Distribution characteristics and diversity of myxomycetes in three parallel rivers in Yunnan, China

Three Parallel Rivers is one of the world's biodiversity hotspots. However, the research on myxomycetes diversity is scarce in this area. Random sampling was used to investigate myxomycetes' diversity and distribution characteristics in this area. One hundred and seventeen species, including three varieties, were obtained, belonging to 28 genera, nine families, and six orders, with Arcyria cinerea and Physarum viride being the dominant species. Moreover, four species and one variety were first reported in China. Twenty-six species and one variety were first reported in Yunnan Province. The species' most commonly utilized substrate for fruiting bodies was decaying wood, and Cribraria was the dominant genus. The species diversity was most abundant in mixed broadleaf-conifer forests. Species similarity between coniferous and broad-leaved forests was much higher than the pairwise comparison of other forest types. NMDS analysis shows that substrate and forest types had insignificant effects on myxomycetes communities, while river valley had a significant effect. The myxomycetes community similarity between river valleys is unrelated to geographical proximity.

Diagnostic performance of SPECT in lumbar spondylolysis: a systematic review and meta-analysis

AIM

To evaluate the diagnostic value and clinical applicability of single-photon-emission computed tomography (SPECT) for lumbar spondylolysis using meta-analysis.

MATERIALS AND METHODS

Stata 12.0, was used to test the heterogeneity, and the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and other effect sizes were collected to generate the summary receiver operating characteristic (SROC) curve for comprehensive evaluation. Meta-regression analysis was used to explore the source of heterogeneity, and subgroup analysis was performed. Funnel plots, Fagan's line diagrams, and likelihood ratio dot plots were drawn to evaluate publication bias and clinical applicability.

RESULTS

Eight studies involving 785 patients were included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, odds ratio, and area under the SROC curve of SPECT for the diagnosis of lumbar spondylolysis were 0.85 (95% confidence interval [CI]: 0.70 0.93), 0.92 (95% CI: 0.60 0.99), 11.01 (95% CI: 1.61 75.18), 0.17 (95% CI: 0.08 0.35), 0.92 (95% CI: 0.90 0.94). Meta-regression analysis showed that the sources of heterogeneity were region and age. Subgroup analysis showed that the specificity of the child and adolescent subgroup was significantly higher than that of the middle-aged and elderly subgroups. Deek's funnel plots showed no significant publication bias. The pooled effect of the likelihood ratio dot plot for diagnosis is in the upper-right quadrant.

CONCLUSION

As a diagnostic tool for spondylolysis, SPECT has a high degree of specificity, moderate sensitivity, and relatively high diagnostic effectiveness. It can be used as an auxiliary sign in the diagnosis and treatment of lumbar spondylolysis.

[Analysis of suspected occupational diseases cases and subsequent diagnosis follow-up investigation in Hubei Province from 2020 to 2021]

Objective: To understand the epidemiological characteristics of suspected occupational diseases cases, and to track the subsequent diagnosis of suspected cases in Hubei Province from 2020 to 2021, and to provide theoretical basis for the supervision of suspected occupational diseases. Methods: In April 2022, the data of suspected occupational diseases cases and occupational diseases in Hubei Province from 2020 to 2021 were collected by the Occupational Diseases and Health Risk Factors Information Surveillance System. The distribution and diagnosis of suspected occupational diseases cases were analyzed. We investigated undiagnosed suspected occupational diseases by telephone. Results: From 2020 to 2021, a total of 1872 cases of suspected occupational diseases in 6 categories and 18 species were reported in Hubei Province. The top three suspected occupational diseases were suspected occupational noise deafness (36.75%, 688/1872), suspected coal worker's pneumoconiosis (33.07%, 619/1872) and suspected silicosis (20.99%, 393/1872). The diagnosis rate of suspected occupational diseases was 33.60% (629/1872). The rate of confirmed diagnosis was 63.59% (400/629). The diagnosis rate (26.86%, 456/1698) and rate of confirmed diagnosis (55.48%, 253/456) of suspected occupational diseases detected by occupational health examination were the lowest. The diagnosis rate of suspected occupational diseases detected by comprehensive medical institutions and private medical institutions were lower than disease prevention and control institutions and occupational disease prevention center (P<0.05). The main reasons for not entering the diagnostic procedure included that workers were not informed that they were diagnosed as suspected occupational diseases (31.55%, 124/393), workers were unwilling to apply for occupational disease diagnosis (18.56%, 73/393), and some workers planned to apply for diagnosis but had not yet applied (10.69%, 42/393) . Conclusion: Occupational noise deafness, coal worker's pneumoconiosis and silicosis are the main diseases of suspected occupational diseases in Hubei Province. In order to increase the diagnosis rate and confirmed diagnosis rate of suspected occupational diseases, it is suggested to strengthen management and supervision from the aspects of case management, information warning and worker notification.

