Survey of the Prosthogonimus spp. metacercariae infection in the second intermediate host dragonfly in Heilongjiang Province, China.

Prosthogonimiasis poses a threat to the reproductive system of poultry and wild birds, which are the definitive hosts of the parasite causing this disease. However, the parasite infection of the second intermediate host (dragonfly), the primary vector of this pathogen, is rarely reported. In this study, the prevalence of Prosthogonimus infection in dragonflies was investigated from June 2019 to October 2022 in Heilongjiang Province, northeast China. The species of metacercariae isolated from dragonfly were identified by morphological characteristics, molecular biology techniques, and animal infection experiments. The results showed that 11 species of dragonflies and one damselfly were identified and among six of the dragonflies infected by Prosthogonimus metacercariae, Sympetrum depressiusculum (28.53%) had the highest infection rate among all positive dragonflies, followed by Sympetrum vulgatum (27.86%) and Sympetrum frequens (20.99%), which are preferred hosts, and the total prevalence was 20.39% (2061/10,110) in Heilongjiang Province. Three species of Prosthogoniumus metacercariae were isolated, including Prosthogonimus cuneatus, Prosthogonimus pullucidus, and Prosthogonimus sp., among which P. cuneatus was the dominant species in dragonflies in Heilongjiang Province. This is the first report on the prevalence of Prosthogonimus in dragonflies in China, which provides baseline data for the control of prosthogonimiasis in Heilongjiang Province and a reference for the prevention of prosthogonimiasis in other areas of China.

Chilling injury monitoring and intensity identification of dryland maize in Heilongjiang.

BACKGROUND: Accurate and timely access to large-scale crop damage information provides an essential reference for responding to agricultural disaster prevention and mitigation needs and ensuring food production security. The present study aimed to reveal the new characteristics of low-temperature cold damage to maize in the context of climate warming. Heilongjiang, one of the provinces with the highest latitude, the most significant climate change and the largest maize production in China, was taken as the study area. We combined meteorological stations and MODIS remote sensing data to spatially identify the occurrence and intensity of cold damage to maize based on the growing season temperature distance level index, as well as to assess the extent of cold damage. RESULTS: The main findings are: (i) The frequency and intensity range of cold damage in the growing season (May to September) in Heilongjiang Province from 1991 to 2020 against climate warming showed a decreasing trend. The average temperature from 1991 to 2000 was 17.777 °C, with seven occurrences of maize cold damage years, of which 5 years comprised widespread cold damage and 2 years comprised regional cold damage. The average temperature from 2000 to 2010 was 18.137 °C, with cold damage three times, of which 2 years comprised regional cold damage and 1 year comprised widespread cold damage. The average temperature from 2010 to 2020 was 18.130 °C, with one maize cold damage year occurring, which comprised regional cold damage. The frequency of maize chilling injury decreased significantly from 1991 to 2020, from 0.23 in 1991-2000 to 0.1 in 2000-2010 and, finally, to 0.03 in 2010-2020. (ii) The good consistency between MODIS_LST data and temperature data from meteorological stations suggests that MODIS_LST data can be used to build a temperature remote sensing estimation model for spatially extensive cold damage monitoring and intensity discrimination. (iii) Taking 2009 as an example of a large-scale cold damage year, the spatial discrimination of maize cold damage intensity shows that the spatial distribution of chilling injury intensity has no obvious geographical features. The intensity of cold damage was mainly mild cold damage. According to administrative regions, the scope of chilling injury was the largest in Mudanjiang City, Heihe City, and Jixi City, accounting for 91.56%, 86.25%, and 84.91%, respectively. The areas with the most extensive range of severe chilling injuries were the Great Khingan Mountains region, Heihe City, Mudanjiang City, Yichun City, and Jixi City. CONCLUSION: In the context of climate warming, the frequency and intensity range of maize cold damage showed a decreasing trend from 1991 to 2020 in Heilongjiang Province. The results of cold damage identification based on MODIS_LST data are accurate and can improve the spatial accuracy. The results of the present study provide a reference and guidance for dealing with the occurrence and defence of spatially refined cold damage. © 2023 Society of Chemical Industry.

