Toward tuberculosis elimination by understanding epidemiologic characteristics and risk factors in Hainan Province, China.

BACKGROUND: The disease burden of tuberculosis (TB) was heavy in Hainan Province, China, and the information on transmission patterns was limited with few studies. This atudy aims to further explore the epidemiological characteristics and influencing factors of TB in Hainan Province, and thereby contribute valuable scientific evidences for TB elimination in Hainan Province. METHODS: The TB notification data in Hainan Province from 2013 to 2022 were collected from the Chinese National Disease Control Information System Tuberculosis Surveillance System, along with socio-economic data. The spatial-temporal and population distributions were analyzed, and spatial autocorrelation analysis was conducted to explore TB notification rate clustering. In addition, the epidemiological characteristics of the cases among in-country migrants were described, and the delay pattern in seeking medical care was investigated. Finally, a geographically and temporally weighted regression (GTWR) model was adopted to analyze the relationship between TB notification rate and socio-economic indicators. The tailored control suggestions in different regions for TB elimination was provided by understanding epidemiological characteristics and risk factors obtained by GTWR. RESULTS: From 2013 to 2022, 64,042 cases of TB were notified in Hainan Province. The estimated annual percentage change of TB notification rate in Hainan Province from 2013 to 2020 was - 6.88% [95% confidence interval (CI): - 5.30%, - 3.69%], with higher rates in central and southern regions. The majority of patients were males (76.33%) and farmers (67.80%). Cases among in-country migrants primarily originated from Sichuan (369 cases), Heilongjiang (267 cases), Hunan (236 cases), Guangdong (174 cases), and Guangxi (139 cases), accounting for 53%. The majority (98.83%) of TB cases were notified through passive case finding approaches, with delay in seeking care. The GTWR analysis showed that gross domestic product per capita, the number of medical institutions and health personnel per 10,000 people were main factors affecting the high TB notification rates in some regions in Hainan Province. Different regional tailored measures such as more TB specialized hospitals were proposed based on the characteristics of each region. CONCLUSIONS: The notification rate of TB in Hainan Province has been declining overall but still remained high in central and southern regions. Particular attention should be paid to the prevalence of TB among males, farmers, and out-of-province migrant populations. The notification rate was also influenced by economic development and medical conditions, indicating the need of more TB specialized hospitals, active surveillance and other tailored prevention and control measures to promote the progress of TB elimination in Hainan Province.

Prevalence, types, and risk factors of functional gastrointestinal diseases in Hainan Province, China.

To investigate the prevalence, types, and risk factors of functional gastrointestinal diseases (FGIDs) in Hainan Province, China, in order to provide insights for future prevention and treatment strategies. A questionnaire survey was conducted from July 2022 to May 2023, using stratified sampling to sample local residents in five cities (20 townships) in Hainan Province. Out of 2057 local residents surveyed, 659 individuals (32.0%) reported experiencing at least one FGID. The most prevalent FGIDs were functional dyspepsia (FD) (10.7%), functional constipation (FC) (9.3%), irritable bowel syndrome (IBS) (6.8%), functional bloating (2.2%), belching disorder (2.2%), functional diarrhea (FDr) (1.5%), functional heartburn (1.5%), and fecal incontinence (0.98%). The study revealed significant associations between FGIDs and factors such as age, sleep quality, anxiety, smoking, alcohol consumption, and the consumption of pickled food (P < 0.05). Older age, poor sleep quality, anxiety, and the consumption of pickled food were identified as independent risk factors for the prevalence of FGIDs (P < 0.05). In Hainan Province, the overall prevalence of FGIDs was found to be 32.0%, with higher prevalences of FC and FD. Older age, poor sleep quality, anxiety, and the consumption of pickled food were identified as risk factors for FGIDs.

Prevalence and serotype distribution of nasopharyngeal carriage of Streptococcus pneumoniae among healthy children under 5 years of age in Hainan Province, China.

