Forecasting higher than expected numbers of health events provides potentially valuable insights in its own right, and may contribute to health services management and syndromic surveillance. This study investigates the use of quantile regression to predict higher than expected respiratory deaths. Data taken from 70,830 deaths occurring in New York were used. Temporal, weather and air quality measures were fitted using quantile regression at the 90th-percentile with half the data (in-sample). Four QR models were fitted: an unconditional model predicting the 90th-percentile of deaths (Model 1), a seasonal/temporal (Model 2), a seasonal, temporal plus lags of weather and air quality (Model 3), and a seasonal, temporal model with 7-day moving averages of weather and air quality. Models were cross-validated with the out of sample data. Performance was measured as proportionate reduction in weighted sum of absolute deviations by a conditional, over unconditional models; i.e., the coefficient of determination (R1). The coefficient of determination showed an improvement over the unconditional model between 0.16 and 0.19. The greatest improvement in predictive and forecasting accuracy of daily mortality was associated with the inclusion of seasonal and temporal predictors (Model 2). No gains were made in the predictive models with the addition of weather and air quality predictors (Models 3 and 4). However, forecasting models that included weather and air quality predictors performed slightly better than the seasonal and temporal model alone (i.e., Model 3 > Model 4 > Model 2) This study provided a new approach to predict higher than expected numbers of respiratory related-deaths. The approach, while promising, has limitations and should be treated at this stage as a proof of concept.
As the 21st century begins, several outbreaks of encephalitis have been reported. An examination of these outbreaks brings into focus important epidemiological developments. Specifically, urbanization and encroachment on natural environments, the ease of world travel, and global trade can lead to spread of vectors and viruses from the developing world to the developed world. This review focuses on two recent epidemics of encephalitis: West Nile virus encephalitis in the eastern United States and Nipah virus encephalitis in Malaysia and Singapore. These examples demonstrate spread of a known viral agent from an endemic area to an area in which it had not previously been found and identification of a new viral agent. Infectious diseases in the developed world once considered "exotic" are now potential threats to all patients.
Soil-transmitted helminths colonize more than 1.5 billion people worldwide, yet little is known about how they interact with bacterial communities in the gut microbiota. Differences in the gut microbiota between individuals living in developed and developing countries may be partly due to the presence of helminths, since they predominantly infect individuals from developing countries, such as the indigenous communities in Malaysia we examine in this work. We compared the composition and diversity of bacterial communities from the fecal microbiota of 51 people from two villages in Malaysia, of which 36 (70.6%) were infected by helminths. The 16S rRNA V4 region was sequenced at an average of nineteen thousand sequences per samples. Helminth-colonized individuals had greater species richness and number of observed OTUs with enrichment of Paraprevotellaceae, especially with Trichuris infection. We developed a new approach of combining centered log-ratio (clr) transformation for OTU relative abundances with sparse Partial Least Squares Discriminant Analysis (sPLS-DA) to enable more robust predictions of OTU interrelationships. These results suggest that helminths may have an impact on the diversity, bacterial community structure and function of the gut microbiota.
Viruses have become more mobile alongside with increasing human mobility and speed of travel. At the same time we get access to information on viral outbreaks and epidemics from large parts of the world faster than ever before. Two recent epidemics will be presented to explore the value and the consequences of communicating epidemiological information through the Internet. The epidemiology, clinical features, diagnostic procedures and prophylaxis of imported viral infections are presented. Risk factors for the emergence and resurgence of viral diseases are being discussed.
Over 100 viruses have been associated with acute central nervous system infections. The present review focuses on some of the most common agents of viral encephalitis, as well as important emerging viral encephalitides. In this context, the initial detection of West Nile virus in the Western Hemisphere during the 1999 New York City outbreak, the first description of Nipah virus in Malaysia, and the appearance in Asia of a new neurovirulent enterovirus 71 strain that causes severe neurologic disease are highlighted. In addition, advances regarding diagnosis, neuroimaging and treatment of Japanese and herpes simplex encephalitis are presented.
We sought to develop a smoking-cessation intervention for male Chinese restaurant workers in New York City that required no seeking out by participants; provided support over a relatively long period of time; and was responsive to participants' cultural backgrounds and daily lives. The resulting intervention consisted of a minimum of 9 proactive phone counseling sessions within a 6-month period for each participant recruited at his worksite. All activities were conducted in Chinese languages. The efficacy of this proactive phone-counseling intervention was assessed in a pretest/posttest design comparing baseline smoking with smoking 6 months after the intervention ended. Of 137 male employees recruited at their restaurants, 101 (median age 40.5) participated in the phone-counseling intervention in 2007-2008, with 75 completing the program with at least 9 counseling calls. We found a linear increase in smoking cessation from 0% at Call 1 to 50.7% at Call 9 for 75 men who completed the program, and we found for all 101 participants a 32.7% intent-to-treat cessation rate for 6 months post-end of program, adjusted to 30.8% by saliva cotinine assessments. The results indicate that combining field outreach with phone counseling over an extended period of time can facilitate smoking cessation for population groups whose environments do not support efforts to quit smoking.