Polarization-dependent photoinduced metal-insulator transitions in manganites.

In correlated oxides, collaborative manipulation on light intensity, wavelength, pulse duration and polarization has yielded many exotic discoveries, such as phase transitions and novel quantum states. In view of potential optoelectronic applications, tailoring long-lived static properties by light-induced effects is highly desirable. So far, the polarization state of light has rarely been reported as a control parameter for this purpose. Here, we report polarization-dependent metal-to-insulator transition (MIT) in phase-separated manganite thin films, introducing a new degree of freedom to control static MIT. Specifically, we observed giant photoinduced resistance jumps with striking features: (1) a single resistance jump occurs upon a linearly polarized light incident with a chosen polarization angle, and a second resistance jump occurs when the polarization angle changes; (2) the amplitude of the second resistance jump depends sensitively on the actual change of the polarization angles. Linear transmittance measurements reveal that the origin of the above phenomena is closely related to the coexistence of anisotropic micro-domains. Our results represent a first step to utilize light polarization as an active knob to manipulate static phase transitions, pointing towards new pathways for nonvolatile optoelectronic devices and sensors.

Electronically phase separated nano-network in antiferromagnetic insulating LaMnO3/PrMnO3/CaMnO3 tricolor superlattice.

Strongly correlated materials often exhibit an electronic phase separation (EPS) phenomena whose domain pattern is random in nature. The ability to control the spatial arrangement of the electronic phases at microscopic scales is highly desirable for tailoring their macroscopic properties and/or designing novel electronic devices. Here we report the formation of EPS nanoscale network in a mono-atomically stacked LaMnO3/CaMnO3/PrMnO3 superlattice grown on SrTiO3 (STO) (001) substrate, which is known to have an antiferromagnetic (AFM) insulating ground state. The EPS nano-network is a consequence of an internal strain relaxation triggered by the structural domain formation of the underlying STO substrate at low temperatures. The same nanoscale network pattern can be reproduced upon temperature cycling allowing us to employ different local imaging techniques to directly compare the magnetic and transport state of a single EPS domain. Our results confirm the one-to-one correspondence between ferromagnetic (AFM) to metallic (insulating) state in manganite. It also represents a significant step in a paradigm shift from passively characterizing EPS in strongly correlated systems to actively engaging in its manipulation.

[Analysis of follow-up and administration of HIV-infected Burmese in Dehong prefecture of Yunnan province].

OBJECTIVE: To compare follow-up and administration of HIV-infected local Chinese and Burmese in Dehong prefecture of Yunnan province, for scientific development of prevention and control measures. METHODS: 14 270 HIV-infected local Chinese and 5 436 HIV-infected Burmese reported from 1989 to December 31, 2013 in Dehong prefecture were recruited as the subjects of study, comparing the differences of follow-up and management, CD4⁺ T lymphocyte count tests and antiretroviral therapy (ART) between the two groups. RESULTS: The proportion of HIV-infected Burmese identified in Dehong prefecture was 27.6% (5 436/19 706) during 1989-2013. The number had been growing rapidly from 17.1% in 1989-2003, 12.4% in 2004 and 14.7% in 2005 to over 51.4% in 2012, hitting 59.4% in 2013 (trends χ² = 1 732.84, P < 0.000 1). The proportion of HIV-infected Burmese among case reports of various characteristics kept rising over the years. By the end of 2013, 8 095 HIV-infected local Dehong residents and 5 326 HIV-infected Burmese were still alive. 95.8% of them were under follow-up, 88.5% having CD4⁺ T lymphocyte count tests, and 78.3% under ART. Among the HIV-infected B urmese, only 19.2% of them were under follow-up, 13.0% having CD4⁺ T lymphocyte count tests, and 6.1% under ART, significantly lower than the local Dehong residents (P < 0.000 1). CONCLUSION: The proportion of follow-up and administration, CD4⁺ T lymphocyte count tests, and ART of HIV-infected Burmese was low in Dehong prefecture, Yunnan province, which called for more effective follow-up and administration measures.

[Study on HIV viral load in plasma and drug resistance among AIDS patients receiving antiretroviral treatment in Dehong prefecture,Yunnan province].