BACKGROUND: The thirteen-valent pneumococcal conjugate vaccine (PCV13) is not included in the national immunization program and is administered voluntarily with informed consent in China. In preparation for assessing the impact of pilot introduction in Hainan Province, we conducted a carriage study among children under 5 years of age from four locations in Hainan Province, China. METHODS: From March to June 2022, nasopharyngeal (NP) swabs, collected from healthy children aged younger than 59 months who lived in the 4 different locations (Haikou, Wanning, Baisha and Qiongzhong) in Hainan Province, were tested for pneumococcus using conventional culture. Pneumococcal isolates were serotyped using the Quellung reaction. Risk factors associated with pneumococcal colonization were assessed using univariate analysis and multivariable logistic regression adjusting for age, daycare attendance and other factors. RESULTS: Pneumococcus was isolated in 710 (30.4%) of the 2333 children enrolled. Of 737 pneumococci, 29 serotypes were identified; 60.9% were PCV13 serotypes; the most common vaccine serotypes were 6B (20.4%), 19F (13.0%), 6A (11.9%) and 23F (6.1%); and the most common nonvaccine serotypes were 23A (12.9%), 34 (6.1%) and nontypeable (NT) pneumococci (5.6%). Children vaccinated with PCV13 had lower carriage (17.7% vs 32.5%; P = 0.0001) and fewer PCV13 serotypes (41.9% vs 62.7%; P = 0.0017) compared to unimmunized children. After adjustment, NP carriage was higher among children attending daycare (aOR = 2.3, 95% CI: 1.7-3.2), living in rural areas (aOR = 1.4, 95% CI: 1.1-1.8), living with siblings (aOR = 1.3, 95% CI: 1.0-1.6) and whose mothers had completed senior high/technical secondary school (aOR = 1.5, 95% CI: 1.1-2.0). In contrast, completion of 3-4 doses of PCV13 were associated with a lower carriage rate (aOR = 0.6, 95% CI: 0.4-0.9). CONCLUSIONS: We established the baseline of pneumococcal carriage, serotype distribution and PCV13 immunization rates among healthy children under 5 years of age in Hainan Province, prior to the introduction of PCV13 into the national immunization program. The high proportion of PCV13 serotypes suggests that PCV13 introduction will likely have a substantial impact on pneumococcal carriage in Hainan Province.

The development of local ambient air quality standards: A case study of Hainan Province, China.

The ambient air quality standard (AAQS) is a vital policy instrument for protecting the environment and human health. Hainan Province is at the forefront of China's efforts to protect its ecological environment, with an official goal to achieve world-leading air quality by 2035. However, neither the national AAQS nor the World Health Organization guideline offers sufficient guidance for improving air quality in Hainan because Hainan has well met the former while the latter is excessively stringent. Consequently, the establishment of Hainan's local AAQS becomes imperative. Nonetheless, research regarding the development of local AAQS is scarce, especially in comparatively more polluted countries such as China. The relatively high background values and significant interannual fluctuations in air pollutant concentrations in Hainan present challenges in the development of local AAQS. Our research proposes a world-class local AAQS of Hainan Province by reviewing the AAQS in major countries or regions worldwide, analyzing the influence of different statistical forms, and carefully evaluating the attainability of the standard. In the proposed AAQS, the annual mean concentration limit for PM2.5, the annual 95th percentile of daily maximum 8-h mean (MDA8) concentration limit for O3, and the peak season concentration limit for O3 are set at 10, 120, and 85 µg/m3, respectively. Our study indicates that, with effective control policies, Hainan is projected to achieve compliance with the new standard by 2035. The implementation of the local AAQS is estimated to avoid 1,526 (1,253-1,789) and 259 (132-501) premature deaths attributable to long-term exposure to PM2.5 and O3 in Hainan in 2035, respectively.

Relationship between anthropogenic factors and freshwater quality in Hainan Province, south China.

Water resource security directly or indirectly affects the development of society, economy, and the environment, and is of massive significance for regional sustainable development. This study addresses whether anthropogenic activities, especially from tourism, significantly affect the freshwater quality in Hainan Province, China. The freshwater quality in Hainan Province was generally good in 2012 to 2015 (at level II, GB3838-2002). Agriculture, fishery, animal husbandry, and chemical oxygen demand discharge mainly affect freshwater quality in the Nandu and Changhua rivers. Water quality in Wanquan River is more susceptible to tourism in comparison with the Nandu and Changhua rivers. DO content in the Wanquan River fluctuated greatly. It remains necessary to closely monitor negative changes in water quality due to increasing tourism, especially in Wanquan River and eastern Hainan Province. The developed radial basis function neural network shows that the changes in water quality are predicted accurately in comparison with experimental values in the present study. Our results suggested that current anthropogenic factors had a modest effect on water quality on Hainan Island, while tourism had a perceptible effect in eastern Hainan. Our findings provide a reference for the interplay of water quality, people's livelihood, and economic development (tourism and port construction) in Hainan Province.

Surveillance and Control of Malaria Vectors in Hainan Province, China from 1950 to 2021: A Retrospective Review.

