Knowledge, attitudes and behaviours towards vaccination: a survey of university students in Europe

Background

Immunisation programs are still facing substantial challenges in achieving target coverage rates. This has been attributed to the growing negative individual vaccination attitudes and behaviours. Most of the current studies assessing vaccination knowledge, attitude and beliefs targets adults. However, young people represent future parents and health care professionals. The objective of this study was to investigate vaccination knowledge attitudes and behaviours among university medical and non-medical students in Europe.

Methods

We performed a cross-sectional online survey between April and July 2018. The study participants were students attending different faculties at the University of Antwerp, Belgium and the University of Pisa, Italy. We described sample characteristics. The effect of risk factors was tested with univariate and multivariate logistic regressions.

Results

A total of 2079 participants completed the survey including 873 medical students and 1206 from other faculties. The average of vaccination knowledge, attitudes, and confidence was respectively 5.51 (SD: 1.41), 4.66 (SD: 0.14) and 5.28 (SD: 0.57) on the 6-points scale. Our respondents demonstrated a high level of awareness with respect to their vaccination history. In total, 67.7% (n = 1407) reported to have received at least one vaccine in the previous five years; only 6.0% (n = 35) did not receive any vaccine in the previous 10 years. According to logistic regression analysis Italian students had significantly higher knowledge, attitude and confidence scores than Belgium respondents. Students of medicine scored significantly higher compared to non-medical students.

Conclusions

In order to reduce the gaps in vaccinations knowledge between non-medical and medical students we should plan educational interventions. In this way the number of future sceptical parents could be decreased. Further studies are required to explain the differences between countries.

Key messages

Young adults are the parents and the health care professionals of the future, for this reason their vaccination knowledge attitudes and behaviours should be carefully monitored. European non-medical students have lower vaccinations knowledge, attitudes and confidence compared with medical student. In order to fill these gaps, we should plan educational interventions.

Potential role of raltegravir-based therapy to induce rapid viral decay in highly viraemic HIV-infected neonates

We report safety and tolerability of raltegravir (RAL) as a forth HIV agent in two highly viraemic newborns. Raltegravir (6 mg/kg) was given orally twice daily. The other antiretrovirals were assumed according to standard dose for newborns. The first baby was born at week 36. An antiretroviral therapy consisting of zidovudine, lamivudine, and lopinavir/ritonavir was started 96 hour after delivery. Raltegravir was added at hour 120, being plasma HIV-1 RNA above 10×10(6) copies/ml. HIV RNA declined to 5·000 copies/ml at day 30. The second baby was born at week 40. He was started on zidovudine, lamivudine, and nevirapine at day 0, while RAL was added at day 3. Plasma HIV-1 RNA declined from 6·6×10(6) at birth to 52 copies/ml at day 28. RAL tolerability was good in both patients, one with gamma-glutamyltransferase increase, which normalized after RAL discontinuation. Raltegravir-based four drug regimen may be effective and well tolerated in highly viraemic HIV neonates up to 4 weeks.

Drug-resistance development differs between HIV-1-infected patients failing first-line antiretroviral therapy containing nonnucleoside reverse transcriptase inhibitors with and without thymidine analogues

OBJECTIVES

We evaluated the emergence of drug resistance in patients failing first-line regimens containing one nonnucleoside reverse transcriptase inhibitor (NNRTI) administered with zidovudine (ZDV) + lamivudine (the ZDV group) or non-thymidine analogues (non-TAs) (tenofovir or abacavir, + lamivudine or emtricitabine; the non-TA group).

METHODS

Three hundred HIV-1-infected patients failing a first-line NNRTI-containing regimen (nevirapine, n = 148; efavirenz, n = 152) were included in the analysis. Virological failure was defined as viraemia ≥ 400 HIV-1 RNA copies/mL for the first time at least 6 months after starting the NNRTI-based regimen. For each patient, a genotypic resistance test at failure was available. The presence of drug-resistance mutations in HIV-1 reverse transcriptase was evaluated by comparing patients treated with NNRTI + zidovudine + lamivudine vs. those treated with NNRTI + non-TA.

