This study characterises changes in the incidence and mortality of hepatitis A in different age groups and provinces of China from 1990 to 2018, and evaluates the effect of the nation-wide expanded programme on immunisation (EPI). A mathematical model was used to estimate the relative change in incidence and mortality in different provinces and age groups. Interrupted time series regression was applied to evaluate the impacts of the inclusion of vaccination in the EPI during 2007–2018. The geographic clustering of hepatitis A incidence was assessed using global Moran's I and changing trends over time were estimated using joinpoint regression analysis. Both the incidence (odds ratio (OR) for overall relative change: 0.86; 95% confidence interval (CI): 0.85–0.87; P < 0.0001) and the mortality rate (OR for overall relative change: 0.84; 95% CI: 0.83–0.85; P < 0.0001) decreased. Most age groups had significant declines in reported incidence over time. The incidence and mortality of hepatitis A significantly reduced after inclusion of hepatitis A vaccine in EPI, showing that the EPI strategy had a continuous effect on the decreasing trend of hepatitis A burden. Increasing the coverage rate of the vaccine and improving hygiene conditions are the key measures for the control of hepatitis A in China.

The aim was to describe food intake over time in children and adolescents, with respect to age and gender. The present study was a repeated cross-sectional study using self-reported data from a health questionnaire. Data were collected from the School Health Services in south-east Sweden from 44 297 students, 10, 13–14 and 16 years of age, 48 % girls and 52 % boys from 2009/2010 to 2015/2016. Reported intakes for eight foods were analysed in relation to the Nordic Nutrition Recommendations. Seventeen per cent of the students reported an intake in line with the recommendations for at least six of the eight foods fish, vegetables, fruit, mealtime beverages, juice/chocolate drinks, sugar-sweetened beverages, sweets/snacks and pastries. Intake of at least two fruits a day was the recommendation that was followed by the lowest proportion of students (30 %), and this result was stable over the study period. There was a gradual increase over time in the proportion of students who reported an intake in line with the recommendations. Younger students compared to older students, as well as girls compared to boys, reported intakes in line with the recommendations to a statistically significant larger extent. Few students reported intakes in line with the recommendations, although the quality of food intake seems to improve over time. The present results indicate a deterioration in reported food intake in the early years of adolescence. Finding methods to support all children and especially older adolescents to eat healthier, including eating more fruit, is of great importance to public health.

Suicide in the US has increased in the last decade, across virtually every age and demographic group. Parallel increases have occurred in non-fatal self-harm as well. Research on suicide across the world has consistently demonstrated that suicide shares many properties with a communicable disease, including person-to-person transmission and point-source outbreaks. This essay illustrates the communicable nature of suicide through analogy to basic infectious disease principles, including evidence for transmission and vulnerability through the agent–host–environment triad. We describe how mathematical modeling, a suite of epidemiological methods, which the COVID-19 pandemic has brought into renewed focus, can and should be applied to suicide in order to understand the dynamics of transmission and to forecast emerging risk areas. We describe how new and innovative sources of data, including social media and search engine data, can be used to augment traditional suicide surveillance, as well as the opportunities and challenges for modeling suicide as a communicable disease process in an effort to guide clinical and public health suicide prevention efforts.

National health statistics report a 2·5-fold increase in laboratory-confirmed Chlamydia trachomatis (CT) cases over the last decade in Switzerland where no CT screening programme exists. We obtained essential denominator information to describe the epidemiology of CT in the canton of Basel-Stadt, an urban canton in north-western Switzerland. Laboratories reporting at least two CT infections from Basel-Stadt residents to the SFOPH in 2010 provided demographic and test-related data. CT positivity rates were calculated for 2002–2010. The influences of test year, age, sex and laboratory on CT positivity were investigated in a multivariable model. Positivity differed between sexes and age groups. In our sample of 32 034 records, female and male CT positivity rates were 4·7% and 11·1%, respectively. Test year was significantly associated with test outcome in the multivariable analysis but no time trend was observed. CT positivity did not change over the past 9 years in Basel-Stadt. In contrast to other European countries without CT screening, we found no evidence that the observed increase of Chlamydia cases in the national notification system represents an epidemiological trend, but rather results from an increased testing frequency.

