The preparedness to share injecting equipment: an analysis using vignettes

This paper reports on the use of vignettes to study drug injectors’preparedness to share injecting equipment. Separate vignettes referring to borrowing and passing on injecting equipment have been submitted to 505 injecting drug users in Glasgow. Injectors were asked to identify their own likely response in each of the situations described within the vignettes. It was shown that even among those injectors not reporting any actual sharing in the last 6 months a significant proportion would still be prepared to share injecting equipment within certain situations. The preparedness to share injecting equipment was seen to be influenced by such factors as social distance, sex and length of time injecting. It is suggested that even in situations where drug injectors may have modified their behaviour in the direction of lower levels of reported sharing, a propensity to share may remain. This suggests the continuing need to provide injectors with easy access to sterile injecting equipment; in addition, services working with injecting drug users may need to focus not only upon actual sharing behaviour but also upon what we have described here as the preparedness to share. Indeed, the latter dimension should stand as a warning to services of the potential for sharing injecting equipment to increase in the future.     

Estimated prevalence of injecting drug use in Glasgow

The prevalence of injecting drug use in Glasgow during 1989 was derived using log-linear analysis to model the relationship between unnamed identifier information obtained from Strathclyde Police, the Scottish HIV-test Reporting Scheme and Treatment Agencies. Whereas previous attempts have required, although rarely demonstrated, independence between samples, the method adopted here did not necessitate this assumption. The best model resulted from taking the dependency between the HIV-test and treatment samples into account, and yielded an estimate of 9424 (95% confidence interval ± 2460), which represents 11–19 per 1000 population aged 15–55 in Glasgow. The estimated male:female ratio was 2.64:1 and the modal injecting drug user (IDU) aged 20–24. While there are no indicators that prevalence has begun to decline, the extent of the hidden population suggests that around 1 in 7 were receiving some form of treatment for drug use. Available evidence suggests that buprenorphine, temazepam and amphetamines, rather than heroin, are the most commonly injected drugs. These findings should facilitate assessment of the service requirements of this group, and provide a basis from which the number of IDUs infected with HIV and the number likely to progress to AIDS can be determined.     

HIV risk behaviours among female prostitute drug injectors in Glasgow

This paper focuses upon HIV-related risk behaviours of 51 female drug injecting prostitutes, interviewed as part of a serial cross-sectional study of injecting drug users in Glasgow. Forty-five per cent injected with used needles and syringes in the 6 months prior to interview. Condom use in private sexual relations was low with only 9% of those with primary partners and 22% of those with casual partners reporting consistent use of condoms with these partners. In contrast, use of condoms for all commercial sexual encounters was almost universal. Prevalence of HIV was 2.2%. Despite this low prevalence, we conclude that the level of injecting-related and private sexual risk behaviours reported here requires the continuing monitoring of drug injecting prostitutes in Glasgow.     

Natural variation in mite antigen density in house dust and relationship to residential factors

To investigate the year-to-year variation of mite antigen density (Der p I, Der f1) in dust from mattresses and the relevance of residential factors for antigen load, information derived from an epidemiologic study including two surveys carried out in the households of a cohort of elementary school children (n= 1291) was analysed. When considering residences with measurements taken in both years in question (n= 1050), rank-correlation indicated a predominance of stability for both antigens (Der p I: r_s= 0-82, p=0.0001; Der f I: r_s=0.72, P= 0.0001), Using multiple regression analyses, significant associations between antigen concentrations and a variety of residential factors were found. Use of a blanket of animal hair, use of a cover or underblanket, wet spots in the bedroom, higher relative humidity and a low storey level were significantly associated with increased concentrations of Der p I, whereas inverse relationships between this antigen and room temperature, number of persons per m² as well as use of underfloor heating were seen. Regarding Der f I, older mattresses, use of a cover or underblanket, higher weight of sampled dust, high educational level and higher ratio of inhabitants per m² were significantly associated with increased concentrations of the antigen. On the other hand, lower Der f I concentrations were found when interior sprung mattresses were used and when the mattress was ‘treated regularly’. In conclusion, two measurements, 1 year apart from each other, show that stability of mite antigen concentrations predominated. Our data suggest that allergic patients should be advised against living in lower storeys and damp homes and to use a newer or encased mattress and to give preference to a residence with underfloor heating.     

Sensitization to four common inhalant allergens within 302 nuclear families

The coincidence of allergic sensitization was investigated in 302 school-aged children and their parents. Specific sensitization to four common inhalant allergens (grass and birch pollens, cat dander, Dermatophagoides pteronyssinus) was ascertained by means of skin-prick tests (SPT) carried out on the complete family unit at the beginning of a 22-month follow-up period. The same test procedure was then repeated on the children twice at 11-month intervals to provide cumulative prevalences of sensitization. A clinical history of atopy in the children (hay fever or asthma; n= 47), which was derived from an interview, is associated with sensitization (positive SPT in 89%). For three allergens (grass and birch pollens, cat dander) sensitization occurs significantly more frequently in the children of mothers who are sensitized to the same allergen (odds-ratios (ORs), 2.5–4.1). Additionally, in three of the four explanatory models related to a single antigen, maternal sensitization to one of the complementary allergens is of importance (ORs, 2.7–3.7). In contrast to this finding, none of the paternal sensitizations has statistical significance. Based on a reaction to at least one of the four allergens, the child's relative risk to be sensitized is increased in case of maternal (OR, 2.88; P= 0.001) but not of paternal (OR, 1.06; P= 0.83) sensitization. In conclusion, our data indicate that the maternal status is more predictive than that of the father with regard to the child's risk of sensitization.     

