Perspective Chapter: Emerging Infectious Diseases As a Public Health Problem

Emerging infectious diseases (EIDs) can be defined as diseases that have recently appeared in a population or are rapidly increasing in incidence or geographic range. An “emerging infection” refers to either a new infection that has never appeared before or a known infection that has experienced a recent increase in prevalence. The Human Immunodeficiency Virus (HIV) pandemic and Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) outbreaks are prototypical examples of emerging infectious diseases that were not prevalent before the 1980s and 2003, respectively. On the other hand, a “re-emerging infection” is a familiar infection that resurfaces. The influenza A virus pandemics of 1918, 1957, and 1968 serve as prototypical examples of re-emerging infections. This chapter aims to define the concepts of emerging and re-emerging infectious diseases and explore their main causes, the microorganisms involved, and why they can become significant global public health problems

Pre-travel health care attendance among migrant travellers visiting friends and relatives (VFR): a 10-year retrospective analysis

Background: Travellers visiting friends and relatives (VFR) define a specific population of travellers exposed to higher risks for health and safety than tourists. The aim of this study was to assess differentials in pre-travel health care in VFR travellers compared to other travellers. Methods: A retrospective cohort study was performed including attendees of the Travel Medicine Clinic of the Hospital Universitari de Bellvitge, Barcelona, Spain, between January 2007 and December 2017. Results: Over the 10-year period, 47,022 subjects presented to the travel clinic for pre-travel health care, 13.7% of whom were VFR travellers. These showed higher rates of vaccination against yellow fever and meningococcus, but lower rates for hepatitis A, hepatitis B, influenza, rabies, cholera, polio, typhoid IM vaccine and tetanus vaccine boosters. Regarding malaria prevention measures, results highlighted that VFR travellers, when compared with tourists, were more likely to be prescribed with chemoprophylaxis, particularly with mefloquine, than with atovaquone/proguanil. Conclusions: Findings from this large-scale study indicated differences in vaccination rates and completion, as well as in chemoprophylaxis for malaria, between VFR and non-VFR travellers, fostering specific interventions for promoting adherence to pre-travel health advice among migrant travellers

Nanoscale color control of TiO2 films with embedded Au nanoparticles

Article in pressWe demonstrate an efficient nanoscale control of the optical properties of TiO2 films by tuning the Surface Plasmon Resonance (SPR) in the embedded Au nanoparticles. The films were grown by reactive magnetron sputtering. SPR tuning was achieved by different annealings, which affected the shape and size of the Au nanoparticles, and also the phase of the dielectric matrix. These changes promoted the variations on the optical properties. As shown by the modeling of the effective dielectric function of the TiO2/Au in the SPR region, the variation of their optical absorption spectra correlates with morphological changes.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/70037/2006

Non-Adherence to Malaria Chemo-Prophylaxis in Travelers: Mind to the Care Gap!

Background: Travelers are at risk of contracting malaria when moving to endemic areas. Yet, despite effective malaria chemoprophylaxis, imported cases of malaria still occur worldwide. Indeed, some studies have shown a varied adherence level; consequently, a traveler care gap could occur. Methods: A prospective cohort study was carried out in 2017 to evaluate the rate of malaria chemoprophylaxis adherence among Spanish travelers. Results: A post-travel questionnaire was completed by 402 travelers to malaria endemic areas that were prescribed chemoprophylaxis: 67 (16.7%) did not take any dose of chemoprophylaxis and 41 (10.2%) had not even carried it while travelling abroad. The adherence of chemoprophylaxis was 68,7% of travelers, being statistically different according to travel duration, onset of adverse events and type of drug prescribed. The non-adherent travelers reported not continuing with administration mainly because of forgetfulness, fear of side effects and low perceived risk because itinerary changes. Regarding the onset of the medication's secondary adverse events, one in three (35.2%) reported at least one, being more frequent among patients that took mefloquine than atovaquone-proguanil (p=0.01). The main adverse events reported by chemoprophylaxis users were gastrointestinal or sleeping disorders. Conclusions: The suboptimal compliance of chemoprophylaxis is a major lost opportunity to achieve malaria prevention, so it is an important contributor to the traveler care gap

Functional and optical properties of Au :TiO2 nanocomposite films : the influence of thermal annealing

