Pesticide poisoning: a major health problem in Sri Lanka

Investigating the therapeutic potential of Allium cepa extract in combating pesticide exposure induced ocular damage

The ocular surface is subject to a range of potentially hazardous environmental factors and substances, owing to its anatomical location, sensitivity, and physiological makeup. Xenobiotic stress exerted by chronic pesticide exposure on the cornea is primarily responsible for ocular irritation, excessive tear production (hyper-lacrimation), corneal abrasions and decreased visual acuity. Traditional medicine hails the humble onion (Allium cepa) for its multi-faceted properties including but not limited to anti-microbial, antioxidant, anti-inflammatory and wound healing. However, there is a lacuna regarding its impact on the ocular surface. Thereby, the current study investigated whether topical application of crude extract of Allium cepa aided in mitigating pesticide-induced damage to the ocular surface. The deleterious effects of pesticide exposure and their mitigation through the topical application of herbal extract of Allium cepa were analysed initially through in vitro evaluation on cell lines and then on the ocular surface via various in-vivo and ex-vivo techniques. Pathophysiological alterations to the ocular surface that impacted vision were explored through detailed neurophysiological screening with special emphasis on visual acuity wherein it was observed that the murine group treated with topical application of Allium cepa extract had comparable visual capacity to the non-pesticide exposed group. Additionally, SOD2 was utilized as an oxidative stress marker along with the expression of cellular apoptotic markers such as Bcl-xL to analyse the impact of pesticide exposure and subsequent herbal intervention on oxidative stress-induced corneal damage. The impact on the corneal epithelial progenitor cell population (ABCG2 and TERT positive cells) was also flowcytometrically analysed. Therefore, from our observations, it can be postulated that the topical application of Allium cepa extract might serve as an effective strategy to alleviate pesticide exposure related ocular damage.

Redox imbalance and inflammation: A link to depression risk in brazilian pesticide-exposed farmers

This study aims to elucidate the mechanisms linking occupational pesticide exposure to depression among rural workers from Maravilha, Brazil. We assessed the mental health, oxidative, and inflammatory profiles of farmers exposed to pesticides (N = 28) and compared them to an urban control group without occupational exposure to pesticides (N = 25). Data on sociodemographic, occupational history, and clinical records were collected. Emotional states were evaluated using the State-Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI). Biochemical, hematological, inflammatory, and redox parameters were examined in blood samples from both groups. Results showed educational disparities between groups and unveiled a concerning underutilization of personal protective equipment (PPEs) among farmers. Glyphosate was the predominant pesticide used by farmers. Farmers exhibited higher BDI scores, including more severe cases of depression. Additionally, elevated levels of creatinine, ALT, AST, and LDH were observed in farmers, suggesting potential renal and hepatic issues due to pesticide exposure. Oxidative stress markers, such as increased lipid peroxidation and superoxide dismutase (SOD) activity, along with decreased catalase (CAT) activity and ascorbic acid levels, were noted in the pesticide-exposed group compared to controls. Elevated levels of inflammatory cytokines, particularly IL-1β, IL-6 and TNF-α, were also observed in pesticide-exposed group. Our findings suggest that inflammation, oxidative distress and lower educational levels may be associated with depression in pesticide-exposed farmers. This study highlights the impact of occupational pesticide exposure on the mental health of rural workers. The underuse of PPEs and the link between depressive symptoms, inflammation, and oxidative stress underscore the urgent need for improved safety measures in agricultural practices. Addressing these issues will contribute to a deeper understanding of the intricate relationship between environmental exposures and mental health outcomes.