The incidence of bacteraemia has increased considerably during the last decades. This may be related to population ageing, increased use of invasive procedures, and increased ascertainment of bacteraemia. Generalized additive and generalized linear models were used to analyse the impact of four successive improvements in blood culture methodology on the recovery of prevalent blood culture isolates while simultaneously controlling for underlying time trend and seasonal variation. Between 1981 and 2006, 20 091 bacteraemias comprising 22 800 blood culture isolates were diagnosed. The changes in methodology increased the recovery of some bacterial groups; the greatest impact was observed for Enterobacteriaceae, pneumococci and Staphylococcus aureus whereas recovery of β-haemolytic streptococci, Pseudomonas aeruginosa, other Gram-negative aerobes, and fungi was not affected. Changes in blood culture methodology should be taken into account when assessing time trends of bacteraemia.

The DONALD study (Dortmund Nutritional and Anthropometric Longitudinally Designed study) gives the opportunity to evaluate long-term food and nutrient intake data on the basis of 3 d weighed dietary records of infants, children and adolescents since 1985. In this paper, we examine changes in energy and macronutrient intakes (protein, fat, saturated, mono- and polyunsaturated fatty acids, carbohydrates and added sugars) of 795 2–18-year-old subjects between 1985 and 2000 (4483 records). No significant changes in intakes of energy and of protein, polyunsaturated fatty acids and added sugars (as % energy intake, E %) were found. Fat intake decreased significantly in all age groups (between -0·20 and -0·26 E %/year), as well as intake of saturated fatty acids (between -0·11 and -0·14 E %/year) and monounsaturated fatty acids (between -0·07 and -0·014 E %/year). This decline was compensated for by a significant increase in carbohydrate intake (between +0·18 and +0·27 E %/year). The changes in macronutrient intake were mainly due to a decreased consumption of fats–oils (between -0·29 and -1·26 g/year) and meat–fish–eggs (between -0·21 and -2·92 g/year), whereas consumption of bread–cereals (between +0·12 and +2·42 g/year) and potatoes–pasta–rice (between +0·15 and +2·26 g/year) increased slightly. However, since recommended fat intake and fatty acid composition was not reached at the end of the study period by far, further efforts will be necessary to improve macronutrient composition and to stabilize favourable dietary habits.

Previously published data from serial slaughter trials on growing pigs of five genotypes were reanalysed. Gompertz curves were fitted to body protein and lipid mass in order to estimate mature protein and lipid mass (P∞, L∞) and the rate parameter (BGomp J that was presumed to be equal for the protein and lipid curves. L∞ was expressed as its ratio to P∞, R L∞P∞. The maximum rate of protein deposition was derived as Pdep,max = P∞ X BGomp/e. The analysed data encompass body weights of 10 to 133 kg, 13 to 217 kg, 18 to 106 kg, 20 to 110 kg and 11 to 145 kg. The Gompertz function fitted all data sets well, as judged by the standard deviations and distribution patterns of the residual terms. Autocorrelations among the residuals were non-significant.

Averaged over sexes (females and entire and castrated males), the P estimates were all close to 31 kg; the RL∞/P∞ estmates ranged from 1·4 to 4·7 kg/kg; the BGomp estimates ranged from 0·009 to 0·017 kg/day per kg. The resulting Pdep,max estimates ranged from 110 to 193 g/day. The genotypes were placed in 1969, 1976, 1984, 1990 and 1993. Plotting the estimates against time (year) showed distinct time trends for all parameters except P∞. RL∞/P∞ seems to gradually reach a plateau around unity, whereas BGomp and Pdep/max increase linearly. These trends were confirmed by an analysis of body weight based on the same data plus data on three other genotypes that spanned the same time period. Analyses of the same protein and lipid data to fit a sigmoid growth function with a flexible point of inflexion did not change the apparently absent time trend of F. The estimates of the inflexion points of the fitted protein accretion curves, expressed as proportions ofF, were indistinguishable from the fixed 0·368 value of the Gompertz function for the earliest three genotypes and then showed a tendency to increase, up to 0·46 for the 1993 population. These time trends must be the consequence of a combination of changes in nutritional and other environmental factors and genetic changes. They cannot be the sole result of within-line selection for growth and body composition traits, since this should increase P∞. It seems as if pig breeders have repeatedly initiated their sire lines from genetic resources with small mature size, to subsequently increase this trait as an indirect result of within-line selection.