Detecting Robust Patterns in the Spread of Epidemics: A Case Study of Influenza in the United States and France

In this paper, the authors develop a method of detecting correlations between epidemic patterns in different regions that are due to human movement and introduce a null model in which the travel-induced correlations are cancelled. They apply this method to the well-documented cases of seasonal influenza outbreaks in the United States and France. In the United States (using data for 1972-2002), the authors observed strong short-range correlations between several states and their immediate neighbors, as well as robust long-range spreading patterns resulting from large domestic air-traffic flows. The stability of these results over time allowed the authors to draw conclusions about the possible impact of travel restrictions on epidemic spread. The authors also applied this method to the case of France (1984-2004) and found that on the regional scale, there was no transportation mode that clearly dominated disease spread. The simplicity and robustness of this method suggest that it could be a useful tool for detecting transmission channels in the spread of epidemics.Comment: 8 pages, 7 figures, 3 table

Surveillance of gastrointestinal disease in France using drug sales data

AbstractDrug sales data have increasingly been used for disease surveillance during recent years. Our objective was to assess the value of drug sales data as an operational early detection tool for gastroenteritis epidemics at national and regional level in France. For the period 2008–2013, we compared temporal trends of drug sales for the treatment of gastroenteritis with trends of cases reported by a Sentinel Network of general practitioners. We benchmarked detection models to select the one with the best sensitivity, false alert proportion and timeliness, and developed a prospective framework to assess the operational performance of the system. Drug sales data allowed the detection of seasonal gastrointestinal epidemics occurring in winter with a distinction between prescribed and non-prescribed drugs. Sales of non-prescribed drugs allowed epidemic detection on average 2.25 weeks earlier than Sentinel data. These results confirm the value of drug sales data for real-time monitoring of gastroenteritis epidemic activity

Epidemic variability in complex networks

We study numerically the variability of the outbreak of diseases on complex networks. We use a SI model to simulate the disease spreading at short times, in homogeneous and in scale-free networks. In both cases, we study the effect of initial conditions on the epidemic's dynamics and its variability. The results display a time regime during which the prevalence exhibits a large sensitivity to noise. We also investigate the dependence of the infection time on nodes' degree and distance to the seed. In particular, we show that the infection time of hubs have large fluctuations which limit their reliability as early-detection stations. Finally, we discuss the effect of the multiplicity of shortest paths between two nodes on the infection time. Furthermore, we demonstrate that the existence of even longer paths reduces the average infection time. These different results could be of use for the design of time-dependent containment strategies

A Robinson characterization of finite PσTP\sigma T-groups

Let $\sigma =\{\sigma_{i} | i\in I\}$ be some partition of the set of all primes $\Bbb{P}$ and let $G$ be a finite group. Then $G$ is said to be $\sigma$-full if $G$ has a Hall $\sigma _{i}$-subgroup for all $i$. A subgroup $A$ of $G$ is said to be $\sigma$-permutable in $G$ provided $G$ is $\sigma$-full and $A$ permutes with all Hall $\sigma _{i}$-subgroups $H$ of $G$ (that is, $AH=HA$) for all $i$. We obtain a characterization of finite groups $G$ in which $\sigma$-permutability is a transitive relation in $G$, that is, if $K$ is a ${\sigma}$-permutable subgroup of $H$ and $H$ is a ${\sigma}$-permutable subgroup of $G$, then $K$ is a ${\sigma}$-permutable subgroup of $G$.Comment: 15 pages. arXiv admin note: text overlap with arXiv:1704.0250

Adult Vaccination Strategies for the Control of Pertussis in the United States: An Economic Evaluation Including the Dynamic Population Effects