Features of fatal pesticide ingestion in South Australia

Pesticides are used to kill, repel or control any animal or plant species which are considered pests, but have also been associated with intentional and unintentional human fatalities. A rapid increase in pesticide suicides was observed during 'The Green Revolution' after pesticides were introduced into low- and middle-income rural households without appropriate guidelines for safe use and storage. While national pesticide bans have contributed to a significant decrease in pesticide-related suicides, such cases still comprise a large proportion of all suicides around the world. The aim of the current study was to provide a profile of pesticide suicides in a high-income country as a point of comparison against studies from low- and middle-income countries. Statistical analyses were performed using R (version 4.2.3). Over the 20-year study period, there were a low, yet consistent number of pesticide suicides which were most common among males over the age of 40. Paraquat and methomyl pesticides collectively contributed to almost half (48.8%) of all fatalities. Consistent with the literature, such cases often occurred with little premeditation in response to an acute emotional crisis. While interpretation of autopsy findings was mostly limited, there were some pesticides that demonstrated findings consisted with previously reported characteristics (e.g., gastroesophageal erosions with paraquat). Given the high proportion of cases where paraquat and methomyl pesticides were implicated, it may be appropriate to review the availability and accessibility of such compounds to reduce the occurrence of pesticide suicides in South Australia and potentially the wider Australian population.

Could pesticide exposure be implicated in the high incidence rates of depression, anxiety and suicide in farmers? A systematic review

Pesticide exposure and poisoning may rise the risk of mental health problems and suicidal tendencies. To explore the potential connection between chronic occupational exposure to pesticides and depression, anxiety, and suicide-related outcomes in farmers, a systematic review was performed. Systematic review protocol is available in PROSPERO registration number CRD42022316285. A total of fifty-seven studies met inclusion criteria: twenty-nine on depression or other mental disorders, twelve on suicide (two of them on both depression and suicide), and fourteen on pesticide poisoning or self-poisoning and death. Among the fifty-seven selected studies, eighteen were conducted in Asia, seventeen in North America, fourteen in South America, seven in European Union, one in Africa, and one in Australia/Oceania. Selected studies demonstrated an increased prevalence of depressive disorders in farmworkers exposed to pesticides as well as an increased self-reported prevalence of depression in this population. Moreover, previous pesticide poisoning increased the risk estimates for depression or other mental disorders as compared with chronic pesticide exposure. Severe pesticide poisoning and multiple poisoning showed increased risks of depressive symptoms compared with milder cases. In addition, financial difficulties and poor health were positively correlated with depression. Among studies on suicide, nine of them found that suicide rates increased in areas devoted to agriculture with intensive pesticide consumption. Moreover, studies demonstrate a higher suicide risk among farmers. The present review suggests more attention to the farmer's mental health and more detailed studies on occupational exposure to the mixture of these compounds.

A Bibliometric Analysis of Scientific Research Publications Related to Pesticide Poisoning in the South Asian Countries

Pesticide self-intoxication leading to suicide is a widespread phenomenon in India. Implementing regulations prohibiting the use of highly toxic pesticides in agriculture has proven effective in reducing the overall suicide rate in various South Asian countries without compromising agricultural production. In this study, we conducted a bibliometric analysis of scientific publications on pesticide poisoning in South Asian countries using various databases, including PubMed, Scopus, and Web of Science, using relevant Medical Subject Heading (MeSH) terms. To analyze the data, we employed R Studio and Microsoft Excel 2019, which enabled us to collect information on the number of scientific publications, citation frequency, and keyword trends. Our analysis involved 417 articles, and the results indicated a crucial need for greater awareness and improved management of pesticide poisoning in South Asian countries. Our findings provide valuable insights for policymakers and offer guidelines for pesticide control.

Investigation of acute organophosphate poisoning in humans based on sociodemographic and role of neurotransmitters with survival study in South India

The aim of this study was to investigate the sociodemographic characteristics of patients based on the poison chosen and different types of organophosphorus compounds. The data were collected to explore the sociodemographic characteristics of organophosphate (OP)-poisoned patients based on the source, site, and route of poisoning, education level, occupational status, and the purpose of poisoning. Furthermore, we estimated the serotonin and dopamine levels in the plasma samples of patients, and survival plots were also described. During the study of OP pesticide poisoning in 116 human subjects and 5 healthy volunteers, we observed, based on the survival plot, that75.9% of the patients were discharged, and the remaining patients died (24.1% of the patients) due to respiratory failure followed by cardiac arrest. Our findings suggest that the serotonin levels significantly (p < 0.01 and p < 0.001) decreased from 12 to 36 h, whereas the dopamine levels slightly increased from 12 to 36 h in the group with OP poisoning compared to the control group. Based on these findings, this study may aid in deciphering the precise mechanism by which pesticides cause behavioural changes that influence serotonin and dopamine levels in OP-poisoned patients. The purpose of this work was to serve as a small reminder of the risk to public health associated with organophosphate pesticides.

