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Dive into the research topics where Alexander Krämer is active.

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Featured researches published by Alexander Krämer.


Journal of Acquired Immune Deficiency Syndromes | 1991

Cigarette smoking: a modifier of human immunodeficiency virus type 1 infection?

David N. Burns; Alexander Krämer; Frances Yellin; Dietmar Fuchs; Helmut Wachter; Richard A. Digioia; William C. Sanchez; Ronald J. Grossman; Fred M. Gordin; Robert J. Biggar; James J. Goedert

SummaryTwo hundred and two homosexual men enrolled in a prospective cohort study of AIDS risk were assessed for differences in the occurrence and progression of human immunodeficiency virus type 1 (HIV-1) infection with respect to cigarette smoking. Among subjects who were initially seronegative, smokers were more likely than nonsmokers to become HIV-1 seropositive (p = 0.03). After seroconversion, serum β2-microglobulin and CD4+ lymphocyte levels were elevated in cigarette smokers relative to nonsmokers (p = 0.02 for both comparisons), but both of these differences disappeared within 2 years. There was no detectable difference in the risk of AIDS or Pneumocystis carinii pneumonia with respect to smoking. Our data suggest that cigarette smoking may alter the immune response to HIV-1 infection, but it appears to have no marked effect on clinical outcome. They also suggest that cigarette smoking may be a surrogate marker for continued high-risk sexual behavior in homosexual men.


Vaccine | 2008

Timeliness of vaccination and its effects on fraction of vaccinated population

Manas K. Akmatov; Mirjam Kretzschmar; Alexander Krämer; Rafael T. Mikolajczyk

Delayed vaccination against childhood diseases may lead to increased mortality and morbidity among children and also affect the fraction of vaccinated population necessary for elimination of a disease. The purpose of this study was to assess the extent of the delay in vaccinations in four countries belonging to Commonwealth of Independent States and to assess how the timeliness of vaccination affects the vaccination coverage. The fraction of children vaccinated with delay was substantial in all the studied countries, and the impact of differences between countries was stronger than individual risk factors assessed in this study. In presence of vaccination delay, up-to-date vaccination is a biased estimator of the fraction of vaccinated population. Age-appropriate vaccination should be taken into account when assessing vaccination coverage.


The Lancet | 1989

SPONTANEOUS LYMPHOCYTE PROLIFERATION IN SYMPTOM-FREE HTLV-I POSITIVE JAMAICANS

Alexander Krämer; Steven Jacobson; Jayne F. Reuben; Edward L. Murphy; Stefan Z. Wiktor; Beverly Cranston; J. Peter Figueroa; Barrie Hanchard; Dale E. McFarlin; William A. Blattner

Spontaneous lymphocyte proliferation was studied in HTLV-1-infected but symptom-free individuals to see if factors such as demographics or socioeconomics influence spontaneous proliferation in Jamaicans. Among the 30 healthy Jamaicans the only demographic feature (age sex socioeconomic status) associated with high lymphoproliferation was low income. However logistic regression analysis revealed that HTLV-1 seropositivity was a stronger risk factor for high lymphoproliferation (odds ratios (OR) = 17.2 95% confidence intervals (CI) 1.8-164.7) than was low income (OR = 8.5 95% CI 0.9-81.6). Besides adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) HTLV-1 infection has been associated with immunodeficiency and in-vitro immunological effects including perturbations in T-cell subsets. The data suggest that increased spontaneous lymphoproliferation is associated with HTLV-1 exposure per se. HTLV-1-negative black Jamaicans had significantly higher lymphoproliferation than US white controls. The reason for this finding is unclear. Genetic factors may account for the difference. However it is also possible that spontaneous proliferation is influenced by exposure to antigens and pathogens; and multiple infections are more common in Jamaica than in the US.


International Journal of Hygiene and Environmental Health | 2011

Particulate matter pollution in the megacities of the Pearl River Delta, China – A systematic literature review and health risk assessment

Heiko J. Jahn; Alexandra Schneider; Susanne Breitner; Romy Eißner; Manfred Wendisch; Alexander Krämer

The exposure to ambient particulate matter (PM) pollution is a major threat to public health. Chinese megacities are coined by high levels of PM. Our aims were to examine the concentration levels of PM in megacities (Guangzhou, Hong Kong, and Shenzhen) of the Pearl River Delta (PRD), South China; to compare the results with international and national air quality guidelines; and to assess the health impact in terms of possible reductions in premature deaths due to PM reduction. The Medline(®) data base was used to identify published studies (systematic literature search). Based on our appraisal criteria 13 studies remained in the analysis. Additionally, publicly available data were extracted from data sources provided by municipal authorities of the cities under study. PM data reported in μg/m(3) were abstracted from single studies and municipal reports. If possible, the PM data were stratified for season of data collection (summer/winter half-year) and simple means were calculated for cities, seasons and months. Based on the abstracted data, a health impact assessment (HIA) was done in order to estimate potential preventable premature deaths due to PM pollution in the cities. Almost all PM data exceeded national and international air quality guidelines. Our HIA showed that in Guangzhou ten thousands of premature deaths could be prevented if the PM burden was reduced to these air quality limit values. We identified no suitable epidemiological study reporting PM according to our study protocol. Further epidemiological studies should be carried out to more precisely determine the spatial distribution of PM-related health risks in PRD. Environmental protection measures and public health interventions are required to reduce burden of PM-related diseases in PRD.


