts. However, helminth-infested individuals had a higher level of CD8(+) T cells at baseline (p < 0.001), which was significantly reduced (p < 0.01) at 12 weeks after antihelminthic treatment. CONCLUSIONS Helminths were found to be associated with an increased HIV RNA level. Successful treatment of intestinal helminths reduced plasma HIV RNA levels in chronic HIV-1 subtype C infection. Considering the high endemicity of helminths in tropical settings, the management of chronically HIV-infected individuals must include deworming.


BMC Infectious Diseases | 2014

Clade homogeneity and Pol gene polymorphisms in chronically HIV-1 infected antiretroviral treatment naive patients after the roll out of ART in Ethiopia

Andargachew Mulu; Thomas Lange; Uwe G. Liebert; Melanie Maier

BackgroundDespite the increasing use of antiretroviral treatment (ART) recent data on frequency and pattern of drug resistance mutations in Ethiopia is not available. Furthermore with increasing mobility of people HIV-1 subtypes other than the predominant subtype C may likely be introduced from the neighbouring countries. This study was aimed to determine the molecular characterization and pre-antiretroviral treatment resistance mutations among HIV-1 chronically infected ART naïve patients after the roll out of ART in Ethiopia.MethodsViral RNA was determined in 160 baseline plasma samples. The entire PR and the first 335 codons (76%) of the RT regions of the pol gene of the HIV-1 genome (N = 160) were amplified and sequenced using an in-house assay. Genotypic drug resistance was defined as the presence of one or more resistance-related mutations as specified by the consensus mutation of Stanford University HIVDB and the International Antiviral Society (IAS) mutation lists.ResultsA predominance of HIV-1 subtype C (98.7%) was observed. The level of drug resistance is found to be 5.6% and 13.1% according to the Stanford University HIVDB drug resistance interpretation algorithms and the International Antiviral Society mutation lists, respectively. Mutations conferring simultaneous resistance to NRTIs and NNRTIs were not detected and no major PR mutation was found. However, a high rate of polymorphic changes both in PR and RT regions were observed. Moreover, twenty four (15%) monophyletic transmission clusters with bootstrap value of 99% were found.ConclusionsStrong evidence for consistent HIV-1C clade homogeneity and low influx of other variant into the country was found. The level of drug resistance observed in chronically infected treatment naïve patients which exceeds the WHO estimates suggests the need for incorporation of HIV-1 drug resistance testing prior to ART initiation. The occurrence of monophyletic transmission clusters affecting (24/160) individuals indicates their potential risk related practice. Thus, an intensified public health intervention program and monitoring of HIV drug resistance testing appears indispensible.


Liver International | 2004

Sequential combination therapy of HBe antigen‐negative/virus‐DNA‐positive chronic hepatitis B with famciclovir or lamivudine and interferon‐alpha‐2a

Ingolf Schiefke; Chris Klecker; Melanie Maier; Ute Oesen; Gunnar Etzrodt; Andrea Tannapfel; Uwe G. Liebert; Frieder Berr

Background/Aims: Hepatitis B e antigen‐negative/hepatitis B virus (HBV) DNA‐positive chronic hepatitis B (CHBe−) exhibits a high relapse rate on monotherapy with lamivudine or interferon‐alpha (IFN‐α). We investigated, whether sequential therapy with famciclovir or lamivudine followed by combination with IFN‐α‐2a improves durable virologic response in CHBe− characterized by mutation analysis of the HBV precore genome region.


Journal of Medical Virology | 2011

Genotypes and viral load of hepatitis C virus among persons attending a voluntary counseling and testing center in Ethiopia

Tesfay Abreha; Yimtubezinash Woldeamanuel; Corinna Pietsch; Melanie Maier; Daniel Asrat; Almaz Abebe; Bereket Hailegiorgis; Abraham Aseffa; Uwe G. Liebert

The prevalence of different genotypes of hepatitis C virus (HCV) in Ethiopia is not known. HCV genotypes influence the response to therapy with alpha‐interferon alone or in combination with ribavirin. A cross sectional study was conducted on attendees of voluntary counseling and testing center. Serum samples from 1,954 (734 HIV positive and 1,220 HIV negative) individuals were screened for HCV antibody. Active HCV infection was confirmed by quantitative PCR in 18 of the 71 samples with anti‐HCV antibodies. The HCV viral load ranged from 39,650 to 9,878,341 IU/ml (median 1,589,631 IU/ml) with no significant difference [χ2(17) = 18.00, P = 0.389] between persons positive or negative for HIV. The viral load of HCV was, however, higher in older study subjects (r = 0.80, P = 0.000). HCV genotypes were determined using the VERSANT HCV Genotype Assay (LiPA) and sequence analysis of the NS5b region of the HCV genome. Diverse HCV genotypes were found including genotypes 1, 2, 4, and 5. There was no difference in the distribution regarding the HIV status. As in other parts of the world, genotyping of HCV must be considered whenever HCV is incriminated as a cause of hepatitis. J. Med. Virol. 83:776–782, 2011.