A set of nanocomposite thin films consisting of Au nanoclusters dispersed in a TiO2 dielectric matrix was deposited by reactive magnetron sputtering, and subjected to thermal annealing in vacuum, at temperatures ranging from 200 to 800 ◦C. The obtained results show that the structure and the size of Au clusters, together with the matrix crystallinity, changed as a result of the annealing, and were shown to be able to change the optical properties of the films and keeping good mechanical properties, opening thus a wide number of possible applications. The crystallization of the gold nanoclusters induced by the annealing was followed by a systematic change in the overall coating behaviour, namely the appearance of surface plasmon resonance (SPR) behaviour. This effect enables to tailor the thin films reflectivity, absorbance and colour coordinates, contributing to the importance of this thin film system. The different attained optical characteristics (reflectance values ranging from interference to metallic-like behaviours and colour varying for interference rainbow-like to several tones of red-brownish), associated with a reasonable mechanical resistance of the coatings (good adhesion to different substrates and hardness values ranging from 5 to 7.5 GPa), induce the possibility to use this film system in a wide range of decorative applications.Fundac¸ ão para a Ciência e Tecnologia (FCT) - PTDC/CTM/70037/2006

Development of new decorative coatings based on gold nanoparticles dispersed in an amorphous TiO2 dielectric matrix

The present work is devoted to the optical properties of Au:TiO2 thin films in order to clarify the role of the Au clusters inclusions in the TiO2 dielectric matrix. Three series of films containing about 30 at.% (29.2), 20 at. % (19.8) and 10 at.% (9.3) Au were deposited by dc reactive magnetron sputtering. On thermal annealing in the range from 300 to 800 °C in protective atmosphere, significant changes on the crystalline phases and clusters dimensions were detected. The most promising optical behavior was found for the film 20% Au:TiO2, where the films revealed some colour changes, evolving from several shades of grey to different tones of red. This change in the optical behaviour of the films was found to be correlated with a cluster size increase from 2 to 17 nm. For higher size values (>20 nm) the films, independently of the Au content, showed a golden appearance colour. The optical changes were confirmed by reflectivity and CIELab colour measurements. Regarding the films with 10 and 30 at.% Au, the results confirmed that there is an evident range of compositions and clusters size where the SPR is more evident. Sample A (10 at.% Au) it seems to be in the lower limit of the SPR showing a typical interferometric behavior on the reflectivity measurements, similar to the TiO2 optical behavior. Regarding the 30 at.% Au one, the results seems to indicate that the amount of gold particles and their grain size is in the upper limit to show a SPR activity.Fundação para a Ciência e Tecnologia (FCT) - PTDC/CTM/70037/200

Stand-by emergency treatment (SBET) of malaria in Spanish travellers: a cohort study

Background: Among strategies for malaria prevention, stand-by emergency treatment (SBET) is a possible approach, but scarce evidences exists investigating travellers' adherence and behaviours toward its use; therefore, the presented study aimed to determine travellers' compliance toward the SBET when prescribed in travel clinics. Methods: A prospective cohort study was performed at the Travel Health Clinic of the Hospital Universitari de Bellvitge, Barcelona, Spain, during 2017. The research was planned on survey-based design, using pre- and post-travel questionnaires. Results: In the study period, of 5436 subjects who attended the HUB Travel Medicine Clinic, 145 travellers to malariaendemic areas were prescribed SBET, and all patients agreed to participate in the study by completing the pre-travel questionnaire. Approximately half the participants were women (n=75, 51.7%), and the median age of all travellers was 29 years (range 13-57), mainly travelling to South-East Asia (n=69, 47.6%), with Indonesia and the Philippines as the most popular destinations. The length of travels had a median duration of 29 days (range 10-213). Of the recruited participants, 98 replied to the online post-travel survey, reaching a response rate of 67.6%. A total of 62.2% of travellers to which SBET was prescribed did not buy and carry drugs while travelling abroad. No participants' baseline or travel characteristic was shown to be signifcantly associated (p>0.05) with this behaviour. Four women (4.1%) experienced fever and self-administered SBET, without seeking medical attention. No malaria cases were observed. Conclusions: This cohort study addressed travellers' adherence and behaviour toward SBET, highlighting an incorrect use of the emergency treatment in case of presumptive malaria symptoms. This should be taken into account during pre-travel consultation, since the success of this strategy for malaria prevention depends on travellers' strong adher‑ ence to it