BMC Public Health | 2015

Sociodemographic and health-(care-)related characteristics of online health information seekers: a cross-sectional German study

Laura Nölke; Monika Mensing; Alexander Krämer; Claudia Hornberg

BackgroundAlthough the increasing dissemination and use of health-related information on the Internet has the potential to empower citizens and patients, several studies have detected disparities in the use of online health information. This is due to several factors. So far, only a few studies have examined the impact of socio-economic status (SES) on health information seeking on the Internet. This study was designed to identify sociodemographic and health-(care-)related differences between users and non-users of health information gleaned from the Internet with the aim of detecting hard-to-reach target groups.MethodsThis study analyzed data from the NRW Health Survey LZG.NRW 2011 (n = 2,000; conducted in North Rhine–Westphalia, Germany, via telephone interviews). Logistic regression analysis was used to examine the determinants of online health information seeking behavior.Results68% of Internet users refer to the Internet for health-related purposes. Of the independent variables tested, SES proved to exert the strongest influence on searching the Internet for health information. The final multivariate regression model shows that people from the middle (OR: 2.2, 95% CI: 1.6–3.2) and upper (OR: 4.0, 95% CI: 2.7–6.2) social classes are more likely to seek health information on the Internet than those from the lower class. Also, women are more likely to look for health information on the Internet than men (OR: 1.5, 95% CI: 1.1–2.1). Individuals with a migration background are less likely to conduct health searches on the Internet (OR: 0.6, 95% CI: 0.4–0.8). Married people or individuals in a stable relationship search the Internet more often for health information than do singles (OR: 1.9, 95% CI: 1.2–2.9). Also, heavy use of health-care services compared to non-use is associated with a higher likelihood of using the Internet for health-related matters (OR: 1.7, 95% CI: 1.2–2.5).ConclusionsIn order to achieve equity in health, health-related Internet use by the socially deprived should be promoted through measures to increase their level of e-health literacy. Furthermore, longitudinal studies are needed in order to gain reliable data/results on determinants of health-related Internet use.


International Journal of Environmental Research and Public Health | 2014

Mobile Phone-Based mHealth Approaches for Public Health Surveillance in Sub-Saharan Africa: A Systematic Review

Johanna Brinkel; Alexander Krämer; Ralf Krumkamp; Juergen May; Julius N. Fobil

Whereas mobile phone-based surveillance has the potential to provide real-time validated data for disease clustering and prompt respond and investigation, little evidence is available on current practice in sub-Sahara Africa. The objective of this review was to examine mobile phone-based mHealth interventions for Public Health surveillance in the region. We conducted electronic search in MEDLINE, EMBASE, IEE Xplore, African Index Medicus (AIM), BioMed Central, PubMed Central (PMC), the Public Library of Science (PLoS) and IRIS for publications used in the review. In all, a total of nine studies were included which focused on infectious disease surveillance of malaria (n = 3), tuberculosis (n = 1) and influenza-like illnesses (n = 1) as well as on non-infectious disease surveillance of child malnutrition (n = 2), maternal health (n = 1) and routine surveillance of various diseases and symptoms (n = 1). Our review revealed that mobile phone-based surveillance projects in the sub-Saharan African countries are on small scale, fragmented and not well documented. We conclude by advocating for a strong drive for more research in the applied field as well as a better reporting of lessons learned in order to create an epistemic community to help build a more evidence-based field of practice in mHealth surveillance in the region.


BMC Pregnancy and Childbirth | 2008

Factors associated with lack of postnatal care among Palestinian women: A cross-sectional study of three clinics in the West Bank

