Many freshwater environments experience dramatic seasonal changes with some systems remaining ice-covered for most of the winter. Freshwater systems are also highly sensitive to environmental change. ...However, little is known about changes in microbial abundance and community composition during lake ice formation and times of persistent ice cover. The goal of this study is to characterize temporal dynamics of microbial communities during ice formation and persistent ice cover. Samples were collected in triplicate, five days per week from surface water in the Keweenaw Waterway between November and April. Environmental conditions along with microbial abundance and microbial community composition was determined. Distinct community composition was found between ice-free and ice-covered time periods with significantly different community composition between months. The microbial community underwent dramatic shifts in microbial abundance and diversity during the transitions into and out of ice cover. The richness of the microbial community increased during times of ice cover. Relatives of microbes involved in nitrogen cycling bloomed during times of ice cover as sequences related to known nitrifying taxa were significantly enriched during ice cover. These results help to elucidate how microbial abundance and diversity change over drastic seasonal transitions and how ice cover may affect microbial abundance and diversity.
Rationale
Stress exposure during adolescence contributes to developing a methamphetamine (METH) use disorder. However, most of the studies investigating addiction-related behaviours include only male ...rodents, despite METH addiction rates being higher in females. Furthermore, animal studies investigating the effects of stress on methamphetamine addiction have used only basic self-administration models which may not be sensitive to the effects of stress.
Objectives
This project explored whether adolescent isolation stress exposure increases the incidence of four key addiction-related behaviours in female rats.
Methods
Thirty-two female rat pups were caged in groups of four or individually during adolescence from postnatal (PND) day 22, with the latter being re-socialised in groups of four on PND 43. In adulthood, rats were tested for addiction-like behaviours in a METH self-administration paradigm modelling motivation to take METH, persistence in drug-seeking behaviour when METH was not available, resistance to extinction, and propensity to reinstate after a period of withdrawal.
Results
Adolescent social isolation resulted in lower METH intake during acquisition; however, the paradigm modelling drug-seeking when the drug was unavailable engendered intermittent METH bingeing in all rats, abolishing the group differences in intake during this phase. Adolescent social isolation also accelerated extinction of non-reinforced lever pressing, and increased stress-primed reinstatement, compared to the group-housed rats.
Conclusions
Adolescent social isolation stress alters various methamphetamine addiction-like behaviours in female rats.
ABSTRACT
Many aquatic environments are at risk for oil contamination and alkanes are one of the primary constituents of oil. The alkane hydroxylase (AlkB) is a common enzyme used by microorganisms to ...initiate the process of alkane-degradation. While many aspects of alkane bioremediation have been studied, the diversity and evolution of genes involved in hydrocarbon degradation from environmental settings is relatively understudied. The majority of work done to-date has focused on the marine environment. Here we sought to better understand the phylogenetic diversity of alkB genes across marine and freshwater settings using culture-independent methods. We hypothesized that there would be distinct phylogenetic diversity of alkB genes in freshwater relative to the marine environment. Our results confirm that alkB has distinct variants based on environment while our diversity analyses demonstrate that freshwater and marine alkB communities have unique responses to oil amendments. Our results also demonstrate that in the marine environment, depth is a key factor impacting diversity of alkB genes.
Diversity of oil degrading genes in the oceans is distinct from freshwater and shows different diversity based on depth.
Background and Aims
Studies often rely upon self‐report and biological testing methods for measuring illicit drug use, although evidence for their agreement is limited to specific populations and ...self‐report instruments. We aimed to examine comprehensively the evidence for agreement between self‐reported and biologically measured illicit drug use among all major illicit drug classes, biological indicators, populations and settings.
Methods
We systematically searched peer‐reviewed databases (Medline, Embase and PsycINFO) and grey literature. Included studies reported 2 × 2 table counts or agreement estimates comparing self‐reported and biologically measured use published up to March 2022. With biological results considered to be the reference standard and use of random‐effect regression models, we evaluated pooled estimates for overall agreement (primary outcome), sensitivity, specificity, false omission rates (proportion reporting no use that test positive) and false discovery rates (proportion reporting use that test negative) by drug class, potential consequences attached to self‐report (i.e. work, legal or treatment impacts) and time‐frame of use. Heterogeneity was assessed by inspecting forest plots.
Results
From 7924 studies, we extracted data from 207 eligible studies. Overall agreement ranged from good to excellent (> 0.79). False omission rates were generally low, while false discovery rates varied by setting. Specificity was generally high but sensitivity varied by drug, sample type and setting. Self‐report in clinical trials and situations of no consequences was generally reliable. For urine, recent (i.e. past 1–4 days) self‐report produced lower sensitivity and false discovery rates than past month. Agreement was higher in studies that informed participants biological testing would occur (diagnostic odds ratio = 2.91, 95% confidence interval = 1.25–6.78). The main source of bias was biological assessments (51% studies).
