Mark-recapture estimates of injecting drug users in Sydney

Abstract: The number of injecting drug users in the Central and Eastern Sydney Area Health Services (CSAHS and ESAHS) in 1989–1990 was estimated by applying the Petersen mark-recapture method to data obtained from the Australian National AIDS and Injecting Drug Use Surveys conducted in 1989 and in 1990. The population estimates for injecting drug users were 8368 (95 per cent confidence interval (CI) 6099 to 11 829) for ESAHS and 1466 (CI 742 to 2841) for CSHS. An estimate was also obtained for the number of injecting opioid users residing within the ESAHS; our figure of 3597 (CI 2731 to 5737) was consistent with previously reported estimates obtained using mark-recapture but based on different data sets.     

Audit of bloodborne virus infections in injecting drug users in general practice

Two hundred and ninety patients attending a single general practice in Edinburgh were known to have used illegal drugs, 145 of whom were identified as past or present injectors. Data on bloodborne virus infections and immunisation against hepatitis B virus (HBV) were gathered during 1998, attempts were made to improve the level of testing for bloodborne viruses and immunisation against HBV, and follow up was carried out between October 1999 and February 2000. One hundred and fifteen patients were studied in detail. Evidence of previous HBV infection was found in 31 of 71 tested in 1998 (44%) and 40 of 99 tested at follow up (40%). In 1998 54 out of the 75 tested for hepatitis C antibodies (72%) were positive compared with 73 out of 108 (68%) at follow up. Twenty-six of the 80 tested for HIV antibodies were positive in 1998 (33%) and 26 of 105 at follow up (25%). Large numbers of injecting drug users in our study were found to be not immune to hepatitis B and required immunisation. An abbreviated protocol for immunisation was devised, including post vaccination checks and boosting as necessary. Hepatitis C testing was requested after counselling in most cases, resulting in important and positive interventions. Prevention opportunities for all three bloodborne viruses were identified.     

The prevalence and risk behaviours associated with the transmission of blood-borne viruses among ethnic-Vietnamese injecting drug users

OBJECTIVE: To measure the prevalence and determinants of blood-borne virus (BBV) transmission in ethnic Vietnamese injecting drug users (IDUs). METHODS:The study was conducted in Melbourne, Australia, in 2003. It was a cross-sectional design with participants recruited from street-based illicit drug markets predominately using a snowball technique. One hundred and twenty-seven participants completed a questionnaire that asked about illicit drug use and participants' blood samples were tested for HIV, HCV and HBV. RESULTS: One hundred and three (81.1%) ethnic Vietnamese IDU study participants were HCV positive and three (2.4%) were HIV positive. More than 60% had evidence of being infected with HBV (either in the past, acute infection or chronic infection). Almost 60% had injected daily over the past 12 months. Fifty-nine participants had recently travelled to Vietnam; 24 (41%) had injected drugs in Vietnam; and three (12.5%) reported sharing injecting equipment in Vietnam. CONCLUSION: The prevalence of BBVs was higher in this study's IDU population compared with IDUs in Australia generally, despite the fact that the injecting risk behaviours were similar to IDUs more generally. IMPLICATIONS: Culturally sensitive drug treatment and education programs need to be developed in Australia for both ethnic Vietnamese IDUs and their families to reduce this group's risk of contracting a BBV.     

Patterns of drug use and associated harms among rural injecting drug users: comparisons with metropolitan injecting drug users

