Andrei DADU

Dr. Andrei DADU

World Health Organization, Regional Office for Europe
orcid

Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 March 2015 in European Respiratory Journal
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Journal Article
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KLKnut Lönnroth
Knut Lönnroth
GMGiovanni Battista Migliori
Giovanni Battista Migliori
IAIbrahim Abubakar
Ibrahim Abubakar
LDLia D'Ambrosio
Lia D'Ambrosio
GVGerard de Vries
Gerard de Vries
MRMario C. Raviglione
Mario C. Raviglione
This paper describes an action framework for countries with low tuberculosis (TB) incidence (<100 TB cases per million population) that are striving for TB elimination. The framework sets out priority interventions required for these countries to progress first towards “pre-elimination” (<10 cases per million) and eventually the elimination of TB as a public health problem (less than one case per million). TB epidemiology in most low-incidence countries is characterised by a low rate of transmission in the general population, occasional outbreaks, a majority of TB cases generated from progression of latent TB infection (LTBI) rather than local transmission, concentration to certain vulnerable and hard-to-reach risk groups, and challenges posed by cross-border migration. Common health system challenges are that political commitment, funding, clinical expertise and general awareness of TB diminishes as TB incidence falls. The framework presents a tailored response to these challenges, grouped into eight priority action areas: 1) ensure political commitment, funding and stewardship for planning and essential services; 2) address the most vulnerable and hard-to-reach groups; 3) address special needs of migrants and cross-border issues; 4) undertake screening for active TB and LTBI in TB contacts and selected high-risk groups, and provide appropriate treatment; 5) optimise the prevention and care of drug-resistant TB; 6) ensure continued surveillance, programme monitoring and evaluation and case-based data management; 7) invest in research and new tools; and 8) support global TB prevention, care and control. The overall approach needs to be multisectorial, focusing on equitable access to high-quality diagnosis and care, and on addressing the social determinants of TB. Because of increasing globalisation and population mobility, the response needs to have both national and global dimensions.

15 December 2001 in The Journal of Infectious Diseases
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JDJan Drobeniuc
Jan Drobeniuc
MFMichael O. Favorov
Michael O. Favorov
CSCraig N. Shapiro
Craig N. Shapiro
BBBeth P. Bell
Beth P. Bell
EMEric E. Mast
Eric E. Mast
HMHarold S. Margolis
Harold S. Margolis
Prevalence of antibody and risk factors to hepatitis E virus (HEV) infection were determined in a cross-sectional study of 2 group-matched population

1 October 2016 in The Lancet Infectious Diseases
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Journal Article
Open access
MZMatteo Zignol
Matteo Zignol
ADAnna S Dean
Anna S Dean
NANatavan Alikhanova
Natavan Alikhanova
SASönke Andres
Sönke Andres
ACAndrea Maurizio Cabibbe
Andrea Maurizio Cabibbe
MRMario C Raviglione
Mario C Raviglione
Pyrazinamide and fluoroquinolones are essential antituberculosis drugs in new rifampicin-sparing regimens. However, little information about the extent of resistance to these drugs at the population level is available. In a molecular epidemiology analysis, we used population-based surveys from Azerbaijan, Bangladesh, Belarus, Pakistan, and South Africa to investigate resistance to pyrazinamide and fluoroquinolones among patients with tuberculosis. Resistance to pyrazinamide was assessed by gene sequencing with the detection of resistance-conferring mutations in the pncA gene, and susceptibility testing to fluoroquinolones was conducted using the MGIT system. Pyrazinamide resistance was assessed in 4972 patients. Levels of resistance varied substantially in the surveyed settings (3·0-42·1%). In all settings, pyrazinamide resistance was significantly associated with rifampicin resistance. Among 5015 patients who underwent susceptibility testing to fluoroquinolones, proportions of resistance ranged from 1·0-16·6% for ofloxacin, to 0·5-12·4% for levofloxacin, and 0·9-14·6% for moxifloxacin when tested at 0·5 μg/mL. High levels of ofloxacin resistance were detected in Pakistan. Resistance to moxifloxacin and gatifloxacin when tested at 2 μg/mL was low in all countries. Although pyrazinamide resistance was significantly associated with rifampicin resistance, this drug may still be effective in 19-63% of patients with rifampicin-resistant tuberculosis. Even though the high level of resistance to ofloxacin found in Pakistan is worrisome because it might be the expression of extensive and unregulated use of fluoroquinolones in some parts of Asia, the negligible levels of resistance to fourth-generation fluoroquinolones documented in all survey sites is an encouraging finding. Rational use of this class of antibiotics should therefore be ensured to preserve its effectiveness. Bill & Melinda Gates Foundation, United States Agency for International Development, Global Alliance for Tuberculosis Drug Development.