Discriminating needle exchange attenders from non-attenders

In 1990, approximately 1500 of Glasgow's estimated 9400 injecting drug users attended the city's four needle and syringe exchanges. In the same year, a multisite and citywide strategy was used to interview an estimated 5% sample of the city's injectors using an internationally agreed WHO structured schedule. Of the 503 injectors who participated in the study 54% (n = 272) had made use of exchanges in the last 6 months (including 165 injectors recruited from exchanges), while the remaining 46% (n = 231) had not. Twenty-seven variables were entered into a stepwise discriminant analysis to predict group membership (attenders vs. non-attenders). Fourteen variables emerged in the final discriminant function, which explained 17.3% of the variance between the two groups. Comparison of the model to random classification of cases resulted in a third fewer cases being wrongly assigned. Needle exchange attenders report injecting fewer drugs, less injecting with and passing on of used equipment and greater use of condoms with casual partners, compared to non-attenders. They also had greater knowledge of AIDS and had made and maintained more harm reduction changes, although they were less likely to have received treatment than non-attenders. The finding that attenders were less likely to inject with or pass on used needles and syringes is discussed in the context of availability of clean equipment and perception of risk. Variables reflecting lifestyle such as housing, employment and prison experience were not found to have any discriminatory power.     

Longitudinal variability of skin prick test results

The skin prick test (SPT) is a commonly used procedure for assessing a specific sensitization. The longitudinal variability of test results is of interest for clinical as well as epidemiological investigations. The sensitization to four common aeroallergens (grass pollen, birch pollen, Dermatophagoides pteronyssinus, cat dander) is investigated within the framework of three consecutive SPTs at 11-month intervals for a population of 587 schoolchildren. The prevalence of sensitization based on a weal diameter of at least 2 mm was between 12.9% (cat dander) and 23.9% (grass pollen) in the initial testing. The positive predictive values of the initial SPT were between 75.3% (birch pollen) and 88.2% (cat dander) for the two subsequent SPTs. In the case of initially negative tests with positive second and third SPTs the incidence ranged between 3.2% (cat dander) and 4.3% (birch pollen) per year. A clear increase in the intensity of reaction in subsequent tests was observed in a number of probands testing positively in the initial SPT. In conclusion, our data indicate a high long-term stability of a specific sensitization to aeroallergens in SPT.     

Assessment of eosinophil granule proteins in various body fluids: is there a relation to clinical variables in childhood asthma?

BACKGROUND: The eosinophil plays a central role in the inflammatory process in bronchial asthma. Recent studies have indicated that the assessment of eosinophil-derived proteins in various body fluids could be used for monitoring disease activity of childhood asthma. Till now, no study exists which compared the levels of eosinophil-derived proteins in various body fluids such as serum, nasal lavage fluid (NALF) and urine. OBJECTIVE: To investigate whether eosinophil granule proteins in different compartments were correlated and whether there is a relationship between disease activity, pulmonary function and bronchial hyperreactivity. METHODS: Twenty-eight children with atopic bronchial asthma were recruited. Serum, NALF and urine samples were obtained and assessed for eosinophil cationic protein (ECP) and eosinophil protein X (EPX). The levels of eosinophil proteins were analysed for a relationship with lung function variables, bronchial hyperreactivity and disease activity. Eleven healthy control subjects were used as controls. RESULTS: Median ECP and EPX concentrations in serum (31.4 and 74.8 microg/L vs 15.8 and 24.3 microg/L, respectively), NALF (9.9 and 44. 9 microg/L vs 0 and 2.5 microg/L, respectively) and urine (49.4 vs 16.5 microg/mmol creatinine) were significantly raised in children with bronchial asthma compared with healthy control subjects. In addition, ECP and EPX levels in serum and urine samples were significantly higher in symptomatic patients compared with asymptomatic subjects with asthma. Although no relationship between eosinophil-derived proteins in serum, NALF or urine and the level of nonspecific bronchial hyperreactivity could be detected, the concentrations of EPX in serum and urine were correlated with variables of pulmonary function. CONCLUSION: Our findings demonstrate increased eosinophil activity in serum, NALF and urine derived from children with bronchial asthma. Due to the relationship between levels of eosinophil proteins in serum/urine samples and lung function, as well as significant concentration differences between symptomatic and asymptomatic asthmatic children, the assessment of eosinophil proteins in serum or urine samples appear to be more appropriate in monitoring disease activity than measurement of ECP or EPX in NALF. Thus, the determination of serum ECP/EPX or urinary EPX may be preferentially used in monitoring eosinophilic inflammation in childhood asthma.     

Mortality and survival among a cohort of drug injectors in Glasgow, 1982–1994

There has been much speculation about the nature and extent of mortality among drug injectors in Glasgow. In order to determine injectors’ mortality rate and compare this rate to the general population, identifier information from 459 drug injectors who received treatment for drug misuse in Glasgow between 1982 and 1994 was linked to the Scottish Mortality Register. The average duration of follow-up from cohort entry was 5.5 years and 10.2 years from commencement of drug injection. By the end of 1994, 53 cohort members had died. The average annual mortality rate of 1.8% was the same as that observed in a London cohort followed-up from 1969 to 1991. However, the excess mortality ratio (EMR) of 22.0 was almost double the London rate (11.9) because of the much lower average age of mortality (26.3 vs. 3S.2 years). There was no significant time trend in EMR. Kaplan-Meier hazard analyses show that younger patients and those who were HIV positive had significantly elevated mortality rates. The main cause of death was overdose, although it is unclear how many were accidental and how many intentional. Three of the six fatalities among HIV positive injectors were AIDS related. This study enables the first realistic assessment of the hypothesis that drug-related deaths in Glasgow are especially high. In relation to other populations of drug injectors, the annual mortality rate is comparable, although the average age of mortality is much lower in Glasgow. Consequently, in comparison to the general population, the mortality rate of drug injectors is higher in Glasgow compared to other cities.