Taylor's Law Detects and Interprets Temporal Trends of the Spatial Distribution of Covid-19 Daily Infection Density Across Italian Provinces

Background: Taylor’s law, which formulates a power-law relationship between the variance and the mean, is used to assess the convergence over time to the spatial uniformity of the density of new infections in Italian provinces during the Covid-19 pandemic.Methods: Using the frequency of the number of new daily COVID 19 infections in the 110 Italian provinces during the period from 25 February 2020 to 15 March 2021, we estimated Taylor's Law using a system of simultaneous equations in five time sub-periods.Results: The infection in Italy initially manifested itself almost exclusively in a few provinces in the north and was very intense. Within a month, the infection spread to the whole country, with varying intensity between provinces. Subsequently, partly as a result of the introduction of containment measures or their relaxation, the infection manifested itself in different ways depending on both the time frame and the geographical area.Conclusions: Our results show that Taylor’s law fits well the temporal dynamics of infection density and can therefore be considered as a useful tool to predict the spatial variability of the Covid-19 infection density. Its slope parameter reflects the temporal correlation of infection density and the effect of nationwide lockdown on the disease spread through the lens of two stochastic population growth models. Our finding suggests that Taylor's law may be used to monitor the Covid-19 outbreak development and to predict the spatial spread of the infection density in the Italian provinces in successive pandemic waves of Covid-19.

Interactions Between Tsetse Endosymbionts and Glossina pallidipes Salivary Gland Hypertrophy Virus in Glossina Hosts

Tsetse flies are the sole cyclic vector for trypanosomosis, the causative agent for human African trypanosomosis or sleeping sickness and African animal trypanosomosis or nagana. Tsetse population control is the most efficient strategy for animal trypanosomosis control. Among all tsetse control methods, the Sterile Insect Technique (SIT) is one of the most powerful control tactics to suppress or eradicate tsetse flies. However, one of the challenges for the implementation of SIT is the mass production of target species. Tsetse flies have a highly regulated and defined microbial fauna composed of three bacterial symbionts (Wigglesworthia, Sodalis and Wolbachia) and a pathogenic Glossina pallidipes Salivary Gland Hypertrophy Virus (GpSGHV) which causes reproduction alterations such as testicular degeneration and ovarian abnormalities with reduced fertility and fecundity. Interactions between symbionts and GpSGHV might affect the performance of the insect host. In the present study, we assessed the possible impact of GpSGHV on the prevalence of tsetse endosymbionts under laboratory conditions to decipher the bidirectional interactions on six Glossina laboratory species. The results indicate that tsetse symbiont densities increased over time in tsetse colonies with no clear impact of the GpSGHV infection on symbionts density. However, a positive correlation between the GpSGHV and Sodalis density was observed in Glossina fuscipes species. In contrast, a negative correlation between the GpSGHV density and symbionts density was observed in the other taxa. It is worth noting that the lowest Wigglesworthia density was observed in G. pallidipes, the species which suffers most from GpSGHV infection. In conclusion, the interactions between GpSGHV infection and tsetse symbiont infections seems complicated and affected by the host and the infection density of the GpSGHV and tsetse symbionts.

Mosquito Control Based on Pesticides and Endosymbiotic Bacterium Wolbachia

Mosquito-borne diseases, such as dengue fever and Zika, have posed a serious threat to human health around the world. Controlling vector mosquitoes is an effective method to prevent these diseases. Spraying pesticides has been the main approach of reducing mosquito population, but it is not a sustainable solution due to the growing insecticide resistance. One promising complementary method is the release of Wolbachia-infected mosquitoes into wild mosquito populations, which has been proven to be a novel and environment-friendly way for mosquito control. In this paper, we incorporate consideration of releasing infected sterile mosquitoes and spraying pesticides to aim to reduce wild mosquito populations based on the population replacement model. We present the estimations for the number of wild mosquitoes or infection density in a normal environment and then discuss how to offset the effect of the heatwave, which can cause infected mosquitoes to lose Wolbachia infection. Finally, we give the waiting time to suppress wild mosquito population to a given threshold size by numerical simulations.

Comparative Analysis of Features of Epizootiological and Epidemic Situation and Risk of Rabies Infection in the Russian Federation in Early XXI Century

The review provides an analysis of the current rabies epidemic situation in the Russian Federation and describes the dynamics of epizootic indicators, such as the epizootic index and infection density. The risk of rabies infection and the characteristics of the epizootic process in various regions of the country were studied. In 2012–2018 in comparison with 2000–2011, a 1.5–fold decrease in the activity of the epizootic process was noted, despite the expansion of the virus areal. The decrease in human hydrophobia morbidity in reference to the long-term average of 3–5 times was revealed. An increase in the value of the dog, cat and raccoon dog in human infection and a decrease of the fox role in this process have been established. The risk of rabies infection remained in almost all regions of the country. During 2012–2018 safe regions were the Arkhangelsk, Murmansk, Irkutsk, Sakhalin, Kamchatka Territory. In the Kaliningrad Region, animal cases have stopped since 2013 due to the successful use of oral vaccination of wild predators as an effective method of combating natural foci of rabies. In 2019, 3 lethal cases of lissavirus infection were recorded: two after bat bites in the Amur Region and Primorsky Territory, and one in the Moscow Region imported from Tajikistan after a dog bite. Typical cases of rabies in Russia associated with terrestrial mammals were not detected in 2019.