Warming/cooling effect of cropland expansion during the 1900s ~ 2010s in the Heilongjiang Province, Northeast of China.

Land cover change (LCC) significantly changed the local/regional temperature. This paper attempts to reveal the effects of cropland expansion in different ways on temperature change from the 1900s to 2010s in Heilongjiang Province. To reach this goal, we conducted four simulation research schemes with the coupled Weather Research and Forecast (WRF)-Noah model to investigate the warming/cooling effect of cropland expansion. The results show that cropland expansion exerted different effects with different land-use type conversions. In the last century, the areas with grassland-to-cropland and wetland-to-cropland transition show the warming effect, and the average surface temperature in Heilongjiang Province increased by 0.023 ℃ and 0.024 ℃, respectively. The areas with forest-to-cropland transition show the cooling effect, in which the average temperature decreased by 0.103 ℃. The variation of air temperature is mainly caused by the variation of surface reflectance and surface net radiation flux. The results provide evidence that cropland expansion changes to biophysical landscape characteristics, warming/cooling the land surface and thus enhancing/reducing the temperature, and lead to regional climate change eventually.

Spatial evolution of cultivated land in the Heilongjiang Province in China from 1980 to 2015.

Sustaining cultivated land is critically important for food security, economic development, and social stability in China. China has been developing rapidly since the adoption of the Chinese Economic Reform of 1978, revealing the spatial evolution characteristics of cultivated land can provide valuable information for estimating and sustaining Chinese food security. In this study, we analyzed the spatial evolution of cultivated land from 1980 to 2015 in the Heilongjiang Province, one of the most important grain production regions in China, by combining five land-use databases, a geographic information system, and mathematical models. The results showed that cultivated land in the Heilongjiang Province increased by 33,234 km2 (23%) from 1980 to 2015. The increase primarily resulted from land conversion from the forest (11,511 km2), grassland (9780 km2), and unused land (9696 km2). Additionally, cultivated land-use change's spatial characteristics differed among decadal periods. Spatial changes were stronger during 1990-2000 than in the other periods (1980-1990, 2000-2010, and 2010-2015). The landscape shape index indicated that cultivated land development had a regular changing pattern but showed a trend toward irregular development over the study period. The spatial expansion of cultivated land showed a strong directional trend, which was further found to be associated with geomorphological factors, indicating the prominent controls of abiotic factors on cultivated land expansion. This study provides an overview of the long-term spatial evolution characteristics of cultivated land and the key abiotic controls on cultivated land use change. This information can help local government policymakers effectively balance regional development, environmental protection, and food security.

[General situation and comprehensive utilization of medicinal fungi resources in Heilongjiang province].

In order to develop and utilize the macrofungi in Heilongjiang province, numerous literatures have been investigated to make a comprehensive analysis of the number of known species of fungi in Heilongjiang province. There exists a total of 546 species of macrofungus in Heilongjiang province belonging to 53 families and 13 orders of 6 classes and 2 subdivisions. And its application value is classified, summarized and reviewed. Three hundred and twenty kinds of edible fungi, 214 species of fungi with medicinal value, medicinal value in the anti-cancer effects of 167 species of fungi, 141 wood rot fungi, 141 species of ectomycorrhizal fungi, 88 poisonous species, 67 macrofungus which are not clarified whether could be edible or toxic. It shows a broad prospects for development and utilization of macrofungus resources in Heilongjiang province.

Peste des petits ruminants virus in Heilongjiang province, China, 2014.

During March 25-May 5, 2014, we investigated 11 outbreaks of peste des petits ruminants in Heilongjiang Province, China. We found that the most likely source of the outbreaks was animals from livestock markets in Shandong. Peste des petits ruminants viruses belonging to lineages II and IV were detected in sick animals.