Gene Expression Analysis of Different Organs and Identification of AP2 Transcription Factors in Flax (Linum usitatissimum L.)

Flax (Linum usitatissimum L.) is an important oilseed crop widely cultivated for its oil and fiber. This study conducted transcriptome analysis to analyze the gene expression profiles of roots, leaves, stamens, pistils, and fruits in the flax cultivar Longya10. A total of 43,471 genes were detected in the RNA-seq data, with 34,497 genes showing differential expression levels between different organs. Gene expression patterns varied across different organs, with differences observed in expression-regulating genes within specific organs. However, 23,448 genes were found to be commonly expressed across all organs. Further analysis revealed organ-specific gene expressions, with 236, 690, 544, 909, and 1212 genes identified in pistils, fruits, leaves, roots, and stamens, respectively. Gene Ontology (GO) enrichment analysis was performed on these organ-specific genes, and significant enrichment was observed in various biological processes, cellular components, and molecular functions, providing new insights for the specific growth patterns of flax organs. Furthermore, we investigated the expression differences of AP2 transcription factors in various tissues and organs of Longya10. We identified 96 AP2 genes that were differentially expressed in different organs and annotated them into various biological pathways. Our results suggest that AP2 transcription factors may play important roles in regulating the growth and development of flax organs including stress response. In summary, our study provides a comprehensive analysis of gene expression patterns in different organs and tissues of flax plant and identifies potential critical regulators of flax organ growth and development. These findings contribute to a better understanding of the molecular mechanisms underlying flax organ development and may have important implications for the genetic improvement of flax crops.

Genome size and GC content of myxomycetes

More than 1272 myxomycetes species have been described, accounting for more than half of all Amoebozoa species. However, the genome size of only three myxomycetes species has been reported. Therefore, we used flow cytometry to present an extensive survey and a phylogeny-based analysis of genome size and GC content evolution in 144 myxomycetes species. The genome size of myxomycetes ranged from 18.7 Mb to 470.3 Mb, and the GC content ranged from 38.7% to 70.1%. Bright-spored clade showed larger genome sizes and more intra-order genome size variations than the dark-spored clade. GC content and genome size were positively correlated in both bright-spored and dark-spored clades, and spore size was positively correlated with genome size and GC content in the bright-spored clade. We provided the first genome size data set in Myxomycetes, and our results will provide helpful information for future Myxomycetes studies, such as genome sequencing.

Evaluation of Differentially Expressed Genes in Leaves vs. Roots Subjected to Drought Stress in Flax (Linum usitatissimum L.)

Drought stress is a common environmental challenge that plants face, severely constraining plant growth and reducing crop yield and quality. Several studies have highlighted distinct responses between monocotyledonous and dicotyledonous plants. However, the mechanisms underlying flax tolerance to abiotic stress, such as drought, remain unclear. In this study, we investigated the morphological, physiological, and biochemical characteristics and the genome-wide gene expression of oil flax and fiber flax in response to drought stress. The results revealed that drought stress caused significant wilting of flax leaves. Within the first 24 h of stress, various physiological and biochemical characteristics exhibited rapid responses. These included fresh weight, relative water content (RWC), proline, soluble protein, soluble sugar, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the leaves or roots of flax. Additionally, drought stress led to a significant rise in lignin content in fiber flax. In addition, the transcriptome analysis demonstrated genome-wide variations in gene expression induced by drought stress. Specifically, genes associated with photosynthesis, proline biosynthesis, and phytohormone metabolism exhibited significant differences in expression levels under stress conditions in flax. These findings highlight the rapid response of flax to drought stress within a short-term period. Our experiment also revealed that, although there were variations in the levels of small compound content or gene expression between Longya10 and Fany under drought stress, most stress-resistance responses were similar. Furthermore, the results provide additional evidence supporting the existence of mechanisms underlying the response to drought stress in plants.

