Risk behaviours of young Indo-Chinese injecting drug users in Sydney and Melbourne.

OBJECTIVE: To investigate patterns of drug use and injection-related risk behaviours among young Indo-Chinese injecting drug users (IDUs). METHOD: Cross-sectional survey. A structured questionnaire was administered to 184 Indo-Chinese IDUs aged 15 to 24 in Sydney and Melbourne. Participants were recruited using snowball sampling techniques; measures included patterns of heroin and other drug use, injection-related risk behaviours, perceived susceptibility to HIV and HCV infection and access to services. RESULTS: Despite perceived high availability of sterile injecting equipment, 36% had ever shared a needle and syringe and 22% had done so in the preceding month. Lifetime sharing was significantly associated with duration of injecting, history of incarceration and residence in Sydney. Sharing of injecting paraphernalia other than needles and syringes was also common, with young women and Sydney residents significantly more likely to report sharing equipment in the preceding month. CONCLUSIONS: Young Indo-Chinese IDUs are at high risk of infection with hepatitis C and other blood-borne viruses. Results indicate an urgent need for culturally appropriate and sustainable risk reduction programs which specifically target this population. IMPLICATIONS: Health services must respond swiftly to implement effective blood-borne virus prevention programs for young Indo-Chinese IDUs. Failure to do so may sustain the current epidemic of hepatitis C among IDUs.

Does weather confound or modify the association of particulate air pollution with mortality? An analysis of the Philadelphia data, 1973-1980.

Because weather has the potential to confound or modify the pollution-mortality relationship, researchers have developed several approaches for controlling it in estimating the independent effect of air pollution on mortality. This report considers the consequences of using alternative approaches to controlling for weather and explores modification of air pollution effects by weather, as weather patterns could plausibly alter air pollution's effect on health. We analyzed 1973-1980 total mortality data for Philadelphia using four weather models and compared estimates of the effects of TSP and SO2 on mortality using a Poisson regression model. Two synoptic categories developed by Kalkstein were selected--the Temporal Synoptic Index (TSI) and the Spatial Synoptic Classification (SSC)--and compared with (1) descriptive models developed by Schwartz and Dockery (S-D); and (2) LOESS, a non-parametric function of the previous day's temperature and dew point. We considered model fit using Akaike's Information Criterion (AIC) and changes in the estimated effects of TSP and SO2. In the full-year analysis, S-D is better than LOESS at predicting mortality, and S-D and LOESS are better than TSI, as measured by AIC. When TSP or SO2 was fit alone, the results were qualitatively similar, regardless of how weather was controlled; when TSP and SO2 were fit simultaneously, the S-D and LOESS models give qualitatively different results than TSI, which attributes more of the pollution effect to SO2 than to TSP. Model fit is substantially poorer with TSI. This pattern was repeated in analyses of summer and winter months, which included SSC. In summary, using synoptic weather categories in regression models does not meaningfully change the association between mortality and air pollution indexes. We also found little evidence that weather conditions modified the effect of pollution, regardless of the approach used to represent weather.

Air pollution and mortality in Philadelphia, 1974-1988.

Analyses involving data from many locations throughout the world have now been conducted to assess the association between air pollution and mortality. To date, six independent analyses of mortality data for Philadelphia, Pennsylvania, have been reported. In this new analysis of Philadelphia data for 1974-1988, Poisson regression models were developed to estimate the increased risk of daily mortality associated with air pollution while controlling for longer-term time trends and season and for weather. Model development was based on prior understanding of the effects of these factors on mortality and on consideration of model fit. The authors found moderate correlations of daily concentrations of total suspended particles (TSP), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO), and only slight correlations of ozone (O3) with other pollutants. When included individually in the model, the means of current and previous days' levels of TSP, SO2, and O3 had statistically significant effects on total mortality; pollutant increases of an interquartile range (34.5 micrograms/m3, 12.9 ppb, and 20.2 ppb, respectively) were associated with increases in mortality of around 1% for TSP and SO2, and of around 2% for O3. The effects of TSP and SO2 were diminished when both pollutants were simultaneously included in the model, whether pairwise or in the full multi-pollutant model. These analyses confirm the association between TSP and mortality found in previous studies in Philadelphia and show that the association is robust to consideration of other pollutants in the model.

PIP: Data from various studies on the association between air pollution and mortality in Philadelphia, Pennsylvania, undertaken in the period 1974-1988 are used in a new analysis in which the authors attempt to control for the effects of temporal factors, weather, and other pollutants in order to estimate the independent effect of total suspended particles (TSP) on mortality. The results confirm the association between TSP and mortality found in previous studies in Philadelphia and show that the association is robust to consideration of other pollutants.

Microscopic polyangiitis after influenza vaccination.

We describe a case of microscopic polyangiitis involving skin and joints after influenza vaccination. Titers of antiinfluenza A antibody were markedly elevated in synovial fluid (SF) relative to those in serum. Antiinfluenza B antibodies were not present in SF but were present in serum, suggesting a reaction specifically involving antiinfluenza A antibodies localized to the affected joint. A review identified 16 other cases of vasculitis after influenza vaccination. The cases reclassified according to the Chapel Hill diagnostic criteria identified multiple forms of vasculitis including 7 other cases of microscopic polyangiitis. Three patients had similar illnesses after previous influenza vaccination or influenza-like illness. As in our case 11 cases resolved without recurrence. While this does not provide conclusive evidence that the vaccination caused the vasculitis, together with the serologic data we present it supports this hypothesis.

Non-parametric estimation of spatial variation in relative risk.

We consider the problem of estimating the spatial variation in relative risks of two diseases, say, over a geographical region. Using an underlying Poisson point process model, we approach the problem as one of density ratio estimation implemented with a non-parametric kernel smoothing method. In order to assess the significance of any local peaks or troughs in the estimated risk surface, we introduce pointwise tolerance contours which can enhance a greyscale image plot of the estimate. We also propose a Monte Carlo test of the null hypothesis of constant risk over the whole region, to avoid possible over-interpretation of the estimated risk surface. We illustrate the capabilities of the methodology with two epidemiological examples.

Gout during pregnancy.

A 34-year-old woman, 12 weeks pregnant, presented with an acute monoarthritis. Gout was proven by joint aspiration. The gout was multifactorial in origin. Only 2 cases of gout during pregnancy have been described previously.

She can lip-read, she'll be all right: improving maternity care for the deaf and hearing-impaired.

In the UK a midwife is unlikely to meet many deaf women during her working life. Therefore very few midwives have a wealth of experience in providing care for these women. Postnatal discussion with one woman showed us that despite our good intentions the care we had given her was inadequate for her individual needs. We recognised that other deaf women were possibly receiving inadequate care. We set out to investigate this, and when we discovered that our suspicions were correct, devised a method that we hoped would improve the care we provided. The process of investigating the needs of deaf women is described in this paper together with the development of a teaching package for student and qualified midwives.

Should school nurses measure blood pressure?

The inclusion of blood pressure measurements in the routine health appraisal of junior school children was acceptable to children and staff and did not create undue anxiety. Of 677 children only 9 (1.33%) required follow up, 2 being referred to hospital out patients. With appropriate support school nurses should be encouraged to measure blood pressure.