Chronic pesticide exposure induced aberrant Notch signalling along the visual pathway in a murine model

Pesticides aid in crop-protection against pests and increase yield. However, the xenobiotic stress exerted by pesticides leads to the deterioration of human and animal health. There is a lacuna in our knowledge about their impact on the ocular surface The present work sheds light on this gap by analysing the deterioration of visual acuity as a consequence of pesticide induced xenobiotic stress and Notch pathway dysregulation. Alteration in the expression of vital components of the notch signalling was analyzed along the visual pathway with special focus on its two terminals-the cornea and the visual cortex, by mimicking the on-field scenario regarding chronic pesticide exposure in experimental murine model (Swiss albino mice; Mus musculus). Various aspects were taken into consideration through visual acuity tests, histological evaluations, culture analyses, wound healing assays, flowcytometric evaluation, fluorescence microscopic studies etc. Complete dysregulation of key players of the Notch signalling pathway was observed in both: cells of the ocular surface as well as those in the murine visual cortex post pesticide exposure, indicating activities relating to cell proliferation, differentiation and wound healing in the pesticide exposed samples. Ultra-microscopic analyses corroborated our findings by revealing the loss of fine neural processes in the visual cortex of the pesticide exposed murine samples, thereby hinting at delayed perception to visual stimuli. In vivo evaluations of the functional capacity of the neuroanatomical structures along the visual pathway also confirmed that pesticide exposure leads to severe damage along the various parts of the visual pathway, right from the ocular surface to the visual cortex.

Non-suicidal self-injury in developing countries: A review

BACKGROUND

Non-suicidal self-injury (NSSI) may be understood as a physical and behavioral expression of emotional distress. Over the past 70 years, it has been variably formulated as a type of emotional reaction to various stressors. NSSI has complex goals, sometimes implicit, but overall it serves as a transient psychological relief. Many believe that NSSI is a maladaptive behavior and is not related to suicide, with the primary differentiating factor between suicide and NSSI being the 'intention' to die. NSSI is an important mental health problem in current modern societies, and it is part of a trend in current psychiatric and mental health practice to medicalize maladaptive behaviors or psychological distress.

AIMS

To review the prevalence, associated factors, purpose, and psychological and social significance of NSSI in developing countries.

METHOD

This article is a narrative review. However, of the total 1,094 articles, 13 articles were included to derive information on the prevalence and methods of NSSI in the developing country.

RESULTS

NSSI rates are very variable, ranging from 11.5% to as high as 33.8%, depending on the nature of the sample and study design, but data show an increasing trend globally, including in developing countries.

CONCLUSION

The recent emerging data does not support the notion that it is common in developed Western countries, though the meaning, context and reason for NSSI might differ in developing and developed countries. NSSI is almost equally prevalent in both developing and developed countries.

Evaluation of the Methylation and Acetylation Profiles of Dinitroaniline Herbicides and Resveratrol on the V79 Cell Line

Objectives

Herbicides are among the most widely used pesticide compounds for plant growth control worldwide. Risk assessment of the dinitroaniline-derived herbicides pendimethalin and trifluralin is important for foodborne or other means of exposure. In this study, we aimed to evaluate the methylation and acetylation profiles of pendimethalin and trifluralin, which we have high levels of exposure to in various ways. Furthermore, we also determined the protective effect of resveratrol, an antioxidant compound, against the possible toxic effects of these pesticides.