OBJECTIVE: Given the harms associated with injecting drug use to both individuals and community and the paucity of such data from rural areas, the study aimed to compare: patterns of drug use, harms, and service access and utilisation among rural and metropolitan injecting drug users (IDU). DESIGN: Cross-sectional survey, using interviewer-administered structured questionnaire. PARTICIPANTS: One hundred and sixty-four rural and 96 metropolitan IDU from seven different New South Wales Area Health Services, recruited through needle and syringe programs (NSPs), snowballing techniques and advertisement. RESULTS: Age, gender, education and employment were similar for rural and metropolitan participants. Both samples reported use of a range of drugs, but rural participants were less likely than metropolitan participants to report daily heroin use (2% vs 10%), but more likely to report having injected morphine (50% vs 21%) in the last six months. Similar proportions reported using a needle/syringe after another person. Rural participants were less likely to report use of NSPs (36% vs 80%) and reported a number of barriers to NSP access and also to drug treatment services. Rural participants reported a significantly longer period of time between blood-borne virus testing. CONCLUSION: Samples of rural IDU are similar to metropolitan, although report some differences in patterns of drug use. Service provision, including access to new injecting equipment, blood-borne virus testing and drug treatment was found to cause considerable problems for rural IDU. These issues warrant further consideration.     

Patterns of drug use among a sample of drug users and injecting drug users attending a General Practice in Iran

Aim  

This study aimed to examine drug use, drug treatment history and risk behaviour among a sample of Iranian drug users seeking treatment through a general practice clinic in Iran.     

Differences in the social networks of ethnic Vietnamese and non-Vietnamese injecting drug users and their implications for blood-borne virus transmission

The social networks of 49 ethnic Vietnamese injecting drug users (IDUs) and 150 IDUs of other ethnicities recruited in Melbourne, Australia, were examined for ethnic differences in distribution of hepatitis C virus infection risk using social network analysis and molecular epidemiology. Vietnamese IDUs were more highly connected than non-Vietnamese IDUs, and more likely to be members of dense injecting sub-networks. More related infections were detected in IDUs with discordant ethnicities than were captured in the social network data; nonetheless, most dyads and most IDU pairs with related infections had matching ethnicity, confirming that mixing was assortative on that criterion. Mixing was not obviously dissortative by risk; low-risk Vietnamese IDUs injected more frequently than did correspondingly low-risk non-Vietnamese IDUs, but results for other measures were reversed or equivocal. Network measurements suggest that ethnic Vietnamese IDUs are at elevated risk of blood-borne infection, a conclusion supported by their relatively high HIV prevalence.     

应用捕获-再捕获法估计某市静脉注射吸毒人员基数的研究

目的探索捕获-再捕获法在静脉注射吸毒人员基数估计中的应用,并对广东省某市静脉注射吸毒人员基数进行估计。方法采用捕获-再捕获法,利用市强制戒毒所登记的资料,估计全市静脉注射吸毒人员的基数。结果用捕获-再捕获法估计全市静脉注射吸毒人数为13017。结论运用捕获-再捕获法对静脉注射吸毒人数进行估计经济易行,结果较为可靠,较适合在卫生资源有限的情况下进行高危人群基数估计。     

Hepatitis C infection in a cohort of injecting drug users

Objectives: To establish prevalence rates for hepatitis C antibodies in a cohort of injecting drug users and to study factors influencing positivity. To record current injecting practices. To identify the entry of hepatitis C into the cohort. To investigate the association between HCV positivity and PCR status.

Design: (i) Questionnaire covering demographic data, injecting behaviour, number of sexual partners, awareness of risk behaviour, awareness of serological status and subsequent behaviour change. (ii) Second questionnaire on recent drug use and injecting practices with a strong focus on frequency of sharing paraphernalia. (iii) PCR testing on HCV positive. (iv) Retrospective testing of subgroup to determine entry of hepatitis C into the cohort.

Setting: Recruitment in a large general practice in North West Edinburgh.

Participants: The main study group consisted of a large cohort (619) of past or present illegal drug injectors. The first, n=95, received the questionnaire (i). If they had injected in the past month they also completed the second questionnaire (n=26). PCR testing was carried out on a subset of the group of 95, selected because they had had a recent blood test (n=33). A random group of 20 of the main cohort of 619 who had hepatitis C antibody positive tests were selected for retrospective testing.

Main outcome measures: Prevalence of HCV antibodies, perceived and actual risk-taking behaviour. Antibody status of randomly selected early stored specimens. HCV PCR status.