Malaria is a serious mosquito-borne tropical disease impacting populations in tropical regions across the world. Malaria was previously hyperendemic in Hainan Province. Due to large-scale anti-malarial intervention, malaria elimination in the province was achieved in 2019. This paper reviews the literature on the ecology, bionomics, and control of malaria vectors in Hainan from 1951 to 2021. We searched PubMed, and the China national knowledge infrastructure (CNKI) database for relevant articles published and included three other important books published in Chinese or English in order to summarize research on species, distribution, vectorial capacity, ecology, the resistance of malaria vectors to insecticides, and malaria vector control in Hainan Province. A total of 239 references were identified, 79 of which met the criteria for inclusion in our review. A total of six references dealt with the salivary gland infection of Anophelines, six with vectorial capacity, 41 with mosquito species and distribution, seven with seasonality, three with blood preference, four with nocturnal activity, two with flight distance, 13 with resistance to insecticides, and 14 with vector control. Only 16 published papers met the criteria of addressing malaria vectors in Hainan over the last 10 years (2012-2021). Anopheles dirus and Anopheles minimus are primary malaria vectors, mainly distributed in the southern and central areas of Hainan. Indoor residual spraying with DDT and the use of ITNs with pyrethroid insecticides were the main interventions taken for malaria control. Previous studies on ecology, bionomics, and resistance of vectors provided scientific evidence for optimizing malaria vector control and contributed to malaria elimination in Hainan Province. We hope our study will contribute to preventing malaria reestablishment caused by imported malaria in Hainan. Research on malaria vectors should be updated to provide scientific evidence for malaria vector control strategies post-elimination as the ecology, bionomics, and resistance of vectors to insecticides may change with changes in the environment.

Synergistic relationship or not? Understanding the resilience and efficiency of the tourism economy: evidence from Hainan Province, China.

The COVID-19 pandemic has dealt a serious blow to the global tourism industry, causing a fracturing of and decline in tourism development efficiency and even a stagnation of tourism development in some regions. To solve the contradiction between efficiency and quality, it is necessary to ensure the endogenous power of tourism resilience while pursuing the efficiency of tourism development. This study assumes that Hainan Province follows a tourism development path led by resilience. The improved weighting method, EBM model and Haken model are used to evaluate the level of resilience, the level of efficiency and their co-evolution. The findings indicate that the core tourism cities represented by Sanya and Haikou have a high level in the individual fields of tourism development efficiency and tourism economic resilience but have limited performance in the synergistic relationship between tourism development efficiency and tourism economic resilience. In contrast, the marginal tourism cities represented by Tunchang County and Ledong County have low tourism development efficiency and resilience, but their synergistic development level is high. This result proves that co-evolution plays a dual forward and reverse driving role. Based on the identification of the order parameters, it is concluded that Hainan Province is characterized by a synergistic evolutionary synergy dominated by resilience, which is in line with the trend of social development and the sustainable development of tourism. While reasonably pursuing the tourism economy and development efficiency, we should pay attention to strengthening resilience construction based on multiple aspects, such as tourists, enterprises, organizations, governments and destinations.

Spoligotyping and drug resistance analysis of 136 drug-resistant Mycobacterium tuberculosis strains in Hainan Province / 中国热带医学

@#Abstract: Objective　In order to understand and master the prevalence of different genotypes and the rate of different drug-resistant Mycobacterium tuberculosis genotypes in Hainan Province, 136 drug-resistant Mycobacterium tuberculosis strains collected in Hainan province in 2022 were genotyped, and to provide scientific basis for tuberculosis prevention and control strategy in Hainan Province. Methods　A total of 136 drug-resistant Mycobacterium tuberculosis strains were collected in Hainan Province. The clinical isolates were genotyped using the Spoligotyping technique, and the drug resistance rates of different genotypes of Mycobacterium tuberculosis were statistically analyzed. Results　Among the 136 strains of drug-resistant Mycobacterium tuberculosis, 54.41% (74/136) belonged to the Beijing types, 27.94% (38/136) to non-Beijing types and newly identified genotypes accounted for 17.65% (24/136). The Beijing type included two genotypes, SIT1 and SIT269 genotypes, accounting for 52.94% (72/136) and 1.47% (2/136) respectively. Among the non-Beijing genotypes, the T type (T1, T2, T3) accounted for 21.32% (29/136), the U type accounted for 6.62% (9/136). Clustering analysis of genotyping results revealed two major clusters, Beijing type and non-Beijing type, as well as several scattered novel genotypes. Clustering analysis of Spoligotyping results classified the 136 drug-resistant strains into 3 clusters, with a clustering rate of 75.74% (103/136). The rates of mono-resistance (MR), poly-resistance (PR), multi-drug resistance (MDR), and other types of drug resistance in Beijing type and non-Beijing type were 41.89% (31/74), 13.51% (10/74), 24.33% (18/74), 20.27% (15/74) and 36.84% (14/38), 15.79% (6/38), 26.32% (10/38), 21.05% (8/38) respectively. Chi-square test results showed no statistically significant differences in drug resistance rates between the Beijing and non-Beijing types (P>0.05). Conclusion　The genotype of Mycobacterium tuberculosis in Hainan Province showed genetic polymorphism, with the main epidemic genotype being SIT1 in the Beijing type. Monitoring of Mycobacterium tuberculosis in this genotype should be strengthened.

