ABSTRACT
Aim Since March of 2020, tight measures against COVID-19, newly declared as pandemic by World Health Organization, affected almost all areas of our lives. Similarly, as with other aspects of community life, marked changes were expected to take place in the drug scene during and after the first lockdown period (16.3.2020–14.4.2020 in Finland). Wastewater-based epidemiology (WBE) is an approach established as an objective means for monitoring regional drug use. In Finland, we began WBE in 2012 with ten cities, and ended up to 27 cities (approximately 60% of Finnish population) since 2020. This study illustrates regional trends in stimulant drug use in Finland during the COVID-19 pandemic as a part of trend monitoring for up to 10 years. Method Composite 24-h samples of untreated wastewater were collected twice a year during one-week sampling periods from the inlets of wastewater treatment plants. Every other year 1-2 sampling campaigns were performed in the four biggest cities only. In 2020, two extra sampling periods (total of four periods) were carried out to evaluate the impact of measures against COVID-19 on drug use. Samples were analyzed with a fully validated UHPLC-MS/MS system. Daily drug consumption was calculated from the measured concentrations of the drugs or their metabolites in wastewater. Results While the stimulant drug consumption has been steadily increasing in Finland during the years of WBE, in 2020 the overall trend leveled off, with drug use being in higher level than ever before. However, the changes observed after the first quarter of 2020 varied markedly in different cities, with deepest decrease in Mariehamn, Åland, and highest increases in Lappeenranta and Vihti. During 2021, consumption of amphetamine, the dominant stimulant drug in Finland, was reduced by half from March to November/December. Instead, cocaine use remained in its newly increased level in Helsinki metropolitan area, bringing consumption of these two drugs record close to each other. COVID-19 measures may have played a role in the leveling observed in overall stimulant drug use trend, but the changes varied regionally and remained minor and transient in most cities. It seems that drug use was less affected by lockdown in 2020, as well as other measures, than many other societal phenomena. The marked fall of amphetamine consumption observed after spring of 2021 is temporally related to large seizures of drugs, which may have exhausted drug supplies. However, it can be speculated whether COVID-19 measures may have, for their part, delayed the recovery of illicit market after the seizures. Although the overall national drug situation is by far dominated by the biggest cities with largest populations, this study with opposing drug use trends in different cities shows again the importance of including a range of cities with different sizes and geographical locations in monitoring programs, both for a realistic picture of the overall drug situation, and to be able to offer objective and comparable data to various actors of both national and local level. Conclusion Drug use was less affected by measures against COVID-19 than many other societal phenomena. To obtain a realistic picture of the multifaceted drug situation, both during normal and exceptional circumstances such as COVID-19, it is essential to include a representative and wide enough selection of cities in monitoring programs.
ABSTRACT
Aim Wastewater-based epidemiology (WBE) has recently become one of the most rapidly evolving disciplines engaged in the measurement of population-level illicit drug use. Still, limited evidence has been presented how population-level WBE data correlates to forensic toxicological statistics and law enforcement activities. Objective was to study (1) how WBE methodology can efficiently give early-warning type of information on drug use and its trends, (2) how WBE findings compared to number of drivers under influence of drugs (DUID), and (3) how (exceptionally large) law enforcement operation affected actual drug use. Method Wastewater analysis: 24-h wastewater influent composite samples (n=190) were collected during 04/2013–03/2022 from Helsinki wastewater treatment plant (WWTP) serving approximately 860,000 inhabitants. Furthermore, several national sampling campaigns up to 28 WWTPs covering approximately 60% of all Finnish population (3.2 million out of 5.5 million) during 2012–2022 were performed. All samples were analysed by validated UHPLC-MS/MS. For comparison, traffic cases: Prevalence of different drugs was studied in all suspected DUID cases in Finland (from 