CERES-Maize model-based simulation of climate change impacts on maize yields and potential adaptive measures in Heilongjiang Province, China.

BACKGROUND: Climate change would cause negative impacts on future agricultural production and food security. Adaptive measures should be taken to mitigate the adverse effects. The objectives of this study were to simulate the potential effects of climate change on maize yields in Heilongjiang Province and to evaluate two selected typical household-level autonomous adaptive measures (cultivar changes and planting time adjustments) for mitigating the risks of climate change based on the CERES-Maize model. RESULTS: The results showed that flowering duration and maturity duration of maize would be shortened in the future climate and thus maize yield would reduce by 11-46% during 2011-2099 relative to 1981-2010. Increased CO2 concentration would not benefit maize production significantly. However, substituting local cultivars with later-maturing ones and delaying the planting date could increase yields as the climate changes. CONCLUSION: The results provide insight regarding the likely impacts of climate change on maize yields and the efficacy of selected adaptive measures by presenting evidence-based implications and mitigation strategies for the potential negative impacts of future climate change.

Prevalence and Molecular Characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in Cattle in Heilongjiang Province, Northeast China.

Crytosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are important diarrheal pathogens with a global distribution that threatens the health of humans and animals. Despite cattle being potential transmission hosts of these protozoans, the associated risks to public health have been neglected. In the present study, a total of 1155 cattle fecal samples were collected from 13 administrative regions of Heilongjiang Province. The prevalence of Cryptosporidium spp., G. duodenalis, and E. bieneusi were 5.5% (64/1155; 95% CI: 4.2-6.9), 3.8% (44/1155; 95% CI: 2.7-4.9), and 6.5% (75/1155; 95% CI: 5.1-7.9), respectively. Among these positive fecal samples, five Cryptosporidium species (C. andersoni, C. bovis, C. ryanae, C. parvum, and C. occultus), two G. duodenalis assemblages (E and A), and eight E. bieneusi genotypes (BEB4, BEB6, BEB8, J, I, CHS7, CHS8, and COS-I) were identified. Phylogenetic analysis showed that all eight genotypes of E. bieneusi identified in the present study belonged to group 2. It is worth noting that some species/genotypes of these intestinal protozoans are zoonotic, suggesting a risk of zoonotic disease transmission in endemic areas. The findings expanded our understanding of the genetic composition and zoonotic potential of Cryptosporidium spp., G. duodenalis, and E. bieneusi in cattle in Heilongjiang Province.

Virome analysis of ticks and tick-borne viruses in Heilongjiang and Jilin Provinces, China.

Ticks transmit diverse human and animal pathogens, leading to an increasing number of public health concerns. In the forest area of northeast China, the spread of tick-borne diseases (TBDs) is severe; however, little is known about the tick virome composition and evolution. Herein, we investigate the geographical distribution of tick species and related viruses in Heilongjiang and Jilin Provinces in Northeast China. To reveal the diversity of tick-borne viruses in parts of Heilongjiang and Jilin, ticks were collected at 9 collection points in these provinces in 2018. Morphology and molecular biology were used to identify tick species, and 1411 ticks from nine sampling sites were collected and analysed by next-generation sequencing (NGS). Four Ixodidae were identified, including Ixodes persulcatus, Haemaphysalis japonica, Dermacentor silvarum, and Haemaphysalis concinna. After removal of host genome sequences, 13,003 high-quality NGS reads were obtained and annotated as viruses. Further phylogenetic analysis based on amplicons revealed that these viral sequences belong to Beiji nairovirus, Alongshan virus, bovine parvovirus-2, and tick-associated circovirus; some distinct sequences are closely related to Songling virus, Changping tick virus, Norway luteo-like virus 2, and Norway partiti-like virus 1. In summary, this study describes the prevalence of local ticks and variety of tick-borne viruses in northeastern China, providing a basis for further research on tick-borne viruses in the future.

[Prediction of potential suitable habitats of Haemphysalis concinna in Heilongjiang Province based on the maximum entropy model].