A cryogenic ion trap for single molecule vibrational spectroscopy

We report on an ion trapping system for performing a novel form of cryogenic messenger spectroscopy with single molecule sensitivity. The system features a cryogenic radio-frequency ion trap loaded with single analyte molecules via a quadrupole mass filter. We demonstrate the ability to controllably attach inert gas particles to buffer gas cooled, trapped molecular ions. Sympathetic cooling by co-trapped, laser cooled 88Sr+ further reduces the translational temperature of trapped molecules to the millikelvin regime. We verify the presence of cryogenic "tags" via non-destructive optical mass spectrometry and selectively remove these adducts by resonantly driving vibrational transitions in the tagged molecular ions. This enables us to derive the vibrational spectrum of a single analyte molecule from the frequency dependence of the tag detachment rate. We have demonstrated these capabilities by measuring transitions in the C-H stretching region for single cationic fragments of both indole (C8H7N) and 1,3-benzodioxole (C6H4O2CH2). These capabilities are not reliant on a specific molecular level structure and thus constitute a general, non-destructive method for vibrational spectroscopy of individual molecular ions.

Assessment of Fungal Diversity in Minqin County, a Typical Arid Region in Northwestern China

Minqin County is located in the Shiyang River Basin. As a typical arid area, it is eroded by the Badain Jaran and Tengger Desert all year round, and knowledge of the fungal diversity in this area is limited. Therefore, fungal community structure and distribution in the soil of the artificial forest, desert transition zone, farmland, and desert were investigated using amplicon sequencing of the fungal ITS gene. Ten fungal phyla and 23 classes were identified, including 1131 fungi OTUs, Sordariomycetes, Dothideomycetes, Pezizomycetes, and Agaricomycetes were the most abundant classes. Although most OTUs are shared among habitats, fungal community composition among samples was highly variable, which may influence the design of restoration practices in this area.

Microsomal glutathione S-transferase 1 targets the autophagy signaling pathway to suppress ferroptosis in gastric carcinoma cells

OBJECTIVE

Ferroptosis is a newly discovered form of programmed cell death; however, the specific mechanisms that regulate ferroptosis have yet to be fully elucidated in gastric carcinoma. In this study, we aimed to investigate how microsomal glutathione S-transferase 1 (MGST1) regulates ferroptosis in gastric carcinoma cells.

METHODS

Gastric adenocarcinoma (SGC7901) cells that overexpressed MGST1 or expressed only low levels of MGST1, were treated with specific compounds (erastin, sorafenib, RSL3, MK-2206 and SC79). Then, we detected the levels of malondialdehyde (MDA), glutathione (GSH), iron and reactive oxygen species (ROS). Protein expression levels of the non-classical autophagy and protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathways were determined by western blotting and cell viability was analyzed by Cell Counting Kit-8 (CCK-8) assays. The expressions of target genes were detected using qRT-PCR.

RESULTS

We evaluated a range of ferroptosis-inducing compounds and found that MGST1 expression was down-regulated during ferroptosis in SGC7901 cells. The ferroptosis inducer RSL3 played a role in classical ferroptotic events while the overexpression of MGST1 impaired these effects. Interestingly, the overexpression of MGST1 resulted in the inactivation of autophagy by repressing the expression of ATG16L1 and the conversion of LC3-I to LC3-II. The upregulation of ATG16L1 eliminated the inhibitory action of MGST1 on ferroptosis. Notably, the overexpression of MGST1 induced the activation of the Akt/GSK-3β pathway. An Akt inhibitor antagonized the inhibitory effects of MGST1 on autophagy and ferroptosis.