Materials and Methods

The effects of pendimethalin and trifluralin alone (25, 50, 100 μM) and in combination with resveratrol (100 μM) on DNA methyltransferase (DNMT1) 1, 3a, and 3b; and histone deacetylase (HDAC) 1 and HDAC3 gene expression were evaluated by real-time polymerase chain reaction.

Results

According to the results, pendimethalin caused a significant decrease in DNMT1, 3a, 3b and HDAC expressions at all concentrations, whereas HDAC1 and 3 expression was increased at the concentration of 25 μM, when applied together with resveratrol. There were no changes in DNMT1 or 3b expression levels. Unlike pendimethalin, trifluralin increased DNMT1 expression in a concentration-dependent manner. While DNMT3a and DNMT3b expression levels increased significantly, HDAC1 and 3 expression levels did not change significantly. The expression levels of HDAC1 and HDAC3 increased at all concentrations of trifluralin combination with resveratrol. Moreover, DNMT levels increased at the concentrations of 50 and 100 μM.

Conclusion

Epigenetic gene expression results showed that pendimethalin and trifluralin might cause tissue function loss and chromosome damage as a result of direct effects on cell viability by causing expression level changes in all studied genes. It can also be concluded that the changes that occur in gene expression may induce tumor development. Further studies are needed to elucidate the possible toxicity mechanisms of these herbicides, considering the relationship between epigenetic changes and various diseases.

Prevalence, Predictors and Treatment Outcome of Acute Poisoning in Western Ethiopia

Background

Acute poisoning is a common reason for visiting the emergency department (ED) worldwide. However, little is known about this issue in the western part of Ethiopia. This study was carried out to determine the prevalence, predictors, and treatment outcome of acute poisoning at the ED of western Ethiopia.

Patients and Methods

A hospital record-based retrospective study design was conducted on all patients admitted to the ED of the two hospitals between 01 January 2018 to 17 March 2019. Socio-demographic, clinical presentation, medication history, poisoning characteristics, time to hospital arrival, treatment given, and outcome of treatment were collected. All collected data were analyzed using SPSS Version 20. Backward multiple logistic regression analysis at p-value ≤0.05 tested the predictor for treatment outcome.

Results

The prevalence of acute poisoning was 134/7883 (1.7%) per ED admissions. The mean ±SD age of the study participants was 23.90±10.606 with female to male ratio of 1:1.06. The most vulnerable patients to poisoning were individuals in the age range of 18 to 29 years 68/134 (50.7%) for both genders. Moreover, the most common poisoning agent was organophosphate 72/134 (53.7%). Besides, intentional poisoning was the most common 103/134 (76.9%) manner of poisoning with family disharmony 37/103 (35.9%) as the common reason. The case fatality rate of acute poisoning in the two hospitals was 2/134 (1.5%). The mean ±SD length of hospital stay was 1.86 ±0.943. The independent predictors of poor treatment outcome of acute poisoning were age ≥35 years [p-value= 0.049], female gender [p-value= 0.027], and hospital stay of >48 hours [p-value= 0.035].

Conclusion

The prevalence of acute poisoning in western Ethiopia is higher than the ever-reported data in Ethiopia. Thus, stakeholders should have to pay more attention to prevention and control strategies and appropriate handling of agrochemical substances to minimize their negative effects on this productive age group.

Use and Avoidance of Pesticides as Responses by Farmers to change Impacts in Rice Ecosystems of Southern Sri Lanka

Since the beginning of the millennium, pesticide use has increased dramatically across Asia. However, it is still unclear what drives pesticide use among low-income farmers. We surveyed 275 farmers to investigate their decisions to apply or avoid pesticides on rice farms in southern Sri Lanka. Based on the information from the survey, we applied the Drivers-Pressures-State-Impacts-Responses framework to assess farmers' decisions as 'Responses' to changes in the rice ecosystem. Organic farmers mainly planted traditional varieties (64-77%) that they perceived as resistant to environmental stresses, including insect herbivores. Pesticide users, including integrated pest management farmers, and insecticide-free farmers (without insecticide use for ≥5 years) mainly planted modern rice varieties. There were no significant differences in reported rice yields among farmers using different management practices. However, fewer organic and insecticide-free farmers reported insect pests, particularly planthoppers, as a production constraint. Insecticide use by farmers was mainly an adaptive response to perceived risks of pest damage to high-yielding varieties. But farmers' responses were largely unsupported by any previous experience, suggesting that an increased availability and marketing of agrochemicals, and pressures to modernize production have influenced their decisions to use insecticides. Organic and insecticide-free farming practices were mainly restorative responses to perceived health risks associated with agrochemicals. We suggest that attention could be placed on promoting 'pesticide-free' or 'insecticide-free' farming through certification schemes as a viable option to break the lock-in of pesticide use on rice farms in the region and to provide additional product choices for rice consumers.