OBJECTIVE: To understand HIV rival suppression and drug resistance (HIVDR) among AIDS patients who were receiving antiretroviral treatment (ART) in Dehong prefecture, Yunnan province. METHODS: All AIDS patients who were aged over 15 years and with experience more than six months on ART by the end of 2012 in Dehong prefecture, were enrolled to receive testing for HIV viral load in plasma and genetic mutations associated with HIVDR. RESULTS: A total of 4 390 AIDS patients were qualified for the study according to the selection criteria, of whom 3 964 (90.3%) finally participated in the study. Among them, 2 307(58.2%) had CD4(+) cell counts more than 350 cells/mm³. 3 169 (79.9%) patients showed undetectable plasma HIV viral load which was lower than the detection threshold. Those who had the following factors as:resided in Ruili city, being female, older than 45 years of age, married, heterosexually infected with HIV, having received ART more than 5 years, and CD4(+) cell counts >500 cells/mm³, were more likely to have undetectable plasma virus load, with the differences statistically significant. 402 (10.1%) patients had plasma viral load ≥ 1 000 copies/ml, of whom 353 (87.8%) were successfully amplified and examined for HIVDR. Among them, 198 (56.1% ) were identified to bear genetic mutations associated with HIVDR. Most mutations were related to the resistance to nucleotide reverse transcriptase inhibitors (NNRTIs) or non-nucleotide reverse transcriptase inhibitors (NNRTIs), with M184V and K103N most frequently seen. 12 patients (3.4%) were found to have mutations resistant to protease inhibitors (PI). Data from multiple logistic regression analysis indicated that the period of receiving ART and the initial ART regimen could both significantly predict the occurrence of HIV resistance. CONCLUSION: Viral suppression was highly achieved among ART-prescribed AIDS patients in Dehong prefecture,Yunnan province. However, among those who did not show effective viral suppression, the proportion of HIVDR was high, underscoring the needs for health education so as to improve the adherence to drugs as well as for improving testing for viral load and HIVDR among AIDS patients.

[Proportion and related influencing factors of HIV-infected individuals that rejecting the antiretroviral therapy among all the HIV infections, Dehong prefecture, Yunnan province].

OBJECTIVE: To examine the proportion and influencing factors on HIV-infected individuals who rejecting the antiretroviral therapy among all the HIV positives, in Dehong prefecture, Yunnan province. METHODS: A cross-sectional analysis was conducted on all the local HIV-infected survivals aged over 16 year old who refused to receive antiretroviral therapy (ART) by the end of 2013 in Dehong prefecture. RESULTS: The proportion of those rejecting the ART among HIV-infected survivals and aged over 16 years old in Dehong prefecture, was 7.4% (605/8 136). Factors related to the 'rejection' among the 605 refusals would include: being male (72.9%), aged 31-45 years (57.2%), peasants (75.4%), married (52.2%), with minor ethnicity (41.3%), illiterate or only having primary school education (58.7%), infected through sexual contacts (61.2%), and with CD4(+)T cell counts >350 cells/mm(3) (66.6%). Data from the multiple logistic regression analysis indicated that rejecting the ART was significantly associated with areas, gender, age, ethnicity and CD4(+)T cell counts of the HIV patients. Those who were from Yingjiang county, female, aged 31-45 years old had lower proportions of ART refusals than those who were from Ruili city, male, aged ≤30 year old. Those who were of Dai minority and had no records on CD4(+)T cell counts, had higher proportions of ART refusals than those who were of Han ethnicity and had CD4(+)T cell counts ≤350 cells/mm(3). Reasons for the 605 HIV-infected patients with rejection to the ART would include fear of disclosure of HIV infection status (84, 13.9%), misunderstandings of the effectiveness and side effects of ART (111, 18.3%), self-realized wellness(340, 56.2%) and others (70, 11.6%). Of them, reasons for the 181 patients with CD4(+)T cell counts ≤350 cells/mm(3) that rejecting ART would include fearfulness on the disclosure of HIV infection status(40, 22.1%), misunderstandings of the effectiveness and side effects of ART (36, 19.9%), self-realized wellness (84, 46.4%) and others (21, 11.6%). Among those who rejected ART, reasons for that would vary by areas, gender, age, marital status and routes of HIV transmission, according to the results from Chi-squared tests. CONCLUSION: A substantial proportion of HIV-infected individuals rejected ART in Dehong prefecture of Yunnan province. It was urgently needed to enhance health education programs of ART tailored for those HIV-infected patients, according to different characteristics and reasons for rejection, so as to promote the ART in this prefecture.

