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Emerging and re-emerging spotted fever group (SFG) rickettsioses are increasingly recognised worldwide as threats to public health, yet their global distribution and associated risk burden remain poorly understood.In this systematic review and modelling analysis, we mapped global distributions of all confirmed species of SFG rickettsiae (SFGR) detected in animals, vectors, and human beings, using data collected from the literature. We assessed ecological drivers for the distributions of 17 major SFGR species using machine learning algorithms, and mapped model-predicted risks.Between Jan 1, 1906, and March 31, 2021, we found reports of 48 confirmed SFGR species, with 66 133 human infections worldwide, with a large spatial variation across the continents. 198 vector species were detected to carry 47 of these Rickettsia spp. (146 ticks, 24 fleas, 15 mosquitoes, six mites, four lice, two keds, and one bug). Based on model-predicted global distributions of the 17 major SFGR species, we found five spatial clusters aggregated by ecological similarity in terms of environmental and ecoclimatic features. Rickettsia felis is the leading SFGR species to which 4·4 billion (95% CI 3·8-5·3 billion) people are at risk, followed by Rickettsia conorii (3·7 billion) and Rickettsia africae (3·6 billion).The wide spectrum of vectors is contributing substantially to the increasing incidence of SFGR infections among humans. Awareness, diagnosis, and surveillance of SFGR infections should be improved in the high-risk regions, especially in areas where human infections are underreported.National Key Research and Development Program of China.

Background Viral pathogens belonging to the order Bunyavirales pose a continuous background threat to global health, but the fact remains that they are usually neglected and their distribution is still ambiguously known. We aim to map the geographical distribution of Bunyavirales viruses and assess the environmental suitability and transmission risk of major Bunyavirales viruses in China. Methods We assembled data on all Bunyavirales viruses detected in humans, animals and vectors from multiple sources, to update distribution maps of them across China. In addition, we predicted environmental suitability at the 10 km × 10 km pixel level by applying boosted regression tree models for two important Bunyavirales viruses, including Crimean-Congo hemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV). Based on model-projected risks and air travel volume, the imported risk of RVFV was also estimated from its endemic areas to the cities in China. Results Here we mapped all 89 species of Bunyavirales viruses in China from January 1951 to June 2021. Nineteen viruses were shown to infect humans, including ten species first reported as human infections. A total of 447,848 cases infected with Bunyavirales viruses were reported, and hantaviruses, Dabie bandavirus and Crimean-Congo hemorrhagic fever virus (CCHFV) had the severest disease burden. Model-predicted maps showed that Xinjiang and southwestern Yunnan had the highest environmental suitability for CCHFV occurrence, mainly related to Hyalomma asiaticum presence, while southern China had the highest environmental suitability for Rift Valley fever virus (RVFV) transmission all year round, mainly driven by livestock density, mean precipitation in the previous month. We further identified three cities including Guangzhou, Beijing and Shanghai, with the highest imported risk of RVFV potentially from Egypt, South Africa, Saudi Arabia and Kenya. Conclusions A variety of Bunyavirales viruses are widely distributed in China, and the two major neglected Bunyavirales viruses including CCHFV and RVFV, both have the potential for outbreaks in local areas of China. Our study can help to promote the understanding of risk distribution and disease burden of Bunyavirales viruses in China, and the risk maps of CCHFV and RVFV occurrence are crucial to the targeted surveillance and control, especially in seasons and locations at high risk. Graphical abstract

Emerging vector-borne pathogens (VBPs) pose a continuous background threat to the global health. Knowledge of the occurrence, distributions and epidemiological characteristics of VBP are lacking in many countries. Outbreaks of novel VBP are of increasing global interest including those arising in China.A systematic review of published literature was undertaken to characterize the spectrum of VBPs causing human illness in China. We searched five databases for VBP-related articles in English and Chinese published between January 1980 and June 2021, that excluded those listed in the National Notifiable Diseases Surveillance System of China. The study is registered with PROSPERO, CRD42021259540.A total of 906 articles meeting the selection criteria were included in this study. A total of 44,809 human infections with 82 species of VBPs including 40 viruses, 33 bacteria (20 Rickettsiales bacteria, eight Spirochaetales bacteria, and five other bacteria) and nine parasites, were identified in China. Rickettsiales bacteria were the most common and widely distributed pathogens with 18,042 cases reported in 33 provinces by 347 reviewed articles, followed by Spirochaetales bacteria with 15,745 cases in 32 provinces (299 articles), viruses with 8455 cases in 30 provinces (139 articles), other bacteria with 2053 cases in 19 provinces (65 articles), parasites with 514 cases in 17 provinces (44 articles), and multiple pathogens with 3626 cases in 14 provinces (23 articles).This review helps improve the understanding of VBPs in China, demonstrating the need to consider a wider surveillance of VBPs in many different settings, thus helping to inform future research and surveillance efforts.Natural Science Foundation of China.

One concern about the use of transgenic plants is their potential risk to natural enemies. In this study, using the eggs of the rice brown planthopper, Nilaparvata lugens, as a food source, we investigated the effects of Cry1Ab rice on the biological characteristics and functional response of an important predator Cyrtorhinus lividipennis. The results showed that the survival ability (adult emergence rate and egg hatching rate), development (egg duration, nymphal developmental duration), adult fresh weight, adult longevity and fecundity of C. lividipennis on Bt rice plants were not significantly different compared to those on non-Bt rice plants. Furthermore, two important parameters of functional response (instantaneous search rate and handling time) were not significantly affected by Bt rice. In conclusion, the tested Cry1Ab rice does not adversely impact the biological character and functional response of C. lividipennis.

