The role of alcohol use in pesticide suicide and self-harm: a scoping review.

PURPOSE: Suicide and self-harm by pesticide self-poisoning is common in low- and middle-income countries (LMICs). Alcohol is an important risk factor for self-harm; however, little is known about its role in pesticide self-poisoning. This scoping review explores the role that alcohol plays in pesticide self-harm and suicide. METHODS: The review followed the Joanna Briggs Institute scoping review guidance. Searches were undertaken in 14 databases, Google Scholar, and relevant websites. Articles were included if they focussed on pesticide self-harm and/or suicide and involvement of alcohol. RESULTS: Following screening of 1281 articles, 52 were included. Almost half were case reports (n = 24) and 16 focussed on Sri Lanka. Just over half described the acute impact of alcohol (n = 286), followed by acute and chronic alcohol use (n = 9), chronic use, (n = 4,) and only two articles addressed harm to others. One systematic review/meta-analysis showed increased risk of intubation and death in patients with co-ingested alcohol and pesticides. Most individuals who consumed alcohol before self-harming with pesticides were men, but alcohol use among this group also led to pesticide self-harm among family members. Individual interventions were recognised as reducing or moderating alcohol use, but no study discussed population-level alcohol interventions as a strategy for pesticide suicide and self-harm prevention. CONCLUSION: Research on alcohol's role in pesticide self-harm and suicide is limited. Future studies are needed to: further assess the toxicological effects of combined alcohol and pesticide ingestion, explore harm to others from alcohol including pesticide self-harm, and to integrate efforts to prevent harmful alcohol use and self-harm.

Differences in the characteristics of people who purchase pesticides from shops for self-harm versus those who use pesticides available in the domestic environment in Sri Lanka.

OBJECTIVE: Data from South Asia indicate that for 15%-20% of suicide attempts, pesticides are purchased from shops; otherwise, pesticides are obtained from an individual's house or nearby environment. We aimed to investigate the difference between individuals who directly purchase pesticides from shops for suicide attempts and suicide deaths versus those related to accessing the pesticides from an individual's house or nearby environment. METHODS: We conducted two comparative studies in rural Sri Lanka: (1) non-fatal shop cases (n = 50) were survivors of self-poisoning with pesticides who ingested the pesticides after purchasing them from a shop; non-fatal domestic cases (n = 192) were survivors who accessed pesticides from their house or nearby environment. (2) fatal shop cases (n = 50) were individuals who died after ingesting pesticides they purchased for the act; fatal domestic cases (n = 102) were patients who died after ingesting pesticides they accessed at house or nearby environment. Logistic regression analysis was used to assess the characteristics which distinguished between the shop and domestic cases. RESULTS: Data indicate that 20.7% and 32.9% of individuals who used pesticides for suicide attempts and suicide deaths had purchased them from shops, respectively. Being a non-farmer was the main distinguishing characteristic of shop cases: adjusted odds ratios (AOR) 8.9, 95% confidence intervals (CI) 3.2-24.4 for non-fatal shop cases, and AOR 4.0, 95% CI 1.5-10.6 for fatal shop cases. Non-fatal shop cases also had higher suicide intent (AOR 3.0, CI 1.0-8.9), and ingesting an insecticide (AOR 4.8, CI 1.8-1.0-8.9) than non-fatal domestic cases. CONCLUSION: A high suicide intent of individuals who purchase pesticides for the event explains the high proportion of such fatal cases. Such high suicide intent makes the prevention implications difficult to spell out for those individuals who purchase pesticides for self-poisoning. However, our findings are valuable for clinicians to assess pesticide poisoning cases in hospitals.

Surveillance of pesticide poisoning in an East and a West Malaysian hospital: characteristics of pesticide poisoning and the early impact of a national Paraquat ban.

BACKGROUND: Previous studies have shown that pesticide bans were associated with reduced fatal pesticide self-poisoning cases in high, and low-and-middle-income countries. We aimed to investigate the characteristics of pesticide poisoning patients admitted to two Malaysian hospitals and the early impact of the national paraquat ban implemented on 1st January 2020 in a culturally heterogenous South-East-Asian upper-middle-income setting. METHODS: Data were collected from an East (Bintulu) and a West (Ipoh) Malaysian hospital medical records in 2015-2021 and 2018-2021, respectively. Logistic regression analyses were conducted to investigate the association of aspects such as socio-demographic and clinical characteristics, paraquat ban with the types of pesticides involved (paraquat versus non-paraquat versus unknown) ,and the outcomes (fatal versus non-fatal). RESULTS: From the study sample of 212 pesticide poisoning patients aged 15 years or above, the majority were self-poisoning cases (75.5%) with a disproportionate over-representation of Indian ethnic minority (44.8%). Most pesticide poisoning cases had socio-environmental stressors (62.30%). The commonest stressors were domestic interpersonal conflicts (61.36%). 42.15% of pesticide poisoning survivors had a psychiatric diagnosis. Paraquat poisoning accounted for 31.6% of all patients and 66.7% of fatalities. Case fatality was positively associated with male gender, current suicidal intent, and paraquat poisoning. After the paraquat ban, the proportion of pesticide poisoning cases using paraquat decreased from 35.8 to 24.0%, and the overall case-fatality dropped slightly from 21.2 to 17.3%. CONCLUSIONS: Socio-environmental stressors in specific domestic interpersonal conflicts, seemed more prominent in pesticide poisoning compared to psychiatric diagnosis. Paraquat accounted for the majority of pesticide-associated deaths occurring in hospitals in the study areas. There was preliminary evidence that the 2020 paraquat ban led to a fall in case fatality from pesticide poisoning.