[Study on the incidence and risk factors of HCV infection among heroin addicts who were on methadone maintenance treatment in Dehong prefecture,Yunnan province].

OBJECTIVE: To determine the incidence and risk factors of HCV infection among heroin addicts who were receiving methadone maintenance treatment(MMT)in Dehong prefecture, Yunnan province. METHODS: All heroin addicts who were HCV negative at the initiation of MMT in June 2005 through March 2012, in Dehong prefecture, were included in this cohort analysis. HCV incidence was calculated and related risk factors determined by using Cox proportional hazard regression model. RESULTS: A total of 2390 MMT clinic attendants were qualified for this cohort study by March 2012. 731(30.6%) of them had never received any follow-up HCV testing so were recognized as loss to follow-up. The other 1659 (69.4%) participants had received at least one follow-up HCV testing and were observed for a total of 3509.12 person-years(py). During this period 99 new HCV infections or HCV sero-converters were identified. The overall HCV incidence was 2.82/100 py and was 3.62/100 py for 2006, 5.36/100 py for 2007, 6.71/100 py for 2008, 2.56/100 py for 2009, 1.90/100 py for 2010, and 0.44/100 py for 2011, respectively. Results from multiple regression analysis, using Cox proportional hazard model, indicated that after controlling for confounding variables, those who were unemployed, being injecting drug users(IDUs)or HIV positive at entry into the MMT program were more likely to be newly infected with HCV or HCV sero-converted during the follow-up period than those who were peasants, non-IDUs or HIV negative at entry into the MMT program(HR = 2.02, 95% CI:1.18-3.48; HR = 9.05, 95% CI:5.49-14.93; HR = 2.12, 95% CI: 1.37-3.56), respectively. CONCLUSION: The incidence of HCV infection among MMT clinic attendants was decreasing since 2009 in Dehong prefecture. Those who were unemployed, injecting drug users and HIV positive were at higher risk of HCV infection.

Total HIV/AIDS expenditures in Dehong Prefecture, Yunnan province in 2010: the first systematic evaluation of both health and non-health related HIV/AIDS expenditures in China.

OBJECTIVE: We assessed HIV/AIDS expenditures in Dehong Prefecture, Yunnan Province, one of the highest prevalence regions in China, and describe funding sources and spending for different categories of HIV-related interventions and at-risk populations. METHODS: 2010 HIV/AIDS expenditures in Dehong Prefecture were evaluated based on UNAIDS' National AIDS Spending Assessment methodology. RESULTS: Nearly 93% of total expenditures for HIV/AIDS was contributed by public sources. Of total expenditures, 52.7% was allocated to treatment and care, 24.5% to program management and administration and 19.8% to prevention. Spending on treatment and care was primarily allocated to the treatment of opportunistic infections. Most (40.4%) prevention spending was concentrated on most-at-risk populations, injection drug users (IDUs), sex workers, and men who have sex with men (MSM), with 5.5% allocated to voluntary counseling and testing. Prevention funding allocated for MSM, partners of people living with HIV and prisoners and other confined populations was low compared to the disproportionate burden of HIV/AIDS in these populations. Overall, people living with HIV accounted for 57.57% of total expenditures, while most-at-risk populations accounted for only 7.99%. CONCLUSIONS: Our study demonstrated the applicability of NASA for tracking and assessing HIV expenditure in the context of China, it proved to be a useful tool in understanding national HIV/AIDS response from financial aspect, and to assess the extent to which HIV expenditure matches epidemic patterns. Limited funding for primary prevention and prevention for MSM, prisoners and partners of people living with HIV, signal that resource allocation to these key areas must be strengthened. Comprehensive analyses of regional and national funding strategies are needed to inform more equitable, effective and cost-effective HIV/AIDS resource allocation.

[Comprehensive evaluation of AIDS spending in Dehong prefecture of Yunnan province in 2010].

