Using molecular network analysis to explore the characteristics of HIV-1 transmission in a China-Myanmar border area.

BACKGROUND: The China-Myanmar border area is considered a hot spot of active HIV-1 recombination in Southeast Asia. To better understand the characteristics of HIV-1 transmission in this area, a cross-sectional HIV-1 molecular epidemiological survey was conducted in Baoshan Prefecture of Yunnan Province. METHODS: In total, 708 newly reported HIV-1 cases in Baoshan Prefecture from 2019 to 2020 were included in this study. HIV-1 gag, pol and env genes were sequenced, and the spatial and demographic distributions of HIV-1 genotypes were analyzed. The characteristics of HIV-1 transmission were investigated using the HIV-1 molecular network method. RESULTS: In the 497 samples with genotyping results, 19 HIV-1 genotypes were found, with URFs being the predominant strains (30.2%, 150/497). The main circulating HIV-1 strains were mostly distributed in the northern area of Baoshan. URFs were more likely identified in Burmese individuals, intravenous drug users and those younger than 50 years old. CRF08_BC was more likely detected in farmers and those of Han ethnicity, CRF01_AE in the young and those of Han ethnicity, and CRF07_BC in the subpopulation with junior middle school education and higher. Moreover, CRF118_BC and CRF64_BC were more likely found in the subpopulation aged ≥40 years and ≥50 years, respectively. Among 480 individuals with pol sequence detection, 179 (37.3%) were grouped into 78 clusters, with Baoshan natives being more likely to be in the network. The proportion of the linked individuals showed significant differences when stratified by the regional origin, marital status, age and county of case reporting. In the molecular network, recent infections were more likely to occur among nonfarmers and individuals aged below 30 years. CONCLUSIONS: HIV-1 genetics has become complex in Baoshan. HIV-1 molecular network analysis provided transmission characteristics in the local area, and these findings provided information to prioritize transmission-reduction interventions.

Genetic Characterization of a Novel HIV-1 Second-Generation Recombinant Form Originating from CRF86_BC and a Unique Recombinant Form in Yunnan, China.

Yunnan is the first place where human immunodeficiency virus type 1 (HIV-1) became prevalent in China, and it is also the place with the most complicated HIV-1 genetic diversity in China. On October 23, 2019, a patient newly diagnosed with acquired immunodeficiency syndrome from a hospital in Baoshan, Yunnan, was recruited for genetic analysis. Near full-length genome of HIV-1 was amplified from the plasma sample. Phylogenetic analysis revealed that this sequence (BS6F24) has a close relationship with CRF86_BC and a unique recombinant form (URF) (KY406739), which was formed by recombination of subtypes B and C. Bootscan analysis confirmed that the first part (HXB2:1022-5832) and last part (HXB2:5833-9120) genomes of BS6F24 had the same recombinant structures as KY406739 and CRF86_BC, respectively. A second-generation recombinant form that originated from CRF86_BC and a URF were reported for the first time. This indicates the need for continuous monitoring of the genetic diversity of HIV-1 in Yunnan, China.

The effects of irrigation and fertilization on the migration and transformation processes of main chemical components in the soil profile.

Understanding the changes in chemical composition of soil plays an important role in effective control of irrigation and fertilization in agricultural productions, which further protects the groundwater quality and predicts its evolution. Field trials were conducted from 2014 to 2016 to investigate the impacts of irrigation and fertilization on mineral composition transformation in the soil profile. Based on HYDRUS-HP1 and Visual MINTEQ, this paper simulated and computed the migration and transformation of chemical components during the irrigation and fertilization in the vadose zone soil of Jinghuiqu district. The results showed that when the nitrogen fertilizer entered the soil, the urea was hydrolyzed to NH4+ and it was nitrified as NO2-, which caused pH value to drop around the first 4 days after irrigation, and rise slightly on the 12th day. Due to the fact that soil belongs to calcareous soil, concentration of CaCO3 and other carbonates (Mg or Na in sodic soils) could buffer the soil pH well above 8.5. Thus, on the 30th day of the post-irrigation the pH reached the same level as it was before irrigation. The change in pH resulted in the main ions reacting, dissolving and precipitating simultaneously in the soil profile. The concentrations of Ca2+, Mg2+ and HCO3- had significant correlations with the increasing ammonia nitrogen hydrolyzed from urea, and this process is accompanied with the saturation index of minerals and the main ion content changing. At the same time, the varying temperature action on pH of the soil was higher in summer than that in winter. Thus, the irrigation, fertilization and temperature had affected pH and main chemical components in the soil.

[Study on the prevalence of loss to follow-up and risk factors among human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients in Baoshan city, Yunnan province].

