A call for better understanding of social media in surveillance and management of noncommunicable diseases

Using social media for health purposes has attracted much attention over the past decade. Given the challenges of population ageing and changes in national health profile and disease patterns following the epidemiologic transition, researchers and policy-makers should pay attention to the potential of social media in chronic disease surveillance, management and support. This commentary overviews the evidence base for this inquiry and outlines the key challenges to research laying ahead. The authors provide concrete suggestions and recommendations for developing a research agenda to guide future investigation and action on this topic.

Effect of Weather Variability on Seasonal Influenza Among Different Age Groups in Queensland, Australia: A Bayesian Spatiotemporal Analysis

Background

The effects of weather variability on seasonal influenza among different age groups remain unclear. The comparative study aims to explore the differences in the associations between weather variability and seasonal influenza, and growth rates of seasonal influenza epidemics among different age groups in Queensland, Australia.

Methods

Three Bayesian spatiotemporal conditional autoregressive models were fitted at the postal area level to quantify the relationships between seasonal influenza and monthly minimum temperature (MIT), monthly vapor pressure, school calendar pattern, and Index of Relative Socio-Economic Advantage and Disadvantage for 3 age groups (<15, 15-64, and ≥65 years).

Results

The results showed that the expected decrease in monthly influenza cases was 19.3% (95% credible interval [CI], 14.7%-23.4%), 16.3% (95% CI, 13.6%-19.0%), and 8.5% (95% CI, 1.5%-15.0%) for a 1°C increase in monthly MIT at <15, 15-64, and ≥65 years of age, respectively, while the average increase in the monthly influenza cases was 14.6% (95% CI, 9.0%-21.0%), 12.1% (95% CI, 8.8%-16.1%), and 9.2% (95% CI, 1.4%-16.9%) for a 1-hPa increase in vapor pressure.

Conclusions

Weather variability appears to be more influential on seasonal influenza transmission in younger (0-14) age groups. The growth rates of influenza at postal area level were relatively small for older (≥65) age groups in Queensland, Australia.

Monitoring Pertussis Infections Using Internet Search Queries

This study aims to assess the utility of internet search query analysis in pertussis surveillance. This study uses an empirical time series model based on internet search metrics to detect the pertussis incidence in Australia. Our research demonstrates a clear seasonal pattern of both pertussis infections and Google Trends (GT) with specific search terms in time series seasonal decomposition analysis. The cross-correlation function showed significant correlations between GT and pertussis incidences in Australia and each state at the lag of 0 and 1 months, with the variation of correlations between 0.17 and 0.76 (p < 0.05). A multivariate seasonal autoregressive integrated moving average (SARIMA) model was developed to track pertussis epidemics pattern using GT data. Reflected values for this model were generally consistent with the observed values. The inclusion of GT metrics improved detective performance of the model (β = 0.058, p < 0.001). The validation analysis indicated that the overall agreement was 81% (sensitivity: 77% and specificity: 83%). This study demonstrates the feasibility of using internet search metrics for the detection of pertussis epidemics in real-time, which can be considered as a pre-requisite for constructing early warning systems for pertussis surveillance using internet search metrics.

Gut microbiota disturbance during helminth infection: can it affect cognition and behaviour of children?

Background

Bidirectional signalling between the brain and the gastrointestinal tract is regulated at neural, hormonal, and immunological levels. Recent studies have shown that helminth infections can alter the normal gut microbiota. Studies have also shown that the gut microbiota is instrumental in the normal development, maturation and function of the brain. The pathophysiological pathways by which helminth infections contribute to altered cognitive function remain poorly understood.

Discussion

We put forward the hypothesis that gastrointestinal infections with parasitic worms, such as helminths, induce an imbalance of the gut-brain axis, which, in turn, can detrimentally manifest in brain development. Factors supporting this hypothesis are: 1) research focusing on intelligence and school performance in school-aged children has shown helminth infections to be associated with cognitive impairment, 2) disturbances in gut microbiota have been shown to be associated with important cognitive developmental effects, and 3) helminth infections have been shown to alter the gut microbiota structure. Evidence on the complex interactions between extrinsic (parasite) and intrinsic (host-derived) factors has been synthesised and discussed.