Relationship Between Alcohol Co-Ingestion and Clinical Outcome in Pesticide Self-Poisoning: A Systematic Review and Meta-Analysis.

AIM: Alcohol is a commonly co-ingested compound during self-poisoning with pesticides. Clinical experiences suggest alcohol co-ingestion (or withdrawal) makes patient management more difficult after self-poisoning and may contribute to poor clinical outcomes. We aimed to systematically review the world literature to explore the relationship between alcohol co-ingestion and outcome in pesticide self-poisoning. METHODS: We searched 13 electronic databases and Google scholar, conducted citation searching and a review of reference lists to find studies which investigated the relationship of alcohol with clinical outcome of pesticide self-poisoning in different countries. Thirteen studies, including 11 case series/reports and two cohort studies were considered for inclusion. RESULTS: Meta-analysis showed that alcohol co-ingestion in pesticide self-poisoning was associated with increased risk of death [odds ratio (OR) 4.9, 95% confidence interval (CI) 2.9-8.2 P<0.0001] and that alcohol co-ingested group required intubation eight times more often than non-co-ingested group in organophosphorus insecticide self-poisoning (OR 8.0, 95% CI 4.9-13.0 P<0.0001). Cases who co-ingested alcohol were older than non-alcohol group in two studies. One cohort study demonstrated that alcohol co-ingestion was associated with larger pesticide ingestions but did not itself affect the outcome. CONCLUSIONS: This systematic review indicates that alcohol co-ingestion may worsen clinical outcome in pesticide self-poisoning.

Banning highly hazardous pesticides saves the lives of young people, particularly females, in low- and middle-income countries.

Pesticide self-poisoning is a public health problem mostly affecting low- and middle-income countries. In Sri Lanka, India and China suicide rates have reduced among young people, particularly females, following highly hazardous pesticides (HHP) bans. This success story requires attention to encourage more research on differential effects of HHP bans.

Suicides by pesticide ingestion in Pakistan and the impact of pesticide regulation.

INTRODUCTION: Suicide is a major public health problem in Pakistan, accounting to approximately 19,331 deaths every year. Many are due to consumption of acutely toxic pesticides; however, there is a lack of national suicide data, limiting knowledge and potential for intervention. In this paper, we aimed to review the literature on pesticide self-poisoning in Pakistan to identify the most problematic pesticides in relation to national pesticide regulations. METHODS: Information on the currently registered and banned pesticides was obtained from Ministry of National Food Security and Research while data on pesticide import and use was extracted from FAOSTAT. We searched the following sources for articles and research papers on poisoning in Pakistan: Cumulative Index to Nursing and Allied Health (CINAHL), Google Scholar, Applied Social Sciences Index and Abstracts (ASSIA), Excerpta Medica (EMBASE), National Library of Medicine's MEDLINE (PUBMED), PS102YCHINFO and Pakmedinet.com using the search terms 'self-poisoning', 'deliberate self-harm', 'suicide', 'methods and means of suicide', 'organophosphate', 'wheat pill', 'aluminium phosphide', 'acute poisoning', OR 'pesticides', AND 'Pakistan'. RESULTS: As of May 2021, 382 pesticide active ingredients (substances) were registered in Pakistan, of which five were WHO hazard class Ia (extremely hazardous) and 17 WHO hazard class Ib (highly hazardous). Twenty-six pesticides, four formulations, and seven non-registered pesticides had been banned, of which two were WHO class Ia and five Ib. We identified 106 hospital-level studies of poisoning conducted in Pakistan, of which 23 did not mention self-poisoning cases and one reported no suicidal poisoning cases. We found no community or forensic medicine studies. Of 52,323 poisoning cases identified in these papers, 24,546 [47%] were due to pesticides. The most commonly identified pesticide classes were organophosphorus (OP) insecticides (13,816 cases, 56%) and the fumigant aluminium phosphide (3 g 56% tablets, often termed 'wheat pills'; 686 cases, 2.7%). Few studies identified the particular pesticides involved or the resulting case fatality. CONCLUSION: We found pesticide poisoning to be a major cause of poisoning in Pakistan, with OP insecticides and the fumigant aluminium phosphide the main pesticides identified. Withdrawal of Class I pesticides (as proposed to occur nationally in 2022) and high concentration aluminium phosphide tablets should rapidly reduce suicidal deaths by reducing the case fatality for low-intention poisoning cases. National cause of death data and forensic toxicology laboratory data identifying the pesticides responsible for deaths will be important to assess impacts of the proposed national ban.