OBJECTIVE: To comprehensive evaluate the rationality of Acquired Immune Deficiency Syndrome (AIDS) expenditure through the analysis of AIDS expenditure circumstances based on the application of National AIDS Spending Assessment in Dehong prefecture in 2010. METHODS: Demographic and economic indicators of Mang City, Yingjiang, Longchuan, Ruili City, Lianghe and Wanting zone in Dehong prefecture of Yunnan province were collected from the reports issued by Dehong Statistical Bureau of 2010, and HIV/AIDS epidemic indicators were collected from the annual report of national AIDS prevention and control data.NASA method was used to analyze the actual spending and demand index was used to calculate the demand of AIDS funding in these counties (cities). The correlations between HIV/AIDS expenditures and demographic, economic and HIV/AIDS epidemic index were analyzed, respectively, as well as the correlation between the expenditures of AIDS prevention and control and proportion of major transmission approaches. RESULTS: In 2010, the actual expenditures on HIV/AIDS in the 5 counties (cities) of Dehong prefecture was ¥28 752 772, the population was 1 211 400, and Gross Domestic Product (GDP) was ¥11 693. The intervention expenditures in injection drug users, sexually transmitted people, and prevention of mother to child transmission in Ruili county were ¥130 345, ¥71 484 and ¥164 100, the proportions of HIV transmission in these groups were 23.9% (49/205), 73.7% (151/205), and 0.5% (1/205), respectively; and in Lianghe county was ¥141 665, ¥257 142, and ¥99 961, and the proportions of HIV transmission were 17.1% (6/35), 80.0% (28/35) and 0.0% (0/35), respectively. The intervention expenditures in Ruili and Lianghe counties were positive related to the proportion of corresponding people with HIV infection (both r values were 0.99, all P values < 0.05). In the other 4 counties (cities) and the development zone, no correlations. The expenditures of government departments, international projects, domestic research programs and personal and family pays (r value were 0.94, 0.83, 0.99 and 0.88, respectively, all P values < 0.05) were positive related to the number.Except the personal and family pays, other sources of expenditures were all positive related to the number of reported HIV/AIDS cases (r values were 0.94, 0.89 and 0.81, respectively, all P values < 0.05). CONCLUSION: Population and HIV/AIDS epidemic index were considered as factors in AIDS spending. The expenditures corresponded with the demand of different areas basically.

[Study on the mortality and risk factors among HIV-infected individuals during 1989 - 2011 in Dehong prefecture, Yunnan province].

OBJECTIVE: To examine the mortality and risk factors among HIV-infected patients during 1989 - 2011 in Dehong prefecture, Yunnan province. METHODS: All HIV-infected patients reported during 1989 - 2011 in Dehong prefecture who held local residency were included in the study. Mortality rates and cumulative survival rates were calculated. Multiple regression analysis under Cox proportional hazard model was conducted to examine the risk factors for deaths. RESULTS: A total of 13 006 HIV-infected patients were included in this study including 73.2% males, 79.1% peasants and 48.7% married at the time of reporting. 64.5% of the patients were ethnic minorities, and 68.7% were illiterate or having received only primary school education. All the patients were followed-up for a total of 55 962.30 person-years with 4648 patients died, with overall mortality rate as 8.31/100 person-years. The mortality rate had been increasing from 1990 to 2004 but decreasing since 2005. The average survival time since the identification of HIV infection was 9.48 years overall, and was 16.65 years for those having received antiretroviral treatment (ART) and 7.67 years for those without ART. Data from multiple regression analysis indicated that ART and socio-demographic characteristics such as age, gender, ethnicity, occupation, marital status, education background etc. were significantly associated with death among HIV-infected patients. CONCLUSION: The comprehensive AIDS campaigns including ART had significantly reduced the deaths among HIV-infected patients in Dehong prefecture. More efforts on the scaling up program of ART as well as the enhanced management and follow-up program tailored for HIV-infected patients with different socio-demographic characteristics were needed to further reduce the deaths in the area.

Prevalence and correlates of HIV discordance and concordance among Chinese-Burmese mixed couples in the Dehong prefecture of Yunnan province, China.