Summary

While evidence in favour of the helminth-gut microbiota-central nervous system hypothesis is circumstantial, it would be unwise to rule it out as a possible mechanism by which gastrointestinal helminth infections induce childhood cognitive morbidity. Further empirical studies are necessary to test an indirect effect of helminth infections on the modulation of mood and behaviour through its effects on the gut microbiota.

Co-distribution and co-infection of chikungunya and dengue viruses

Background

Chikungunya and dengue infections are spatio-temporally related. The current review aims to determine the geographic limits of chikungunya, dengue and the principal mosquito vectors for both viruses and to synthesise current epidemiological understanding of their co-distribution.

Methods

Three biomedical databases (PubMed, Scopus and Web of Science) were searched from their inception until May 2015 for studies that reported concurrent detection of chikungunya and dengue viruses in the same patient. Additionally, data from WHO, CDC and Healthmap alerts were extracted to create up-to-date global distribution maps for both dengue and chikungunya.

Results

Evidence for chikungunya-dengue co-infection has been found in Angola, Gabon, India, Madagascar, Malaysia, Myanmar, Nigeria, Saint Martin, Singapore, Sri Lanka, Tanzania, Thailand and Yemen; these constitute only 13 out of the 98 countries/territories where both chikungunya and dengue epidemic/endemic transmission have been reported.

Conclusions

Understanding the true extent of chikungunya-dengue co-infection is hampered by current diagnosis largely based on their similar symptoms. Heightened awareness of chikungunya among the public and public health practitioners in the advent of the ongoing outbreak in the Americas can be expected to improve diagnostic rigour. Maps generated from the newly compiled lists of the geographic distribution of both pathogens and vectors represent the current geographical limits of chikungunya and dengue, as well as the countries/territories at risk of future incursion by both viruses. These describe regions of co-endemicity in which lab-based diagnosis of suspected cases is of higher priority.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1417-2) contains supplementary material, which is available to authorized users.

Intestinal Epithelial Cell Tyrosine Kinase 2 Transduces IL-22 Signals To Protect from Acute Colitis

In the intestinal tract, IL-22 activates STAT3 to promote intestinal epithelial cell (IEC) homeostasis and tissue healing. The mechanism has remained obscure, but we demonstrate that IL-22 acts via tyrosine kinase 2 (Tyk2), a member of the Jak family. Using a mouse model for colitis, we show that Tyk2 deficiency is associated with an altered composition of the gut microbiota and exacerbates inflammatory bowel disease. Colitic Tyk2(-/-) mice have less p-STAT3 in colon tissue and their IECs proliferate less efficiently. Tyk2-deficient primary IECs show reduced p-STAT3 in response to IL-22 stimulation, and expression of IL-22-STAT3 target genes is reduced in IECs from healthy and colitic Tyk2(-/-) mice. Experiments with conditional Tyk2(-/-) mice reveal that IEC-specific depletion of Tyk2 aggravates colitis. Disease symptoms can be alleviated by administering high doses of rIL-22-Fc, indicating that Tyk2 deficiency can be rescued via the IL-22 receptor complex. The pivotal function of Tyk2 in IL-22-dependent colitis was confirmed in Citrobacter rodentium-induced disease. Thus, Tyk2 protects against acute colitis in part by amplifying inflammation-induced epithelial IL-22 signaling to STAT3.