Quantification of Organophosphorus Insecticide Removed by Gastric Lavage in Acutely Poisoned Patients: An Observational Study.

Introduction: The effectiveness of gastric lavage in organophosphorus (OP) poisoning has not been established. We assessed the ability of gastric lavage to remove OP insecticides as a preliminary stage in assessing effectiveness. Patients and methods: Organophosphorus poisoning patients presenting within 6 hours were included, irrespective of prior gastric lavage. A nasogastric tube was placed and gastric contents aspirated, followed by at least three cycles of gastric lavage with 200 mL of water. Samples from the initial aspirate and the first three lavage cycles were sent for identification and quantification of the OP compounds. Patients were monitored for complications of gastric lavage. Results: Around 42 patients underwent gastric lavage. Eight (19.0%) patients were excluded from the study because of a lack of analytical standards for ingested compounds. Insecticides were detectable in the lavage samples of 24 of 34 (70.6%) patients. Lipophilic OP compounds were detected in 23 of 24 patients, while no hydrophilic OP compounds could be detected in six patients with reported ingestion of hydrophilic compounds. For chlorpyrifos poisoning (n = 10), only 0.65 mg (SD 1.2) of the estimated ingested amount (n = 5) of 8,600 mg (SD 3,200) was recovered by gastric lavage. The mean proportion of the compound removed by initial gastric aspirate was 79.4% and subsequent three cycles removed 11.5, 6.6, and 2.7%. Conclusion: Lipophilic OP insecticides could be quantified in the stomach contents of OP poisoning patients with the first aspiration or lavage being most effective. The amount removed was very low; hence, routine use of gastric lavage for OP poisoning patients arriving within 6 hours is unlikely to be beneficial. How to cite this article: Mathansingh AJ, Jose A, Fleming JJ, Abhilash KPP, Chandiraseharan VK, Lenin A, et al. Quantification of Organophosphorus Insecticide Removed by Gastric Lavage in Acutely Poisoned Patients: An Observational Study. Indian J Crit Care Med 2023;27(6):397-402.

Novel Clinical Toxicology and Pharmacology of Organophosphorus Insecticide Self-Poisoning.

Organophosphorus insecticide self-poisoning is a major global health problem, killing over 100,000 people annually. It is a complex multi-organ condition, involving the inhibition of cholinesterases, and perhaps other enzymes, and the effects of large doses of ingested solvents. Variability between organophosphorus insecticides-in lipophilicity, speed of activation, speed and potency of acetylcholinesterase inhibition, and in the chemical groups attached to the phosphorus-results in variable speed of poisoning onset, severity, clinical toxidrome, and case fatality. Current treatment is modestly effective, aiming only to reactivate acetylcholinesterase and counter the effects of excess acetylcholine at muscarinic receptors. Rapid titration of atropine during resuscitation is lifesaving and can be performed in the absence of oxygen. The role of oximes in therapy remains unclear. Novel antidotes have been tested in small trials, but the great variability in poisoning makes interpretation of such trials difficult. More effort is required to test treatments in adequately powered studies.

CON: Oximes should not be used routinely in organophosphorus insecticide poisoning.

Organophosphorus (OP) insecticide poisoning causes respiratory failure due to acetylcholinesterase (AChE) inhibition. The AChE reactivating antidote pralidoxime was developed in the 1950s and was soon noted to benefit patients occupationally poisoned with the highly potent OP insecticide parathion. Routine use of pralidoxime and other oximes such as obidoxime then became widely recommended. However, nearly all severe cases of OP poisoning now result from self-poisoning with large volumes of less potent (WHO hazard class Ib and II) insecticides and co-formulated solvents. Unfortunately, oxime clinical trials have never shown benefit from their use for these patients, and some have shown that pralidoxime may be associated with harm, including increased mortality. Oximes should not be used routinely for the care of OP insecticide-poisoned patients until translational and clinical studies have identified a safe and effective oxime regimen and identified the patients who benefit.

Antagonistic postsynaptic and presynaptic actions of cyclohexanol on neuromuscular synaptic transmission and function.