CONCLUSION

Collectively, our findings demonstrate a novel molecular mechanism and signaling pathway for ferroptosis. We also characterized that the overexpression of MGST1 induces gastric carcinoma cell proliferation by activating the Akt/GSK-3β signaling pathway.

[Effect of peer education on knowledge, attitude and practices towards schistosomiasis among primary school students in endemic foci of Wuhan City]

OBJECTIVE

To evaluate the effect of peer education on knowledge, attitude and practices towards schistosomiasis control among primary school students in endemic foci of Wuhan City.

METHODS

Yucai Hankou Primary School in Jiang' an District, Wuhan City was selected in 2021, and all students at grades 4 and 5 were sampled using a cluster sampling method to receive peer education about schistosomiasis. The changes of knowledge, attitude and practices towards schistosomiasis control were compared before and after peer education to evaluate the effect of peer education on knowledge, attitude and practices towards schistosomiasis control.

RESULTS

The overall awareness of schistosomiasis control knowledge and the overall proportion of correct attitudes towards schistosomiasis control and correct schistosomiasis-related behaviors increased from 51.50%, 93.70% and 92.99% before peer education to 86.50%, 98.98% and 98.72% after peer education among primary school students, respectively (χ²=149.457, 21.692 and 20.691, all P values < 0.05). The overall awareness of schistosomiasis control knowledge and the overall proportion of correct attitudes towards schistosomiasis control and correct schistosomiasis-related behaviors were 49.19%, 92.20% and 92.72% among Grade 4 primary school students and 53.83%, 95.21% and 93.28% among Grade 5 primary school students prior to peer education (χ² = 1.214, 2.034 and 0.096, all P values > 0.05), and increased to 75.93%, 98.09% and 97.59% among Grade 4 primary school students and 97.16%, 99.87% and 99.87% among Grade 5 primary school students after peer education, respectively (χ² = 40.798, 9.572, 7.207, 133.194, 9.678 and 14.926, all P values < 0.05). The overall awareness of schistosomiasis control knowledge and the overall proportion of correct attitudes towards schistosomiasis control and correct schistosomiasis-related behaviors were 51.25%, 76.92% and 77.97% among male primary school students and 51.80%, 94.42% and 95.70% among female primary school students prior to peer education, the differences in the overall proportion of correct attitudes towards schistosomiasis control and correct schistosomiasis-related behaviors between male primary school students and female primary school students were significant (χ² = 30.462 and 33.416, both P values < 0.05), and increased to 86.23%, 98.25% and 97.79% among male primary school students and 86.83%, 99.85% and 99.85% among female primary school students after peer education (χ² = 0.081, 3.529 and 3.335, all P values > 0.05), respectively.

CONCLUSIONS

Peer education is effective to improve the knowledge, attitude and practices towards schistosomiasis control among primary school students in endemic foci of Wuhan City, which may be more effective to improve the awareness of schistosomiasis control knowledge and proportion of correct schistosomiasis-related behaviors among primary school students at high grades.

Comprehensive Analysis of Differentially Expressed Genes and Epigenetic Modification-Related Expression Variation Induced by Saline Stress at Seedling Stage in Fiber and Oil Flax, Linum usitatissimum L

The ability of different germplasm to adapt to a saline-alkali environment is critical to learning about the tolerance mechanism of saline-alkali stress in plants. Flax is an important oil and fiber crop in many countries. However, its molecular tolerance mechanism under saline stress is still not clear. In this study, we studied morphological, physiological characteristics, and gene expression variation in the root and leaf in oil and fiber flax types under saline stress, respectively. Abundant differentially expressed genes (DEGs) induced by saline stress, tissue/organ specificity, and different genotypes involved in plant hormones synthesis and metabolism and transcription factors and epigenetic modifications were detected. The present report provides useful information about the mechanism of flax response to saline stress and could lead to the future elucidation of the specific functions of these genes and help to breed suitable flax varieties for saline/alkaline soil conditions.