BACKGROUND: Many people from Burma have migrated to Dehong prefecture and married local residents during the past decades; however, little is known about HIV risk-taking behaviours and HIV prevalence among these mixed couples. We investigated factors correlated with HIV discordance and concordance within Chinese?Burmese mixed couples in Dehong prefecture, Yunnan province, China. METHODS: A cross-sectional study with face-to-face questionnaire interviews and HIV blood testing was conducted. RESULTS: Of 5742 couples, 1.6% couples were HIV-infected concordant, 2.2% were HIV serodiscordant with an HIV-infected male spouse and 0.9% were HIV serodiscordant with an HIV-infected female spouse. HIV discordance with an HIV-infected male spouse was significantly associated with characteristics of the male spouse, including being aged =30 years, non-Han ethnic minority, a marital relationship of <3 years, commercial sex and injection drug use by the male spouse. HIV discordance with an HIV-infected female spouse was significantly associated with an education level of primary school (v. illiterate); a marital status of being in their second marriage, widowed or divorced; a history of sexually transmissible infection diagnosis of the female spouse; noncommercial extramarital sex by the female spouse or by both spouses; and injection drug use by the male spouse. A marital relationship of =3 years was the only significant independent correlate of HIV-infected seroconcordance. CONCLUSIONS: The study findings underscore the importance of premarital HIV counselling and testing for this population, and the need for targeted interventions among HIV serodiscordant mixed couples to reduce secondary transmission as early as possible when the relationship begins.

[The application of National AIDS spending assessment in a county of Dehong prefecture, Yunnan province, China].

OBJECTIVE: To calculate the actual expenditures in a county of Dehong prefecture, Yunnan province, China by using the method of National AIDS Spending Assessment (NASA) in 2010. METHODS: Data were collected through NASA data collection form based on adapted NASA classification in the county of Dehong prefecture from October to December, 2011, and complemented by semi-structured interview with 16 well trained programmatic and financial representatives in 8 spending units. Data were entered in Resource Tracking Software (RTS) V 2009.3.0, and SPSS 13.0 was used for data processing and analysis. RESULTS: The NASA estimations showed that the county spent a total of ¥16 235 954 on HIV/AIDS in 2010. Public funds constituted 96.3% of the total expenditure (¥15 630 937), followed by Global Fund which accounted for 3.0% (¥484 585) and private sources which accounted for 0.7% (¥120 432). Findings based on NASA categories showed that AIDS spendings were mainly on 4 areas, and expenditure on Care & Treatment was ¥12 401 382 (76.4% of total expenditure), followed by Prevention which accounted for 14.3% (¥2 325 707), Program Management & Administration which accounted for 7.8% (¥1 268 523) and human resources which accounted for 1.5% (¥240 342). The most beneficial population group was People Living with HIV (PLHIV), accounting for 84.7% of total expenditure. (¥13 753 428), followed by 4.8% for high risk population, including female sex workers and their partners (¥297 333), injection drug users and their partners (¥293 143), men having sex with men and their partners (¥185 136) and 1.5% (¥241 429) for the general population. CONCLUSION: The local funds for HIV/AIDS in this county was insufficient. The local government should increase corresponding funds based on central government funding. Care and treatment was the first spending priority in the county and the investment of prevention services needs to be increased. Prevention and treatment and care should be combined to ensure the effectiveness of comprehensive prevention and treatment of AIDS.

[Adherence and related determinants on methadone maintenance treatment among heroin addicts in Dehong prefecture, Yunnan province].

OBJECTIVE: To determine the adherence to and its determinants of methadone maintenance treatment (MMT) among heroin addicts in Dehong prefecture in Yunnan province from 2005 to 2009. METHODS: A dynamic cohort analysis was conducted with the time of treatment initiation as the time of cohort entry, to calculate the proportion of adhering to the treatment at different time points after initiation of the treatment, and to study the determinants of adherence. RESULTS: A total of 3758 had been treated. Among them, 95.8% were males, 75.8% aged between 20 - 39 years, 90.4% were peasants or unemployed, 57.0% were ethnic minorities, 35.0% were single and 55.5% were married with spouses, 43.9% were illiterate or educated at most primary school. The age of first using drugs averaged at 23.93 years. About 96.3% of the study subjects had used heroin and 21.7% were HIV-infected. The minimum time under MMT was less than 1 month and the maximum 61 months. The median methadone dose at first delivery was 25 ml, with the minimum 1 ml and the maximum 330 ml. By the end of the study or observation period, a total of 1798 patients had withdrawn from treatment and 1960 were still under treatment. The proportions of adherence to or still being under the treatment after 1, 3, 6, 9, 12, 24, 36, 48 and 60 months treatment were 0.919, 0.847, 0.756, 0.690, 0.637, 0.519, 0.417, 0.360 and 0.321, respectively. Multiple regression analysis using Cox proportional hazard model indicated that withdraw from the methadone maintenance treatment was significantly associated with location of the treatment clinics, year of treatment initiation, marital status, HIV infection status, methadone dose of first delivery and the result of last urine test for heroin use. CONCLUSION: MMT attendants in Dehong prefecture had a relatively high withdraw rate and low adherence rate. More efforts are needed to provide tailored counseling and education to MMT attendants, to provide family and community support, appropriate methadone dose at first delivery, and to better coordinate with local police department.