OBJECTIVE: To determine the prevalence of loss to follow-up (PLF) and risk factors among human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients from 1989 to 2012 in Baoshan city, Yunnan province. METHODS: The epidemic and follow-up databases of HIV/AIDS patients by the end of 2012 were downloaded from "the history card downloading site" of HIV/AIDS database in China Information System for Disease Control and Prevention and obtained the related data of patients from 1989 to 2012 who had local residence in Baoshan city. These data included demographic characteristics (genders, age at the time of HIV testing positive, and occupation, marital status, and education levels, et al), transmission routes, and disease staging, antiretroviral therapy (ART), and sources of samples, the first CD4(+)T cell counts, and status of follow-up, et al. Descriptive epidemiological study was used to describe the general characteristics of loss to follow-up. Multivariable Cox regression was used for determining risk factors associated with loss to follow-up. RESULTS: A total of 3 295 eligible HIV/AIDS patients from 1989 to 2012 were included. The accumulative study person-year was 11 416.59 years, 222 HIV/AIDS patients were lost to follow-up, and the PLF was 0.019 4/ person years (py). The highest PLF was 0.052 8/py in 2008, the lowest was 0.006 2/py in 2012. The lost patients included 56.76% (126/222) males and 43.24% (96/222) females, the PLFs were 0.020 4/py, 0.018 3/py, respectively. Baoshan city, other cities in Yunnan province, and other provinces, foreign nationality as the family register reached 53.60% (119/222) , 28.83% (64/222) , and 5.86% (13/222) , 11.71% (26/222) , respectively, and their PLFs were 0.012 5/py, 0.046 3/py, and 0.053 6/py, 0.095 6/py, respectively. Receiving ART and not receiving ART occupied 6.76% (15/222) , 93.24% (207/222) , respectively, and the PLFs were 0.001 9/py, 0.0588/py. AIDS and HIV staging standed at 8.11% (18/222) , 91.89% (204/222) , respectively, and the PLFs were 0.003 3, 0.034 5/py. The first CD4(+)T cell counts < 200, 200-350, and > 350 cells /ml accounted for 4.95% (11/222) , 73.87% (164/222) , 21.17% (47/222) , respectively, and the PLFs were 0.004 8/py, 0.024 0/py, 0.020 3/py. The results of multivariable Cox regression showed the risks of loss to follow-up (RLFs) of family register as other cities in Yunnan province (HR = 3.11, 95%CI:2.28-4.25) , other provinces (HR = 2.55, 95%CI:1.42-4.56) , and foreign nationality (HR = 2.12, 95%CI:1.35-3.33) higher than that of Baoshan city, respectively. The RLFs of not receiving ART (HR = 20.83, 95%CI:11.74-36.96) and HIV staging (HR = 3.61, 95%CI:1.82-7.16) were higher than those of receiving ART and AIDS staging, respectively, moreover, the RFLs of the first CD4(+)T cell counts between 200-350 cells/ml (HR = 0.35, 95%CI:0.15-0.82) and the first CD4(+)T cell counts > 350 cells/ml (HR = 0.29, 95%CI:0.12-0.72) were less than that of first CD4(+)T cell counts < 200 cells /ml, respectively. The RLF of transmission route as injecting drug (HR = 0.60, 95%CI:0.41-0.88) was less than that of heterosexual contact. CONCLUSION: Overall, the prevalence of loss to follow-up among HIV/AIDS patients shows a downward trend, moreover, patients of outsiders, heterosexual contact, HIV staging, baseline CD4(+)T cell counts < 200 cells/ml are at higher risk of loss to follow-up.

Hydrochemical characterization of a groundwater aquifer and its water quality in relation to irrigation in the Jinghuiqu irrigation district of China.

The Jinghuiqu irrigation district is located in the semi-arid regions of northwestern China, where groundwater is the most important natural source for local industry, agriculture and residents. The present work was conducted in the Jinghuiqu irrigation district to characterize the groundwater aquifer, which has undergone long-term flood irrigation for over 2000 years. Isotopic and hydrochemical analyses, along with geological and hydrogeological tools, were used to determine the chemical properties and evolutionary processes of the groundwater aquifer. Results showed that the groundwater chemistry had changed significantly from 1990 to 2009. Water with concentrations of CaMgSO4 had decreased significantly, from 60% to 28% of the total water samples, during the period, while water with concentrations of NaSO4 and NaCl increased significantly, from 28% to 72%. The salinity of the groundwater increased rapidly and the affected area had expanded to most of the irrigation district. Stable isotope studies showed that most of the groundwater concentrations were derived from sulfate mineral dissolution. The minerals saturation indices (SI), ion ratios and oxygen isotope values of the groundwater indicated that the shallow groundwater had mainly experienced mineral dissolution, cation exchange, and mixing of the irrigated surface waters and groundwater. The groundwater quality had continuously evolved toward salinization as concentrations of SO4(2-) and Na+ grew to dominate it. Water quality risk analyses showed that most of the saline groundwater is not suitable for domestic and irrigation uses, especially in the middle and eastern parts of the irrigation district. These findings indicate that the irrigation district should strengthen the groundwater resources management.