Awareness of human papillomavirus vaccine knowledge and willingness to receive human papillomavirus vaccination among women in Hainan Province / 预防医学

Objective@#To investigate the awareness of human papillomavirus (HPV) vaccine knowledge among women in Hainan Province and the willingness to receive HPV vaccination among women and their daughters, so as to provide insights into HPV vaccine promotion and cervical cancer control. @*Methods@#Women aged 20 to 64 years who participated in the cervical cancer screening program in Hainan Province from July 2021 to February 2022 were enrolled, and participants' demographics, awareness of knowledge about HPV vaccine, and willingness to receive HPV vaccination among themselves and their daughters using a questionnaire survey. The factors affecting willingness to receive HPV vaccination were identified using a multivariable logistic regression model.@*Results@#A total of 4 300 questionnaires were allocated and 4 023 valid questionnaires were recovered, with an effective recovery rate of 93.56%. The respondents had a mean age of (35.52±6.48) years, and their daughters had a mean age of (8.93±4.83) years. There were 826 participants knowing HPV vaccine-related knowledge, with an awareness rate of 20.35%. The proportions of willingness to receive HPV vaccination were 75.07% among respondents and 71.36% among their daughters. Multivariable logistic regression analysis identified age (20 to <30 years, OR=1.474, 95%CI: 1.167-1.862; 30 to <40 years, OR=1.455, 95%CI: 1.199-1.765), urban-registered residence (OR=1.251, 95%CI: 1.016-1.541), monthly household income (3 000 to <5 000 Yuan, OR=1.568, 95%CI: 1.314-1.873; 5 000 Yuan and more, OR=1.231, 95%CI: 1.014-1.496), affordable fees for a single dose of HPV vaccination (100 to <500 Yuan, OR=1.358, 95%CI: 1.159-1.590; 500 Yuan and higher, OR=1.609, 95%CI: 1.188-2.180), and awareness of HPV vaccine-related knowledge (OR=4.473, 95%CI: 3.416-5.855) as factors affecting respondents' willingness to receive HPV vaccination, and participation in New Rural Cooperative Medical Insurance (OR=1.652, 95%CI: 1.087-2.511), affordable fees for a single dose of HPV vaccination (100 to <500 Yuan, OR=1.905, 95%CI: 1.633-2.221; 500 Yuan and higher, OR=1.683, 95%CI: 1.275-2.223), awareness of HPV vaccine-related knowledge (OR=3.625, 95%CI: 2.847-4.615), daughter's active request for HPV vaccination (OR=1.695, 95%CI: 1.293-2.222), and frequency of sexual health education for daughters (frequently, OR=2.142, 95%CI: 1.789-2.564; occasionally, OR=1.707, 95%CI: 1.416-2.059) as factors affecting the willingness to receive HPV vaccination among respondents' daughters. @*Conclusions@#The awareness of HPV vaccine-related knowledge is low among women aged 20 to 64 years in Hainan Province, and the women's and their daughters' willingness to receive HPV vaccination is associated with age, household registration, economic level, price of HPV vaccine and awareness of HPV vaccine-related knowledge.

Distribution and change of poor vision among school students aged 6-19 in Hainan Province, 2013-2020 / 中国热带医学

@#Abstract: Objective　To explore the regional, age and annual characteristics of distribution and variation trend of children and adolescents with poor vision in Hainan Province, and to provide a theoretical basis for the formulation of targeted and effective prevention and treatment strategies. Methods　The eyesight monitoring data of 5 657 231 children and adolescents aged 6 to 19 from 17 cities and counties in Hainan Province from 2013 to 2020 were analyzed. Using the "Standard Logarithmic Vision Chart" (GB11533-2011) that complies with national standards for testing. Results　The rate of poor vision among children and adolescents in Hainan Province increased significantly from 2013 to 2020, and the difference between the years was statistically significant (P<0.001). The total poor vision rate in the left eye increased 10.09% (32.79% to 42.88%), and that of severe poor vision rate increased 6.68%, while that of the right eye increased 9.80% (33.11% to 42.91%) and 6.49%. The poor vision rate was significantly higher in females than in males of same year (P<0.001), but the increase pattern was the same. In 2020, there were significant differences between the same age groups in different cities and counties and between different age groups in the same city and county (P<0.001), and they all tended to increase with age. The result of analyzing the distribution characteristics of the total poor vision rate of different age groups children in the eastern (Qionghai), southern (Sanya), western (Changjiang), northern (Haikou) and central (Dingan) cities showed that the regional rate difference was small at 6-7 years old, and then increased with the increase of age. The poor vision rate of Haikou City ranked the first in all age groups, and reached the highest at 17 years old, with 76.32% and 80.89% of total poor vision rate of left and right eyes respectively. Sanya City ranked second, Qionghai ranked third. The poor vision rate of Changjiang County was lower and the growth rate was slower according to age. Conclusions　From 2013 to 2020, the total and severe poor vision rates in left and right eyes of children aged 6-19 in Hainan Province increased year by year, with the ascension range of female higher than that of male, and right eye higher than that of left eye. In the same year, the poor vision rate increase rapidly with age. It is recommended to further strengthen the daily intervention and management of key populations and special age groups to reduce the rate of low vision in children and adolescents.