Intentional ingestion of agricultural organophosphorus insecticides is a significant public health issue in rural Asia, causing thousands of deaths annually. Some survivors develop a severe, acute or delayed myasthenic syndrome. In animal models, similar myasthenia has been associated with increasing plasma concentration of one insecticide solvent metabolite, cyclohexanol. We investigated possible mechanisms using voltage and current recordings from mouse neuromuscular junctions (NMJs) and transfected human cell lines. Cyclohexanol (10-25 mM) reduced endplate potential (EPP) amplitudes by 10-40% and enhanced depression during repetitive (2-20 Hz) stimulation by up to 60%. EPP decay was prolonged more than twofold. Miniature EPPs were attenuated by more than 50%. Cyclohexanol inhibited whole-cell currents recorded from CN21 cells expressing human postjunctional acetylcholine receptors (hnAChR) with an IC50 of 3.74 mM. Cyclohexanol (10-20 mM) also caused prolonged episodes of reduced-current, multi-channel bursting in outside-out patch recordings from hnAChRs expressed in transfected HEK293T cells, reducing charge transfer by more than 50%. Molecular modelling indicated cyclohexanol binding (-6 kcal/mol) to a previously identified alcohol binding site on nicotinic AChR α-subunits. Cyclohexanol also increased quantal content of evoked transmitter release by ∼50%. In perineurial recordings, cyclohexanol selectively inhibited presynaptic K+ currents. Modelling indicated cyclohexanol binding (-3.8 kcal/mol) to voltage-sensitive K+ channels at the same site as tetraethylammonium (TEA). TEA (10 mM) blocked K+ channels more effectively than cyclohexanol but EPPs were more prolonged in 20 mM cyclohexanol. The results explain the pattern of neuromuscular dysfunction following ingestion of organophosphorus insecticides containing cyclohexanol precursors and suggest that cyclohexanol may facilitate investigation of mechanisms regulating synaptic strength at NMJs. KEY POINTS: Intentional ingestion of agricultural organophosphorus insecticides is a significant public health issue in rural Asia, causing thousands of deaths annually. Survivors may develop a severe myasthenic syndrome or paralysis, associated with increased plasma levels of cyclohexanol, an insecticide solvent metabolite. Analysis of synaptic transmission at neuromuscular junctions in isolated mouse skeletal muscle, using isometric tension recording and microelectrode recording of endplate voltages and currents, showed that cyclohexanol reduced postsynaptic sensitivity to acetylcholine neurotransmitter (reduced quantal size) while simultaneously enhancing evoked transmitter release (increased quantal content). Patch recording from transfected cell lines, together with molecular modelling, indicated that cyclohexanol causes selective, allosteric antagonism of postsynaptic nicotinic acetylcholine receptors and block of presynaptic K+ -channel function. The data provide insight into the cellular and molecular mechanisms of neuromuscular weakness following intentional ingestion of agricultural organophosphorus insecticides. Our findings also extend understanding of the effects of alcohols on synaptic transmission and homeostatic synaptic function.

Suicide by pesticide ingestion in Nepal and the impact of pesticide regulation.

BACKGROUND: Nepal recorded 5754 suicides in 2018-19 - a high number for a relatively small country. Over 24% of these suicides were by poisoning, most by ingestion of highly concentrated agricultural pesticides. Nepal has actively regulated pesticides to reduce their health impacts since 2001. We aimed to analyse Nepal's history of pesticide regulation, pesticides responsible for poisonings, and relate them to national suicide rates. METHODS: Information on pesticide regulation was collected from the Plant Quarantine and Pesticide Management Centre of the Ministry of Agriculture and Livestock Development. National data on suicides from 1980 to 2019 were obtained from the National Statistical Bureau and Nepal Police. Data on the pesticides responsible for self-poisoning and pesticide suicides over time were obtained from a systematic literature review. RESULTS: As of June 2020, 171 pesticides were registered for use in Nepal, of which one was extremely hazardous (WHO Class Ia), one other highly hazardous (WHO Class Ib), and 71 moderately hazardous (WHO Class II). Twenty-four pesticides have been banned since 2001, with eight (including five WHO Class I compounds) banned in 2019. Although the suicide rate has increased more than twelve-fold since 1980, particularly for hanging (15-fold increase from 1980 to 2018), fatal pesticide self-poisoning has increased by 13-fold. Methyl-parathion is reported to be the key pesticide responsible for pesticide self-poisoning in Nepal, despite being banned in 2006. CONCLUSION: The full effect of the recent pesticide policy reform in Nepal remains to be seen. Our analysis shows a continuing increase in suicide numbers, despite bans of the most important pesticide in 2006. This may indicate smuggling across the border and the use of the brand name (Metacid) for pesticides in general making it difficult to identify the responsible pesticide. More information is required from forensic toxicology labs that identify the individual compounds found. The effect of recent bans of common suicide pesticides needs to be monitored over the coming years. Evidence from other Asian countries suggests that HHPs bans will lead to a marked reduction in suicides, as well as fewer cases of occupational poisoning.

