From this brief review, it is evident that the biological roles of chemokines in host defense and/or disease in response to viral infection of the CNS are constantly evolving. An emerging picture has developed that indicates that chemokines and their receptors are intimately involved in generation of effective host responses to viral infections within the CNS. Paradoxically, chemokine expression has also been associated with neuropathology. Thus, chemokines and/or chemokine receptors are potentially relevant targets for treating various viral-induced neuropathies by dampening specific biological functions associated with disease. Recent evidence has emerged implicating chemokines, specifically CCR5 are attracted by the chemokines CXCL10 and CCL5, respectively, and mediate viral control through direct cytolytic activity and/or cytokine secretion. CXCL12, which signals through CXCR4, may, however, sequester T lymphocytes within the perivascular space and regulate penetration of the parenchyma, thus inhibiting efficient viral clearance. doi:10.1371/journal.ppat.1000937.g001 CXCR4 and CXCL12, as important mediators of neurogenesis [34] ; thus, chemokines produced during viral infections may influence neural precursor cell function and therefore influence recovery and repair. We can only look forward to future research that will undoubtedly uncover new and exciting roles for the chemokines in host defense, disease, and recovery within the context of the virally infected CNS. A cross-sectional survey to evaluate knowledge, attitudes and practices (KAP) regarding seasonal influenza vaccination among European travellers to resource-limited destinations BACKGROUND: Influenza is one of the most common vaccine-preventable diseases in travellers. By performing two cross-sectional questionnaire surveys during winter 2009 and winter 2010 among European travellers to resource-limited destinations, we aimed to investigate knowledge, attitudes and practices (KAP) regarding seasonal influenza vaccination. METHODS: Questionnaires were distributed in the waiting room to the visitors of the University of Zurich Centre for Travel' Health (CTH) in January and February 2009 and January 2010 prior to travel health counselling (CTH09 and CTH10). Questions included demographic data, travel-related characteristics and KAP regarding influenza vaccination. Data were analysed by using SPSS(® )version 14.0 for Windows. Differences in proportions were compared using the Chi-square test and the significance level was set at p ≤ 0.05. Predictors for seasonal and pandemic influenza vaccination were determined by multiple logistic regression analyses. RESULTS: With a response rate of 96.6%, 906 individuals were enrolled and 868 (92.5%) provided complete data. Seasonal influenza vaccination coverage was 13.7% (n = 119). Only 43 (14.2%) participants were vaccinated against pandemic influenza A/H1N1, mostly having received both vaccines simultaneously, the seasonal and pandemic one. Job-related purposes (44, 37%), age > 64 yrs (25, 21%) and recommendations of the family physician (27, 22.7%) were the most often reported reasons for being vaccinated. In the multiple logistic regression analyses of the pooled data increasing age (OR = 1.03, 95% CI 1.01 - 1.04), a business trip (OR = 0.39, 95% CI 0.17 - 0.92) and seasonal influenza vaccination in the previous winter seasons (OR = 12.91, 95% CI 8.09 - 20.58) were independent predictors for seasonal influenza vaccination in 2009 or 2010. Influenza vaccination recommended by the family doctor (327, 37.7%), travel to regions with known high risk of influenza (305, 35.1%), and influenza vaccination required for job purposes (233, 26.8%) were most frequently mentioned to consider influenza vaccination. CONCLUSIONS: Risk perception and vaccination coverage concerning seasonal and pandemic influenza was very poor among travellers to resource-limited destinations when compared to traditional at-risk groups. Previous access to influenza vaccination substantially facilitated vaccinations in the subsequent year. Information strategies about influenza should be intensified and include health professionals, e.g. family physicians, travel medicine practitioners and business enterprises. Pandemic and seasonal influenza are still a challenging field of the public health system. Influenza -a mild to severe respiratory infection caused by RNA viruses of the family Orthomyxoviridae -is one of the most common vaccine-preventable disease in travellers. Worldwide, between 250'000 and 500'000 deaths are estimated to be due to seasonal influenza infection each year [1] . Influenza is also responsible for tremendous economic costs both from admissions to hospital and loss of productivity [2] . Influenza affects all age groups and is usually self-limited. Common symptoms include acute fever, muscles pain, headache, cough and chills [3] . Special risk groups, such as very young children, the elderly and those suffering from chronic lung or heart diseases are at risk for serious influenza complications, e.g. bacterial pneumonia [4, 5] . Influenza reaches peak prevalence in winter in the Northern hemisphere (Nov-Apr) -as well as in the Southern hemisphere (Apr-Oct) and circulates yearround in the tropics [6, 7] . Seasonal influenza vaccination is an effective prevention strategy and is therefore routinely recommended for special risk groups [8, 9] . Of note, the seasonal influenza vaccine recommendations of the U.S. Centres for Disease Control were recently expanded and include now about 80% of the population [10] .