[Assessment of MS-Score and HScore in timeliness of diagnosis of macrophage activation syndrome associated with adult-onset Still's disease]

The data of 33 patients with adult-onset still's disease (AOSD)-associated macrophage activation syndrome (MAS) were retrospectively collected from January 2013 to December 2020 in Peking Union Medical College Hospital. Hemophagocytic lymphohistiocytosis (HLH)-2004 criteria, macrophage activation syndrome/juvenile idiopathic arthritis (MS-Score) and hemophagocytic syndrome diagnostic score (HScore) were used to diagnose AOSD-associated MAS, respectively. The time of diagnosis of AOSD-associated MAS by MS-Score was 19.0 (4.5, 31.0) days [M (Q₁,Q₃)] earlier than by HLH-2004 criteria, and 13.5 (0.5, 21.5) days earlier than by HScore (both P<0.05). The difference was not statistically significant between the time of diagnosis of AOSD-associated MAS by Hscore and by HLH-2004 criteria (P>0.05). There was significant difference among the three criteria (P<0.001). MS-Score can be used to diagnose AOSD-associated MAS earlier than HLH-2004 criteria, while the timeliness of HScore is not certain.

[Analysis of hepatic pathological inflammation and fibrosis condition and its influencing factors in 721 patients with chronic hepatitis B with normal ALT]

Objective: To analyze the hepatic pathological inflammation and fibrosis condition in order to explore the relationship with related clinical indicators in patients with chronic hepatitis B patients with normal alanine aminotransferase (ALT). Methods: 721 cases of chronic hepatitis B with normal ALT who were initially diagnosed in the Department of Infectious Diseases of Henan Provincial People's Hospital from August 2016 to December 2019 were retrospectively collected. Liver biopsy was performed in all patients. General data of patients such as gender, age, liver function indexes, blood routine indexes, HBsAg level, HBeAg status, HBV DNA level, spleen thickness and prothrombin time were collected. Univariate and multivariate analysis methods were used to determine the influencing factors of inflammation and fibrosis degree with liver biopsy. A receiver operating characteristic curve (ROC) was used to evaluate the established multi-factor prediction model. Alpha=0.05 was considered as a standard orientation of test. Results: The average age of 721 cases with chronic hepatitis B was 36.1±9.7 years, and the male to female ratio was 1.28/1, with inflammation and fibrosis grade mainly concentrated in G1S1 (349 cases), G1S2 (132 cases), G2S2 (119 cases), and G2S1 (57 cases). Among them, there were 349 (48.4%) cases of G1S1, and 372 (51.6%) cases of G/S≥2. The main manifestations were mild to moderate inflammation and fibrosis, and only 64 (8.88%) cases had severe G/S≥3. HBsAg level (stratified with 4 log10 IU/ml as the boundary) analyzed in 721 cases were correlated with the relevant clinical indicators stratification and liver pathological inflammation and fibrosis, and the difference was statistically significant (inflammation grade, χ²=6.182, P=0.013; Fibrosis grade, χ²=36.534, P=0.001). Univariate analysis of the relevant clinical indicators that may influence the patient's liver pathological G/S ≥2 showed the patient's age, albumin, γ- glutamyltransferase (GGT), platelet, prothrombin time (PT), spleen thickness and HBsAg level were all statistically significant (P<0.05), while multivariate analysis showed that age, GGT, PT, and spleen thickness had statistical differences (P<0.05). The prediction model was established in accordance to multivariate analysis, and the area under the ROC curve was 0.642. Maximization of the sum of sensitivity and specificity as cut-off value of Logit P=0.497, the diagnostic sensitivity, specificity, and Youden's index were 60.6%, 64.5%, and 0.252, respectively. Conclusion: More than half of patients with chronic hepatitis B with normal ALT have significant inflammation and fibrosis and require timely antiviral therapy. Age, GGT, PT and spleen thickness can help comprehensively evaluate the liver inflammation and fibrosis status among patients, but the lack of accurate prediction models suggests that more effective indicators that can help predict the inflammation and fibrosis status of such patients have yet to be discovered. Therefore, liver biopsy should still be actively performed in patients with normal ALT to confirm the diagnosis and timely treatment.