1 June 2018 in The Lancet Infectious Diseases
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Journal Article
Open access
MZMatteo Zignol
Matteo Zignol
ACAndrea Maurizio Cabibbe
Andrea Maurizio Cabibbe
ADAnna S Dean
Anna S Dean
PGPhilippe Glaziou
Philippe Glaziou
NANatavan Alikhanova
Natavan Alikhanova
MRMario C Raviglione
Mario C Raviglione
In many countries, regular monitoring of the emergence of resistance to anti-tuberculosis drugs is hampered by the limitations of phenotypic testing for drug susceptibility. We therefore evaluated the use of genetic sequencing for surveillance of drug resistance in tuberculosis. Population-level surveys were done in hospitals and clinics in seven countries (Azerbaijan, Bangladesh, Belarus, Pakistan, Philippines, South Africa, and Ukraine) to evaluate the use of genetic sequencing to estimate the resistance of Mycobacterium tuberculosis isolates to rifampicin, isoniazid, ofloxacin, moxifloxacin, pyrazinamide, kanamycin, amikacin, and capreomycin. For each drug, we assessed the accuracy of genetic sequencing by a comparison of the adjusted prevalence of resistance, measured by genetic sequencing, with the true prevalence of resistance, determined by phenotypic testing. Isolates were taken from 7094 patients with tuberculosis who were enrolled in the study between November, 2009, and May, 2014. In all tuberculosis cases, the overall pooled sensitivity values for predicting resistance by genetic sequencing were 91% (95% CI 87-94) for rpoB (rifampicin resistance), 86% (74-93) for katG, inhA, and fabG promoter combined (isoniazid resistance), 54% (39-68) for pncA (pyrazinamide resistance), 85% (77-91) for gyrA and gyrB combined (ofloxacin resistance), and 88% (81-92) for gyrA and gyrB combined (moxifloxacin resistance). For nearly all drugs and in most settings, there was a large overlap in the estimated prevalence of drug resistance by genetic sequencing and the estimated prevalence by phenotypic testing. Genetic sequencing can be a valuable tool for surveillance of drug resistance, providing new opportunities to monitor drug resistance in tuberculosis in resource-poor countries. Before its widespread adoption for surveillance purposes, there is a need to standardise DNA extraction methods, recording and reporting nomenclature, and data interpretation. Bill & Melinda Gates Foundation, United States Agency for International Development, Global Alliance for Tuberculosis Drug Development.

26 November 2012 in Bulletin of the World Health Organization
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Journal Article
Closed access
ASAlena Skrahina
Alena Skrahina
HHHenadz Hurevich
Henadz Hurevich
AZAksana Zalutskaya
Aksana Zalutskaya
ESEvgeni Sahalchyk
Evgeni Sahalchyk
AAAndrei Astrauko
Andrei Astrauko
MZMatteo Zignol
Matteo Zignol
To assess the problem of multidrug-resistant tuberculosis (MDR-TB) throughout Belarus and investigate the associated risk factors. In a nationwide survey in 2010-2011, 1420 tuberculosis (TB) patients were screened and 934 new and 410 previously treated cases of TB were found to meet the inclusion criteria. Isolates of Mycobacterium tuberculosis from each eligible patient were tested for susceptibility to anti-TB drugs. Sociobehavioural information was gathered in interviews based on a structured questionnaire. MDR-TB was found in 32.3% and 75.6% of the new and previously treated patients, respectively, and, 11.9% of the 612 patients found to have MDR-TB had extensively drug-resistant TB (XDR-TB). A history of previous treatment for TB was the strongest independent risk factor for MDR-TB (odds ratio, OR: 6.1; 95% confidence interval, CI: 4.8-7.7). The other independent risk factors were human immunodeficiency virus (HIV) infection (OR: 2.2; 95% CI: 1.4-3.5), age < 35 years (OR: 1.4; 95% CI: 1.0-1.8), history of imprisonment (OR: 1.5; 95% CI: 1.1-2.0), disability sufficient to prevent work (OR: 1.9; 95% CI: 1.2-3.0), alcohol abuse (OR: 1.3; 95% CI: 1.0-1.8) and smoking (OR: 1.5; 95% CI: 1.1-2.0). MDR-TB is very common among TB patients throughout Belarus. The numerous risk factors identified for MDR-TB and the convergence of the epidemics of MDR-TB and HIV infection call not only for stronger collaboration between TB and HIV control programmes, but also for the implementation of innovative measures to accelerate the detection of TB resistance and improve treatment adherence.

25 October 2012 in European Respiratory Journal
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Journal Article
Open access
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HJHelen E. Jenkins
Helen E. Jenkins
VPValeriu Plesca
Valeriu Plesca
ACAnisoara Ciobanu
Anisoara Ciobanu
VCValeriu Crudu
Valeriu Crudu
IGIrina Galusca
Irina Galusca
TCTed Cohen
Ted Cohen
Multidrug-resistant tuberculosis (MDR-TB) is a major concern in countries of the former Soviet Union. The reported risk of resistance among tuberculosis (TB) cases in the Republic of Moldova is among the highest in the world. We aimed to produce high-resolution spatial maps of MDR-TB risk and burden in this setting.We analysed national TB surveillance data collected between 2007 and 2010 in Moldova. High drug susceptibility testing coverage and detailed location data permitted identification of subregional areas of higher MDR-TB risk. We investigated whether the distribution of cases with MDR-TB risk factors could explain this observed spatial variation in MDR-TB.3447 MDR-TB cases were notified during this period; 24% of new and 62% of previously treated patients had MDR-TB. Nationally, the estimated annual MDR-TB incidence was 54 cases per 100 000 persons and >1000 cases per 100 000 persons within penitentiaries. We identified substantial geographical variation in MDR-TB burden and hotspots of MDR-TB. Locations with a higher percentage of previously incarcerated TB cases were at greater risk of being MDR-TB hotspots.Spatial analyses revealed striking geographical heterogeneity of MDR-TB. Methods to identify locations of high MDR-TB risk and burden should allow for better resource allocation and more appropriate targeting of studies to understand local mechanisms driving resistance.