Alex Vorsters
University of Antwerp
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Alex Vorsters.
Journal of Viral Hepatitis | 2008
Greet Hendrickx; K. van Herck; Alex Vorsters; S. Wiersma; C. Shapiro; J. K. Andrus; A. M. Ropero; Daniel Shouval; W. Ward; P. Van Damme
Summary. For the first time a global meeting on hepatitis A virus (HAV) infection as vaccine preventable disease was organized at the end of 2007. More than 200 experts from 46 countries gathered to investigate the changing global HAV epidemiology reflecting the increasing numbers of persons at risk for severe clinical disease and mortality from HAV infection. The benefits of childhood and adult hepatitis A (HepA) vaccination strategies and the data needed by individual countries and international health organizations to assess current HepA prevention strategies were discussed. New approaches in preventing HAV infection including universal HepA vaccination were considered. This introductory paper summarizes the major findings of the meeting and describes the changing epidemiology of HAV infections and the impact of HepA vaccination strategies in various countries. Implementation of HepA vaccination strategies should take into account the level of endemicity, the level of the socio‐economic development and sanitation, and the risk of outbreaks. A stepwise strategy for introduction of HepA universal immunisation of children was recommended. This strategy should be based on accurate surveillance of cases and qualitative documentation of outbreaks and their control, secure political support on the basis of high‐quality results, and comprehensive cost‐effectiveness studies. The recognition of the need for increased global attention towards HepA prevention is an important outcome of this meeting.
European Journal of Clinical Microbiology & Infectious Diseases | 2012
Alex Vorsters; I. Micalessi; Joke Bilcke; Margareta Ieven; Johannes Bogers; P. Van Damme
The detection of human papillomavirus (HPV) DNA in urine, a specimen easily obtained by a non-invasive self-sampling method, has been the subject of a considerable number of studies. This review provides an overview of 41 published studies; assesses how different methods and settings may contribute to the sometimes contradictory outcomes; and discusses the potential relevance of using urine samples in vaccine trials, disease surveillance, epidemiological studies, and specific settings of cervical cancer screening. Urine sampling, storage conditions, sample preparation, DNA extraction, and DNA amplification may all have an important impact on HPV DNA detection and the form of viral DNA that is detected. Possible trends in HPV DNA prevalence in urine could be inferred from the presence of risk factors or the diagnosis of cervical lesions. HPV DNA detection in urine is feasible and may become a useful tool but necessitates further improvement and standardization.
European Journal of Clinical Microbiology & Infectious Diseases | 2014
Alex Vorsters; J. Van den Bergh; I. Micalessi; Samantha Biesmans; Johannes Bogers; Annick Hens; I. De Coster; Margareta Ieven; P. Van Damme
The benefits of using urine for the detection of human papillomavirus (HPV) DNA have been evaluated in disease surveillance, epidemiological studies, and screening for cervical cancers in specific subgroups. HPV DNA testing in urine is being considered for important purposes, notably the monitoring of HPV vaccination in adolescent girls and young women who do not wish to have a vaginal examination. The need to optimize and standardize sampling, storage, and processing has been reported.In this paper, we examined the impact of a DNA-conservation buffer, the extraction method, and urine sampling on the detection of HPV DNA and human DNA in urine provided by 44 women with a cytologically normal but HPV DNA-positive cervical sample. Ten women provided first-void and midstream urine samples. DNA analysis was performed using real-time PCR to allow quantification of HPV and human DNA.The results showed that an optimized method for HPV DNA detection in urine should (a) prevent DNA degradation during extraction and storage, (b) recover cell-free HPV DNA in addition to cell-associated DNA, (c) process a sufficient volume of urine, and (d) use a first-void sample.In addition, we found that detectable human DNA in urine may not be a good internal control for sample validity. HPV prevalence data that are based on urine samples collected, stored, and/or processed under suboptimal conditions may underestimate infection rates.
Vaccine | 2010
Alex Vorsters; S. Tack; Greet Hendrickx; N. Vladimirova; Paolo Bonanni; A. Pistol; T. Metličar; M.J. Alvarez Pasquin; M.A. Mayer; B. Aronsson; H. Heijbel; P. Van Damme
Immunisation is one of the corner stones of public health. Most health care consumers see the health care worker as their major source of information on immunisation and vaccine safety. Doctors, nurses and midwives should be appropriately and timely trained for that role. Within the Vaccine Safety, Attitudes, Training and Communication (VACSATC) EU-project a specific work package focused on the possible improvements of pre-service training of future health care workers. Surveys to assess current pre-service training about knowledge, skills and competences towards immunisation were distributed to students and curriculum managers of medical schools, universities and nursing training institutions in seven EU countries. In all responding institutions training on vaccines and immunisation is disseminated over a wide range of courses over several academic years. Topics as immunology and vaccine-preventable diseases are well covered during the pre-service training but major gaps in knowledge and competences were identified towards vaccine safety, communication with parents, addressing anti-vaccine arguments and practical skills. This assessment underlined the rationale for adequate pre-service training and identified opportunities for improvement of pre-service training. A prototype of an accurate pre-service immunisation curriculum was developed, implemented and evaluated in the summer of 2009 with a group of 36 students from 19 countries during a summer school on vaccinology at the Antwerp University, Belgium.