Multicenter epidemiological characteristics of Mycoplasma pneumoniae infection in children in Hainan Province, 2012-2020 / 中国热带医学

@#Abstract: Objective　To analyze the epidemiological characteristics (season, age, gender, mixed infection and clinical manifestations, etc.) of Mycoplasma pneumoniae (MP) infection in children in Hainan Province, so as to provide epidemiological evidence-based medical basis for the prevention and control of MP infection in children in Hainan Province. Methods　The serum IgM antibodies of MP, Legionella pneumophila, Chlamydia pneumoniae, adenovirus, respiratory syncytial virus (RSV), Q fever Rickettsia, parainfluenza virus, influenza A virus and influenza B virus in children with respiratory tract infections (RTIs) who were hospitalized in pediatrics of many hospitals in Hainan Province from March 2012 to February 2020 were detected by indirect immunofluorescence method. The positive serum MP-IgM antibody was defined as MP infection. The epidemiological and clinical data of MP infected cases were analyzed retrospectively. Results　From March, 2012 to February, 2020, a total of 35 731 qualified pediatric inpatients with RTIs in many hospitals in Hainan Province were tested for serum MP-IgM with the total positive rate of 39.12% (13 978/35 731). The yearly positive rates of MP-IgM from 2012 to 2020 were 48.39%, 56.23%, 56.62%, 47.04%, 29.71%, 24.14%, 47.55%, 36.84% and 24.46% respectively. The positive rates of MP-IgM in 2013 and 2014 were significantly higher than those in other years (P<0.05). The positive rate of MP-IgM in summer in Hainan Province was the highest (41.34%) and the lowest in winter (35.77%) (P<0.05). MP infection occurred in all age groups, the positive rate of MP-IgM in children of preschool (51.80%) was significantly higher than that in other age groups (P<0.01), and the positive rate of MP IgM in children of infancy (15.36%) was lower than that in other age groups (P<0.01). The positive rate of MP-IgM in female was 44.77%, which was significantly higher than that in male (35.83%) (P<0.05). MP infection combined with positive IgM of another pathogen accounted for 32.63% (4 561 cases), positive IgM of another two pathogens accounted for 1.26% (176 cases). MP infection was mostly found in pneumonia (68.73%), and the main clinical symptoms were cough (84.72%), fever (51.01%) and wheezing (3.16%). Conclusions　MP is an important pathogen of respiratory tract infection in children in Hainan Province, and infection is more common in children in early school age and early childhood. Mp-specific tests should be performed to identify the pathogen in children suspected of MP infection. In the high incidence season, health education should be strengthened in kindergartens, schools and other places to prevent respiratory tract infection.

Analysis of mental health status of Hainan residents / 中国热带医学

@#Abstract: Objective To understand the mental health literacy level of residents in Hainan Province, and to provide evidence for promoting mental health promotion and improving the mental health literacy level of residents. Methods Multi-stage random sampling method was used to investigate The National Mental Health Literacy Questionnaire among 6 895 residents in 12 districts including Changjiang, Chengmai, Dongfang, Ledong, Lingshui, Haikou Longhua District, Haikou Meilan District, Qionghai, Sanya, Tunchang, Wenchang and Wuzhishan. Results　In the survey 6 895 residents in 12 counties, cities, districts of Hainan Province, 365 of them reached the standard of mental health with the standard rate of 5.3%. The mental health knowledge score was (54.00±17.02) with the standard rate of 7.7%; the self-assessment score was (26.11±3.99) with the standard rate of 75.9%; the score of mental health skill was (26.22±7.25) with the standard rate of 44.8%. The mental health literacy level of medical workers was the highest, with the standard rate of 13.5% (112/830), and the mental health literacy level of farmers was the lowest, with the standard rate of 0.8% (13/1 647). The results of unconditional Logistic regression showed that the factors entering the regression model included educational background (OR=2.268), personal monthly income (OR=1.129), gender (OR=1.302), household registration (OR=0.776), and whether they had participated in mental health related courses OR training (OR=0.511). The higher the educational background and personal monthly income, the higher the psychological quality. The mental health of women was higher than that of men, and that of urban was higher than that of rural, and those who had participated in mental health related courses were higher than those who had not. Conclusions The mental health literacy level of Hainan residents is at a low level, and the influencing factors are multifaceted. It is suggested to strengthen the mental health monitoring comprehensively and carry out rich health education service mode for different groups.

