Public health and economic impact of switching from a trivalent to a quadrivalent inactivated influenza vaccine in Mexico.

Most influenza vaccines in Mexico are trivalent, containing two influenza A strains and a single B strain. Quadrivalent influenza vaccines (QIVs) extend protection by including an additional B strain to cover both co-circulating B lineages. Here, we retrospectively estimated how a switch to QIV in Mexico would have impacted influenza-related health outcomes over the 2010/2011 to 2015/2016 influenza seasons, and prospectively estimated the budget impact of using QIV in Mexico's national immunization program from 2016/2017 to 2020/2021. For the retrospective estimation, we used an age-stratified static model incorporating Mexico-specific input parameters. For the prospective estimation, we used a budget impact model based on retrospective attack rates considering predicted future vaccination coverage. Between 2010/2011 and 2015/2016, a switch to QIV would have prevented 270,596 additional influenza cases, 102,000 general practitioner consultations, 140,062 days of absenteeism, 3,323 hospitalizations, and 312 deaths, saving Mex$214 million (US$10.8 million) in third-party payer costs. In the prospective analysis, a switch to QIV was estimated to prevent an additional 225,497 influenza cases, 85,000 general practitioner consultations, 116,718 days of absenteeism, 2,769 hospitalizations, and 260 deaths, saving Mex$178 million (US$9 million) in third-party payer costs over 5 years. Compared to the trivalent vaccine, the benefit and costs saved with QIV were sensitive to the distribution of influenza A vs. B cases and trivalent vaccine effectiveness against the mismatched B strain. These results suggest switching to QIV in Mexico would benefit healthcare providers and society by preventing influenza cases, morbidity, and deaths, and reducing associated use of medical resources.

I. THE ROLE OF RESEARCH ETHICS COMMITTEES IN OBSERVATIONAL STUDIES: EPIDEMIOLOGICAL REGISTRIES, CASE REPORTS, INTERVIEWS, AND RETROSPECTIVE STUDIES.

It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

I. The role of research ethics committees in observational studies: epidemiological registries, case reports, interviews, and retrospective studies

Abstract It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

Rapid detection of ESBL-producing gram-negative bacteria isolated from blood: a reasonable and reliable tool for middle and low resource countries.

INTRODUCTION: Delay in appropriate treatment in patients with bacteraemia can increase morbidity, mortality, and health expenditures. We compared the Rapid Direct Test (RDT) designed to detect ESBL-producing gram-negative bacteria (GNB) directly from positive blood cultures bottles, with two conventional ESBL detection tests: Screening and Confirmatory Disk Diffusion Assay (SC-DDA) and an MIC Screening and ESBL E-test (MIC/ET). MATERIAL AND METHODS: We screened all blood cultures in a tertiary care facility from August to December 2005. We only included one positive bottle per patient in which GNB were observed. RDT: Blood from each bottle was inoculated on Mueller-Hinton agar. Ceftazidime and cefotaxime disks with and without clavulanic acid were added and incubated at 35 degrees C +/- 2 degrees C for 24 h. Results were interpreted according to CLSI recommendations for the SC-DDA and MIC/ET. All methods were performed simultaneously. Time for reporting as an ESBL-producer and cost of the tests were recorded. RESULTS: We isolated 124 GNB in 114 episodes of bacteraemia, 10 of them (8.8%) polymicrobial; 79 (63.7%) of the GNB were enteric bacteria, 44 (35.5%) glucose non-fermenter GNB and one Haemophilus influenzae. The most common microorganism was Escherichia coli in 56 episodes (45.2%), followed by Pseudomonas aeruginosa in 24 (19.3%), and Klebsiella pneumoniae in 13 (10.5%). Of the 114 episodes, 41 (36%) had at least one GNB resistant to 3rd generation cephalosporins, and 25 (21.9%) were caused by an ESBL-producing GNB. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the RDT were 96%, 98.9%, 96% and 98.9%, respectively. Agreement by kappa index between RDT and SC-DDA was 0.95 and between the RDT and MIC/ET was 0.92. The RDT detected 24/25 ESBL-producing bacteria. The mean time to detect an isolate as an ESBL producer after a positive blood culture bottle signal was 1.02 +/- 0.19 days when using the RDT, and 3.40 +/- 0.59 days when using any other method. The difference in reporting time was 2.38 +/- 0.63 days (p < 0.0001). Our estimated cost per test was $1.54 for RDT, $2.32 for screening/ confirmatory SC-DDA, and $49.65 for MIC screening and MIC/ET. Conclusions. The RDT is a rapid, reliable and easy analysis to perform, as well as cost-effective.