BACKGROUND: Prior economic evaluations of adult and adolescent vaccination strategies against pertussis have reached disparate conclusions. Using static approaches only, previous studies failed to analytically include the indirect benefits derived from herd immunity as well as the impact of vaccination on the evolution of disease incidence over time. METHODS: We assessed the impact of different pertussis vaccination strategies using a dynamic compartmental model able to consider pertussis transmission. We then combined the results with economic data to estimate the relative cost-effectiveness of pertussis immunization strategies for adolescents and adults in the US. The analysis compares combinations of programs targeting adolescents, parents of newborns (i.e. cocoon strategy), or adults of various ages. RESULTS: In the absence of adolescent or adult vaccination, pertussis incidence among adults is predicted to more than double in 20 years. Implementing an adult program in addition to childhood and adolescent vaccination either based on 1) a cocoon strategy and a single booster dose or 2) a decennial routine vaccination would maintain a low level of pertussis incidence in the long run for all age groups (respectively 30 and 20 cases per 100,000 person years). These strategies would also result in significant reductions of pertussis costs (between -77% and -80% including additional vaccination costs). The cocoon strategy complemented by a single booster dose is the most cost-effective one, whereas the decennial adult vaccination is slightly more effective in the long run. CONCLUSIONS: By providing a high level of disease control, the implementation of an adult vaccination program against pertussis appears to be highly cost-effective and often cost-saving

Quantitative assessment of preventive behaviors in France during the Fukushima nuclear crisis.

BACKGROUND: The Fukushima nuclear disaster has generated worldwide concern on the risk of exposure to nuclear radiations. In Europe, health authorities had to issue statements about the lack of usefulness of iodine based preventive treatments within their borders. However a lack of confidence in official messages has developed in various European countries due to recent perceived failures in managing public health crises. The lay population preventive behaviors in this context are largely unknown. Consequently, to examine the effects of public health crisis on lay behaviors leading to pharmaceuticals purchases, we studied the sales of iodine-based products in France before, during and after the crisis. METHODS: We focused our study on 58 iodine-based drugs available with and without a physician prescription. Our data came from a stratified sample of 3004 pharmacies in metropolitan France. Our study period was from January 2010 to April 2012, with a focus on March-April 2011. We differentiated sales of drugs prescribed by physicians from sales of drugs obtained without a prescription. We used a CUSUM method to detect abnormal increases in sales activity and cross-correlations to assess shifts in sales timing. RESULTS: Sales of iodine-based nutritional complements, and later sales of iodine-based homeopathic remedies, substantially increased (up to 3-fold) during a period of 20 days. Their temporal patterns were correlated to specific events during the crisis. Prescriptions for iodine-based homeopathy increased (up to 35% of all sales). Iodine pills, strictly regulated by health authorities, have also been sold but on a very small scale. CONCLUSION: These results indicate uncontrolled preventive behaviors resulting in the potentially unjustifiable consumption of available drugs. They have implications in public policy, and demonstrate the usefulness of drug sales surveillance for instantaneous evaluation of population behavior during a global crisis

Networks characteristics of the French healthcare networks.

<p>Networks characteristics of the French healthcare networks.</p

Comparison between 2009–2010 observed acute diarrhea incidence and the expected incidence estimated from previous years (2004–2009) in France.

<p>Low and high incidence scenarios are given by the bound of bootstrapped 95% confidence interval. The studied period is divided in two sub-periods, before and after the week 52 when the observed and expected incidences intersect.</p

Healthcare facility types among the general, suspected-HAI, and HAI-specific networks and their hub hospitals.

<p>Healthcare facility types among the general, suspected-HAI, and HAI-specific networks and their hub hospitals.</p

Regional clustering of communities detected with greedy algorithm.

<p>Network hospitals and patient trajectories of the healthcare network in France of (a) the general healthcare network, (b) the suspected-HAI healthcare network, and (c) the HAI-specific healthcare network. In the general healthcare network, 18 communities were detected by the community clustering algorithm. Four of the 18 communities identified by the algorithm combine hospitals from two regions each, such that the 22 geographical regions are mapped into 18 communities. The original 22 French metropolitan regions before they were reformed to 13 regions implemented in 2016 are shown to correspond to the 2014 data. For the HAI-specific and suspected-HAI networks, the algorithm detected a higher number of communities (36 and 21 communities respectively). The communities, which overlapped the same regional communities in the general network, were given the same color and the newly detected communities were given different colors.</p