Importance of pesticides for lethal poisoning in India during 1999 to 2018: a systematic review.

BACKGROUND: Poisoning is a major problem in India. However, there is little systematic information on the key poisons responsible for most deaths by geographical area and over time. We aimed to review the literature to identify the poison classes causing the greatest number of deaths in India over the last 20 years. METHODS: We performed a systematic literature review in Medline, Embase and Google Scholar (1999-2018), and Indian online medical journals, to find papers that reported deaths from all forms of poisoning in India, with last search 20 April 2020. We included epidemiological studies, observational studies, randomised trials, interventional studies, and case series published from 1999 to 2018 that showed the number of deaths and autopsy studies indicating the specific poisons or poison classes. Studies providing the case fatality for specific poisons or classes, which enabled calculation of the number of deaths, were also included. We excluded deaths due to animal bites and stings, ethanol or methanol poisoning, and gas inhalation as well as papers reporting a single death (case study of single patient). We grouped the papers into 5-year intervals and identified the two most common poison classes in each paper. We used descriptive statistics to summarise the findings over time based on the causative poison and the location of the study. RESULTS: We identified 186 papers reporting 16,659 poisoning deaths between 1999 and 2018. The number of publications per 5-year interval showed no clear trend over the period (48, 38, 67, and 36 for consecutive periods). Half of the deaths (n = 8338, 50.0%) were reported during the first 5 years of the study (1999-2003), the number of deaths declining thereafter (to n = 1714 in 2014-2018). Deaths due to pesticide poisoning (94.5%) were dominant across the study period compared to other classes of poison [hair dye paraphenylenediamine poisoning (2.6%), medicine overdose (1.4%) or plant poisoning (1.0%)]. Among the pesticides, aluminium phosphide was the most important lethal poison during the first 10 years before declining markedly; organophosphorus insecticides were important throughout the period, becoming dominant in the last decade as aluminium phosphide cases declined. Unfortunately, few papers identified the specific organophosphorus insecticide responsible for deaths. CONCLUSION: Use of the published literature to better understand the epidemiology of lethal poisoning in India has clear limitations, including secular variation in publishing practices and interest in poisoning. Unfortunately, there are no long-term detailed, combination hospital and community studies from India to provide this information. In their absence, our review indicates that pesticides are the most important poison in India, with organophosphorus insecticides replacing aluminium phosphide as the key lethal poison after government regulatory changes in 2001 reduced the latter's lethality. Plant and hair dye poisoning and medicines overdose caused few deaths. Aluminium phosphide deaths mostly occurred in northern Indian states, whereas deaths from organophosphorus insecticide poisoning occurred throughout India. Paraquat poisoning has become a clinical problem in the last 10 years. Lethal pesticide poisoning remains alarmingly common, emphasising the need for additional regulatory interventions to curtail the burden of pesticide poisoning deaths in India. More detailed reporting about the specific pesticide involved in lethal poisoning will be helpful to guide regulatory decisions.

Risk factors for deliberate self-harm in young people in rural Sri Lanka: a prospective cohort study of 22,000 individuals.

Background: Over 90% of youth suicide deaths occur in low- and middle-income countries. Despite this relatively little is known about risk factors in this context. Aims: Investigate risk factors for deliberate self-harm (non-fatal) in young people in rural Sri Lanka. Methods: A prospective cohort study of 22,401 individuals aged 12-18 years with complete data on sex, student status, household asset score, household access to pesticides and household problematic alcohol use. Deliberate self-harm was measured prospectively by reviewing hospital records. Poisson regression estimated incidence rate ratios (IRRs) for the association of risk factors with deliberate self-harm. Results: Females were at higher risk of deliberate self-harm compared to males (IRR 2.05; 95%CI 1.75 - 2.40). Lower asset scores (low compared to high: IRR 1.46, 95%CI 1.12 - 2.00) and having left education (IRR 1.61 95%CI 1.31 - 1.98) were associated with higher risks of deliberate self-harm, with evidence that the effect of not being in school was more pronounced in males (IRR 1.94; 95%CI 1.40 - 2.70) than females. There was no evidence of an association between household pesticide access and deliberate self-harm risk, but problematic household alcohol use was associated with increased risk (IRR 1.23; 95%CI 1.04 - 1.45), with evidence that this was more pronounced in females than males (IRR for females 1.42; 95%CI 1.17 - 1.72). There was no evidence of deliberate self-harm risk being higher at times of school exam stress. Conclusion: Indicators of lower socioeconomic status, not being in school, and problematic alcohol use in households, were associated with increased deliberate self-harm risk in young people.