RESULTS

A total of 208 patients were failing with NNRTI + zidovudine + lamivudine and 92 with NNRTI + non-TA. No significant differences were observed between the non-TA group and the ZDV group regarding the time of virological failure [median (interquartile range): 12 (8-25) vs. 13 (9-32) months, respectively; P = 0.119] and viraemia [median (interquartile range): 4.0 (3.2-4.9) vs. 4.0 (3.3-4.7) log₁₀ copies/mL, respectively; P = 0.894]. Resistance to reverse transcriptase inhibitors (RTIs) occurred at a significant lower frequency in the non-TA group than in the ZDV group (54.3 vs. 75.5%, respectively; P = 0.001). This difference was mainly attributable to a significantly lower prevalence of NNRTI resistance (54.3 vs. 74.0%, respectively; P = 0.002) and of the nucleoside reverse transcriptase inhibitor (NRTI) mutation M184V (23.9 vs. 63.5%, respectively; P < 0.001) in the non-TA group compared with the ZDV group. As expected, the mutation K65R was found only in the non-TA group (18.5%; P < 0.001).

CONCLUSIONS

At first-line regimen failure, a lower prevalence of RTI resistance was found in patients treated with NNRTI + non-TA compared with those treated with NNRTI + zidovudine + lamivudine. These results confirm that the choice of backbone may influence the prevalence of drug resistance at virological failure.

Prevalence of etravirine (ETR)-RAMs at NNRTI failure and predictors of resistance to ETR in a large Italian resistance database (ARCA)

The prevalence of drug resistance associated with the failure of non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens and the predictors of resistance to Etravirine (ETR) were assessed in 2854 subjects: 39 < 18 (paediatric) and 2815 ≥ 18 (adult) years old. These subjects failed to respond to their current NNRTI treatment, were three-class experienced and had been exposed to NNRTI for ≥3 months. A total of 1827 adult (64.9%) and 32 paediatric subjects (82.1%) harboured the virus with at least one ETR mutation. V179I, Y181C and G190A were the most frequent mutations in both groups. A significantly increased risk of ETR resistance with all three algorithms (Monogram (MGR) >3, Tibotec (TBT) >2 and enhanced MGR (ENH) ≥4) emerged in the paediatric population. Multivariate analysis revealed an increased risk of developing TBT >2 for NNRTI exposure, ENH ≥4 for NNRTI and EFV exposure in paediatric subjects; NVP exposure and higher (≥3.5 log10) HIV-RNA values for all three algorithms in adult subjects, whereas CD4 ≥ 200/μL appeared to be protective. The risk of being ETR resistant was more than doubled for paediatric vs. adult subjects, probably due to a more extensive use of NNRTI and an incomplete virological control.

The Cox shared frailty model with log-skew-normal frailties

Clustered survival data arise when groups of failure times share a common ingredient; typically, they refer to the same individual or individuals with a common factor. When the association between failure times within the same cluster is of interest, statistical methods called frailty models have been used. The frailty is an unobserved random component which affects the risk level, changing from cluster to cluster but shared by all observations within the same cluster. Various probability distributions have been proposed for the frailty term, with special emphasis on the gamma and log-normal distribution. Since adequate modelling of the frailty distribution is essential to properly investigate the dependence structure, we introduce a new class of frailty models with a flexible distribution form. Specifically, we adopt the skew-normal distribution for the log-transformed frailty, leading to an extension of the log-normal model. After presenting the methodology connected to this choice, we illustrate it with a case study of multiple myeloma patients with autologous stem cells transplantation.

Human immunodeficiency virus-1 B and non-B subtypes with the same drug resistance pattern respond similarly to antiretroviral therapy

We analysed the 12-week virological response to protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) therapy in 1108 patients carrying B or non-B human immunodeficiency virus (HIV)-1 subtypes with matched resistance mutation patterns. Response rates were not significantly different for non-B and B subtypes stratified for treatment status (51.5% vs. 41.5% in naïve patients; 46.7% vs. 38.7% in experienced patients) or regimens (46.9% vs. 39.7% with PI; 56.7% vs. 40% with NNRTI). No difference in response was detected in patients harbouring B and non-B subtypes with any resistance profile. Further studies are advisable to fully test this approach on larger datasets.

Allele-sharing statistics using information on family history

When conducting genetic studies for complex traits, large samples are commonly required to detect new genetic factors. A possible strategy to decrease the sample size is to reduce heterogeneity using available information. In this paper we propose a new class of model-free linkage analysis statistics which takes into account the information given by the ungenotyped affected relatives (positive family history). This information is included into the scoring function of classical allele-sharing statistics. We studied pedigrees of affected sibling pairs with one ungenotyped affected relative. We show that, for rare allele common complex diseases, the proposed method increases the expected power to detect linkage. Allele-sharing methods were applied to the symptomatic osteoarthritis GARP study where taking into account the family-history increased considerably the evidence of linkage in the region of the DIO2 susceptibility locus.