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.

Pleiotropic effects and pharmacological properties of penehyclidine hydrochloride

Background

Penehyclidine hydrochloride (PHC) is an anticholinergic drug manufactured in China. It is used widely in clinics as a reversal agent in cases of organic phosphorus poisoning and as a preanesthetic medication. Compared with other anticholinergic agents, PHC confers substantial advantages. Here, in this review, we focus on its important clinical effects for organic phosphorus poisoning, preanesthetic medication, and the protective effects on certain visceral organs.

Materials and methods

Our bibliographic sources include the PubMed and China National Knowledge Infrastructure (CNKI) databases, updated in March 2018. To assess the data in detail, we used the search terms “penehyclidine hydrochloride,” “preanesthetic medication,” and “organic phosphorus.” Papers were restricted to those published in the English and Chinese languages, and to “paper” and “review” as the document type.

Results

PHC can effectively antagonize the symptoms of central and peripheral poisoning caused by organophosphorus poisoning. As a preanesthetic medication, it can not only effectively reduce mucus secretion and vascular infiltration but can also relax airway smooth muscles, dilate bronchioles in pulmonary conditions such as bronchiectasis, and increase pulmonary dynamic compliance. It can also prevent reflexive actions of the vagus nerve caused by excessive acetylcholine release such as abnormal airway contraction. Furthermore, it can strengthen sedation, bidirectionally regulate heart rate, and effectively inhibit respiratory secretions. In recent studies, PHC was shown to also have protective effects on various organs, such as the heart, lungs, brain, kidneys, intestines, and liver.

Conclusion

PHC has beneficial pharmacological properties used in the treatment of organophosphorus poisoning and as a preanesthetic medication for its few side effects. It also has protective effects on multiple organs, suggesting that PHC has extensive clinical application value which is worth further research. This review should be of help to those intending to research these topics further.

Relative Risk and Clinical Severity Assessment in Patients with Non-Oral Route Organophosphate Poisoning Compared with Oral Route Poisoning

PURPOSE

Organophosphates, commonly used in agricultural pesticides, pose high risks and incidences of poisoning. In the present study, we investigated the relative risk and clinical severity, including laboratory results, of non-oral route poisoning (NORP) patients, compared to oral route poisoning (ORP) patients.

MATERIALS AND METHODS

A single institutional toxicology database registry was utilized to gain information on clinical laboratory results on organophosphate poisoning patients who visited the emergency department (ED) between January 2000 and October 2016. Clinical outcomes, such as mortality and complication rates, were compared using 1:2 propensity score matching in the total cohort.

RESULTS

Among a total of 273 patients in our study, 34 experienced NORP. After 1:2 propensity score matching, rates of respiratory complications and mortality were higher in the ORP group than in the NORP group. However, there was no difference in hospitalization time and time spent in the intensive care unit between the two groups. Compared with ORP patients after matching, the relative risk of mortality in NORP patients was 0.34, and the risk of respiratory distress was 0.47. The mean level of pseudocholinesterase was significantly higher in the NORP group than in the ORP group, while recovery rates were similar between the two groups.

CONCLUSION

Although the majority of NORP patients were admitted to the ED with unintentional poisoning and the relative risk of NORP was lower than that for ORP, we concluded that NORP is as critical as ORP. Considerable medical observation and intensive therapeutic approaches are also needed for NORP patients.