Enas Dhaher; Rafael T. Mikolajczyk; Annette E. Maxwell; Alexander Krämer

BackgroundOnly about one-third of women in Palestine (West Bank and Gaza) obtain postpartum care. Therefore, the goal of this study was to assess factors associated with lack of postnatal care, womens reasons for not obtaining postnatal care, and their attitudes towards its importance.MethodsIn early 2006, a cross-sectional survey was conducted at three clinics run by the Ministry of Health providing Mother and Child Health Care in West Bank, Palestine. A total of 264 postpartum women attending the clinics were interviewed face-to-face, using a structured questionnaire.ResultsAlthough the majority of women considered postnatal care necessary (66.1%), only 36.6% of women obtained postnatal care. The most frequent reason for not obtaining postnatal care was that women did not feel sick and therefore did not need postnatal care (85%), followed by not having been told by their doctor to come back for postnatal care (15.5%). Based on a multivariable analysis, use of postnatal care was higher among women who had experienced problems during their delivery, had a cesarean section, or had an instrumental vaginal delivery than among women who had a spontaneous vaginal delivery. Use of postnatal care was also higher among women who delivered in a private hospital as compared to those who delivered in a public hospital. In addition, we found regional differences.ConclusionThe higher use of postnatal care among high-risk women is appropriate, but some clinically dangerous conditions can also occur in low-risk women. Future efforts should therefore focus on providing postnatal care to a larger number of low-risk women.


Allergy | 2003

Association between infections and signs and symptoms of 'atopic' hypersensitivity - results of a cross-sectional survey among first-year university students in Germany and Spain

Wolfgang Uter; Christiane Stock; A. Pfahlberg; Francisco Guillén-Grima; Inés Aguinaga-Ontoso; C. Brun-Sandiumenge; Alexander Krämer

Background: This study assessed the hypothesis that a decreased exposure to childhood infectious diseases is associated with signs and symptoms of ‘atopic’ hypersensitivity diseases.


European Journal of Public Health | 2013

Changing epidemiology of Hepatitis B and migration—a comparison of six Northern and North-Western European countries

Janet JunQing Chu; Tanja Wörmann; Johann Popp; Gunnar Pätzelt; Manas K. Akmatov; Alexander Krämer; Ralf Reintjes

BACKGROUND Increased migration volume and different Hepatitis B prevalence between immigration and emigration countries have changed the Hepatitis B virus (HBV) epidemiology considerably in Northern and North-Western European migrants-receiving countries. Due to the difference in migration status monitoring, the HBV infection data on migrants are not easily comparable among those countries. The study aims were: to compare the migration status indicators used by the national surveillance system in six Northern and North-Western European countries (the Netherlands, Germany, Finland, Denmark, Sweden and the UK); to determine the impact of the migration status on HBV infection by comparing the available data on prevalence and transmission routes of Hepatitis B in the migration and the general population in the six countries; to recommend sensible indicators and pertinent measures for HBV infection surveillance and control in the region. METHODS Literature review, statistical data analysis on migration and HBV infection in the six countries; expert interviews to identify migration status indicators used in national surveillance systems. RESULTS Evident differences were found between the migration and the general population in Hepatitis B prevalence and transmission routes in the six countries. Migration status is monitored differently in six surveillance systems; immigrants from high/intermediate Hepatitis B endemic countries constitute a substantial proportion of HBsAg(+) and chronic cases in all six countries. CONCLUSIONS International migration has an obvious impact on Hepatitis B prevalence in the six countries. It is important to include common migration status indicators and to collect comparable data for HBV infection surveillance in different notification systems.


European Journal of Epidemiology | 2001

Risk factors of herpes simplex type 1 (HSV-1) infection and lifestyle factors associated with HSV-1 manifestations

Christiane Stock; Francisco Guillén-Grima; Juan Hermoso de Mendoza; B. Marin-Fernandez; Inés Aguinaga-Ontoso; Alexander Krämer

This study investigated risk factors for herpes simplex virus type 1 (HSV-1) infection in a population of university students in Germany and Spain. In addition, factors associated with the occurrence of oral lesions were studied. Serum samples were collected from 596 Spanish students from the Navarra Public University in Pamplona and 174 German students from the University of Bielefeld aged 17–41 years and tested by a HSV-1 type-specific immunoassay using monoclonal antibody-selected gG1 as antigen. Information on clinical manifestations and risk factors were obtained by a standardized questionnaire. The rate of HSV-1 infection was 55.3 and 27.4% of these infected students reported having had oral lesions within the last 12 months. Prevalence of HSV-1 infection did not differ between study sites, and did not vary according to gender or age. Students with coitus experience were more likely to be infected with HSV-1 (Odds ratio (OR), 1.88; 95%CI: 1.31–2.69), while other lifestyle factors were not associated with HSV-1 infection. Risk factors for the occurrence of oral lesions included HSV-1 seropositivity (OR: 6.90; 95%CI: 3.84–12.37) and a higher level of perceived stress, as measured by the Cohen scale of perceived stress (OR: 1.79; 95%CI: 1.15–2.78). Drinking alcohol was found to be a protective factor (OR: 0.59; 95%CI: 0.37–0.93). There was no difference in the clinical pattern and course of infection between the young adults in Germany and Spain. We conclude, that lifestyle factors appear to play an important role in the epidemiology and clinical manifestations of HSV-1.

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Christiane Stock

University of Southern Denmark

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