Journal of Medical Virology | 2015

Limited increase in primary HIV-1C drug resistance mutations in treatment naïve individuals in Ethiopia

Kahsay Huruy; Melanie Maier; Andargachew Mulu; Uwe G. Liebert

Antiretroviral drug resistance is a major challenge for management and control of HIV‐1 infection worldwide and particularly in resource limited countries. The frequency of primary drug resistance mutations (DRMs) and of naturally occurring polymorphisms was determined in 83 antiretroviral treatment (ART) naïve Ethiopian individuals infected with HIV‐1, consecutively enrolled in 2010. In all individuals HIV‐1C was found. The median (interquartile range) of CD4+ T‐cell count and viral load were 100 (49–201) cells/μl and 44,640 (12,553–134,664) copies/ml, respectively. Protease (PR) and reverse transcriptase (RT) genes of HIV‐1 RNA were amplified and sequenced. The proportion of primary DRM to any drug class, using the World Health Organization mutation lists, was 7.2% (6/83), thus exceeding the WHO threshold limit of 5%. Three individuals (3.6%) had non‐nucleoside reverse transcriptase inhibitor (NNRTI) mutations, two individuals (2.4%) had protease inhibitor mutations, and one (1.2%) had mutations associated with two drug classes (nucleoside reverse transcriptase inhibitor and NNRTI). In addition, the frequency of polymorphisms in the PR and RT genes was higher compared with previous studies in Ethiopian as well as worldwide isolates. Hence, genotypic drug resistance testing as part of routine management of individuals seems reasonable even in resource limited countries prior to treatment in order to allow proper choice of ART. J. Med. Virol. 87:978–984, 2015.


European Journal of Gastroenterology & Hepatology | 2013

Evaluation of a rapid on-site anti-HCV test as a screening tool for hepatitis C virus infection.

Juliane Kant; B. Möller; R. Heyne; Adam Herber; Stephan H. Bohm; Melanie Maier; Uwe G. Liebert; Joachim Mössner; T. Berg; Johannes Wiegand

Background In settings such as needle-stick injuries or intravenous drug abuse, immediate knowledge of the anti-hepatitis C virus (HCV) serostatus instead of waiting for the results of a laboratory-based test can be important to guide further medical procedures and appropriate hygienic advises. Thus, a rapid on-site anti-HCV test was evaluated in daily clinical routine and compared with a laboratory-based certified assay. Patients and methods Ten microliters of serum or EDTA whole blood was analyzed using a chromatographic immunoassay (Toyo anti-HCV test). Results were available on-site 5–15 min after sample centrifugation. The Architect anti-HCV test served as a reference method. Results Sera of 189 patients were analyzed (without HCV infection: n=105; HCV infection: n=84). The assay was evaluable in 185 cases (98%). The sensitivity and specificity were 99 and 88%, respectively. With EDTA whole blood, the test was evaluable in 47/52 samples (90%). Forty-six of 47 evaluable EDTA tests were concordant with serum results. The one HCV patient with an unevaluable serum test was diagnosed correctly with the EDTA sample. Conclusion The rapid chromatographic anti-HCV immunoassay has limited specificity, which impairs clinical practicability. A positive result warrants re-evaluation with a certified serologic assay.


PLOS ONE | 2013

Clinical Relevance of Minimal Residual Viremia during Long-Term Therapy with Nucleos(t)ide Analogues in Patients with Chronic Hepatitis B

Melanie Maier; Uwe G. Liebert; Christian Wittekind; Thorsten Kaiser; T. Berg; Johannes Wiegand

Background Successful therapy of chronic hepatitis B with nucleos(t)ide analogues (NUCs) has been defined by undetectable HBV-DNA determined with conventional PCR (lower limit of detection (LLD) 60–80 IU/mL) in clinical registration trials. However, current EASL guidelines recommend highly sensitive real-time PCR (LLD<10–20 IU/mL) and define treatment response by HBV-DNA<10 IU/mL. Aim We evaluated frequency and relevance of minimal residual viremia (MRV) during long-term NUC-treatment in a real-life setting. Methods Frozen serum samples (HBV-DNA negative by in-house PCR, LLD <73 IU/mL) were re-analyzed by real-time PCR (LLD<10 IU/mL, Abbott, Germany). MRV was defined by real time PCR positivity and conventional PCR negativity. Results 237 samples of six HBsAg carriers and 27 NUC-treated CHB patients were analyzed (treatment period 28 (11–111) months, different treatment regimens with mono- or combination therapy). MRV was detected in 31/33 individuals (n = 160/237 serum samples) and more frequent in HBsAg carriers (95%) and HBeAg positive (87%) compared to HBeAg negative patients (53%) (p<0.0001, respectively). Five HBsAg carriers, five HBeAg positive, and four HBeAg negative individuals were continuously HBV-DNA positive. MRV was not significantly more often observed during NUC-monotherapies compared to combination therapies. Concomitant immunosuppressive therapy was present in nine cases and did not influence the results. Viral resistance occurred in three immunocompetent patients with adefovir or lamivudine monotherapy. Conclusions MRV is frequently observed during long-term NUC-therapy. Adjustment of treatment with highly potent NUCs does not seem to be necessary in case of minimal residual viremia in a real-life setting.

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T. Berg

Royal Netherlands Academy of Arts and Sciences

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