Decreasing sperm quality: a global problem?

<p>Abstract</p> <p>Background</p> <p>Carlsen and coworkers (1992) reviewed 61 heterogeneous observational studies on semen quality published between 1938 and 1990. This review indicates that mean sperm density decreased significantly between 1940 and 1990. An extended meta-analysis with 101 studies confirmed a decline in sperm density for the period from 1934 to 1996 (2000). The key message of the meta-analyses is that sperm counts have decreased globally by about 50% over the past decades. This assessment has been questioned.</p> <p>Discussion</p> <p>A major methodological problem of the meta-analysis is the use of data collected in different countries, at different times, on different populations and with different methods of semen analysis. Furthermore, the results of studies concerning semen analysis are frequently biased e.g. by selection criteria of volunteers. In most studies on human semen characteristics the populations under study are insufficiently defined and the study participants are not a representative population sample. The incidence of testicular cancer has increased in Caucasian men worldwide. The investigation of common risk factors for male reproductive disorders requires well designed epidemiological studies and the collection of individual data.</p> <p>Summary</p> <p>Former meta-analyses of sperm count data show a global downward trend. This conclusion should be interpreted with caution. The included studies are of great heterogeneity due to geographical and/or ethnical variation, different study designs and different methodological standards. Population-based prospective studies are needed to investigate secular trends in male reproductive disorders.</p

Changing Epidemiology of Human Brucellosis, Germany, 1962–2005

This endemic occupational disease has become a foodborne and travel-associated zoonosis primarily affecting Turkish immigrants

Paediatric CT scan usage and referrals of children to computed tomography in Germany-a cross-sectional survey of medical practice and awareness of radiation related health risks among physicians

<p>Abstract</p> <p>Background</p> <p>Computed tomography (CT) is a major source of ionizing radiation exposure in medical diagnostic. Compared to adults, children are supposed to be more susceptible to health risks related to radiation. The purpose of a cross-sectional survey among office-based physicians in Germany was the assessment of medical practice in paediatric CT referrals and to investigate physicians' knowledge of radiation doses and potential health risks of radiation exposure from CT in children.</p> <p>Methods</p> <p>A standardized questionnaire was distributed to all paediatricians and surgeons in two defined study areas. Furthermore, the study population included a random sample of general practitioners in the two areas. The questionnaire covered the frequency of referrals for paediatric CT examinations, the medical diagnoses leading to paediatric CT referrals, physicians' knowledge of radiation doses and potential health risks of radiation exposure from CT in children.</p> <p>Results</p> <p>A total of 295 (36.4%) physicians responded. 59% of the doctors had not referred a child to CT in the past year, and approximately 30% referred only 1-5 children annually. The most frequent indications for a CT examination in children were trauma or a suspected cancer. 42% of the referrals were related to minor diagnoses or unspecific symptoms. The participants underestimated the radiation exposure due to CT and they overestimated the radiation exposure due to conventional X-ray examinations.</p> <p>Conclusions</p> <p>In Germany, the frequency of referrals of children to computed tomography is moderate. The knowledge on the risks from radiation exposure among office-based physicians in our sample varied, but there was a tendency to underestimate potential CT risks. Advanced radiological training might lead to considerable amendments in terms of knowledge and practice of CT referral.</p

Incidence of childhood leukemia before and after shut down of nuclear power plants in Germany in 2011: A population-based register study during 2004 to 2019

The association between leukemia and proximity to nuclear-power-plants (NPPs) has been assessed in several countries with inconsistent results. A case-control study from Germany had shown an increased risk for childhood leukemia (diagnoses 1980-2003) near NPPs. Germany began shutting down nuclear reactors in 2011, following the Fukushima disaster. We tested whether the previously observed association between leukemia and proximity to NPP persisted despite the shutdown. We used an ecological study design to investigate the incidence of leukemia during 2004 to 2019 in children aged 0 to 14 years living near NPPs where at least one reactor was shut down in 2011. We defined study and control areas as municipalities whose surface area was at least 75% within 10 km or between 10 and 50 km of NPPs, respectively. We calculated age-standardized rates and incidence rate ratios (IRR) using control-areas as the reference. We also computed standardized incidence ratios (SIR) separately for each NPP using incidence rates of the German population as a reference. IRR decreased from 1.20 (95% confidence interval: 0.81-1.77) in 2004 to 2011 to 1.12 (0.75-1.68) in 2012 to 2019. Analyses of single plants showed an excess of childhood leukemia during 2004 to 2019 for the Unterweser-NPP, based only on three cases, and the Krümmel-NPP (n = 14; SIR: 1.98, 1.17-3.35). We found slightly decreasing of leukemia incidence rate ratios after the shutdown of nuclear reactors in 2011. Due to the small number of cases, risk estimates have large uncertainty. Further research including a longer follow-up is warranted. The consistent excess of incidence cases around Krümmel may require analytical epidemiological analysis

Retrospective assessment of self-reported exposure to medical ionizing radiation: Results of a feasibility study conducted in Germany

BACKGROUND: Exposure to medical ionizing radiation has been increasing over the past decades and constitutes the largest contributor to overall radiation exposure in the general population. While occupational exposures are generally monitored by national radiation protection agencies, individual data on medical radiation exposure for the general public are not regularly collected. The aim of this study was to determine the feasibility of assessing lifetime medical ionizing radiation exposure from diagnostic and therapeutic procedures retrospectively and prospectively within the framework of the German National Cohort study. METHODS: Retrospective assessment of individual medical radiation exposure was done using an interviewer-based questionnaire among 199 participants (87 men and 112 women) aged 20–69 randomly drawn from the general population at two recruitment locations in Germany. X-ray cards were distributed to 97 participants at one recruitment center to prospectively collect medical radiation exposure over a 6-month period. The Wilcoxon–Mann–Whitney test was used to test differences in self-reported median examination frequencies for the variables age, sex, and recruitment center. To evaluate the self-reported information on radiological procedures, agreement was assessed using health insurance data as gold standard for the time period 2005 to 2010 from 8 participants. RESULTS: Participants reported a median of 7 lifetime X-ray examinations (interquartile range 4–13), and 42% (n = 83) reported having had a CT scan (2, IQR = 1–3). Women reported statistically significant more X-ray examinations than men. Individual frequencies above the 75th percentile (≥15 X-ray examinations) were predominantly observed among women and in individuals &gt;50 years of age. The prospective exposure assessment yielded a 60% return-rate of X-ray cards (n = 58). 16 (28%) of the returned cards reported radiological examinations conducted during the 6-month period but generally lacked more detailed exposure information. X-ray examinations reported for the period for which health insurance data were available provided a moderately valid measure of individual medical radiation exposure. CONCLUSIONS: The assessment of more recent medical examinations seems in the German National Cohort study feasible, whereas lifetime medical radiation exposure appears difficult to assess via self-reports. Health insurance data may be a potentially useful tool for the assessment of individual data on medical radiation exposure both retrospectively and prospectively