Best Practice & Research in Clinical Gastroenterology | 2008
Koen Van Herck; Alex Vorsters; P. Van Damme
As hepatitis B and C share modes of transmission, their combined occurrence is not uncommon, particularly in areas where both viruses are endemic and in individuals at high-risk of parenteral infection. Both viral hepatitis infections form an important global public health problem, responsible for over half a billion chronic infections worldwide. Their distinctive characteristics impact upon their epidemiology, transmission, and the success of the different prevention strategies. Since several decades a safe and effective vaccine has been available to prevent hepatitis B virus (HBV) infection. Universal vaccination is the cornerstone of global HBV control. Despite major success, vaccine uptake is hampered, and increasing efforts are required to eliminate acute and chronic hepatitis B. Unlike hepatitis C and HIV, HBV has not captured sufficient attention from policymakers, advocacy groups, or the general public: a major challenge for the future. Although progress has been made in the development of an hepatitis C vaccine, short-term successes are not expected. Even without a vaccine, successes can be reported in the field of hepatitis C due to e.g. implementation of universal precautionary measures in health-care settings, screening of blood and blood products, and identification and counselling of infected people. Despite important efforts, transmission in injecting drug users is increasing.
BMJ | 2013
Pierre Van Damme; Elke Leuridan; Greet Hendrickx; Alex Vorsters; Heidi Theeten; Tuija Leino; Mika Salminen; Markku Kuusi
WHO recommends that hepatitis B virus should be included in childhood vaccination programmes. Pierre Van Damme and colleagues argue that universal immunisation is essential to stop people becoming carriers but Tuija Leino and colleagues think that a targeted approach is a better use of resources in countries with low endemicity
BMJ | 2014
Alex Vorsters; Pierre Van Damme; Gary M. Clifford
We agree that urine testing for human papillomavirus (HPV) in cervical cancer screening needs further evaluation, and that the heterogeneity of urine sampling and testing protocols should be resolved.1 2 In particular, attention should be given to the rationale and evidence for using first void urine for HPV testing. During urination, urine is contaminated by impurities, including …
Vaccine | 2014
David FitzSimons; Greet Hendrickx; Tinne Lernout; Selim Badur; Alex Vorsters; Pierre Van Damme
A meeting of the Viral Hepatitis Prevention Board in Barcelona in November 2012 brought together health care professionals concerned with viral hepatitis and those concerned with other vaccine-preventable diseases (especially influenza) in order to share experiences and find ways to increase the protection of health care workers through vaccination. Despite the existence of numerous intergovernmental and national resolutions, recommendations or published guidelines, vaccine uptake rates in health care workers are often shockingly low and campaigns to increase those rates have been generally unsuccessful. Participants reviewed the numerous incentives and barriers to vaccine uptake. Reasons for low uptake range from lack of commitment by senior management of health facilities and unclear policies to lack of knowledge, and denial of risk. Positive factors included leadership, involvement of all concerned parties, reminders and peer pressure. Innovative approaches, including the use of social media, are needed. It was concluded that strategies should be modified appropriately to reach specific health care worker populations at risk and that policies for preventing infection of health care workers could include obligatory health checks to determine vaccination status or immunity. Further, mandatory vaccination of health care workers may be the only effective means in order to achieve high vaccination coverage rates. Suggested possible future activities included: refurbishment of the image of the occupation health profession; resolving the logistical problems of administering vaccine; elaborating policy on managing health care workers who have been vaccinated against hepatitis B at birth or in early childhood and who are now starting to work in the health professions; and embedding and applying policies on vaccination against vaccine-preventable diseases in all health care facilities and training institutions. Above all, national action plans need to be written, with the involvement of health care workers in their design and implementation.
Clinical Microbiology and Infection | 2014
Tinne Lernout; Greet Hendrickx; Alex Vorsters; L. Mosina; Nedret Emiroglu; P. Van Damme
Despite the availability of safe and effective hepatitis B virus (HBV) vaccines for more than 30 years, the burden of hepatitis B disease is still substantial. In 1992, the WHO recommended the inclusion of HBV vaccination in all national vaccination programmes. As of 2012, 47 of the 53 European countries (89%) had implemented a universal hepatitis B vaccination programme. The most recent countries to follow the recommendation were Ireland (in 2008) and the Netherlands (in 2011). Still, six countries (Denmark, Finland, Iceland, Norway, Sweden and the UK) adopt risk-group-targeted vaccination only, instead of adding a universal vaccination programme. However, changing demography, increasing immigration and the current vaccine costs make the cost–benefit ratios in these remaining low endemicity countries strongly in favour of universal HBV vaccination. Global efforts, including a cohesive European vaccination policy, are essential to control and prevent hepatitis B.
Journal of Virological Methods | 2012
M.I. Micalessi; G.A. Boulet; Alex Vorsters; K. de Wit; G. Jannes; W. Mijs; Margareta Ieven; P. Van Damme; Johannes Bogers
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.