VOCCluster: Untargeted Metabolomics Feature Clustering Approach for Clinical Breath Gas Chromatography/Mass Spectrometry Data.

Metabolic profiling of breath analysis involves processing, alignment, scaling, and clustering of thousands of features extracted from gas chromatography/mass spectrometry (GC/MS) data from hundreds of participants. The multistep data processing is complicated, operator error-prone, and time-consuming. Automated algorithmic clustering methods that are able to cluster features in a fast and reliable way are necessary. These accelerate metabolic profiling and discovery platforms for next-generation medical diagnostic tools. Our unsupervised clustering technique, VOCCluster, prototyped in Python, handles features of deconvolved GC/MS breath data. VOCCluster was created from a heuristic ontology based on the observation of experts undertaking data processing with a suite of software packages. VOCCluster identifies and clusters groups of volatile organic compounds (VOCs) from deconvolved GC/MS breath with similar mass spectra and retention index profiles. VOCCluster was used to cluster more than 15 000 features extracted from 74 GC/MS clinical breath samples obtained from participants with cancer before and after a radiation therapy. Results were evaluated against a panel of ground truth compounds and compared to other clustering methods (DBSCAN and OPTICS) that were used in previous metabolomics studies. VOCCluster was able to cluster those features into 1081 groups (including endogenous and exogenous compounds and instrumental artifacts) with an accuracy rate of 96% (±0.04 at 95% confidence interval).

Using ex-ante economic evaluation to inform research priorities in pesticide self-poisoning prevention: the case of a shop-based gatekeeper training programme in rural Sri Lanka.

OBJECTIVES: Suicide by pesticide self-poisoning is a major public health challenge in low- and middle-income countries. While effectiveness studies are required to test alternative prevention approaches, economic evidence is lacking to inform decision-making in research priority setting. Therefore, this study aimed to estimate the costs of a shop-based gatekeeper training programme for pesticide vendors seeking to prevent pesticide self-poisoning in rural Sri Lanka and assess its potential for cost-effectiveness. METHODS: Ex-ante cost and cost-effectiveness threshold (CET) analyses were performed from a governmental perspective based on a three-year analytic horizon, using 'no programme' as a comparator. A programme model targeting all 535 pesticide shops in the North Central Province and border areas was applied. Total programme costs (TPC) were estimated in 2019 USD using an ingredients approach and 3% annual discounting. The Sri Lankan gross domestic product per capita and life years saved were used as CET and effectiveness measure, respectively. Sensitivity analyses were performed. RESULTS: TPC were estimated at 31 603.03 USD. TPC were sensitive to cost changes of training material and equipment and the programme lifetime. The programme needs to prevent an estimated 0.23 fatal pesticide self-poisoning cases over three years to be considered cost-effective. In the sensitivity analyses, the highest number of fatal cases needed to be prevented to obtain cost-effectiveness was 4.55 over three years. CONCLUSIONS: From an economic perspective, the programme has a very high potential to be cost-effective. Research assessing its effectiveness should therefore be completed, and research analysing its transferability to other settings prioritised.

OBJECTIFS: Le suicide par auto-intoxication par les pesticides est un défi majeur de santé publique dans les pays à revenu faible ou intermédiaire. Bien que des études d'efficacité soient nécessaires pour tester d'autres approches de prévention, les données économiques manquent pour informer la prise de décision dans les priorités de recherche. Par conséquent, cette étude visait à estimer les coûts d'un programme de formation des vendeurs dans les magasins de pesticides visant à prévenir l'auto-intoxication par les pesticides dans les régions rurales du Sri Lanka et à évaluer son potentiel de rentabilité. MÉTHODES: Les analyses ex-ante des coûts et des seuils de rentabilité (SR) ont été réalisées dans une perspective gouvernementale sur la base d'un horizon analytique de trois ans, en utilisant «l'absence de programme¼ comme comparateur. Un modèle de programme ciblant les 535 magasins de pesticides de la province du Centre-Nord et des zones frontalières a été appliqué. Les coûts totaux du programme (CTP) ont été estimés en USD 2019 en utilisant une approche d'ingrédients et une remise annuelle de 3%. Le produit intérieur brut sri-lankais par habitant et les années de vie sauvées ont été utilisés comme SR et mesure d'efficacité, respectivement. Des analyses de sensibilité ont été effectuées. RÉSULTATS: le CTP a été estimé à 31.603,03 USD. Le CTP était sensible aux changements de coût du matériel et de l'équipement de formation et de la durée de vie du programme. Le programme devrait prévenir environ 0,23 cas d'auto-intoxication mortelle par des pesticide sur trois ans pour être considéré comme rentable. Dans les analyses de sensibilité, le plus grand nombre de cas mortels à prévenir pour obtenir une rentabilité était de 4,55 sur trois ans. CONCLUSIONS: D'un point de vue économique, le programme a un potentiel très élevé pour être rentable. La recherche évaluant son efficacité doit donc être complétée et la recherche analysant sa transférabilité à d'autres contextes doit être priorisée.