Acute organophosphate poisoning: 17 years of experience of the National Poison Control Center in Serbia

Based on human toxicity studies, by appropriate regulatory decisions, the number of organophosphates (OP) on Serbian market has reduced significantly over the last two decades, followed by a gradual decrease in the number of poisonings by organophoshates, treated at the National Poison Control Centre (NPCC).

METHODOLOGY

The aim of this retrospective study is to present data regarding the clinical management of poisoning with OP pesticides at the NPCC, that we collected during the 17 years period (1998-2014).

RESULTS

In the period 1998-2014, about 17.250 patients were hospitalized at the NPCC, there were around 14.000 patients treated for poisoning by various toxic agents, and among them 410 cases (3%) due to poisoning with OP pesticides. In this period, 92% of OPI poisonings treated in the NPCC were suicidal by intention, while only 8% were due to accidental ingestion or inhalation. The most common clinical signs of poisoning in patients exposed to anticholinesterase pesticides, observed at Clinic of Toxicology of the NPCC were miosis (63.4%), bronchorrhoea (51.9%), vomiting and diarrhea (44.8%), hypotension (19.5%). Acute respiratory insufficiency was registered in 81 (19.7%) and acute cardiocirculatory failure in 16 (3.9%) patients. There were about 25% of most severely poisoned patients. Besides general supportive measures (decontamination, respiratory support), specific pharmacological treatment (atropine, oxime, diazepam) was applied. The highest total administered dose of atropine at NPCC was 6400 mg. However, the most patients received total doses of atropine up to 500 mg (32%).

CONCLUSION

Acute poisoning with OP pesticides is not frequent in Serbia, however, it represents important clinical feature due to severity, possible complications and their impact on duration and costs of hospitalization. Initial treatment involves prevention of further absorption and provision of supportive care, followed by administration of specific antidotes. According to its role, the National Poison Control Centre in Belgrade, in addition to treatment of acute poisonings, continuously performs toxicovigilance, i.e. the identification, investigation and evaluation of various toxic risks in the community in order to undertake adequate and timely procedures. Permanent efforts are being made in order to reduce availability and to improve control measures for pesticides marketing.

Sri Lanka and the possibilities of achieving universal health coverage in a poor country

Sri Lanka has been lauded for providing good health coverage at a low cost despite having a modest per capita income. This article identifies the unique historical factors that enabled Sri Lanka to achieve near universal coverage, but it also discusses how this achievement is now being undermined by inadequate government investment in health services, the burdens of non-communicable diseases, and the growing privatisation of health services. In doing so, the article highlights the challenges of achieving and maintaining universal health coverage in a relatively low income country with a health system designed to treat infectious diseases and provide child and maternal health services as the country undergoes an epidemiological transition from infectious to non-communicable diseases. Using updated information on developments in the Sri Lankan health system, this article argues, in contrast with earlier publications, that Sri Lanka is no longer providing good health at a low cost. It shows that Sri Lanka's low investment in health is detrimental and not an asset to achieving good health. The article also questions the possibilities of providing coverage for noncommunicable diseases at a low cost. The article has four main sections. The first details Sri Lanka's accomplishments in moving toward universal health coverage. The second identifies the factors enabling Sri Lanka to do so. The third describes the equity and access challenges the health system now confronts. The fourth assesses what the Sri Lankan experience suggests about the requirements for universal health coverage when providing health services for treating non-communicable diseases becomes an important consideration.

Similar Active Sites and Mechanisms Do Not Lead to Cross-Promiscuity in Organophosphate Hydrolysis: Implications for Biotherapeutic Engineering

