Luc de Montigny

The spatial epidemiology of cocaine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) use: a demonstration using a population measure of community drug load derived from municipal wastewater.

AIMS To determine the utility of community-wide drug testing with wastewater samples as a population measure of community drug use and to test the hypothesis that the association with urbanicity would vary for three different stimulant drugs of abuse. DESIGN AND PARTICIPANTS Single-day samples were obtained from a convenience sample of 96 municipalities representing 65% of the population of the State of Oregon. MEASUREMENTS Chemical analysis of 24-hour composite influent samples for benzoylecgonine (BZE, a cocaine metabolite), methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). The distribution of community index drug loads accounting for total wastewater flow (i.e. dilution) and population are reported. FINDINGS The distribution of wastewater-derived drug index loads was found to correspond with expected epidemiological drug patterns. Index loads of BZE were significantly higher in urban areas and below detection in many rural areas. Conversely, methamphetamine was present in all municipalities, with no significant differences in index loads by urbanicity. MDMA was at quantifiable levels in fewer than half the communities, with a significant trend towards higher index loads in more urban areas. CONCLUSION; This demonstration provides the first evidence of the utility of wastewater-derived community drug loads for spatial analyses. Such data have the potential to improve dramatically the measurement of the true level and distribution of a range of drugs. Drug index load data provide information for all people in a community and are potentially applicable to a much larger proportion of the total population than existing measures.

The Effects of Weather on Walking Rates in Nine Cities

This study examined whether locally felt weather had a measurable effect on the amount of walking occurring in a given locale, by examining the observed walking rate in relation to air temperature, sunlight, and precipitation. Web-based cameras in nine cities were used to collect 6,255 observations over 7 months. Walking volumes and levels of precipitation and sunlight were captured by visual inspection; air temperature was obtained from local meteorological stations. A quasi-Poisson regression model to test the relationship between counts of pedestrians and weather conditions revealed that all three weather variables had significant associations with fluctuations in volumes of pedestrians, when controlling for city and elapsed time. A 5°C increase in temperature was associated with a 14% increase in pedestrians. A shift from snow to dry conditions was associated with an increase of 23%, and a 5% increase in sunlit area was associated with a 2% increase.

Residential address errors in public health surveillance data: A description and analysis of the impact on geocoding

The residential addresses of persons with reportable communicable diseases are used increasingly for spatial monitoring and cluster detection, and public health may direct interventions based upon the results of routine spatial surveillance. There has been little assessment, however, of the quality of address data in reportable disease notifications and of the corresponding impact of these errors on geocoding and routine public health practices. The objectives of this study were to examine address errors for a selected reportable disease in a large urban center in Canada and to assess the impact of identified errors on geocoding and the estimated spatial distribution of the disease. We extracted data for all notifications of campylobacteriosis from the Montreal public health department from 1995 to 2008 and used an address verification algorithm to determine the validity of the residential address for each case and to suggest corrections for invalid addresses. We assessed the types of address errors as well as the resulting positional errors, calculating the distance between the original address and the correct address as well as changes in disease density. Address errors and missing addresses were prevalent in the public health records (10% and 5%, respectively) and they influenced the observed distribution of campylobacteriosis in Montreal, with address correction changing case location by a median of 1.1 km. Further examination of the extent of address errors in public health data is essential, as is the investigation of how these errors impact routine public health functions.

Assessing a drop box programme: A spatial analysis of discarded needles

BACKGROUND Distributing sterile injection equipment to injection drug users is one of few proven ways of lowering the transmission rate of blood borne viruses. Distribution of equipment has also been linked to increased needle discarding, which is a public health risk for both injectors and their host communities. Drop boxes (anonymous and public-access sharps containers) are a promising and increasingly popular means of reducing unsafe disposal, yet there is little empirical research to support or guide their implementation. METHODS Using a dataset containing the locations of 7274 discarded needles and syringes collected monthly in the non-park open spaces of a 2.5km(2) neighbourhood of Montréal, Canada for a period of five years, we compared levels of discards before and after the installation of 12 drop boxes. We used quasi-Poisson regression to test the effects of drop boxes on monthly counts of collected discards for areas within a walking distance of 25, 50, 100 and 200m of a drop box. We adjusted for known time-dependent covariates linearly and unknown time-dependent covariates using a smoothing function. RESULTS We found strong evidence of reduced discarding following the installation of drop boxes; drop boxes were associated with reductions of up to 98% (95% CI: 72-100%) and significant reductions for areas up to 200m from a drop box. Reductions were inversely proportional to walking distance from drop boxes. No measure of weather or use of needle exchange programmes (NEPs) had a consistent relationship with discard counts. CONCLUSION Our research suggests that IDUs changed their needle-disposal behaviour in response to increased safe disposal options. In addition to being relatively low-threshold, economical and rapid, drop boxes appear to be a highly effective intervention to reduce discarded needles.