Ecological niche selection shapes the assembly and diversity of microbial communities in Casuarina equisetifolia L.

The plant microbiome profoundly affects many aspects of host performance; however, the ecological processes by which plant hosts govern microbiome assembly, function, and dispersal remain largely unknown. Here, we investigated the bacterial and fungal communities in multiple compartment niches (bulk soil, rhizosphere soil, root endosphere, phylloplane, and leaf endosphere) of Casuarina equisetifolia L. at three developmental stages in Hainan Province, China. We found that microbiome assemblages along the soil-plant continuum were shaped by the compartment niches. Bacterial diversity and richness decreased from the soils to roots to leaves, with the highest network complexity found in the roots and the lowest found in the phylloplane. However, fungal diversity gradually increased from the soils to roots to phyllosphere, whereas fungal richness decreased from the soils to roots but increased from the roots to phyllosphere; the greatest network complexity was found in bulk soils and the lowest was found in the roots. Different biomarker taxa occurred in the different ecological niches. Bacterial and fungal communities exhibited distinct ecological functions; the former played important roles in maintaining plant growth and providing nutrients, whereas the latter predominantly decomposed organic matter. The bacterial community of C. equisetifolia mostly originated from bulk soil, whereas the fungal community was mainly derived from rhizosphere soil and air. Leaf endophytes were positively correlated with organic carbon, and root and soil microorganisms were positively correlated with total nitrogen, total phosphorus, and total potassium. Our findings provide empirical evidence for plant-microbiome interactions and contribute to future research on non-crop management and the manipulation of non-crop microbiomes.

Molecular Spectrum, Ethnic and Geographical Distribution of Thalassemia in the Southern Area of Hainan, China.

Background: Thalassemia is one of the most common genetic diseases in southern China. Accurate population frequency data regarding the occurrence and distribution of thalassemia are important for designing appropriate prevention strategies for thalassemia. This study aims to reveal the molecular spectrum, ethnic and geographical distribution of thalassemia in the southern area of Hainan Province, China. Methods: A total of 9813 suspected carriers of thalassemia were screened for genetic analysis by using the PCR-reverse dot blot hybridization method targeting three known deletions of α-thalassemias (--SEA, -α3.7, and -α4.2), three nondeletional mutations of α-thalassaemias (αCS, αQS, and αWS) and the 17 most common mutations of ß-thalassaemias in the Chinese population. Results: Approximately 6,924 subjects were genetically diagnosed as thalassemia carriers or patients, including 5812 cases of α-thalassemia (83.9%), 369 cases of ß-thalassemia (5.3%), and 743 cases of α-composite ß-thalassemia (10.7%). A total of 21 distinct genotypes were identified among the 5,812 α-thalassemia carriers, -α4.2/αα, -α3.7/αα, and -α3.7/-α4.2 were the most common α-thalassemia genotypes. The most frequent ß-thalassemia genotype was ßCD41-42/ßN, with a notable proportion of 69.6%, followed by the ß-28M /ßN, ßIVS-II-654/ßN, ßCD71-72/ßN, ßE/ßN, and ßCD17/ßN genotypes. In addition, 37 genotypes were detected among the 743 cases of both α- and ß-thalassemia mutations. The α-thalassemia genotypes were most commonly found in the Li people, who accounted for 73.5% of α-thalassemia carriers. The ß-thalassemia genotypes were most commonly identified in the Han people, who accounted for 59.4% of ß-thalassemia carriers. Among the subjects carrying both α- and ß-thalassemia variations, only three ethnic minorities were identified, including the Li, Han, and Miao people, accounting for 82.0, 17.4, and 0.7%, respectively. Conclusions: Our study indicates that there is high genetic heterogeneity, geographical and ethnic differences in thalassemia in populations in the southern area of Hainan Province. These findings will be helpful in guiding genetic counseling and prenatal diagnosis of thalassemia in Hainan Province.

Establishment of a Real-Time Quantitative PCR Assay for Porcine Circovirus-Like Virus and the First Evidence of Its Spread to Hainan and Jiangxi Provinces of China.