Organophosphate hydrolases are proficient catalysts of the breakdown of neurotoxic organophosphates and have great potential as both biotherapeutics for treating acute organophosphate toxicity and as bioremediation agents. However, proficient organophosphatases such as serum paraoxonase 1 (PON1) and the organophosphate-hydrolyzing lactonase SsoPox are unable to hydrolyze bulkyorganophosphates with challenging leaving groups such as diisopropyl fluorophosphate (DFP) or venomous agent X, creating a major challenge for enzyme design. Curiously, despite their mutually exclusive substrate specificities, PON1 and diisopropyl fluorophosphatase (DFPase) have essentially identical active sites and tertiary structures. In the present work, we use empirical valence bond simulations to probe the catalytic mechanism of DFPase as well as temperature, pH, and mutational effects, demonstrating that DFPase and PON1 also likely utilize identical catalytic mechanisms to hydrolyze their respective substrates. However, detailed examination of both static structures and dynamical simulations demonstrates subtle but significant differences in the electrostatic properties and solvent penetration of the two active sites and, most critically, the role of residues that make no direct contact with either substrate in acting as "specificity switches" between the two enzymes. Specifically, we demonstrate that key residues that are structurally and functionally critical for the paraoxonase activity of PON1 prevent it from being able to hydrolyze DFP with its fluoride leaving group. These insights expand our understanding of the drivers of the evolution of divergent substrate specificity in enzymes with identical active sites and guide the future design of organophosphate hydrolases that hydrolyze compounds with challenging leaving groups.

Effectiveness of household lockable pesticide storage to reduce pesticide self-poisoning in rural Asia: a community-based, cluster-randomised controlled trial

BACKGROUND

Agricultural pesticide self-poisoning is a major public health problem in rural Asia. The use of safer household pesticide storage has been promoted to prevent deaths, but there is no evidence of effectiveness. We aimed to test the effectiveness of lockable household containers for prevention of pesticide self-poisoning.

METHODS

We did a community-based, cluster-randomised controlled trial in a rural area of North Central Province, Sri Lanka. Clusters of households were randomly assigned (1:1), with a sequence computer-generated by a minimisation process, to intervention or usual practice (control) groups. Intervention households that had farmed or had used or stored pesticide in the preceding agricultural season were given a lockable storage container. Further promotion of use of the containers was restricted to community posters and 6-monthly reminders during routine community meetings. The primary outcome was incidence of pesticide self-poisoning in people aged 14 years or older during 3 years of follow-up. Identification of outcome events was done by staff who were unaware of group allocation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT1146496.

FINDINGS

Between Dec 31, 2010, and Feb 2, 2013, we randomly assigned 90 rural villages to the intervention group and 90 to the control group. 27 091 households (114 168 individuals) in the intervention group and 26 291 households (109 693 individuals) in the control group consented to participate. 20 457 household pesticide storage containers were distributed. In individuals aged 14 years or older, 611 cases of pesticide self-poisoning had occurred by 3 years in the intervention group compared with 641 cases in the control group; incidence of pesticide self-poisoning did not differ between groups (293·3 per 100 000 person-years of follow-up in the intervention group vs 318·0 per 100 000 in the control group; rate ratio [RR] 0·93, 95% CI 0·80-1·08; p=0·33). We found no evidence of switching from pesticide self-poisoning to other forms of self-harm, with no significant difference in the number of fatal (82 in the intervention group vs 67 in the control group; RR 1·22, 0·88-1·68]) or non-fatal (1135 vs 1153; RR 0·97, 0·86-1·08) self-harm events involving all methods.

INTERPRETATION

We found no evidence that means reduction through improved household pesticide storage reduces pesticide self-poisoning. Other approaches, particularly removal of highly hazardous pesticides from agricultural practice, are likely to be more effective for suicide prevention in rural Asia.

FUNDING

Wellcome Trust, with additional support from the American Foundation for Suicide Prevention, Lister Institute of Preventive Medicine, Chief Scientist Office of Scotland, University of Copenhagen, and NHMRC Australia.