Enhancing disease surveillance with novel data streams: challenges and opportunities

Novel data streams (NDS), such as web search data or social media updates, hold promise for enhancing the capabilities of public health surveillance. In this paper, we outline a conceptual framework for integrating NDS into current public health surveillance. Our approach focuses on two key questions: What are the opportunities for using NDS and what are the minimal tests of validity and utility that must be applied when using NDS? Identifying these opportunities will necessitate the involvement of public health authorities and an appreciation of the diversity of objectives and scales across agencies at different levels (local, state, national, international). We present the case that clearly articulating surveillance objectives and systematically evaluating NDS and comparing the performance of NDS to existing surveillance data and alternative NDS data is critical and has not sufficiently been addressed in many applications of NDS currently in the literature.

Modelling parasite aggregation: disentangling statistical and ecological approaches

The overdispersion in macroparasite infection intensity among host populations is commonly simulated using a constant negative binomial aggregation parameter. We describe an alternative to utilising the negative binomial approach and demonstrate important disparities in intervention efficacy projections that can come about from opting for pattern-fitting models that are not process-explicit. We present model output in the context of the epidemiology and control of soil-transmitted helminths due to the significant public health burden imposed by these parasites, but our methods are applicable to other infections with demonstrable aggregation in parasite numbers among hosts.

Methylotrophic methanogenic Thermoplasmata implicated in reduced methane emissions from bovine rumen

Rumen methanogens are major sources of anthropogenic methane emissions, and these archaea are targets in strategies aimed at reducing methane emissions. Here we show that the poorly characterised Thermoplasmata archaea in bovine rumen are methylotrophic methanogens and that they are reduced upon dietary supplementation with rapeseed oil in lactating cows. In a metatranscriptomic survey, Thermoplasmata 16S rRNA and methyl-coenzyme M reductase (mcr) transcripts decreased concomitantly with mRNAs of enzymes involved in methanogenesis from methylamines that were among the most abundant archaeal transcripts, indicating that these Thermoplasmata degrade methylamines. Their methylotrophic methanogenic lifestyle was corroborated by in vitro incubations, showing enhanced growth of these organisms upon methylamine supplementation paralleled by elevated methane production. The Thermoplasmata have a high potential as target in future strategies to mitigate methane emissions from ruminant livestock. Our findings and the findings of others also indicate a wider distribution of methanogens than previously anticipated.

Phylotype-level 16S rRNA analysis reveals new bacterial indicators of health state in acute murine colitis

Human inflammatory bowel disease and experimental colitis models in mice are associated with shifts in intestinal microbiota composition, but it is unclear at what taxonomic/phylogenetic level such microbiota dynamics can be indicative for health or disease. Here, we report that dextran sodium sulfate (DSS)-induced colitis is accompanied by major shifts in the composition and function of the intestinal microbiota of STAT1(-/-) and wild-type mice, as determined by 454 pyrosequencing of bacterial 16S rRNA (gene) amplicons, metatranscriptomics and quantitative fluorescence in situ hybridization of selected phylotypes. The bacterial families Ruminococcaceae, Bacteroidaceae, Enterobacteriaceae, Deferribacteraceae and Verrucomicrobiaceae increased in relative abundance in DSS-treated mice. Comparative 16S rRNA sequence analysis at maximum possible phylogenetic resolution identified several indicator phylotypes for DSS treatment, including the putative mucin degraders Akkermansia and Mucispirillum. The analysis additionally revealed strongly contrasting abundance changes among phylotypes of the same family, particularly within the Lachnospiraceae. These extensive phylotype-level dynamics were hidden when reads were grouped at higher taxonomic levels. Metatranscriptomic analysis provided insights into functional shifts in the murine intestinal microbiota, with increased transcription of genes associated with regulation and cell signaling, carbohydrate metabolism and respiration and decreased transcription of flagellin genes during inflammation. These findings (i) establish the first in-depth inventory of the mouse gut microbiota and its metatranscriptome in the DSS colitis model, (ii) reveal that family-level microbial community analyses are insufficient to reveal important colitis-associated microbiota shifts and (iii) support a scenario of shifting intra-family structure and function in the phylotype-rich and phylogenetically diverse Lachnospiraceae in DSS-treated mice.