Factors associated with purchasing pesticide from shops for intentional self-poisoning in Sri Lanka.

OBJECTIVE: In South Asia, up to one in five individuals who ingest pesticides for self-poisoning and survive purchased them from a shop immediately prior to the event. Thus far, no research has taken place to determine whether interventions implemented through the pesticide sellers might be acceptable or effective, despite the hundreds of thousands of such risk purchases each year. We aimed to investigate factors associated with purchasing pesticides for self-poisoning in Sri Lanka. METHODS: We used a case-control study. Cases (n = 50) were individuals who ingested pesticides after purchasing them for the act, and controls (n = 200) were customers who bought pesticides but did not use them for self-harm. Logistic regression analysis was used to assess socio-demographic and purchase-specific risk factors. RESULTS: Alcohol intoxication (adjusted odds ratios [AOR] 36.5, 95% confidence intervals [CI] 1.7-783.4) and being a non-farmer AOR 13.3, 95% CI 1.8-99.6 were the main distinguishing factors when purchasing pesticides for self-poisoning. The positive predictive values were 93.3% (95% CI 68.0-99.8%) and 88.2% (95% CI 72.5-96.7%), respectively. One and/or other of these factors characterised 72.0% of cases but only 2.5% controls. CONCLUSION: While results need to be interpreted cautiously, sales restrictions to prevent alcohol-intoxicated persons and non-farmers purchasing pesticides for self-poisoning may be effective.

OBJECTIF: En Asie du Sud, jusqu'à une personne sur cinq qui ingère des pesticides pour s'auto­intoxiquer et survi les a achetés dans un magasin immédiatement avant l'événement. Jusqu'à présent, aucune recherche n'a eu lieu pour déterminer si les interventions mises en œuvre chez les vendeurs de pesticides pourraient être acceptables ou efficaces, malgré les centaines de milliers d'achats à risque chaque année. Nous visions à étudier les facteurs associés à l'achat de pesticides pour l'auto­intoxication au Sri Lanka. MÉTHODES: Nous avons utilisé une étude cas­témoins. Les cas (n = 50) étaient des personnes qui avaient ingéré des pesticides après les avoir achetés pour l'acte et les témoins (n = 200) étaient des clients qui achetaient des pesticides mais ne les utilisaient pas pour se faire du mal. Une analyse de régression logistique a été utilisée pour évaluer les facteurs de risque sociodémographiques et spécifiques à l'achat. RÉSULTATS: L'intoxication alcoolique (rapport de cotes ajusté [AOR] 36,5, intervalles de confiance à 95% [IC] 1,7­783,4) et étant un non­agriculteur AOR 13,3 ; IC95%: 1,8­99,6 étaient les principaux facteurs distinctifs lors de l'achat de pesticides pour l'auto­intoxication. Les valeurs prédictives positives étaient respectivement de 93,3% (IC95%: 68,0% ­99,8%) et 88,2% (IC95%: 72,5% ­96,7%). L'un et/ou l'autre de ces facteurs caractérisaient 72,0% des cas mais seulement 2,5% des témoins. CONCLUSION: Bien que les résultats doivent être interprétés avec prudence, des restrictions de vente visant à empêcher les personnes intoxiquées à l'alcool et les non­agriculteurs d'acheter des pesticides pour l'auto­intoxication peuvent être efficaces.

Suicide by pesticide poisoning in India: a review of pesticide regulations and their impact on suicide trends.