Prevalence of mutations and determinants of genotypic resistance to etravirine (TMC125) in a large Italian resistance database (ARCA)

OBJECTIVES

To evaluate whether etravirine (TMC125) might be effective in patients failing therapy with current nonnucleoside reverse transcriptase inhibitors (NNRTIs), we analysed the prevalence of TMC125 mutations and the possible determinants of genotypic resistance to this drug among sequences reported to a large database in Italy [Antiretroviral Resistance Cohort Analysis (ARCA)].

METHODS

We analysed the prevalence of TMC125 resistance-associated mutations (RAMs) and the TMC125 weighted genotypic score (WGS) together with the determinants of genotypic resistance. A total of 5011 sequences from 2955 patients failing NNRTI therapy were evaluated.

RESULTS

Among the sequences in ARCA, 68% had at least one and 9.8% at least three TMC125 RAMs, whereas 31% had a WGS>2. Frequent RAMs were Y181C, G190A, K101E and A98G, whereas V179F, Y181V and G190S appeared in <5% of sequences. Multivariate analysis revealed a higher risk of developing at least three TMC125 RAMs associated with both nevirapine and efavirenz exposure, whereas CD4 counts > or = 200 cells/microL retained their protective effect. An increased risk of WGS>2 was linked to higher HIV RNA values (maximum risk at >5 log(10) copies/mL) and nevirapine exposure; CD4 counts > or = 200 cells/microL were protective.

CONCLUSIONS

The prevalence of TMC125 resistance mutations in the ARCA cohort was 68%. The DUET studies showed that at least three TMC125-associated mutations were required to impair the efficacy of the drug and Y181C/V, V179F and G190S had the greatest effect on response. The prevalence of these mutations among the patients examined in our study was low. However, WGS>2 was found for one-third of our sequences. Previous nevirapine exposure was associated with an increased risk of having WGS>2 (adjusted odds ratio 1.76).

Score test for age at onset genetic linkage analysis in selected sibling pairs

A new score statistic is derived, which uses information from registries (age-specific incidences) and family studies (sib-sib marginal correlation) to weight affected sibling pairs according to their age at onset. Age at onset of sibling pairs is modelled by a gamma frailty model. From this model we derive a bivariate survival function, which depends on the marginal survival and on the marginal correlation. The score statistic for linkage is a classical nonparametric linkage (NPL) statistic where the identical by descent sharing is weighted by a particular function of the age at onset data. Since the statistic is based on survival models, it can also be applied to discordant and healthy sibling pairs. Simulation studies show that the proposed method is robust and more powerful than standard NPL methods. As illustration we apply the new score statistic to data from a breast cancer study.

Weighted statistics for aggregation and linkage analysis of human longevity in selected families: the Leiden Longevity Study

Typically long-lived sibling pairs have been collected for linkage analysis of human longevity and information on life span of first-degree relatives is available to assess familial aggregation of life span. We propose a new weighted statistic for aggregation analysis, which tests for a relationship between a family history of excessive survival of the sibships of the long-lived pairs and the survival of their parents and their offspring. For linkage analysis, we derive a new weighted score statistic from a simple gamma frailty model, which assigns more weight to excessive long-lived pairs. We apply the methods to data from the Leiden Longevity Study, which consists of sibling pairs of age 90 years or above and their first-degree relatives. The pairs have been genotyped for microsatellite markers in a candidate region. Association was present between survival within the sibships and survival of the offspring, but not with the parental generation. For linkage analysis, weighting increased the value of the test statistic, but the result was not statistically significant. About the methods we conclude that the statistic for aggregation provides insight into clustering of life span and the statistic for linkage provides a new tool to include demographic information into the analysis.

A locally adaptive statistical procedure (LAP) to identify differentially expressed chromosomal regions

MOTIVATION

The systematic integration of expression profiles and other types of gene information, such as chromosomal localization, ontological annotations and sequence characteristics, still represents a challenge in the gene expression arena. In particular, the analysis of transcriptional data in context of the physical location of genes in a genome appears promising in detecting chromosomal regions with transcriptional imbalances often characterizing cancer.

RESULTS

A computational tool named locally adaptive statistical procedure (LAP), which incorporates transcriptional data and structural information for the identification of differentially expressed chromosomal regions, is described. LAP accounts for variations in the distance between genes and in gene density by smoothing standard statistics on gene position before testing the significance of their differential levels of gene expression. The procedure smooths parameters and computes p-values locally to account for the complex structure of the genome and to more precisely estimate the differential expression of chromosomal regions. The application of LAP to three independent sets of raw expression data allowed identifying differentially expressed regions that are directly involved in known chromosomal aberrations characteristic of tumors.