[Studies on the determinants and changes related to the natural CD4(+) T cell counts among antiretroviral treatment-naive HIV/AIDS patients in Dehong prefecture, Yunnan province].

OBJECTIVE: To explore the determinants and changes of CD4(+) T cell counts among antiretroviral treatment-naive HIV/AIDS patients in Dehong prefecture, Yunnan province. METHODS: A retrospective cohort analysis was conducted on HIV-infected local residents, being reported during 1989 through May 2010, in Dehong prefecture. The patients had received at least two CD4(+) T cell counting tests before receiving the antiretroviral treatment (ART). Difference between the first and the last CD4(+) T cell counts was calculated and described. Logistic regression analysis was conducted to examine the determinants of significant depletion of CD4(+) T cell counts among them. RESULTS: A total of 4487 HIV/AIDS patients were included in the study. The change of CD4(+) T cell counts between the first and the last CD4(+) T cell count tests had a median of -2.0 cells/µl in month (IQR: -8.2 - 3.6) and was significantly associated with socio-demographic characteristics, HIV transmission mode, the first or baseline CD4(+) T cell counts and the time interval between the first and the last CD4(+) T cell counting tests etc. About 60.0% (2693/4487) of the HIV/AIDS patients had deletions of CD4(+) T cell counts, and 31.2% (1400/4487) had significant (≥ 30%) deletions of CD4(+) T cell counts. Results from the multiple logistic regression analysis indicated that age, ethnicity, marital status, HIV transmission mode, the first CD4(+) T cell counts and the interval between the first and the last CD4(+) T cell counting tests were significantly associated with the significant depletion of CD4(+) T cell counts. CONCLUSION: The changing rate of CD4(+) T cell count among ART-naive local HIV-infected patients in Dehong prefecture, Yunnan province was relatively slow. However, substantial proportion of them showed significant decreases of CD4(+) T cell counts, which was determined by many factors. More efforts were needed to systematically and consistently follow-up those HIV-infected patients and measure their CD4(+) T cell counts in China, in order to instantaneously monitor the disease progression, and the initiation of ART, if necessary.

[Causes of death among HIV-infected patients in Dehong prefecture, Yunnan province: 1989-2010].

OBJECTIVES: To analyze the fatality and causes of death related to comprehensive prevention and care programs among HIV-infected patients in Dehong prefecture of Yunnan province, from 1989 to 2010. METHODS: Data on HIV/AIDS death cases in Dehong prefecture were extracted from the "Chinese National Comprehensive HIV/AIDS Prevention and Care Information System" and were analyzed. RESULTS: From 1989 to the end of 2010, a total of 13 493 HIV/AIDS cases registered as local residents or currently living in Dehong, had been reported. Among them, 8569 were reported as HIV cases with 2036 deaths and the other 4924 were reported as AIDS cases with 2251 deaths. A few of the cases had survived for 15 - 20 years. By the end of 2010, the number of deaths was higher than the number of survivors among HIV/AIDS cases reported before 2004, whereas the number of survivors was higher than the number of deaths among HIV/AIDS cases reported in 2004 and there after. During the twenty years' period, the proportion of reported HIV/AIDS cases died in the same year showed a secular trend of being low-highest-low, rising up to > 10.0% in 2001, peaking at 18.9% in 2003 and then continuously going down to 5.8% in 2010. The proportion of HIV/AIDS cases who survived at the beginning but died later in the year was going down since 2007. The proportion of HIV/AIDS deaths died directly from AIDS was increasing whereas the proportion of HIV/AIDS deaths dying directly from overuse of drugs was decreasing in the recent years. Among HIV/AIDS deaths, the proportion of ever received CD4(+) T-cell testing and the proportion of ever having received antiretroviral treatment were also increasing in the past years, reaching to 89.9% and 25.5% in 2010, respectively. CONCLUSION: The case fatality of HIV/AIDS was decreasing in the past years in Dehong prefecture. More efforts were needed to scale up the CD4(+) T-cell count testing and antiretroviral treatment in order to further reduce both morbidity and mortality among HIV/AIDS patients in Dehong prefecture. It is critical to improve surveillance program on HIV/AIDS deaths in the rural areas.

