Human respiratory syncytial virus (HRSV) is the major cause of lower respiratory tract infections in children under 5 years of age and the elderly, causing annual disease outbreaks during the fall and winter. Multiple lineages of the HRSVA and HRSVB serotypes co-circulate within a single outbreak and display a strongly temporal pattern of genetic variation, with a replacement of dominant genotypes occurring during consecutive years. In the present study we utilized phylogenetic methods to detect and map sites subject to adaptive evolution in the G protein of HRSVA and HRSVB. A total of 29 and 23 amino acid sites were found to be putatively positively selected in HRSVA and HRSVB, respectively. Several of these sites defined genotypes and lineages within genotypes in both groups, and correlated well with epitopes previously described in group A. Remarkably, 18 of these positively selected tended to revert in time to a previous codon state, producing a “flip-flop” phylogenetic pattern. Such frequent evolutionary reversals in HRSV are indicative of a combination of frequent positive selection, reflecting the changing immune status of the human population, and a limited repertoire of functionally viable amino acids at specific amino acid sites.

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SUMMARYNotified cases of dengue infections in Singapore reached historical highs in 2004 (9459 cases) and 2005 (13 817 cases) and the reason for such an increase is still to be established. We apply a mathematical model for dengue infection that takes into account the seasonal variation in incidence, characteristic of dengue fever, and which mimics the 2004-2005 epidemics in Singapore. We simulated a set of possible control strategies and confirmed the intuitive belief that killing adult mosquitoes is the most effective strategy to control an ongoing epidemic. On the other hand, the control of immature forms was very efficient in preventing the resurgence of dengue epidemics. Since the control of immature forms allows the reduction of adulticide, it seems that the best strategy is to combine both adulticide and larvicide control measures during an outbreak, followed by the maintenance of larvicide methods after the epidemic has subsided. In addition, the model showed that the mixed strategy of adulticide and larvicide methods introduced by the government seems to be very effective in reducing the number of cases in the first weeks after the start of control.

RESUMO -Os desempenhos em testes neuropsicológicos de trinta pacientes, com diagnóstico de demência leve ou moderada baseado nos critérios do DSM-III-R, com escore no Mini-exame do Estado Mental inferior a 24 pontos e escolaridade mínima de 4 anos, foram comparados aos de trinta voluntários normais equiparados quanto a idade, escolaridade e sexo. Foram calculadas as sensibilidades e especificidades dos testes na distinção entre doentes e controles normais Dentre os testes empregados, o que demonstrou maior acurácia nesta distinção, calculada através de curva ROC, foi o de informação-memória-concentração de Blessed, seguido em ordem decrescente de acurácia, pelos de construção (cópias de figuras simples), memória verbal tardia (após 5 minutos), reconhecimento de 10 figuras e fluencia verbal (animais). Seis testes de aplicação e interpretação simples (fluencia verbal, percepção visual, memória visual incidental, cálculo, desenho de um relógio e memória tardia após 5 minutos) permitiram definir função linear discriminante que revelou elevada capacidade de discriminação entre pacientes e controles, na amostra. Esta função deve ser submetida à comprovação em outra casuística. Em virtude da simplicidade e rapidez de aplicação, poderá ser associada ao MEM para identificar indivíduos com demência e indivíduos sadios em estudos epidemiológicos. PALAVRAS-CHAVE: demência, avaliação, testes neuropsicológicos.Brief and easy-to-administer neuropsychological tests in the diagnosis of dementia SUMMARY -Thirty patients with dementia defined by DSM-III-R criteria (Alzheimer's disease (22), vascular dementia (3), Parkinson's disease, frontal lobe dementia, possible diffuse Lewy body dementia, normal pressure hydrocephalus and uncertain diagnosis), with scores below 24 points in the Mini-Mental Status Examination and more than 4 years of education were submitted to a neuropsychological evaluation. The scores in the neuropsychological tests were compared to those obtained by thirty normal volunteers paired for age, sex and education. Sensivity, specificity and accuracy of the tests in the distinction of demented and normal volunteers were determined. The accuracies were calculated using ROC curves. Blessed's information-memory-concentration test showed greatest accuracy, followed by copy of simple figures, delayed memory of 10 figures (after 5 minutes), recognition of 10 figures and verbal fluency test (animals). A linear discriminant function, composed by 6 tests: visual perception, incidental memory, delayed memory (after 5 minutes), drawing of a clock, verbal fluency (animals) and calculation tests, was able to discriminate all controls from patients and only one patient was wrongly classified as normal control. These tests were chosen because they can be applied in less than 10 minutes and are very easy to interpret. This discriminant function must be applied in another group of patients and controls in order to demonstrate its value. When associated to the MMSE it may be useful to discriminate patients with dementia from normal...

