A systematic review of varicella seroprevalence in European countries before universal childhood immunization: deriving incidence from seroprevalence data.

Surveillance systems for varicella in Europe are highly heterogeneous or completely absent. We estimated the varicella incidence based on seroprevalence data, as these data are largely available and not biased by under-reporting or underascertainment. We conducted a systematic literature search for varicella serological data in Europe prior to introduction of universal varicella immunization. Age-specific serological data were pooled by country and serological profiles estimated using the catalytic model with piecewise constant force of infection. From the estimated profiles, we derived the annual incidence of varicella infection (/100·000) for six age groups (<5, 5-9, 10-14, 15-19, 20-39 and 40-65 years). In total, 43 studies from 16 countries were identified. By the age of 15 years, over 90% of the population has been infected by varicella in all countries except for Greece (86·6%) and Italy (85·3%). Substantial variability across countries exists in the age-specific annual incidence of varicella primary infection among the <5 years old (from 7052 to 16 122 per 100 000) and 5-9 years old (from 3292 to 11 798 per 100 000). The apparent validity and robustness of our estimates highlight the importance of serological data for the characterization of varicella epidemiology, even in the absence of sampling or assay standardization.

Contribution of respiratory pathogens to influenza-like illness consultations.

Influenza-like illnesses (ILIs) are caused by several respiratory pathogens. These pathogens show weak to strong seasonal activity implying seasonality in ILI consultations. In this paper, the contribution of pathogens to seasonality of ILI consultations was statistically modelled. Virological count data were first smoothed using modulation models for seasonal time series. Second, Poisson regression was used regressing ILI consultation counts on the smoothed time series. Using ratios of the estimated regression parameters, relative measures of the underreporting of pathogens were obtained. Influenza viruses A and B, parainfluenza virus and respiratory syncytial virus (RSV) significantly contributed to explain the seasonal variation in ILI consultations. We also found that RSV was the least and influenza virus A is the most underreported pathogen in Belgian laboratory surveillance. The proposed methods and results are helpful in interpreting the data of clinical and laboratory surveillance, which are the essential parts of influenza surveillance.

Salmonella serosurveillance: different statistical methods to categorise pig herds based on serological data.

This study proposes three different statistical methods that can be applied in order to categorise pig herds into two groups (high seroreactors vs. low seroreactors) based on serological test results for Salmonella-specific antibodies in pigs. All proposed statistical methods were restricted to allocate about 10% of the herds into the group defined by each of the statistical approaches as high seroreactors. Previously, semi-parametric quantile regression has been used for this purpose, and here we compare it with two other alternatives: a naive method (based on the mean values) and another based on activity region finder methodology in combination with random forest regression models. The serological response values (the sample-to-positive ratio (S/P ratio)) of 13 649 pigs from 314 Belgian pig herds were used for this comparison. Nearly 14% of these herds were assigned to the high-seroreactor-herd group by at least one of these three methods. The corrected level of agreement was calculated together with the pair-wise agreement among all three methods in order to classify herds as high- or low-level seroreactors, resulting in an agreement level greater than 92%. The results obtained from a fourth method, which is adopted by the Belgian Federal Agency for the Safety of the Food Chain (FASFC), were also compared to the previous three methods. The methods were compared in terms of their agreement as well as their advantages and disadvantages. Recommendations for each applied method are presented in relation to the objectives and the requisite policy for classifying pig herds based on serological data.

Risk factors for Salmonella and hygiene indicators in the 10 largest Belgian pig slaughterhouses.

A survey was conducted to collect data on Salmonella prevalence, Escherichia coli counts (ECCs), and aerobic bacteria colony counts (ACCs) on pig carcasses after chilling at the 10 largest Belgian pig slaughterhouses during 2000 through 2004. Potential risk factors of contamination associated with production parameters, technical descriptions of the installations, and cleaning and disinfection methods were assessed during investigations in the slaughterhouses. These variables were used first in a univariate analysis and then were extended to a multivariate analysis with a logistic mixed regression model for Salmonella and a linear mixed model for ECCs and ACCs with slaughterhouses as the random effect. The results indicated high variability concerning Salmonella contamination among the 10 slaughterhouses, with prevalence ranging from 2.6 to 34.3% according to the area of origin. The median ECC and median ACC ranged from -0.43 to 1.11 log CFU/cm2 and from 2.37 to 3.65 log CFU/cm2, respectively. The results of the logistic and linear regressions revealed that some working practices such as scalding with steam, second flaming after polishing, and complete cleaning and disinfection of the splitting machine several times a day were beneficial for reducing Salmonella prevalence, ECCs, and ACCs. Changing the carcass hooks just before chilling, using water as the cleaning method, and a higher frequency of disinfection of the lairage seemed to be protective against E. coli in the multivariate mixed linear model. The monitoring of critical points, slaughterhouse equipment, good slaughtering practices, and effective washing and disinfection are the keys to obtaining good microbiological results.

Antihyperglycaemic therapy in elderly patients with type 2 diabetes: potential role of incretin mimetics and DPP-4 inhibitors.

Management of elderly patients with type II diabetes is complicated by age-related changes in physiology, comorbidities, polypharmacy and heterogeneity of functional status. A minimum goal in antidiabetic treatment in this population is to achieve a level of glycaemic control that avoids acute complications of diabetes, adverse effects and reduction in quality of life. Hypoglycaemia is a particular problem in elderly patients, and many antidiabetic agents pose increased risk for hypoglycaemia. In addition, many standard agents pose risks for older patients because of reduced renal function and common comorbidities. Newer agents based on enhancing incretin activity, including the glucagon-like peptide-1 mimetics exenatide and liraglutide and the oral dipeptidyl peptidase-4 inhibitors sitagliptin and vildagliptin, may offer particular advantages in elderly patients with diabetes.