An in vivo animal model of bone adaptation was used to examine a possible role for matrix metalloproteinase-1 in the local mediation of bone remodeling: to corrode the coupling of osteocytes to the matrix in an attempt to autoregulate the cell's perception of its mechanical environment. Twelve young (12-16 months old) skeletally mature turkeys were separated into groups to be studied for stimulus periods of either 3 or 30 days. In each animal, the left ulna was functionally isolated and subjected to either disuse or 3,000 microstrain at 1 Hz for 10 minutes per day. The right ulna remained intact and served as an intra-animal control. No significant differences in bone area were detected at 3 days; however, ulnae subjected to disuse lost 8 +/- 4% (+/-SD) of bone area by 30 days. Over the same period, ulnae subjected to the mechanical stimulus gained 21 +/- 9% of bone area. With use of in situ reverse transcription-polymerase chain reaction, less than 2% of the osteocytes examined from the intact control ulnae stained positively for matrix metalloproteinase-1 mRNA. An antibody raised against matrix metalloproteinase-1 revealed no positively labeled osteocytes in the intact ulnae. This low percentage of osteocytes expressing matrix metalloproteinase-1 mRNA was similar to that seen in ulnae subjected to the osteogenic mechanical stimuli. In contrast, ulnae subjected to either 3 or 30 days of disuse showed evidence of matrix metalloproteinase-1 mRNA activity in a high percentage of osteocytes (89 +/- 5 and 66 +/- 8%, respectively; each time point significantly different from intact ulnae, as well as from each other, p < 0.05). The percentage of osteocytes labeled with the anti-matrix metalloproteinase-1 antibody was also highly elevated following 3 days of disuse (74 +/- 17%). These data demonstrate that an early response of bone to disuse is the upregulation of matrix metalloproteinase-1 activity in osteocytes. It is proposed that this upregulation of collagenase activity is indicative of the cell's degradation of coupling to the matrix, and it thus reflects the osteocyte's regulation of its own mechanical environment. We believe that such autoregulation of the osteocyte's physical environment will accommodate subtle changes in the bone's functional environment without the need to add or resorb bone tissue.

Reverse transcript polymerase chain reaction (RT-PCR) was developed for use in situ to measure mechanically mediated changes in gene expression activity in osteocytes within dense cortical bone. Using the functionally isolated turkey ulna model of bone adaptation, the left ulna of 6 old adult (36-40 months) male turkeys were subject to 4 weeks of a mechanical regimen consisting either of (1) 3000 microstrain at 1 Hz for 5 minutes/day or (2) 500 microstrain at 30 Hz for 10 minutes/day. The right ulna of each bird remained intact and served as control. Only a small percentage of osteocytes in the intact control bones and the 3000 microstrain ulnae showed any evidence of mRNA for collagen (each 1.2% +/- 0.3%). However, mRNA for collagen type I was strongly evident in 92.4% (+/-2%) of the osteocytes within the ulnae subject to the high frequency, low magnitude load. Sense primer control sections from both experimental and intact animals were used to verify that only osteocytes of the loaded bone had elevated the level of collagen mRNA. This high frequency, low magnitude mechanical stimulus was also sufficient to stimulate substantial new bone formation (14% +/- 5% over intact controls), whereas the low frequency, high magnitude stimulus failed to elicit any bone formation (-3% +/- 7%). These experiments show that specific mechanical regimens can activate the osteocyte's expression of a message responsible for the synthesis of proteins remote from the site where the formation of bone is ultimately to occur, even under systemic distress such as aging. Further, these data suggest that osteocytes perceive the strain environment and that they play a role in orchestrating the modeling/remodeling response. By developing a technique as flexible and powerful as RT-PCR for use in dense cortical bone, determining the relative contribution of specific proteins to the transduction of regulatory signals to formative or resorptive responses is facilitated.

The surgical treatment of comminuted die-punch patellar fracture can be challenging. Anatomic reduction and stable fixation can be achieved using an appropriate operative technique.

The discovery of growth factors, such as osteogenic growth peptide (OGP), that stimulate bone formation led to experiments to discover whether they can accelerate fracture healing. To determine whether OGP enhances the rate of healing in rabbits, fractures were made in the tibiae of New Zealand White rabbits and immobilized with either a plastic plate (unstable mechanical conditions), or a dynamic compression plate (stable mechanical conditions). OGP was administered to experimental animals by intravenous injection from day 4 until the day before sacrifice; control animals were not injected. After treatment with OGP, callus development under unstable mechanical conditions was accelerated. At 7 days, the cartilage in the centre of the callus was covered by bone and endochondral ossification had started; these events occur at 10 days in control fractures. Subsequently, endochondral ossification is completed earlier which allows the invasion of the fracture gap by cells, so that cortical union is complete by 21 to 28 days. In control fractures, bone is only beginning to form in the gaps at 28 days. There was no increase in the size of the callus in any of the experimental fractures compared to the untreated controls. Treatment with OGP has no observable effect on the rate of healing of fractures under stable mechanical conditions. These observations suggest that under unstable mechanical conditions only, the rate of callus formation and subsequent cortical healing is enhanced by treatment with OGP, but that the size of the callus is determined by mechanical and other factors.