OBJECTIVE: To predict the potential suitable habitat of Haemaphysalis concinna in Heilongjiang Province under different climatic scenarios. METHODS: The geographic locations of ticks in Heilongjiang Province from 1980 to 2022 were captured from literature review and field ticks monitoring data from Harbin Center for Disease Control and Prevention in Heilongjiang Province, and the tick distribution sites with spatial correlations were removed using the software ArcGIS 10.2. The environment data under historical climatic scenarios from 1970 to 2000 and the climatic shared socioeconomic pathways (SSP) 126 scenario model from 2021 to 2040 and from 2041 to 2060 were downloaded from the WorldClim website, and the elevation (1 km, 2010), population (1 km grid population dataset of China, 2010) and annual vegetation index (1 km, 2010) data were downloaded from the Resource and Environmental Science and Data Center, Institute of Geographical Sciences and Natural Resources, Chinese Academy of Sciences. The contribution of environmental factors to H. concinna distribution was evaluated and environmental variables were screened using the software MaxEnt 3.4.1 and R package 4.1.0, and the areas of suitable habitats of H. concinna and changes in center of gravity were analyzed using the maximum entropy model in Heilongjiang Province under different climatic scenarios. In addition, the accuracy of the maximum entropy model for prediction of H. concinna distribution was assessed using the area under curve (AUC) of the receiver operating characteristic curve. RESULTS: A total of 79 H. concinna distribution sites and 24 environmental variables were collected, and 70 H. concinna distribution sites and 9 environmental factors that contributed to distribution of the potential suitable habitats of H. concinna in Heilongjiang Province were screened. The three most significant contributing factors included precipitation seasonality, annual precipitation, and mean temperature of the driest quarter, with cumulative contributions of 60.7%. The total area of suitable habitats of H. concinna was 29.05 × 104 km2 in Heilongjiang Province under historical climatic scenarios, with the center of gravity of suitable habitats located at (47.31° N, 129.16° E), while the total area of suitable habitats of H. concinna reduced by 0.97 × 104 km2 in Heilongjiang Province under the climatic SSP126 scenario from 2041 to 2060, with the center of gravity shifting to (47.70° N, 129.28° E). CONCLUSIONS: The distribution of suitable habitats of H. concinna strongly correlates with temperature and humidity in Heilongjiang Province. The total area of potential suitable habitats of H. concinna may appear a tendency towards a decline with climatic changes in Heilongjiang Province, and high-, medium- and low-suitable habitats may shift.

Remote nursing training model combined with proceduralization in the intensive care unit dealing with patients with COVID-19.

The shortage of personal protective equipment and lack of proper nursing training have been endangering health care workers dealing with coronavirus disease 2019 (COVID-19). In our treatment center, the implementation of a holistic care model of time-sharing management for severe and critical COVID-19 patients has further aggravated the shortage of intensive care unit (ICU) professional nurses. Therefore, we developed a short-term specialized and targeted nursing training program to help ICU nurses to cope with stress and become more efficient, thus reducing the number of nurses required in the ICU. In order to avoid possible human-to-human spread, small teaching classes and remote training were applied. The procedural training mode included four steps: preparation, plan, implementation, and evaluation. An evaluation was conducted throughout the process of nursing training. In this study, we documented and shared experiences in transitioning from traditional face-to-face programs to remote combined with proceduralization nursing training mode from our daily work experiences during the COVID-19 pandemic, which has shown to be helpful for nurses working in the ICU.

Exploration of transmission chain and prevention of the recurrence of coronavirus disease 2019 in Heilongjiang Province due to in-hospital transmission.

