Seasonality and adaptive dynamics in host-parasite systems in wildlife

I parametri ecologici sono solitamente difficili da stimare nella fauna selvatica, ma, nel caso di malattie infettive, il tasso di trasmissione del patogeno è il processo più complesso da valutare. Tra i tratti caratteristici dell’ospite la taglia corporea è sicuramente il più influente, in quanto molti parametri demografici scalano allometricamente con essa. In questo lavoro ho mostrato come le relazioni allometriche possono legare la taglia dell’ospite al tasso di trasmissione della malattia e al suo tasso netto di riproduzione. Quindi ho analizzato come le dinamiche epidemiologiche variano in funzione della taglia. Inoltre, sotto le stesse ipotesi, ho studiato l’effetto della variazione stagionale di parametri come tasso di trasmissione e natalità, sulla dinamica della malattia. Per quanto riguarda il controllo dell’infezione, ho analizzato l’effetto di politiche di abbattimento in diverse condizioni ecologiche. In particolare, mi sono concentrato sull’efficacia del controllo in presenza di ceppi a diversa virulenza e in presenza di struttura d’età nella popolazione ospite. In entrambi i casi ho trovato che esistono determinate condizioni ecologiche per cui una politica di eradicazione della malattia basata sull’abbattimento può avere conseguenze peggiori dell’alternativa zero. Ho inoltre mostrato in quali condizioni semplici politiche di abbattimento tempo-variante possono migliorare significativamente il controllo della malattia.Ecological parameters are usually hard to estimate correctly in wild populations, but, in the case of infectious diseases, the rate of transmission of the pathogen agent is often the most complex process to evaluate. Of the many traits characterizing host species demography, body size is probably the most influential one, as many demographic parameters scale allometrically with host body size. In this work I show how the allometric relationships, usually found for demographic parameters, may link host body size with the disease transmission rate and its basic reproduction number. Then, I analysed the effect of seasonal variation in different ecological and epidemiological parameters on disease dynamics. Under the point of view of disease control, I analysed the effectiveness of depopulation policies in different ecological conditions. In particular, I focused on control effectiveness when strains with different virulence co-circulate in the host population and when disease transmission is a function of the age/stage class of the host individuals. In both cases, I found that (under certain conditions) culling policies may perform worse, in terms of disease control, than the do-nothing alternative. I also show in which conditions simple time-variant control policies can improve disease control in wildlife

Enhancement of Aedes albopictus collections by ovitrap and sticky adult trap

Abstract Background: In the last decades, Aedes albopictus has become an increasing public health threat in tropical as well as in more recently invaded temperate areas due to its capacity to transmit several human arboviruses, among which Dengue, Chikungunya and Zika. Enhancing the efficiency of currently used collection approaches, such as ovitraps and sticky traps, is desirable for optimal monitoring of the species abundance, for assessment of the risk of arbovirus transmission and for the optimisation of control activities. Findings: Two sets of 4 × 4 Latin-square experiments were carried out in Tirana (Albania) to test whether modifications in ovitrap shape and size and in oviposition substrate would increase collections of Ae. albopictus eggs and whether hay-infusion would increase adult catches by sticky trap. Generalized Linear Mixed Models with negative binomial error distribution were carried out to analyse the data. Cylindrical ovitraps lined with germination paper yielded significantly higher egg catches than those exploiting either the (commonly used) wooden paddles or floating polystyrene blocks as oviposition substrates. No difference was observed between cylindrical and conical shaped ovitraps. Ovitraps and sticky traps baited with hay infusion yielded significantly higher egg and adult catches than un-baited ones. A significant relationship between ovitrap and sticky trap catches was observed both in the absence and in the presence of attractants, with ovitrap catches increasing more than sticky trap catches at increasing adult female densities. Conclusions: This study provides grounds for optimisation of ovitraps and sticky traps as monitoring tools for Ae. albopictus by (i) supporting use of germination paper as most appropriate oviposition substrate; (ii) suggesting the possible use of stackable conical ovitraps for large scale monitoring; (iii) confirming the use of hay-infusion to increase egg catches in ovitraps, and showing that hay-infusion also significant increases adult catches by sticky traps

Geographical restriction of Hepatitis E virus circulation in wild boars (Sus scrofa) in Emilia-Romagna region, Northern Italy

Hepatitis E virus (HEV) is a single‐strand RNA virus that causes an acute viral hepatitis in humans. Among its eight recognized genotypes, HEV-3 and HEV-4 are zoonotic, infecting humans, pigs and feral pigs. Recently, HEV-3 has been also detected in red deer, which represents another reservoir of HEV. Consumption of raw pork products (mainly liver sausages), undercooked wild boar meat, raw wild boar liver and deer meat has been responsible for foodborne HEV human worldwide. From November 2018 to March 2019, liver samples collected from 97 wild boars hunted in Emilia-Romagna region (Northern Italy) were tested for HEV RNA. The hunting area included two territories for an extension of 33 km2, named A (about 13 km2, natural park, deciduous wood) and B (about 20 km2, cultivated fields in proximity of a river) areas. Distance between the two areas ranged between 8 to 10 km. A total of 73 wild boars were hunted in area A, and 24 in area B. HEV RNA was detected by Real‐time RT–PCR in 23/73 liver samples of wild boars living in area A only (31.5% - 95% CI: 22.0-42.8%). The HEV sequences (n=13) clustered within genotype 3. The majority of positives belonged to animals < 12 months (12/25; 48%), followed by subadults (13-24 months) (7/16; 43.8%) and adults (4/32; 12.5%). This difference was found to be statistically significant (p = 0.0024). In absence of pig farms, the restriction of HEV-positive animals to a well-defined territory of 13 km2 (Boschi di Carrega Regional Park) could hypothetically be related to the presence of red deer (Cervus elaphus), which lived in area A at the beginning of the hunting season. Further studies are needed to confirm or deny our hypothesis

Gabapentin affects the expression of inflammatory mediators on healthy gingival cells

Gabapentin is one of the most used drugs to treat postoperative pain with antihyperalgesic properties and has a unique mechanism of action, which differentiates it from other commonly used drugs. Various studies have shown that the perioperative use of gabapentin reduces postoperative pain. In our study, fragments of gingival tissue of healthy volunteers were collected during operation. Gene expression of 29 genes was investigated in gingival fibroblasts cell culture treated with gabapentin, compared with untreated cells. Of the different chemokines and interleukins studied, only 10 were statistically significant (CCL1, CCR1, CCR4, CCR5, CCR6, ILI1A, ILI1B, IL5, IL6R, TNFSF10). The overexpression of these cytokines, obtained in many studies, leads us to think that gabapentin can interact and cause post-inflammatory gingival hyperplasia, but, probably, in our study the gabapentin has not the same effect, because we used gingival fibroblasts of healthy peopl

La realcalinización y la extracción electroquímica de los cloruros en las construcciones de hormigón armado

Realkalisation and electrochemical chloride removal techniques, developed for rehabiliting carbonated and chloride-containing structures, are presented. Electrolysis and electromigration mechanisms and consequences as well as electrochemical conditions at the reinforcement surface are discussed and compared with cathodic protection ones. Furthermore, possible side effects are commented. Se presentan técnicas electroquímicas de realcanización y extracción de cloruros, desarrolladas con el fin de rehabilitar estructuras carbonatadas y que contengan cloruros. Se discuten y comparan los mecanismos y consecuencias de la electrólisis y la electromigración, así como las condiciones electroquímicas en la superficie de las armaduras con los de protección catódica. Se comentan, también, los posibles efectos secundarios