Remarkable Histopathological Improvement of Experimental Toxoplasmosis Treated with Spiramycin-loaded Chitosan Nanoparticles

The present study investigated the anti-Toxoplasma effect of chitosan nanoparticles [CS NPs], spiramycin, spiramycin co-administered with metronidazole and spiramycin-CS NPs formulation on the parasite burden and histopathological changes in the liver, spleen and brain in experimentally infected mice. Seventy male Swiss albino mice were classified into seven equal groups: healthy control (I), infected untreated control (II), infected group receiving CS NPs (III), spiramycin administered infected group (IV), infected group receiving spiramycin-metronidazole (V), infected receiving 400 mg/kg spiramycin-CS NPs (VI) and infected treated with spiramycin-loaded CS NPs 100 mg/kg (VII). All groups were inoculated intraperitoneally with 2500 T. gondii tachyzoites RH strain except the healthy control group. All groups were sacrificed on the 8th day after infection. Density of the parasite and histopathological examination of the liver, spleen and brain of all treated mice revealed reduction in the mean tachyzoites count as well as decreased inflammation, congestion and necrosis within tissue sections. Spiramycin-loaded NPs displayed the highest significant reduction in the pathological insult tailed by spiramycin-metronidazole and CS NPs. In conclusion, spiramycin-loaded CS NPs showed a promising synergistic combination in the treatment of the histopathology caused by toxoplasmosis.

Variability of phytoplasma infection density in poinsettia and evaluation of its association with the level of branching in host plants

It has long been established that phytoplasma infection is the cause of the free-branching phenotype in poinsettia. However, relatively limited is known about the ecology of the pathogen in planta. The present study evaluated the infection pattern of poinsettia branch-inducing phytoplasma (PoiBI) and its association with poinsettia phenotype during cutting propagation. The presence of this pathogen in the poinsettia variety 'Luv U Pink' was determined using polymerase chain reaction (PCR) and sequence analysis. The infection density of PoiBI in distinct tissue types of different plant segments were then determined using quantitative PCR coupled with plasmid-based standard curves. Both vegetative stage and flowering stage plants were tested. The results showed that despite being considerably variable among plants, the infection densities of PoiBI tend to be higher in source leaves located in the lower parts of the plant. The densities were consistently lower in tissues located at the top of the plants, regardless of the tissue type. Analysis on the infection densities among samples collected from six stock plants used in commercial production also revealed significantly different levels of PoiBI load. An association between PoiBI infection density in the stock plants and the level of branching in cutting-propagated plants (derived from the stock plants) was also observed; stock plants with low infection densities tend to produce smaller proportions of plants exhibiting higher degrees of branching both before and after pinching. These data suggest that uneven distribution of PoiBI within and among stock plants may lead to the production of cuttings with variable phytoplasma densities, which may in turn affect the phenotypic uniformity of the plants produced. Overall, findings from the present work add to the understanding of PoiBI’s ecology and could provide implications to commercial poinsettia production.

Pneumonia and the role of dentistry on ICU Staff

Ventilator-associated pneumonia (VAP) is one ofthe most prevalent healthcare-associated infections (HAI) andcauses of death in intensive care units (ICUs), and studies haveshown its relation to oral health. Aim: To report the impact ofthe incorporation of dental professionals into multidisciplinaryICU staff on the incidence of VAP. Methods: A retrospectiveobservational study was carried out to collect and analyzehealth indicators of patients in the ICUs from 2011 to 2018 andto differentiate these indicators between the periods beforeand after the participation of dental staff in the ICU. This studywas approved by the Research Ethics Committee. Results:The average number of monthly ICU admissions was 105.89 ±169.72, and the discharge was 105.21 ± 168.96, with a monthlyaverage number of deaths within 24 h of 38.61 ± 62.27. Theaverage number of monthly HAI-related deaths decreasedfrom 2011 to 2018, followed by a reduction in cases of HAIper month. The average monthly number of HAIs relatedto mechanical ventilation (MV) decreased, and the samewas observed for the infection density of HAIs related to MV(p < 0.001). In multivariate analysis, there was a significantdecrease in the number of HAIs related to MV (p = 0.005).Conclusion: Although a reduction in the number of admissionsor complexity of cases was not observed in the study period,multidisciplinary staff practices were essential for controllingHAIs and the presence of dental professionals can assist in thecontrol of HAIs related to MV.

Phylogeny and Density Dynamics of Wolbachia Infection of the Health Pest Paederus fuscipes Curtis (Coleoptera: Staphylinidae)

The maternally inherited obligate intracellular bacteria Wolbachia infects the reproductive tissues of a wide range of arthropods and affects host reproduction. Wolbachia is a credible biocontrol agent for reducing the impact of diseases associated with arthropod vectors. Paederus fuscipes is a small staphylinid beetle that causes dermatitis linearis and conjunctivitis in humans when they come into contact with skin. Wolbachia occur in this beetle, but their relatedness to other Wolbachia, their infection dynamics, and their potential host effects remain unknown. In this study, we report the phylogenetic position and density dynamics of Wolbachia in P. fuscipes. The phylogeny of Wolbachia based on an analysis of MLST genotyping showed that the bacteria from P. fuscipes belong to supergroup B. Quantitative PCR indicated that the infection density in adults was higher than in any other life stage (egg, larva or pupa), and that reproductive tissue in adults had the highest infection densities, with similar densities in the sexes. These findings provide a starting point for understanding the Wolbachia infection dynamics in P. fuscipes, and interactions with other components of the microbiota.