The coronavirus disease 2019 (COVID-19) epidemic is a major public health emergency characterized by fast spread, a wide range of infections, and enormous control difficulty. Since the end of December 2019, Wuhan has become the first core infection area of China's COVID-19 outbreak. Since March 2020, the domestic worst-hit areas have moved to the Heilongjiang Province due to the increased number of imported COVID-19 cases. Herein, we reported the major COVID-19 outbreak, which caused a rebound of the epidemic in Harbin, China. After the rebound, different levels of causes for the recurrence of COVID-19, including city-level, hospital-level, and medical staff-level cause, were investigated. Meanwhile, corresponding countermeasures to prevent the recurrence of the epidemic were also carried out on the city level, hospital level, and medical staff level, which eventually showed the effect of infection control function in a pandemic. In this study, we described the complete transmission chain, analyzed the causes of the outbreak, and proposed corresponding countermeasures from our practical clinical experience, which can be used as a valuable reference for COVID-19 control.

Prevalence of Porcine Pseudorabies Virus and Its Coinfection Rate in Heilongjiang Province in China from 2013 to 2018.

Pseudorabies (PR) is a highly contagious disease affecting a wide range of animals, which annually causes great economic losses in China. In this study, a total number of 18,815 serum samples and 1,589 tissue samples were collected from 311 intensive pig farms (≥350 sows) located in eight cities in Heilongjiang province, and tested by ELISA and PCR. Overall, the serum positive rates of gE and gB protein were 16.3% and 84.5%, respectively. The PCR-positive rate of PR virus (PRV) in tissue samples was 17.8%. The coinfection rates of PRV with porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), and classical swine fever virus (CSFV) were also measured. The rate of PRV coinfected with PRRSV was 36.0% followed by 12.9% with PCV2 and 1.8% with CSFV, respectively. These results clearly demonstrate PRV prevalence and its coinfection rate in Heilongjiang province, indicating high PR endemic in pig farms in this region. This study provides data for further epidemiological investigations and a reference for developing PRV control strategies in this region and in China.

Comparison of the Photosynthetic Capacity of Phragmites australis in Five Habitats in Saline‒Alkaline Wetlands.

Water shortages have an important impact on the photosynthetic capacity of Phragmites australis. However, this impact has not been adequately studied from the perspective of photosynthesis. An in-depth study of the photosynthetic process can help in better understanding the impact of water shortages on the photosynthetic capacity of P. australis, especially on the microscale. The aim of this study is to explore the photosynthetic adaptation strategies to environmental changes in saline‒alkaline wetlands. The light response curves and CO2 response curves of P. australis in five habitats (hygrophilous, xerophytic, psammophytic, abandoned farmland, paddy field drainage) in saline‒alkaline wetlands were measured at different stages of their life history, and we used a nonrectangular hyperbolic model to fit the data. It was concluded that P. australis utilized coping strategies that differed between the growing and breeding seasons. P. australis in abandoned farmland during the growing season had the highest apparent quantum efficiency (AQE) and photosynthetic utilization efficiency for weak light because of the dark environment. The dark respiration rate of P. australis in the drainage area of paddy fields was the lowest, and it had the highest values for photorespiration rate, maximum photosynthetic rate (Pmax), photosynthetic capacity (Pa), biomass, maximum carboxylation rate (Vcmax), and maximum electron transfer rate (Jmax). The light insensitivity of P. australis increased with the transition from growing to breeding season, and the dark respiration rate also showed a downward trend. Moreover, Vcmax and Jmax would decline when Pmax and Pa showed a declining trend, and vice versa. In other words, Vcmax and Jmax could explain changes in the photosynthetic capacity to some extent. These findings contribute to providing insights that Vcmax and Jmax can directly reflect the variation in photosynthetic capacity of P. australis under water shortages in saline‒alkaline wetlands and in other parts of world where there are problems with similarly harmful environmental conditions.

[Time-series characteristics of drought and flood in spring soybean growing season and its effect on soybean yield in Heilongjiang Province, China]. / é»‘é¾™æ±Ÿçœå¤§è±†ç”Ÿé•¿å­£æ—±æ¶æ—¶åºç‰¹å¾åŠå ¶å¯¹äº§é‡çš„å½±å“.