AVAILABILITY

Functions in R for implementing the LAP method are available at http://www.dpci.unipd.it/Bioeng/Publications/LAP.htm

Algorithm for automatic genotype calling of single nucleotide polymorphisms using the full course of TaqMan real-time data

Single nucleotide polymorphisms (SNPs) are often determined using TaqMan real-time PCR assays (Applied Biosystems) and commercial software that assigns genotypes based on reporter probe signals at the end of amplification. Limitations to the large-scale application of this approach include the need for positive controls or operator intervention to set signal thresholds when one allele is rare. In the interest of optimizing real-time PCR genotyping, we developed an algorithm for automatic genotype calling based on the full course of real-time PCR data. Best cycle genotyping algorithm (BCGA), written in the open source language R, is based on the assumptions that classification depends on the time (cycle) of amplification and that it is possible to identify a best discriminating cycle for each SNP assay. The algorithm is unique in that it classifies samples according to the behavior of blanks (no DNA samples), which cluster with heterozygous samples. This method of classification eliminates the need for positive controls and permits accurate genotyping even in the absence of a genotype class, for example when one allele is rare. Here, we describe the algorithm and test its validity, compared to the standard end-point method and to DNA sequencing.

Comparison of MB/Bact alert 3D system with radiometric BACTEC system and Löwenstein-Jensen medium for recovery and identification of mycobacteria from clinical specimens: a multicenter study

The MB/BacT ALERT 3D System (MB/BacT) (Organon Teknika, Boxtel, The Netherlands) is a fully automated, nonradiometric system with a revised antibiotic supplement kit designed for the recovery of mycobacteria from clinical specimens. In a multicenter study, the recovery rate of acid-fast bacilli (AFB) and the mean time to their detection from clinical specimens was determined by using the MB/BacT system. Data were compared to those assessed by the radiometric BACTEC 460 system (B460) and by culture on Löwenstein-Jensen (L-J) solid medium. A total of 2,859 respiratory and extrapulmonary specimens were processed by the N-acetyl-L-cysteine (NALC)-NaOH method using two different concentrations of sodium hydroxide; 1.5% was adopted in study design A (1,766 specimens), and 1.0% was used in study design B (1,093 specimens). The contamination rates for MB/BacT were 4.6% (study design A) and 7.1% (study design B). One hundred seventy-nine mycobacterial isolates were detected by study design A, with 148 Mycobacterium tuberculosis complex (MTB) isolates and 31 nontuberculous mycobacteria (NTM) isolates. Overall recovery rates were 78.8% for MB/BacT (P = 0.0049), 64.2% for L-J (P < 0.0001), and 87.1% for B460, whereas they were 84.5, 70.9, and 91.2%, respectively, for MTB alone. A total of 125 mycobacteria were detected by study design B, with 46 MTB and 79 NTM. Overall recovery rates by the individual systems were 57.6% (P = 0.0002), 56.8% (P = 0.0001), and 80% for MB/BacT, L-J, and B460, respectively, whereas the rates were 91.3, 78.3, and 97.8% for MTB alone. By study design A, the mean times to detection of smear-positive MTB, smear-negative MTB, and NTM were 11.5, 19.9, and 19.6 days, respectively, with the MB/BacT; 8.3, 16.8, and 16.6 days, respectively, with the B460; and 20.6, 32.1, and 27.8 days, respectively, with L-J medium. By study design B, the mean times were 15.1, 26.7, and 26 days with the MB/BacT; 11.7, 21.3, and 24.8 days with the B460; and 20.4, 28.7, and 28.4 days with L-J medium. Identification was attempted by probing (Accuprobe) MB/BacT-positive bottles within the first working day following instrument positive flag. Results were compared to those obtained in the B460 positive vials by the p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) test (study design A) or by the Accuprobe assay (study design B). About 90% of MTB and 100% of NTM could be identified, showing turnaround times closely related to those obtained by combining B460 and the NAP test or the Accuprobe assay. In conclusion, even though recovery rates were shown to be lower than B460, especially for NTM, and contaminants were somewhat higher, MB/BacT represents a valuable alternative to the radiometric system, especially in those laboratories where disposal of radioactive waste is restricted. Finally, when AFB are cultured in nonradiometric liquid media, our data (detection times and bacterial overgrowth rates) suggest that decontamination with 1.5% NaOH may be more suitable than the standard NALC-NaOH.