Porcine Circovirus-like (PCL) virus, a new emerging virus, has been widely detected in Guangdong, Guangxi, and Anhui provinces in China, which may be a novel agent causing severe diarrhea in newborn piglets and tending to spread widely. Evidence suggests that the virus is related to hemorrhagic enteritis and diarrhea, and many newborn piglets were emaciated to death after infection. Therefore, a sensitive, quick, and accurate detection system for virus detection and epidemiological investigation is necessary. In this study, we developed a real-time quantitative PCR assay based on SYBR green for the detection of PCL virus. The ORF4 conserved region of PCL virus was found by the alignment of the uploaded genome sequences to design specific primers, and the primers were tested and showed good specificity, sensitivity, and reproducibility. Approximately, 138 fecal samples were obtained from diarrheal pigs in South China from June to December 2021. Approximately, 22.46% (31/138) of the samples and 40% (8/20) of the pig farms were positive for PCL virus, respectively, by using this method. Moreover, it is worth noting that the virus was first detected in Hainan and Jiangxi Provinces of China, which means that the virus may spread widely in China. Through evolutionary tree analysis and partial sequence comparison, there are some differences of virus genes in each province, suggesting that there is a risk of variation, and the four PCL virus strains showed a sequence similarity of 86.7%-87.8% for the rep gene and 92.2%-92.9% for the Rep protein, respectively, with Bo-Circo-like virus that is detected in bovine, which further demonstrates a close relationship between the two viruses that originated from different animals. In conclusion, our study provides a useful diagnostic approach to PCL virus detection and epidemiological inquiry. Meanwhile, the epidemic data using this real-time qPCR assay provide evidence for the widespread variations and epidemic of the virus in South China, and warn the appropriate measures for prevention, and control of porcine circovirus-like virus infection should be under consideration in pig production.

Heavy metal pollution in agricultural soils of a typical volcanic area: Risk assessment and source appointment.

Heavy metals are naturally occurring elements with high natural background levels in the volcanic area. Therefore, it is necessary to conduct a risk assessment and identify potential sources of heavy metals. In this study, 4488 soil samples (0-20 cm) were collected in Chengmai County, a typical volcanic area in Hainan Province, and analyzed for eight heavy metals and major oxides. Pollution level, ecological risks, and health risks were evaluated by geo-accumulation index (Igeo), pollution index (PI), potential ecological risk index (RI), hazard index (HI), and carcinogenic risks (CR). The positive matrix factorization (PMF) model was further used to determine the priority source of heavy metals. The average values of heavy metal concentrations in soil were 7.06, 0.07, 156.88, 33.43, 0.05, 72.47, 19.48, and 67.51 mg kg-1 for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. Except for Pb, the average concentrations of all heavy metals exceeded background concentration in Hainan soils, indicating different degrees of heavy metal enrichment. The Igeo and PI showed that the main pollutant element in volcanic soils was Ni, followed by Cr and Cu. The RI shows that the percentage of soil samples with considerable or worse potential ecological risk was 44.4% of the total samples, with Hg, As, Cd, and Ni causing high ecological risks. The estimated average daily doses of heavy metals were below the tolerable limits and the HI values were below one for both adults and children, indicating that the residents had an acceptable potential non-carcinogenic risk. However, the potential carcinogenic risk of exposure to Cr, Ni, and As was unacceptable for residents, with high CR values exceeding 10-4, especially for children. Based on the PMF, five major sources of heavy metals were found in the study area: Ni, Cu, and Zn mainly from parent materials, As and Pb from daily life and vehicle emissions, Cd from agricultural activities, Hg from industrial activities, and Cr from parent materials under different environmental conditions. Significant positive correlations between Al2O3, TFe2O3, Mn, soil organic carbon (SOC), and heavy metals reflect that aluminium-rich minerals, Fe-Mn oxides, and SOC are the most critical factors affecting heavy metal accumulation in volcanic agricultural soils.

Assessment and dynamic mechanisms of the land-use dominant morphology transition: a case study of Hainan Province, China.

This paper was aimed at providing a perspective on the assessment of land-use dominant transition. Based on the transfer matrix of land-use type, the dynamic degree of dominant morphology transition was measured, and an active degree index was proposed. The spatiotemporal differentiation characteristics were assessed and analyzed by land use change characteristics in different phases. Our assessment resulted in three types of spatiotemporal differentiation of Hainan Province in China. The whole island can be divided into three regions with two parallel lines at 45° based on spatiotemporal differentiation characteristics. The "slow-type" was distributed in four eastern counties (cities), "steady-type" was distributed in 13 central and western counties (cities), and the "active-type" was distributed in four central counties (cities). Over three phases, namely 2010-2011, 2012-2015, and 2015-2018, four levels of spatiotemporal differentiation of the 21 counties (cities) were assessed, and they were relatively stable, leaping, declining, and unstable. Areas of new construction and fixed assets investments consumed by increased construction land were the positive factors of land-use dominant transition, while output values of secondary industries and area of industrial-mining per capita were the negative factors. Based on these results, a more informative examination of LULC was proposed, and all resulting land management policies will be more targeted and effective.