Under the background of climate change, the spatial-temporal distribution of precipita-tion in Heilongjiang Province is uneven, and drought and flood frequently change, which is not conducive to the safety of soybean production for the province. To clarify the influence mechanism of drought and flood in the growing season on soybean yield in Heilongjiang Province, we analyzed the time-series characteristics of drought and flood in soybean growing season and its effect on soybean yield in different growth stages, based on data of daily precipitation from 60 meteorological stations during 1961 to 2018 and soybean yield in the same period, with the standardized precipitation index (SPI) as the drought and flood evaluation index. The results showed that, from 1961 to 2018, the influence range of drought in soybean growing season in Heilongjiang Province showed a weak decreasing trend, while that of flood showed a weak increasing trend. In the same period, the intensity of both drought and flood showed a weak increasing trend, with slightly stronger role of flood intensity. The probability of the co-occurrence of drought and flood accounted for 60.3%. The soybean growing season in Heilongjiang Province may become wetter. From 2012 to 2018, the influence range and occurrence intensity of flood were significantly higher than that of drought, six years of the whole or regional flood occurred, in which five years were moderate degrees. The effects of drought and flood on soybean yield differed across regions in soybean growing season. The effect of flood on soybean yield was significantly stronger than that of drought in the Northwest, North and East, and were similar in the Midland, while in the Southwest, South and Southeast, the effect of drought was much greater than that of flood. The fluctuation of soybean yield was closely related to drought and flood during bloom-seed-filling period. Among them, in the Northwest, Southwest, Midland, South and Southeast of Heilongjiang, soybean yield would reach a high level when there was a little bit more precipitation, but the moderate and above-moderate levels of flood would cause the reduction. In the North, the fluctuation of soybean yield was mainly affected by flood, while in the East, the effects of drought and flood on soybean yield were similar.

Molecular Identification and Phylogenetic Analysis of Nuclear rDNA Sequences of Clonorchis sinensis Isolates From Human Fecal Samples in Heilongjiang Province, China.

Studying the genetic diversity of parasite is important for understanding their biogeography and molecular epidemiology, as well as for establishing disease prevention and control strategies. Clonorchis sinensis is an important foodborne parasite worldwide. However, despite its epidemiological significance, the genetic diversity of C. sinensis has not been well studied from human in northeastern China. In this study, a total of 342 fecal specimens were collected from residents living in five villages in Heilongjiang Province and analyzed for the presence of C. sinensis by PCR amplification and sequencing of the internal transcribed spacer 1 (ITS1) and ITS2 regions of nuclear ribosomal DNA. 21.64% (74/342) of fecal samples were found to be positive for C. sinensis by PCR. The sequences of the ITS1 region in 34 of the 74 samples (45.95%) matched that of MK179278, Genetic polymorphisms were observed at six nucleotide sites. The ITS2 gene sequence of 37 of the 74 samples (50%) matched that of MK179281. In conclusion, a low degree of genetic diversity between C. sinensis isolates from China and different geographical regions was found at ITS loci. Despite this conservation, sequencing of the rDNA region has provided important data that will be useful for future studies addressing the molecular evolution, biology, medical implications and ecology of C. sinensis.

Opportunities for low-carbon socioeconomic transition during the revitalization of Northeast China: Insights from Heilongjiang province.

The Strategies of Reviving the Old Industrial Bases provide opportunities for low-carbon transition in Northeast China, which is one of the earliest regions to industrialize and the largest rustbelt in China, but study on the impacts of its socioeconomic factors on CO2 emissions is still in short, though it is essential for guiding the pathways to achieve low-carbon socioeconomic transition. We adopted the structural decomposition analysis (SDA) to identify the main contributors to emissions increase in Heilongjiang province during 2002-2012, which is the heartland of Northeast revitalization. The results show that the increase in CO2 emissions was mainly driven by growth in per-capita final demand, which generated 203.8 Mt (153.6%) upstream CO2 emissions between 2002 and 2012. Changes in production structure and final demand structure had smaller impacts on CO2 emissions increase (36.1 Mt and 27.0 Mt). However, the positive influences were largely overwhelmed by change in emission intensity, which avoided 135.4 Mt (-102%) CO2 emissions. Therefore, appropriate measures related to energy structure optimization and efficiency improvement should be implemented. Especially, increasing the proportion of wind, solar and biomass energy in Heilongjiang, where renewable energy is abundant, would reduce the CO2 emissions significantly. In addition, domestic export took the lead position in driving the CO2 emissions in Heilongjiang, accounting for 37.6%-43.1% annual emissions between 2002 and 2012. Thus, some financial instrument, such as tax relief for less carbon intensive exports could be adopted to prompt upstream suppliers to decarbonize their production processes.