BACKGROUND: Pesticide self-poisoning is a common means of suicide in India. Banning highly hazardous pesticides from agricultural use has been successful in reducing total suicide numbers in several South Asian countries without affecting agricultural output. Here, we describe national and state-level regulation of highly hazardous pesticides and explore how they might relate to suicide rates across India. METHODS: Information on pesticide regulation was collated from agriculture departments of the central government and all 29 state governments (excluding union territories). National and state-level data on suicides from 1995 to 2015 were obtained from the National Crime Records Bureau (NCRB). We used joinpoint analysis and negative binomial regression to investigate the trends in suicide rates nationally and in Kerala, in view of the robust measures Kerala has taken to restrict a number of HHPs, to identify any effect on suicides. RESULTS: As of October 2019, 318 pesticides were registered for use in India, of which 18 were extremely (Class Ia) or highly (Class Ib) hazardous according to World Health Organization toxicity criteria. Despite many highly hazardous pesticides still being available, several bans have been implemented during the period studied. In our quantitative analyses we focused on the permanent bans in Kerala in 2005 (of endosulfan) and 2011 (of 14 other pesticides); and nationally in 2011 (of endosulfan). NCRB data indicate that pesticides were used in 441,918 reported suicides in India from 1995 to 2015, 90.3% of which occurred in 11 of the 29 states. There was statistical evidence of lower than expected rates of pesticide suicides (rate ratio [RR] 0.52, 95% CI 0.49-0.54) and total suicides nationally by 2014 (0.90, 0.87-0.93) after the 2011 endosulfan ban. In Kerala, there was a lower than expected rate of pesticide suicides (0.45, 0.42-0.49), but no change to the already decreasing trend in total suicides (1.02, 1.00-1.05) after the 2011 ban of 14 pesticides. The 2005 ban on endosulfan showed a similar effect - lower than expected pesticide suicides (0.79, 0.64-0.99), but no change to the decreasing trend of total suicides (0.97, 0.93-1.02) in 2010. There was no evidence of a decline in agricultural outputs following the bans. CONCLUSION: Highly hazardous pesticides continue to be used in India and pesticide suicide remains a serious public health problem. However, some pesticide bans do appear to have impacted previous trends in the rates of both pesticide suicides and all suicides. Comprehensive national bans of highly hazardous pesticides could lead to a reduction in suicides across India, in addition to reduced occupational poisoning, with minimal effects on agricultural yield.

Emerging pesticides responsible for suicide in rural Sri Lanka following the 2008-2014 pesticide bans.

BACKGROUND: Sri Lanka has reduced its overall suicide rate by 70% over the last two decades through means restriction, through a series of government regulations and bans removing highly hazardous pesticides from agriculture. We aimed to identify the key pesticide(s) now responsible for suicides in rural Sri Lanka to provide data for further pesticide regulation. METHODS: We performed a secondary analysis of data collected prospectively during a cluster randomized controlled trial in the Anuradhapura district of Sri Lanka from 2011 to 16. The identity of pesticides responsible for suicides were sought from medical or judicial medical notes, coroners' records, and the person's family. Trend analysis was done using a regression analysis with curve estimation to identify relative importance of key pesticides. RESULTS: We identified 337 suicidal deaths. Among them, the majority 193 (57.3%) were due to ingestion of pesticides while 82 (24.3%) were due to hanging. A specific pesticide was identified in 105 (54.4%) of the pesticide suicides. Ingestion of carbosulfan or profenofos was responsible for 59 (56.2%) of the suicides with a known pesticide and 17.5% of all suicides. The increasing trend of suicides due to carbosulfan and profenofos over time was statistically significant (R square 0.846, F 16.541, p 0.027). CONCLUSION: Ingestion of pesticides remains the most important means of suicides in rural Sri Lanka. The pesticides that were once responsible for most pesticide suicides have now been replaced by carbosulfan and profenofos. Their regulation and replacement in agriculture with less hazardous pesticides will further reduce the incidence of both pesticide and overall suicides in rural Sri Lanka.

Are left-behind families of migrant workers at increased risk of attempted suicide? - a cohort study of 178,000+ individuals in Sri Lanka.

BACKGROUND: There are an estimated 258 million international migrants worldwide. In Asia low-skilled workers often emigrate on a temporary basis (2-3 years) without their families. There is significant concern over the mental health and wellbeing of left-behind families in this region. No previous study has examined whether the risk of suicidal behaviour is elevated in left-behind family members. METHODS: Cohort study using baseline data from a large randomised controlled trial in Sri Lanka (n = 178,730 participants; 8% households had a current temporary foreign migrant) and prospective hospital presentations of suicide attempts. Using multilevel Poisson regression models, we compared the risk of attempted suicide in households with left-behind and non-left-behind family members. We also investigated whether the sex of the migrant or the age/sex of the household member left behind altered any associations. RESULTS: The risk of an attempted suicide was elevated in female migrant households (IRR 1.60 95% CI 1.38, 1.85), but not male migrant households (IRR 1.01 95% CI 0.76,1.36)) with strong evidence that risk differed for female vs. male migrant households (p-value = 0.005). We found no evidence that the age or sex of the left-behind household member altered the association observed. CONCLUSIONS: This analysis suggests that members of households with a temporary female foreign migrant are at an increased risk of attempted suicide, but these findings must be interpreted with caution. The increased risk of suicidal behaviour in these households may be due to factors that were present before the migration and persist post-migration (e.g. household violence, poverty).