Conclusions
While there are limitations associated with self‐report and biological testing to measure illicit drug use, overall agreement between the two methods is high, suggesting both provide good measures of illicit drug use. Recommended methods of biological testing are more likely to provide reliable measures of recent use if there are problems with self‐disclosure.
Many aquatic environments are at risk for oil contamination and alkanes are one of the primary constituents of oil. The alkane hydroxylase (AlkB) is a common enzyme used by microorganisms to initiate ...the process of alkane-degradation. While many aspects of alkane bioremediation have been studied, the diversity and evolution of genes involved in hydrocarbon degradation from environmental settings is relatively understudied. The majority of work done to-date has focused on the marine environment. Here we sought to better understand the phylogenetic diversity of alfeB genes across marine and freshwater settings using culture-independent methods. We hypothesized that there would be distinct phylogenetic diversity of alfeB genes in freshwater relative to the marine environment. Our results confirm that alfeB has distinct variants based on environment while our diversity analyses demonstrate that freshwater and marine alkB communities have unique responses to oil amendments. Our results also demonstrate that in the marine environment, depth is a key factor impacting diversity of alfeB genes. Keywords: oil biodegradation; alkane monooxygenase; phylogeny; diversity
Harm reduction and treatment programmes are essential for reducing harms for people who inject drugs (PWID). We aimed to update estimates from a 2017 review of global coverage of needle and syringe ...exchange programmes (NSPs), opioid agonist treatment (OAT), and other harm reduction services that target PWID (eg, take-home naloxone THN programmes, supervised consumption facilities, and drug checking services).
We did a systematic review of available evidence from peer-reviewed and grey literature databases for studies published between Jan 1, 2017, and May 31, 2022. Programmatic data were collected on the availability of services, the number of sites, people accessing services, and equipment distributed in countries where there is evidence of injecting drug use. National estimates of coverage of OAT (ie, number of people accessing OAT per 100 PWID) and NSPs (ie, number of needles and syringes distributed per PWID per year) were generated where available using the most recent data. Regional and global estimates were derived and compared with WHO indicators. The study was registered with PROSPERO (CRD42020173974).
We included 195 studies and found there were 90 countries implementing OAT (75% of the PWID population) and 94 countries implementing NSPs (88% of the global PWID population). Only five countries (2% of the global PWID population) are providing high coverage of both services. Far fewer countries were implementing THN programmes (n=43), supervised consumption facilities (n=17), and drug checking services (n=26), with nine countries implementing all five services. Globally, we estimated there were 18 (95% uncertainty interval UI 12–27) people accessing OAT per 100 PWID, and 35 (95% UI 24–52) needles and syringes being distributed per person who injects drugs per year. More countries reported high (OAT 24; NSPs 10), moderate (OAT 8; NSPs 15), and low (OAT 38; NSPs 47) coverage of services compared with the previous review.
Global coverage of OAT and NSPs has increased modestly in the past 5 years but remains low for most countries. Programmatic data on other key harm reduction interventions are scarce.
Australian National Health and Medical Research Council.
People who inject drugs are exposed to various and changing risk environments and are at risk of multiple harms related to injecting drug use (IDU). We aimed to undertake a global systematic review ...of the prevalence of IDU, key IDU-related harms (including HIV, hepatitis C virus HCV, and hepatitis B virus HBV infection and overdose), and key sociodemographic characteristics and risk exposures for people who inject drugs.
We systematically searched for data published between Jan 1, 2017, and March 31, 2022, in databases of peer-reviewed literature (MEDLINE, Embase, and PsycINFO) and grey literature as well as various agency or organisational websites, and disseminated data requests to international experts and agencies. We searched for data on the prevalence, characteristics, and risks of people who inject drugs, including gender, age, sexuality, drug-use patterns, HIV, HCV, and HBV infections, non-fatal overdose, depression, anxiety, and injecting-related disease. Additional data were extracted from studies identified in our previous review. Meta-analyses were used to pool the data where multiple estimates were available for a country. We present country, regional, and global estimates for each variable examined.
We screened 40 427 reports published between 2017 and 2022, and the 871 eligible reports identified were added to the 1147 documents from the previous review. Evidence of IDU was documented in 190 of 207 countries and territories, and 14·8 million people (95% uncertainty interval UI 10·0–21·7) aged 15–64 years globally were estimated to inject drugs. Existing evidence suggests that there might be 2·8 million (95% UI 2·4–3·2) women and 12·1 million (95% UI 11·0–13·3) men who inject drugs globally, and that 0·4% (95% CI 0·3–1·3) of people who inject drugs identify as transgender. The amount of available data on key health and social risks among people who inject drugs varied widely across countries and regions. We estimated that 24·8% (95% CI 19·5–31·6) of people who inject drugs globally had experienced recent homelessness or unstable housing, 58·4% (95% CI 52·0–64·8) had a lifetime history of incarceration, and 14·9% (95% CI 8·1–24·3) had recently engaged in sex work, with substantial geographical variation. Injecting and sexual risk behaviour varied considerably geographically, as did risks of harms. Globally, we estimated that 15·2% (95% CI 10·3–20·9) of people who inject drugs are living with HIV, 38·8% (95% CI 31·4–46·9) have current HCV infection, 18·5% (95% CI 13·9–24·1) have recently overdosed, and 31·7% (95% CI 23·6–40·5) have had a recent skin or soft tissue infection.