[Survey on contact tracing of newly reported HIV infections in 2009 in Dehong prefecture, Yunnan province].

OBJECTIVE: To explore a new method for finding more HIV/AIDS. METHODS: In September 2009, newly reported HIV-infected individuals from May to August, 2009 in Dehong prefecture were asked to participate in a survey which requested demographic characteristics, history of high-risk behaviors and contact information of individuals with whom they had high risky contacts. People with risky contacts with HIV-infected cases (index cases) were also approached to participate in this survey and HIV testing was provided. RESULTS: A total of 342 HIV-infected individuals were newly reported and served as index cases from May to August, 2009. Among them, 47.1% (161/342) were transmitted by regular sexual partners. Through three-round surveys, 218 contacts were traced and among them, 84.9% (185/218) were traced by regular heterosexual partners. HIV positive rate of the tested was 34.7% (60/173) in the first-round tracing and 12.5% (1/8) in the second one. Among the 560 individuals (index cases and their high-risk contacts), the proportions of having regular heterosexual partners, non-regular and non-commercial sexual partners, commercial sexual heterosexual partners and men having sex men were 87.9% (492/560), 18.9% (106/560), 22.3% (125/560) and 0.3% (1/318), respectively, while the proportion of having never used condoms when having sex with the above four types sexual partners were 73.8% (363/492), 72.6% (77/106), 63.2% (79/125) and 0.0% (0/1), respectively. CONCLUSION: As an epidemiological method for HIV/AIDS finding, contact tracing identified a large number of HIV infectors who were traced by newly reported HIV-infected individuals.

[Study on incidence of HIV infection among heroin addicts receiving methadone maintenance treatment in Dehong prefecture, Yunnan province].

OBJECTIVE: To determine the incidence and risk factors of HIV infection among heroin addicts receiving methadone maintenance treatment (MMT) in Dehong prefecture, Yunnan province. METHODS: All heroin addicts who were HIV negative at the initiation of MMT in June 2005 and through June 2011, in Dehong prefecture were included in the cohort analysis. HIV incidence was calculated and related risk factors determined by using Cox proportional hazard regression model. RESULTS: A total of 3154 MMT clinic attendants were qualified for this cohort study. By June 2011, 1023 (32.4%) of them had never received any follow-up HIV testing so were thus referred as loss to follow-up. The other 2131 (67.6%) members had received at least one follow-up HIV testing and were observed for a total of 4615.86 person-years. During the period, 22 new HIV infections or seroconverters were identified, making the overall HIV incidence as 0.48/100 person-years. The HIV incidence was higher among those who were unemployed, never married, self-reported being injecting drug users (IDUs) and HCV positive at entry into the MMT program. None of those who were always negative on follow-up-urine-testing of morphine was discovered as HIV newly infected during the follow-up period. Data from multiple regression analysis under Cox proportional hazard model indicated that after controlling for confounding variables, non-IDUs at the entry point for the MMT program, were less likely to be HIV newly-infected or seroconverted than IDUs (HR = 0.29, 95%CI: 0.11 - 0.76). CONCLUSION: MMT program in Dehong prefecture was demonstrated to be fairly effective in reducing HIV transmission through drug use. Those HIV negative attendants at the MMT clinic who were IDUs or keep using drugs during the treatment, were at higher risk of HIV seroconvertion. More efforts were needed to improve the follow-up and HIV testing programs for the MMT clinic attendants.

[Proportions and correlates of recent HIV infections among newly reported HIV/AIDS cases from 2005 through 2009 in Dehong prefecture, Yunnan province].

