Detecting nested clusters of human alveolar echinococcosis

Abstract

Recent changes in the epidemiology of alveolar echinococcosis (AE) in Eurasia have led to increasing concerns about the risk of human AE and the need for a thorough evaluation of the epidemiological situation. The aim of this study was to explore the use of a National Register to detect complex distribution patterns on several scales. The data were human AE cases from the FrancEchino register, diagnosed in France from 1982 to 2011. We used the Kulldorff spatial scan analysis to detect non-random locations of cases. We proposed an exploratory method that was based on the successive detection of nested clusters inside each of the statistically significant larger clusters. This method revealed at least 4 levels of disease clusters during the study period. The spatial variations of cluster location over time were also shown. We conclude that National Human AE registers, although not exempted from epidemiological biases, are currently the best way to achieve an accurate representation of human AE distribution on various scales. Finally, we confirm the multi-scale clustered distribution of human AE, and we hypothesize that our study may be a reasonable starting point from which to conduct additional research and explore the processes that underlie such distributions.

Support for targeted sampling of red fox (Vulpes vulpes) feces in Sweden: a method to improve the probability of finding Echinococcus multilocularis

“…Such micro-foci are considered as high risk areas for E. multilocularis transmission to suitable rodents and possibly also for humans. Increased incidence of human alveolar echinococcosis has been documented in areas with foci of highly infected definitive and intermediate host species [12], and these human cases can also be clustered into foci of infection [37]. Although there have been no autochthonous human cases in Sweden [38] and the estimated prevalence E. multilocularis in of foxes in Sweden is very low (0.1%) [4, 38, 39], the presence of such micro-foci suggest a need for continued research and monitoring for this parasite in Sweden.…”

Echinococcus multilocularis infection in animals

“…Approximate working intensity per person per day (according to Conraths and Deplazes, 2015):  Conventional-PCR or Multiplex-PCR withsieving procedure for egg isolation from faeces: 40-80 samples depending on taeniid prevalence (for procedures see Mathis et al, 1996;Trachsel et al, 2007);  Nested-PCR for total DNA isolation from faeces: around 70 samples (for procedures see Monnier et al, 1996;Dinkel et al, 1998;Van der Giessen et al, 1999);  Real Time-PCR for total DNA isolation from faeces: 70 samples (for procedures see Dinkel et al, 2011;Knapp et al, 2013);  MC-PCR with manual DNA fishing from faeces: 70 samples (for procedures see ;  MC-PCR with automated DNA fishing from faeces: 240 samples (for procedures see Isaksson et al, 2014).…”

On the Synergistic Use of Optical and SAR Time-Series Satellite Data for Small Mammal Disease Host Mapping

“…A neglected zoonotic disease, HAE is responsible for a significant burden of human disease across continental Asia, and is expanding in the prevalence and range in Europe, North America, and Asia [4][5][6]. In China and central Asia, HAE prevalence in humans can exceed 10% locally [7][8][9] even though geographical patterns are highly variable, as elsewhere in the world [10]. The reasons for this variability are unknown.…”

“…However, resources are limited and implementation lacks appropriate geographical targeting, which reduces the effectiveness of these measures. humans can exceed 10% locally [7][8][9] even though geographical patterns are highly variable, as elsewhere in the world [10]. The reasons for this variability are unknown.…”