IDU is being identified in a growing number of countries and territories that comprise more than 99% of the global population. IDU-related health harms are common, and people who inject drugs continue to be exposed to multiple adverse risk environments. However, quantification of many of these exposure and harms is inadequate and must be improved to allow for better targeting of harm-reduction interventions for these risks.
Australian National Health and Medical Research Council.
•Limited research on non-injecting and licit drug use among people who inject drugs.•Diversity in types of drugs and routes of administration used in this population globally.•Licit drug use commonly ...reported; tobacco was the most widely used drug overall.•Need for increased availability of non-injection harm reduction interventions.
A better understanding of global patterns of drug use among people who inject drugs can inform interventions to reduce harms related to different use profiles. This review aimed to comprehensively present the geographical variation in drug consumption patterns among this population.
Systematic searches of peer reviewed (PsycINFO, Medline, Embase) and grey literature published from 2008–2022 were conducted. Data on recent (past year) and lifetime drug use among people who inject drugs were included. Data were extracted on use of heroin, amphetamines, cocaine, benzodiazepines, cannabis, alcohol, and tobacco; where possible, estimates were disaggregated by route of administration (injecting, non-injecting, smoking). National estimates were generated and, where possible, regional, and global estimates were derived through meta-analysis.
Of 40,427 studies screened, 394 were included from 81 countries. Globally, an estimated 78.1 % (95 %CI:70.2–84.2) and 71.8 % (65.7–77.2) of people who inject drugs had recently used (via any route) and injected heroin, while an estimated 52.8 % (47.0–59.0) and 19.8 % (13.8–26.5) had recently used and injected amphetamines, respectively. Over 90 % reported recent tobacco use (93.5 % 90.8–95.3) and recent alcohol use was 59.1 % (52.6–65.6). In Australasia recent heroin use was lowest (49.4 % 46.8–52.1) while recent amphetamine injecting (64.0 % 60.8–67.1) and recent use of cannabis (72.3 % 69.9–74.6) were higher than in all other regions. Recent heroin use (86.1 % 78.3–91.4) and non–injecting amphetamine use (43.3 % 38.4–48.3) were highest in East and Southeast Asia. Recent amphetamine use (75.8 % 72.7–78.8) and injecting heroin use (84.8 % (81.4–87.8) were highest in North America while non–injecting heroin use was highest in Western Europe (45.0 % 41.3–48.7).
There is considerable variation in types of drugs and routes of administration used among people who inject drugs. This variation needs to be considered in national and global treatment and harm reduction interventions to target the specific behaviours and harms associated with these regional profiles of use.
•Vaccination coverage estimates for people who inject drugs were limited.•Estimates were often outdated and reliant upon self-report.•Data were unavailable for low-income countries and scarce for ...middle-income countries.•The majority of estimates pertained to hepatitis B vaccination.•Where available, data were indicative of suboptimal vaccine coverage.
People who inject drugs may be at excess risk of acquiring vaccine-preventable diseases and negative associated health outcomes, but experience barriers to vaccination. We aimed to determine vaccination coverage among people who inject drugs globally.
We conducted systematic searches of the peer-reviewed and grey literature, date limited from January 2008 to August 2023, focusing on diseases for which people who inject drugs are at elevated risk for and for which an adult vaccination dose is recommended (COVID-19, hepatitis A, hepatitis B, human papillomavirus, influenza, pneumococcal disease, tetanus). To summarise available data, we conducted a narrative synthesis.
We included 78 studies/reports comprising 117 estimates of vaccination coverage across 36 countries. Most estimates were obtained from high income countries (80%, n=94). We located estimates for hepatitis B vaccination in 33 countries, which included 18 countries with data on serological evidence of vaccine-derived hepatitis B immunity (range: 6-53%) and 22 countries with self-report data for vaccine uptake (<1-96%). Data for other vaccines were scarcer: reported hepatitis A vaccination coverage ranged 3-89% (five countries), COVID-19 ranged 4-84% (five countries), while we located estimates from fewer than five countries for influenza, tetanus, pneumococcal disease, and human papillomavirus.
Estimates were sparse but where available indicative of suboptimal vaccination coverage among people who inject drugs. Improving the consistency, timeliness, and geographic coverage of vaccine uptake data among this population is essential to inform efforts to increase uptake.
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