Comparative evaluation of the new gen-probe Mycobacterium tuberculosis amplified direct test and the semiautomated abbott LCx Mycobacterium tuberculosis assay for direct detection of Mycobacterium tuberculosis complex in respiratory and extrapulmonary specimens

Two commercial assays that detect Mycobacterium tuberculosis complex (MTB) in clinical specimens by rRNA target amplification (AMTDII) and ligase chain reaction (LCx) were evaluated. The tests were applied to 457 respiratory (n = 273) and extrapulmonary (n = 184) specimens collected from 357 patients. The results were compared with those of acid-fast staining and culture. The combination of culture and clinical diagnosis was considered to be the "gold standard." Seventy specimens were from patients with pulmonary tuberculosis and 28 specimens were from patients with extrapulmonary tuberculosis. After resolution of discrepant results, the overall sensitivities, specificities, and positive and negative predictive values for respiratory specimens were 92.8, 99.4, 98.5, and 97%, respectively, for AMTDII and 75.7, 98.8, 96.4, and 90.5%, respectively, for LCx. With extrapulmonary specimens, the overall sensitivities, specificities, and positive and negative predictive values were 78.6, 99.3, 95.6, and 96.2%, respectively, for AMTDII and 53.6, 99.3, 93.7, and 92.1%, respectively, for LCx. The level of agreement between AMTDII and LCx assay results was 78.2%. We conclude that although both nucleic acid amplification methods are rapid and specific for the detection of MTB in clinical specimens, AMTDII is significantly more sensitive than LCx with both respiratory (P = 0.005) and extrapulmonary (P = 0.048) specimens.

Comparative evaluation of two commercial amplification assays for direct detection of Mycobacterium tuberculosis complex in respiratory specimens

Two commercial assays detecting the presence of Mycobacterium tuberculosis complex in clinical specimens by rRNA target amplification (Gen-Probe Amplified M. tuberculosis Direct Test [AMTD]) and PCR (Amplicor) were evaluated. The tests were applied to 327 digested, decontaminated respiratory specimens collected from 236 patients. Results were compared with those of acid-fast staining and culture. The combination of culture and clinical diagnosis was considered the "gold standard." A total of 60 specimens were collected from 27 patients with a diagnosis of pulmonary tuberculosis. Thirteen of these specimens were from patients receiving standard antituberculosis therapy and therefore were not included in the comparison. Of the remaining 47 specimens, 33 were smear positive, 40 were culture positive, 45 were AMTD positive, and 39 were Amplicor positive. After resolution of discrepant results, the overall sensitivities, specificities, and positive and negative predictive values were 77, 100, 100, and 95 for staining; 87, 100, 100, and 97.4 for culture; 95.9, 98.9, 94, and 99.2 for AMTD; and 85.4, 99.6, 97.9, and 97.1 for Amplicor, respectively. Agreement between AMTD and Amplicor assay results was 96.8%. It is concluded that although both nucleic acid amplification methods are rapid and specific for the detection of M. tuberculosis complex in respiratory specimens, AMTD appeared to be more sensitive than Amplicor.

Financial impact in the Italian Health Service of laparoscopic versus laparotomic surgery for the treatment of ovarian cysts

To assess the cost of two procedures for the removal of ovarian cysts, 200 pre-menopausal women were recruited for the surgical removal of ovarian cysts by laparoscopy (n = 100) and laparotomy (n = 100) according to case-control criteria. Patients operated by laparoscopy (mean age +/- SD 32.22 +/- 9.98 years) and laparotomy (mean age +/- SD 29.57 +/- 6.62 years) for ovarian cysts (mean diameters +/- SD 4.98 +/- 3.62 and 4.83 +/- 2.78 cm) had a post-surgical hospital stay of 3.12 +/- 0.41 and 7.25 +/- 1.08 days (P < 0.001) respectively. The total rate of complications occurring in patients operated by laparoscopy was 9 versus 53% (P < 0.001) of those operated by laparotomy; body temperature > 38 degrees C was recorded in 52/100 of patients operated by laparotomy versus 6/100 of those operated by laparoscopy. The mean cost for each pure surgical treatment performed by laparoscopy was US $498.17 versus US $642.47 when it was performed by laparotomy (P < 0.001). The laparoscopic surgical approach is more expensive in the first 36 operations, thereafter becoming cheaper. The mean of the entire overall expenditure was US $1142.08 and US $2138.72 for laparoscopy and laparotomy (P < 0.001) respectively. The entire expenditure for laparoscopy is higher than laparotomy only until eight operations. In conclusion, laparoscopy versus laparotomy has resulted in a saving of US $14,429.3 for 100 operations while the saving on entire costs was US $99,664.8.