[Effects of sodium iodide symporter co-expression on proliferation and cytotoxic activity of chimeric antigen receptor T cells in vitro]

OBJECTIVE

To investigate the effects of co-expression of sodium iodide symporter (NIS) reporter gene on the proliferation and cytotoxic activity of chimeric antigen receptor (CAR)-T cells in vitro.

METHODS

T cells expressing CD19 CAR (CAR-T cells), NIS reporter gene (NIS-T cells), and both (NIS-CAR-T cells) were prepared by lentiviral infection. The transfection rates of NIS and CAR were determined by flow cytometry, and the cell proliferation rate was assessed using CCK-8 assay at 24, 48 and 72 h of routine cell culture. The T cells were co-cultured with Nalm6 tumor cells at the effector-target ratios of 1∶2, 1∶1, 2∶1 and 4∶1 for 24, 48 and 72 h, and the cytotoxicity of CAR-T cells to the tumor cells was evaluated using lactate dehydrogenase (LDH) assay. ELISA was used to detect the release of IFN-γ and TNF-β in the co-culture supernatant, and the function of NIS was detected with iodine uptake test.

RESULTS

The CAR transfection rate was 91.91% in CAR-T cells and 99.41% in NIS-CAR-T cells; the NIS transfection rate was 47.83% in NIS-T cells and 50.24% in NIS- CAR-T cells. No significant difference in the proliferation rate was observed between CAR-T and NIS-CAR-T cells cultured for 24, 48 or 72 h (P> 0.05). In the co-cultures with different effector-target ratios, the tumor cell killing rate was significantly higher in CAR-T group than in NIS-CAR-T group at 24 h (P < 0.05), but no significant difference was observed between the two groups at 48 h or 72 h (P>0.05). Higher IFN-γ and TNF-β release levels were detected in both CAR-T and NIS-CAR-T groups than in the control group (P < 0.05). NIS-T cells and NIS-CAR-T cells showed similar capacity of specific iodine uptake (P>0.05), which was significantly higher than that in the control T cells (P < 0.05).

CONCLUSION

The co-expression of the NIS reporter gene does not affect CAR expression, proliferation or tumor cell-killing ability of CAR-T cells.

Alkaline Stress Induces Different Physiological, Hormonal and Gene Expression Responses in Diploid and Autotetraploid Rice

Saline−alkaline stress is a critical abiotic stress that negatively affects plants’ growth and development. Considerably higher enhancements in plant tolerance to saline−alkaline stress have often been observed in polyploid plants compared to their diploid relatives, the underlying mechanism of which remains elusive. In this study, we explored the variations in morphological and physiological characteristics, phytohormones, and genome-wide gene expression between an autotetraploid rice and its diploid relative in response to alkaline stress. It was observed that the polyploidization in the autotetraploid rice imparted a higher level of alkaline tolerance than in its diploid relative. An eclectic array of physiological parameters commonly used for abiotic stress, such as proline, soluble sugars, and malondialdehyde, together with the activities of some selected antioxidant enzymes, was analyzed at five time points in the first 24 h following the alkaline stress treatment between the diploid and autotetraploid rice. Phytohormones, such as abscisic acid and indole-3-acetic acid were also comparatively evaluated between the two types of rice with different ploidy levels under alkaline stress. Transcriptomic analysis revealed that gene expression patterns were altered in accordance with the variations in the cellular levels of phytohormones between diploid and autotetraploid plants upon alkaline stress. In particular, the expression of genes related to peroxide and transcription factors was substantially upregulated in autotetraploid plants compared to diploid plants in response to the alkaline stress treatment. In essence, diploid and autotetraploid rice plants exhibited differential gene expression patterns in response to the alkaline stress, which may shed more light on the mechanism underpinning the ameliorated plant tolerance to alkaline stress following genome duplication.