Factors influencing quality of life and work of male nurses in Hainan Province: logistic regression analysis.

OBJECTIVE: The purpose of this study was to explore the factors affecting the quality of life and work of male nurses in Hainan Province, so as to provide a theoretical basis to improve the motivation of male nurses, reduce job-hopping intentions, and maintain the stability of labor force. METHODS: A total of 393 male and 393 female nurses with registered nurse qualifications from 53 hospitals in Hainan Province were selected as the research subjects. The distribution in various hospital departments, quality of life, stress coping ability, social support and job satisfaction were compared. The factors affecting the quality of life of male nurses were analyzed. RESULTS: Male nurses worked mainly in the intensive care unit (ICU), operating rooms and emergency departments, while female nurses worked mainly in general wards. There were significant differences in physical function, general health, social functioning, and mental health between male and female nurses (P<0.05), and female nurses had significantly higher Physical Component Summary and Mental Component Summary scores than male nurses (P<0.05). There was no significant difference in coping styles between male and female nurses in stressful working environments (P>0.05). Male nurses scored significantly lower than female nurses in objective support, subjective support, support utilization and total score (P<0.05), and male nurses exhibited significantly lower job satisfaction than female nurses (P<0.05). Univariate and multivariate analyses showed that years of experience, work unit, monthly income, social support and job satisfaction were the independent risk factors affecting the quality of life of male nurses. CONCLUSION: Male nurses in Hainan Province mostly worked in departments with high work intensity and pressure, and the overall quality of life, social support and job satisfaction were significantly lower than those of female nurses. Therefore, psychological guidance for male nurses should be strengthened, the salary of male nurses should be increased, higher social support should be provided, to reduce job burnout and thus improve their quality of life.

[Temporal and Spatial Variations in Ozone and Its Causes over Hainan Province from 2015 to 2020].

This study investigated temporal and spatial variations in O3-8h (defined as the maximum 8 h average result) in Hainan Province from 2015 to 2020 and further analyzed its relationships with precursors and meteorological factors based on a dataset of observations from 32 environmental monitoring stations in Hainan. Basic statistical methods, including the empirical orthogonal function (EOF), climatic tendency rate, and climatic trend coefficient analysis, were used here. The results showed that ρ(O3-8h) was higher in northern and western Hainan than that in other regions, with the maximum value occurring in Dongfang City (91.5 µg·m-3). Twelve cities and counties experienced a downward trend from 2015 to 2020, and six cities and counties reached a 95% confidence level. The variation in ρ(O3-8h) in Hainan Province demonstrated remarkable seasonal changes, which were the largest in the autumn, spring, and winter followed by the smallest in the summer, exhibiting a clear declining trend in all seasons except autumn. In addition, the cumulative variance of the first two eigenvector fields decomposed by EOF was 72.58%, which could well describe the distributed characteristics of ρ(O3-8h) in Hainan Province. The first mode reflected the consistency of ρ(O3-8h) variation, and the second mode reflected regional differences. Meanwhile, the change in ρ(O3-8h) had a good correlation with the precursors and meteorological factors. Among them, the correlation coefficients between ρ(O3-8h) and ρ(NO2), precipitation, sunshine duration, average temperature, average wind speed, atmospheric pressure, and total radiation passed the 99% confidence test. The results of multiple linear regression showed that the variation in regressed ρ(O3-8h) was consistent with the observed ρ(O3-8h), and the correlation coefficient between them was 0.853, which passed the 99.9% confidence test. The regression value explained 0.72 variance of the observed value.

Spatiotemporal evolution, pattern of diffusion, and influencing factors of the COVID-19 epidemic in Hainan Province, China.

Within 1 month after the first case occurred in Hainan Province, China, the number of confirmed cases rose to 168, and there was no increase in almost 3 months. As the southernmost province and a famous tourist destination in China, its regular economic exchanges and high-intensity population movements may affect the spread of the epidemic. It is of great theoretical and practical significance to investigate the spatiotemporal evolution, the pattern of diffusion, and factors influencing the coronavirus disease 2019 (COVID-19) epidemic in Hainan Province. Basic and geographic information of confirmed COVID-19 cases was obtained from government websites and other official media. We examined the groups of infection and calculated the diffusion ratio to demonstrate the trend of the epidemic. Map drawing, spatial analysis, and partial least squares regression were used to express the spatiotemporal evolution, the pattern of diffusion, and factors affecting the epidemic. Furthermore, we have made recommendations on the formulation and adaptation of possible future preventive steps. Results show that the COVID-19 epidemic in Hainan Province has substantial spatial heterogeneity but minimal distribution. The tourist city and central city have formed a dual-core pattern for the spread of the epidemic, which could extend to other similar regions. Population density, mobility, and level of urban development have been the major factors of epidemic distribution in the study area.