Clinic accessibility and clinic-level predictors of the geographic variation in 2009 pandemic influenza vaccine coverage in Montreal, Canada

Nineteen mass vaccination clinics were established in Montreal, Canada, as part of the 2009 influenza A/H1N1p vaccination campaign. Although approximately 50% of the population was vaccinated, there was a considerable variation in clinic performance and community vaccine coverage.

Predictors of the Timing of Vaccination Uptake: The 2009 Influenza Pandemic (H1N1) in Montreal

BACKGROUND In response to the 2009 H1N1 influenza pandemic, Canada undertook the largest vaccination campaign in its history. The effort mobilized thousands of healthcare workers, cost many hundreds of millions of dollars, and vaccinated more than 40% of the population. Despite the large investment in mass vaccination internationally, little is known about the factors that drive the timing of vaccination uptake. PURPOSE Data from 2009 were used to investigate three potential determinants of vaccination uptake in Montreal, Canada. METHODS Poisson regression was used to analyze daily vaccination before and after a telephone intervention targeting households in 12 of the citys 29 health neighborhoods. The effect of an eligibility strategy based on risk groups, and of weather, on uptake was then estimated. Data were analyzed in 2013. RESULTS Considerable variation in daily mass vaccination was observed, with the peak day (30,204 individuals) accounting for nearly five times the uptake of the slowest day (6298 individuals). No evidence was found that the telephone intervention led to a significant increase in vaccination. Daily vaccination was associated significantly with weather conditions, including mean temperature (relative risk [RR]=1.28, 95% CI=1.12, 1.46) and heavy precipitation (RR=0.63, 95% CI=0.45, 0.89), even after accounting for changes to eligibility, which also were associated with increased vaccination. CONCLUSIONS Considerable temporal variation in uptake can occur during mass vaccination efforts. Targeted interventions to increase vaccination should be evaluated further, as a large intervention had no observable effect. Mass vaccination campaigns should, however, attempt to optimize priority sequences and account for weather when estimating vaccine demand.

The spatial epidemiology of cocaine, methamphetamine and MDMA use: A demonstration using a population measure of community drug load derived from municipal wastewater

AIMS To determine the utility of community-wide drug testing with wastewater samples as a population measure of community drug use and to test the hypothesis that the association with urbanicity would vary for three different stimulant drugs of abuse. DESIGN AND PARTICIPANTS Single-day samples were obtained from a convenience sample of 96 municipalities representing 65% of the population of the State of Oregon. MEASUREMENTS Chemical analysis of 24-hour composite influent samples for benzoylecgonine (BZE, a cocaine metabolite), methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). The distribution of community index drug loads accounting for total wastewater flow (i.e. dilution) and population are reported. FINDINGS The distribution of wastewater-derived drug index loads was found to correspond with expected epidemiological drug patterns. Index loads of BZE were significantly higher in urban areas and below detection in many rural areas. Conversely, methamphetamine was present in all municipalities, with no significant differences in index loads by urbanicity. MDMA was at quantifiable levels in fewer than half the communities, with a significant trend towards higher index loads in more urban areas. CONCLUSION; This demonstration provides the first evidence of the utility of wastewater-derived community drug loads for spatial analyses. Such data have the potential to improve dramatically the measurement of the true level and distribution of a range of drugs. Drug index load data provide information for all people in a community and are potentially applicable to a much larger proportion of the total population than existing measures.

The spatial epidemiology of cocaine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) use

AIMS To determine the utility of community-wide drug testing with wastewater samples as a population measure of community drug use and to test the hypothesis that the association with urbanicity would vary for three different stimulant drugs of abuse. DESIGN AND PARTICIPANTS Single-day samples were obtained from a convenience sample of 96 municipalities representing 65% of the population of the State of Oregon. MEASUREMENTS Chemical analysis of 24-hour composite influent samples for benzoylecgonine (BZE, a cocaine metabolite), methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). The distribution of community index drug loads accounting for total wastewater flow (i.e. dilution) and population are reported. FINDINGS The distribution of wastewater-derived drug index loads was found to correspond with expected epidemiological drug patterns. Index loads of BZE were significantly higher in urban areas and below detection in many rural areas. Conversely, methamphetamine was present in all municipalities, with no significant differences in index loads by urbanicity. MDMA was at quantifiable levels in fewer than half the communities, with a significant trend towards higher index loads in more urban areas. CONCLUSION; This demonstration provides the first evidence of the utility of wastewater-derived community drug loads for spatial analyses. Such data have the potential to improve dramatically the measurement of the true level and distribution of a range of drugs. Drug index load data provide information for all people in a community and are potentially applicable to a much larger proportion of the total population than existing measures.