Practical Indicators for Risk of Airborne Transmission in Shared Indoor Environments and Their Application to COVID-19 Outbreaks

Some infectious diseases, including COVID-19, can undergo airborne transmission. This may happen at close proximity, but as time indoors increases, infections can occur in shared room air despite distancing. We propose two indicators of infection risk for this situation, that is, relative risk parameter (H_r) and risk parameter (H). They combine the key factors that control airborne disease transmission indoors: virus-containing aerosol generation rate, breathing flow rate, masking and its quality, ventilation and aerosol-removal rates, number of occupants, and duration of exposure. COVID-19 outbreaks show a clear trend that is consistent with airborne infection and enable recommendations to minimize transmission risk. Transmission in typical prepandemic indoor spaces is highly sensitive to mitigation efforts. Previous outbreaks of measles, influenza, and tuberculosis were also assessed. Measles outbreaks occur at much lower risk parameter values than COVID-19, while tuberculosis outbreaks are observed at higher risk parameter values. Because both diseases are accepted as airborne, the fact that COVID-19 is less contagious than measles does not rule out airborne transmission. It is important that future outbreak reports include information on masking, ventilation and aerosol-removal rates, number of occupants, and duration of exposure, to investigate airborne transmission.

Practical Indicators for Risk of Airborne Transmission in Shared Indoor Environments and Their Application to COVID-19 Outbreaks

Some infectious diseases, including COVID-19, can undergo airborne transmission. This may happen at close proximity, but as time indoors increases, infections can occur in shared room air despite distancing. We propose two indicators of infection risk for this situation, that is, relative risk parameter (H_r) and risk parameter (H). They combine the key factors that control airborne disease transmission indoors: virus-containing aerosol generation rate, breathing flow rate, masking and its quality, ventilation and aerosol-removal rates, number of occupants, and duration of exposure. COVID-19 outbreaks show a clear trend that is consistent with airborne infection and enable recommendations to minimize transmission risk. Transmission in typical prepandemic indoor spaces is highly sensitive to mitigation efforts. Previous outbreaks of measles, influenza, and tuberculosis were also assessed. Measles outbreaks occur at much lower risk parameter values than COVID-19, while tuberculosis outbreaks are observed at higher risk parameter values. Because both diseases are accepted as airborne, the fact that COVID-19 is less contagious than measles does not rule out airborne transmission. It is important that future outbreak reports include information on masking, ventilation and aerosol-removal rates, number of occupants, and duration of exposure, to investigate airborne transmission.

Intra-couple discordance in preconception syphilis screening for both spouses: a national and population-based survey in China, 2013-2018

OBJECTIVE

The antenatal screening strategy remains inadequate for eliminating congenital syphilis. To further eliminate maternal fetal transmission, preconception syphilis screening is considered an option. In this study, we investigated syphilis seropositivity and intra-couple discordance among married couples planning a pregnancy in China to provide essential baseline evidence for preconception syphilis screening.

DESIGN

Population-based survey.

SETTING

National preconception registered data.

POPULATION

Married Chinese couples planning conception within 6 months between 2013 and 2018.

METHODS

Syphilis was screened using rapid plasma reagin (RPR); infection self-reporting and sociodemographic characteristics were collected through questionnaires and medical records, respectively. r 3.2.2 and arcgis 10.2 were used for statistical analyses and geographic mapping.

MAIN OUTCOME MEASURES

RPR seropositivity.

RESULTS

Among 31 955 041 couples, 29 737 172 (93.06%) had complete RPR results for both spouses; of those, 0.62% (186 100) were seropositive, with dramatic intra-couple discordance, with 0.33% positivity in wives, 0.24% positivity in husbands and 0.05% positivity in both spouses. Across time, both seropositivity and intra-couple discordance remained stable. Seropositivity in different regions varied significantly, with provincial rates ranging geographically from Tibet (0.8%) to Hebei (0.2%) (P < 0.05). Economic level was an independent factor for this regional variation, with seropositivity increasing as gross domestic product income decreased (P < 0.05).

CONCLUSIONS

Intra-couple discordance in seropositivity for syphilis is notable among couples, with a considerable rate of pre-existing syphilis before pregnancy. Thus, screening both spouses during integrated preconception health care is recommended for further eliminating maternal-fetal transmission.

TWEETABLE ABSTRACT

Intra-couple discordance in seropositivity for syphilis is notable among couples, with a considerable rate of pre-existing syphilis before pregnancy. Screening both spouses during integrated preconception health care is recommended to further eliminate maternal-fetal transmission.