Results: Positivity was associated with age, year of first use, sharing of injecting paraphernalia, year of most sharing, as well as length of use of injected drugs.

Awareness of HCV as a risk was found to be later than either HBV or HIV. No significant difference was found in numbers of sexual partners between those who were HCV positive and negative. Women and younger drug users were found to engage in more sharing of injecting paraphernalia, with women having more sharing partners. The entry of HCV into the cohort predated the early stored blood samples. No correlation was identified between length of drug use and PCR status.

Conclusions: HCV is acquired early in drug injecting careers. Whether or not this is changing is unclear but attempts to educate and support need to be directed towards younger drug users and women, who are at risk. Knowledge of risks from sharing injecting paraphernalia is poor. The impact of the hepatitis C epidemic is likely to continue to escalate with cases progressing to advanced clinical stages. PCR tests could be employed to select cases for referral or treatment. The harm reduction message needs to be clarified and re-emphasised.     

Hepatitis C virus antibody status, sociodemographic characteristics, and risk behaviour among injecting drug users in Croatia

The study was conducted among 76 injecting drug users (IDU) from seven Croatian cities during a three-year period (2005-2007). Each participant completed a questionnaire on sociodemographic characteristics and potential risk factors for hepatitis C virurs (HCV) infection followed by anti-HCV and anti-HIV antibody testing. The mean patient age was 30. The majority of patients (69.8%) reported more than one potential exposure to HCV: 97.1% had shared injecting equipment, 75% reported risk sexual behaviour, and 56.3% reported a history of travelling abroad. The overall HCV seroprevalence was 51.3% (95% CI = 40-63%). HCV seroprevalence increased with increasing number of risk behaviours (p = 0.026). Needle sharing frequency was the most important risk factor for hepatitis C. The HCV seroprevalence rate ranged from 27.3% in IDUs who answered that they shared needles occasionally to 100% in IDUs who always shared needles (p < 0.001). No other risk factors (age, gender, educational level, marital and employment status, history of travelling abroad and sexual risk behaviour) were associated with HCV seropositivity.     

Establishing safe injecting rooms in Australia: attitudes of injecting drug users

OBJECTIVE: To investigate the attitudes of injecting drug users (IDUs) towards the establishment of safe injecting rooms (SIRs) in Melbourne, Australia. METHODS: Multi-site convenience sampling at Needle and Syringe Exchange Programs (NSEPs) within six Melbourne suburbs. Four hundred current IDUs were recruited directly through NSEP and participant snowballing. Respondents completed either a semi-structured interview, anonymous self-report questionnaire, face-to-face interview or participated in a focus group. Participants were asked to report on their knowledge and attitudes about SIR, their experiences and concerns as participants of street-based illicit drug markets, and their willingness to use SIRs if established. RESULTS: Participants (91%) were knowledgeable about the SIR issue and thought such a strategy had potential to address both personal and wider community harms associated with public injecting. Most (77%) indicated they would be willing to use a SIR if established in Melbourne. Gender, lifetime non-fatal overdose episodes and frequency of heroin use were all significantly related to a person's willingness to use SIRs. A significant number also reported a preference for injecting at their own place of residence due to concerns regarding privacy, safety and police presence within street-based market places. CONCLUSIONS: This study has identified a number of important issues relating to the likely demand and uptake of SIRs that should be addressed when considering the feasibility of establishing SIRs within Australia.     

Contraceptive practices of non-HIV-seropositive injecting drug users

Aims: To study the sociodemographic characteristics and sexual behaviours in contraception choices of injecting drug users (IDUs) and to compare the contraceptive practices of non-HIV-positive IDUs to those of the general population. Design: Two surveys were used: a sample of IDUs attending 10 drug abuse treatment centres in the Paris region (IDU) and the Parisian subsample of the National French Survey of Sexual Behaviour (ACSF). Measurements: Percentages of contraception practices were estimated separately for 81 IDU and 130 ACSF women, and for 175 IDU and 168 ACSF men, aged 25–34, not reporting prostitution or HIV seropositivity. Findings: Most IDU (77%) and ACSF (84%) women, and IDU (73%) and ACSF (75%) men currently used a contraceptive method. Male condoms were more widely used by IDUs than by the general population (64 vs. 10% in women, 75 vs. 14% in men), for all subgroups of educational level, marital status, recent multipartnership status and sexual activity. Conclusions: Contraceptives are used as often by IDUs as by the general population aged 25–34. However, the methods employed differ, with higher condom use by IDUs, which suggest that IDUs take into account the risk of HIV contamination in their contraceptive practices.     