Warming temperatures may increase the geographic spread of vector-borne diseases into temperate areas. Although a tropical mosquito-borne viral disease, a dengue outbreak occurred in Madeira, Portugal, in 2012; the first in Europe since 1920s. This outbreak emphasizes the potential for dengue re-emergence in Europe given changing climates. We present estimates of dengue epidemic potential using vectorial capacity (VC) based on historic and projected temperature (1901–2099). VC indicates the vectors' ability to spread disease among humans. We calculated temperature-dependent VC for Europe, highlighting 10 European cities and three non-European reference cities. Compared with the tropics, Europe shows pronounced seasonality and geographical heterogeneity. Although low, VC during summer is currently sufficient for dengue outbreaks in Southern Europe to commence–if sufficient vector populations (either Ae. aegypti and Ae. albopictus) were active and virus were introduced. Under various climate change scenarios, the seasonal peak and time window for dengue epidemic potential increases during the 21st century. Our study maps dengue epidemic potential in Europe and identifies seasonal time windows when major cities are most conducive for dengue transmission from 1901 to 2099. Our findings illustrate, that besides vector control, mitigating greenhouse gas emissions crucially reduces the future epidemic potential of dengue in Europe.

Yellow fever and dengue are viral infections that in urban centres are transmitted by the same arthropod vector, a mosquito of the genus Aedes. In order to estimate the risk of an epidemic of urban yellow fever in a dengue-infested area we calculated the threshold in the basic reproduction number, R0, of dengue, above which any single sylvatic yellow fever-infected individual will trigger an urban yellow fever epidemic. Specifically, we analysed the relationship between the extrinsic incubation period and the duration of viraemia, from which it is possible to define the R0 for dengue that would also suggest an outbreak potential for yellow fever. We also calculated the critical proportion of people to vaccinate against yellow fever in order to prevent an epidemic in a dengue-endemic area. The theory proposed is illustrated by the case of São Paulo State in southern Brazil, where dengue is endemic and the risk of urban yellow fever is already imminent.

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 15, No.

In Singapore, the frequency and magnitude of dengue epidemics have increased significantly over the past 40 years. It is important to understand the main drivers for the rapid increase in dengue incidence. We studied the relative contributions of putative drivers for the rise of dengue in Singapore: population growth, climate parameters and international air passenger arrivals from dengue endemic countries, for the time period of 1974 until 2011. We used multivariable Poisson regression models with the following predictors: Annual Population Size; Aedes Premises Index; Mean Annual Temperature; Minimum and Maximum Temperature Recorded in each year; Annual Precipitation and Annual Number of Air Passengers arriving from dengue-endemic South-East Asia to Singapore. The relative risk (RR) of the increase in dengue incidence due to population growth over the study period was 42.7, while the climate variables (mean and minimum temperature) together explained an RR of 7.1 (RR defined as risk at the end of the time period relative to the beginning and goodness of fit associated with the model leading to these estimates assessed by pseudo-R2 equal to 0.83). Estimating the extent of the contribution of these individual factors on the increasing dengue incidence, we found that population growth contributed to 86% while the residual 14% was explained by increase in temperature. We found no correlation with incoming air passenger arrivals into Singapore from dengue endemic countries. Our findings have significant implications for predicting future trends of the dengue epidemics given the rapid urbanization with population growth in many dengue endemic countries. It is time for policy-makers and the scientific community alike to pay more attention to the negative impact of urbanization and urban climate on diseases such as dengue.