Preliminary Study on Prevalence, Risk Factor and Genetic Homogeneity of Porcine Reproductive and Respiratory Syndrome Virus in Registered Pig Farms in Heilongjiang, China.

While porcine reproductive and respiratory syndrome (PRRS) causes great economic losses in southern and central China, systematic studies on the epidemiology of PRRS virus (PRRSV) in Heilongjiang Province had not been performed. Therefore, we conducted a preliminary study to estimate the prevalence and risk factors associated with PRRSV infection, as well as characterize the PRRSV in registered pig farms in Heilongjiang Province, China in 2011. A total of 1237 blood samples were collected from 72 farms and tested by reverse transcription polymerase chain reaction (RT-PCR) for PRRSV. Risk factors associated to PRRSV infection were analysed using logistic regression models. Genes of non-structural protein-2 (Nsp2) and glycoprotein 5 (GP5) from 22 isolates were sequenced for phylogenetic analysis. The results showed that the herd apparent prevalence was 9.7% (95% CI: 6.3, 13.1) in Heilongjiang Province. An increased risk of PRRSV infection on farms was associated with unrestricted movement of external people (OR = 14.1, 95% CI: 1.68, 119.07), close proximity (<1 km) to the nearest house, road or neighbouring farm (OR = 16.2, 95% CI: 1.52, 171.80), and selling farm products at both local and provincial markets (OR = 20.6, 95% CI: 2.02, 210.56). Phylogenetic analysis based on partial amino acid sequences of GP5 and Nsp2 showed that all the 22 PRRSV isolates in Heilongjiang are closely related to the highly pathogenic PRRSV strain JXA1 and belong to the Genotype 2 (American genotype). The prevalence, determination of risk factors and phylogenetic characterization will provide information for future epidemiological studies and a reference for developing surveillance and control strategies in this region.

The HIV/AIDS epidemic characteristics in a northeast province of China--men who have sex with men have made a tremendous contribution to the growth of the HIV epidemic.

OBJECTIVE: To investigate the characteristics and trends of the HIV epidemic in Heilongjiang province of China between 1993 and 2012. METHODS: Data from the provincial surveillance system for HIV infections and AIDS were reviewed. Local health staff reviewed medical records, including dates of HIV/AIDS diagnoses and deaths, exposure category, treatment, laboratory testing, and demographics. RESULTS: By 31 October 2012, a total of 3062 HIV-infections were detected with 426 deaths and 206 who presently live outside Heilongjiang province, 38.1% of whom were diagnosed as AIDS. Since 2007, homosexual transmission has increased and become the dominant route of HIV transmission, accounting for 57.9% of cases during 2009-2010, and 69.0% during 2011-2012. Men who have sex with men (MSM) with HIV-infections had the following characteristics: 21-30 year age group (42.4%); unmarried (61.6%); urban residents (46.7%); and college or higher education (36.8%). In addition, the proportion of MSM ≤ 30 years of age and rural residents showed an uptrend across the study years. CONCLUSIONS: The HIV/AIDS epidemic has continued to increase in Heilongjiang province, and has shown an explosive growth since 2008, with MSM making a tremendous contribution to the HIV outbreak. Homosexual contact has become the dominant route of HIV transmission. Urgent intervention is needed to recognize this target population, especially those ≤30 years of age, unmarried, and urban residents.