Travel health. Part 3: illness in the returning traveller.

A significant number of travellers present for medical advice each year on return from overseas travel, and it is in the primary care setting where many of these will be seen. While most of the conditions will be familiar to those in general practice, there are some travel-associated infections (e.g. malaria) which, if left untreated, can lead to rapid deterioration and death. It is important, therefore, to be able to appreciate and recognize travel-associated diseases, which require prompt attention, and those that need referral for specialist expertise. This article reviews a range of health problems typically seen in returned travellers, their investigation and management. Details of the Hospital for Tropical Diseases post-tropical screening protocol for asymptomatic returned travellers are outlined.

Incidence rate and risk factors for giardiasis and strongyloidiasis in returning UK travellers.

BACKGROUND: Few studies have investigated incidence rate and risk factors for giardiasis and strongyloidiasis in returning UK travellers. The clinical presentations of these two diseases are often similar and difficult to distinguish. This study was conducted to investigate the incidence rate and the risk factors for symptomatic giardiasis and strongyloidiasis in returned tropical travellers. METHODS: We retrospectively analysed 3306 consecutive attendances presenting to the emergency clinic at the Hospital for Tropical Diseases in London, the UK from September 2008 to May 2010. Odds ratios between the diagnoses and patient variables were analysed by logistic regression. RESULTS: Giardiasis was diagnosed in 92/3306 cases (2.8%, proportionate morbidity), and the incidence rate per 1000 person-months was 12.5. Multivariate analysis with logistic regression revealed that Caucasian ethnicity (adjusted odds ratio (aOR): 2.37, 95% confidence interval (CI): 1.12-5.03, P value = 0.025), travel length ≥32 days (aOR: 2.63, 95%CI: 1.43-4.83, P = 0.002), travelling to South or South East Asia (aOR: 4.90, 95%CI: 2.03-11.8, P < 0.001, aOR: 3.36, 95%CI: 1.43-7.93, P = 0.006), afebrile presentation (aOR: 2.14, 95%CI: 1.14-4.03, P = 0.018), and presenting with gastro-intestinal symptoms (aOR: 14.6, 95%CI: 6.08-35.0, P < 0.001) were all associated with giardiasis. In contrast, strongyloidiasis was found only in 0.94% (proportionate morbidity) of the cases (31/3306), and the incidence rate per 1000 person-months was 3.1. Multivariate analysis revealed that male sex (aOR: 3.05, 95%CI: 1.36-6.85, P = 0.007), and non-Caucasian ethnicity (aOR: 2.69, 95%CI: 1.32-5.49, P = 0.007) were associated with strongyloidiasis. CONCLUSIONS: The incidence rate and risk factors for both infectious diseases were identified. The results of this study might guide clinicians to make more accurate and timely diagnoses in returned tropical travellers.

In situ adsorption studies of a 14-amino acid leucine-lysine peptide onto hydrophobic polystyrene and hydrophilic silica surfaces using quartz crystal microbalance, atomic force microscopy, and sum frequency generation vibrational spectroscopy.

The adsorption of a 14-amino acid amphiphilic peptide, LK14, which is composed of leucine (L, nonpolar) and lysine (K, charged), on hydrophobic polystyrene (PS) and hydrophilic silica (SiO2) was investigated in situ by quartz crystal microbalance (QCM), atomic force microscopy (AFM), and sum frequency generation (SFG) vibrational spectroscopy. The LK14 peptide, adsorbed from a pH 7.4 phosphate-buffered saline (PBS) solution, displayed very different coverage, surface roughness and friction, topography, and surface-induced orientation when adsorbed onto PS versus SiO2 surfaces. Real-time QCM adsorption data revealed that the peptide adsorbed onto hydrophobic PS through a fast (t < 2 min) process, while a much slower (t > 30 min) multistep adsorption and rearrangement occurred on the hydrophilic SiO2. AFM measurements showed different surface morphologies and friction coefficients for LK14 adsorbed on the two surfaces. Surface-specific SFG spectra indicate very different ordering of the adsorbed peptide on hydrophobic PS as compared to hydrophilic SiO2. At the LK14 solution/PS interface, CH resonances corresponding to the hydrophobic leucine side chains are evident. Conversely, only NH modes are observed at the peptide solution/SiO2 interface, indicating a different average molecular orientation on this hydrophilic surface. The surface-dependent difference in the molecular-scale peptide interaction at the solution/hydrophobic solid versus solution/hydrophilic solid interfaces (measured by SFG) is manifested as significantly different macromolecular-level adsorption properties on the two surfaces (determined via AFM and QCM experiments).