云南省德宏州静脉注射吸毒人群艾滋病毒感染自然史研究

目的 了解静脉注射吸毒人群艾滋病毒(HIV)感染的生存与死亡规律及其影响因素.方法 收集并分析云南省德宏州1989年8-12月发现的196例静脉注射吸毒HIV感染者20年跟踪随访资料.结果 截止观察终点2009年12月31日,196例HIV感染者中177例(90.3%)死亡,10例(5.1%)存活,9例(4.6%)失访.总死亡密度为98.1/1000人年,艾滋病死亡密度为54.9/1000人年.因艾滋病死亡者占所有死亡者的55.9%,其他疾病死亡原因中以疟疾(2.8%)、败血症(2.3%)为主,非病死亡原因中以吸毒过量(13.0%)、意外伤亡(6.8%)为主.以死亡为结局,静脉注射吸毒人群HIV感染者中位生存时间为8.6年(95%CI:7.6～9.7).以艾滋病死亡为结局,则中位生存时间为11.3年(95%CI:10.3～12.8),估计的潜伏期约为10.3年.30岁及以上HIV感染者死亡的危险性是30岁以下者的1.9倍(95%CI:1.2～2.7).吸毒时间越长,生存时间越短(HR=0.7,95%CI:0.6～0.7).结论 静脉注射吸毒人群非艾滋病死亡人数较多.注射吸毒人群中位生存时间和潜伏期低于发达国家同类人群.年龄是影响HIV感染生存时间的重要因素.     

社区注射吸毒人群前瞻性队列5年HIV和HCV新发感染研究

目的:探索社区注射吸毒人群HIV和HCV发病率。方法:自2014年6月至2019年6月,在云南省保山市隆阳区以当地的清洁针具交换点为平台,开展前瞻性队列研究,招募社区注射吸毒者200人作为研究对象。队列每6个月进行1次随访评估,调查高危吸毒行为和性行为情况,并采集血样进行HIV和HCV血清抗体检测。采用开放队列,每12...     

云南省德宏州静脉注射吸毒人群艾滋病毒感染自然史研究

目的 了解静脉注射吸毒人群艾滋病毒(HIV)感染的生存与死亡规律及其影响因素.方法 收集并分析云南省德宏州1989年8-12月发现的196例静脉注射吸毒HIV感染者20年跟踪随访资料.结果 截止观察终点2009年12月31日,196例HIV感染者中177例(90.3%)死亡,10例(5.1%)存活,9例(4.6%)失访.总死亡密度为98.1/1000人年,艾滋病死亡密度为54.9/1000人年.因艾滋病死亡者占所有死亡者的55.9%,其他疾病死亡原因中以疟疾(2.8%)、败血症(2.3%)为主,非病死亡原因中以吸毒过量(13.0%)、意外伤亡(6.8%)为主.以死亡为结局,静脉注射吸毒人群HIV感染者中位生存时间为8.6年(95%CI:7.6～9.7).以艾滋病死亡为结局,则中位生存时间为11.3年(95%CI:10.3～12.8),估计的潜伏期约为10.3年.30岁及以上HIV感染者死亡的危险性是30岁以下者的1.9倍(95%CI:1.2～2.7).吸毒时间越长,生存时间越短(HR=0.7,95%CI:0.6～0.7).结论 静脉注射吸毒人群非艾滋病死亡人数较多.注射吸毒人群中位生存时间和潜伏期低于发达国家同类人群.年龄是影响HIV感染生存时间的重要因素.