OBJECTIVE: To determine the proportions and correlates of recent HIV infections among newly reported HIV/AIDS cases from 2005 through 2009 in Dehong prefecture, Yunnan province. METHODS: All available serum samples of newly reported HIV/AIDS cases during 2005 - 2009 period in Dehong prefecture, were tested using the BED HIV incidence capture enzyme immunoassay (BED-CEIA). RESULTS: A total of 9367 HIV/AIDS cases were newly reported in 2005 through 2009, of whom 7252 (77.4%) were tested with BED-CEIA. Among the tested, 954 (13.2%) were positive for BED-CEIA and were regarded as recent HIV infections. The proportion of recent HIV infection among newly reported HIV/AIDS cases was 11.21% in 2005, 11.87% in 2006, 17.55% in 2007, 13.22% in 2008, and 12.22% in 2009. Multiple logistic regression analysis indicated that the proportion of recent HIV infections among newly reported HIV/AIDS cases in 2009 was significantly higher among females, those aged 11 - 19 years, and internal residents outside of Dehong prefecture, but significantly lower among immigrants who were mostly from Myanmar, than local residents. CONCLUSION: From 2005 to 2009, the proportion of recent HIV infections among newly reported HIV/AIDS cases in Dehong prefecture in Yunnan province was fluctuating slightly. Future research is needed to examine its long-term and secular trend. Such proportion was significantly different by different sociodemographic characteristics.

[Survival analysis on 3103 HIV/AIDS patients receiving antiretroviral treatment in Dehong prefecture, Yunnan province].

OBJECTIVE: To determine the survival rate of HIV/AIDS patients after receiving free antiretroviral treatment in Dehong prefecture, Yunnan province. METHODS: A retrospective cohort analysis was conducted on all the HIV/AIDS patients aged over 16 years who had started antiretroviral treatment during January 2007 throughout December 2009 in Dehong prefecture. RESULTS: A total of 3103 HIV/AIDS patients had received antiretroviral treatment during the study period. Among them, the mean age was (36.0 ± 9.9) years and 62.4% were males. 66.2% of them were infected with HIV through heterosexual transmission, and the mean treatment follow-up time was 21.7 months. Most patients well complied with the treatment, i.e., the average times of not taking the medicine were less than 5 per month. The cumulative survival rate of antiretroviral treatment after 1, 2, 3, 4, and 5 years were 0.95, 0.94, 0.93, 0.92, and 0.92, respectively. Data from the Cox proportional hazard regression model analysis indicated that, after adjustment for age, gender, and marital status, the baseline CD4(+)T cell counts and transmission route could significantly predicate the rates of survival. Those who were with baseline CD4(+)T cell counts as 200 - 350/mm(3)were less likely to die of AIDS than those with CD4(+) T cell counts < 200/mm(3) (Hazard Ratio or HR = 0.16, 95%CI: 0.09 - 0.28), and HIV-infected through mother-to-child transmission or routes other than heterosexual transmission were less likely to die of AIDS than through injecting drug use (HR = 0.35, 95%CI: 0.13 - 1.00). CONCLUSION: Free antiretroviral treatment had significantly improved the survival of HIV/AIDS patients. Earlier initiation of antiretroviral treatment was likely to have achieved better survival effects.

[Natural history of HIV infections among injecting drug users in Dehong prefecture, Yunnan province].

OBJECTIVE: To study the natural history of HIV-1 infection among intravenous drug users (IDUs) detected in late 1989 in the study area and the factors related to survival of these IDUs infected with HIV. METHODS: 196 injecting drug users first detected during August and December, 1989 were observed in Ruili county, Yunnan province. Data gathered from the 20-year follow-up program was collected and analyzed retrospectively. RESULTS: After 20 years' follow-up period, 90.3% of the 196 IDUs with HIV infection died, 5.1% of them were still alive, and 4.6% were lost. The crude pre-AIDS mortality rate was 98.1/1000 person-years, and the AIDS mortality rate was 54.9/1000 person-years. Malaria, septicemia were the main causes of death among the natural diseases whereas overdose and accidental causes were the principal causes related to those non-disease deaths. The median survival time from sero-conversion to death was 8.6 years (95%CI: 7.6 - 9.7). The median survival time from sero-conversion to death due to AIDS was 11.3 years (95%CI: 10.3 - 12.8) with the incubation time as around 10.3 years. People older than 30 years at seroconversion and length of drug usage were associated with shorter survival time, with hazards ratios as 1.9 and 0.7, respectively. CONCLUSION: A high pre-AIDS mortality was observed among IDUs. Both the median survival time from sero-conversion to death and the HIV incubation period were shorter than that observed in the developed countries. Age of HIV infection seemed to have a strong effect on survival.