2013 to 2021). All cases (whole blood) were systematically analysed by chromatographic mass spectrometric techniques. Law enforcement operation of illicit drugs: Information on Operation Greenlight (Trojan Shield), which was an exceptional operation in size together with Finnish and several international law enforcement authorities worldwide starting in February 2021 in Finland. Results Both wastewater analysis data and suspected DUID cases confirm the significant rise of amphetamine and cocaine use between 2013 to early 2021 in Finland. Based on WBE, amphetamine use peaked at record-high level from mid-2020 (after COVID-19 lockdown) to spring 2021 in the capital area of Finland. Mean amphetamine mass loads were 92mg/1000 persons/day in 2013, 335 in 2020, 322 in H1/2021, 234 in H2/2021 and 162 in Q1/2022 at the wastewater of Helsinki WWTP. The use of amphetamine significantly decreased in 2021 after the start of Operation Greenlight, while for cocaine effects on population-level use were more temporary. The number of amphetamine positive DUID in Finland showed similar trend: 2064 cases in 2013 (45.9% of all suspected DUID cases), 7913 (65.8%) in 2020 and 6228 (63.6%) in 2021 for amphetamine. For cocaine, the similar figures in wastewater were 18 (2013), 119 (2020), 110 (H1/2021), 144 (H2/2021) and 141mg/1000 persons/day (Q1/2022), respectively. The number of cocaine-related DUID increased from 81 (2013) to 501 (2021). Cocaine use is still highly concentrated in the capital area of Finland and there has been 6-8-fold increase in cocaine use at population-level during the last eight years. Based on WBE, the use of amphetamine was partially replaced by methamphetamine and synthetic cathinones, such as alfa-PHP, at the end of 2021, but not close to the same extent as amphetamine use was reduced. The results show in detail how use of various illicit drugs has changed during the last decade in Finland. WBE and DUID results have strongly correlated with each other concerning drug use and its trends: increase/decrease in population-level drug use has also increased/decreased harmful societal phenomena of illicit drugs, such as DUID. The results obtained during the last year indicate that unexceptionally large and successful law enforcement operations may affect drug supply, reduce actual drug use and diminish harmful societal effects, such as DUID. Conclusion Extensive 10-year data and experience on WBE approach shows that objective, novel and early-warning type of information on drug use and its trends for various illicit drugs can be obtained. More comprehensive picture and unique perspectives on drug use and drug markets are further obtained when combining different indicators and information, as exemplified here with WBE and DUID data linked to law enforcement activities.
ABSTRACT
Wastewater-based surveillance of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is used to monitor the population-level prevalence of the COVID-19 disease. In many cases, due to lockdowns or analytical delays, the analysis of wastewater samples might only be possible after prolonged storage. In this study, the effect of storage conditions on the RNA copy numbers of the SARS-CoV-2 virus in wastewater influent was studied and compared to the persistence of norovirus over time at 4 °C, -20 °C, and -75 °C using the reverse-transcription quantitative PCR (RT-qPCR) assays E-Sarbeco, N2, and norovirus GII. For the first time in Finland, the presence of SARS-CoV-2 RNA was tested in 24 h composite influent wastewater samples collected from Viikinmäki wastewater treatment plant, Helsinki, Finland. The detected and quantified SARS-CoV-2 RNA copy numbers of the wastewater sample aliquots taken during 19-20 April 2020 and stored for 29, 64, and 84 days remained surprisingly stable. In the stored samples, the SARS betacoronavirus and SARS-CoV-2 copy numbers, but not the norovirus GII copy numbers, seemed slightly higher when analyzed from the pre-centrifuged pellet-that is, the particulate matter of the influent-as compared with the supernatant (i.e., water fraction) used for ultrafiltration, although the difference was not statistically significant. Furthermore, when wastewater was spiked with SARS-CoV-2, linear decay at 4 °C was observed on the first 28 days, while no decay was visible within 58 days at -20 °C or -75 °C. In conclusion, freezing temperatures should be used for storage when immediate SARS-CoV-2 RNA analysis from the wastewater influent is not possible. Analysis of the particulate matter of the sample, in addition to the water fraction, can improve the detection frequency.