Low doses of chlorpyrifos interfere with spermatogenesis of rats through reduction of sex hormones

Use of pesticides results in indirect effects on human health. We aimed to evaluate implications of toxicological effects of subchronic chlorpyrifos exposure on reproductive function in male rats. A total of 48 adult Wistar male rats were separated into four groups (n = 12). Animals were gavaged with 2.5 mg/kg (T1), 5 mg/kg (T2), or 10 mg/kg (T3) body weight of chlorpyrifos (CPF) or distilled water (control) daily for 30 days. Organ weights, epididymal sperm parameters, DNA integrity, sex hormonal (FHS and LH) levels, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), and creatinine concentrations were determined on day 31. Another two sets of (four groups/set; n = 10) animals were orally treated with the same doses of CPF, control animal groups were treated with distilled water only for 30 days, and fertility indices and blood plasma acetylcholine esterase (AchE) were determined on day 31. Exposure to CPF resulted in a significant (p < 0.05) decrease in weights of testis and epididymis. An increase in liver weight resulted in reduced sperm counts and sperm motility and an increase in sperm abnormalities. Significant reduction in serum testosterone (p < 0.01), luteinizing hormone (p < 0.05), and follicular stimulating hormone (p < 0.05) levels was evident in animals treated with the highest dose. A significant decrease in the number of viable implantation sites and pups was observed in female rats mated with the T3 (p < 0.01) and T2 (p < 0.05) males. The ALT, AST, GGT, and creatinine contents were significantly increased (p < 0.05 and p < 0.01, respectively) on CPF exposure. A significant (p < 0.01) reduction in blood plasma AchE enzyme was observed with the highest dose. Our results demonstrated that prolonged exposure of CPF induces spermatogenesis damage, possibly through interference with sex hormones and AchE enzyme resulting in reduction of fertility. Therefore, awareness programs on handling CPF (pesticides) to enhance safety warrant minimization of its hazards.

Patterns of acute poisoning with pesticides in the paediatric age group

Background

Pesticides are identified as one of the dangerous poisons globally in children and are associated with increased short- and long-term morbidity. Pesticide poisoning is the most common method of self-poisoning among adults in rural Sri Lanka, and the clinical management is associated with significant healthcare costs to the country. There is however little data published on acute pesticide poisoning among children in rural Sri Lanka. The current study aimed to comprehensively evaluate clinical profiles, harmful first aid measures, emergency clinical management, complications and outcomes related to acute pesticide poisoning among children in the rural community of Sri Lanka.

Methods

This multicenter study was conducted in the North Central Province of Sri Lanka involving all children with acute pesticide poisoning and who were between 9 months and 12 years of age. Data were collected over 7 years (2007–2014), and children from 36 hospitals were recruited. Data collection was carried out by pretested, multi-structured, interviewer-administered questionnaires to identify clinical profiles of children, harmful first aid measures, emergency clinical management, reasons for delayed management, complications and outcomes of pesticide poisoning events.

Results

Among 1621 children with acute poisoning, 9.5% (155) comprised children with acute pesticide poisoning. Male children outnumbered female children, and the majority of children were less than 5 years. Most common pesticides implicated in poisoning of children were organophosphates and carbamates. Gastrointestinal and neurological symptoms were predominant clinical features. Limited transport and lack of concern regarding urgency among caregivers were leading reasons for delayed management. Most common location for poisoning was cultivation lands. Harmful first aid measures were practiced in 32.4%. 7.1% had intentional pesticide poisoning. The case fatality rate of all pesticide poisonings in the study was 1.9%. 58.1% of patients were transferred between regional hospitals and teaching hospital. Cardiac and respiratory arrests, aspiration pneumonia and convulsions were among the reported complications.

Conclusions

Acute pesticide poisoning in paediatric age group (<12 years) is a relatively uncommon yet significant cause of child health-related morbidity and mortality in rural Sri Lanka. Patterns of poisoning represent the pattern of pesticide use by the rural community. The practice of harmful first aid measures by caregivers and delay in attending the emergency department may negatively impact patient outcomes.

Pattern of acute poisoning in Tehran-Iran in 2003

To characterize the poisoning cases admitted to the Loghman-Hakim Hospital Poison Center (a teaching reference hospital of poisoning) in Tehran, Iran. All admitted acutely poisoned patients from January to December 2003 were evaluated retrospectively. Information of socio-demographic characteristics, agents and cause of poisoning, and the mortality rate were collected from medical records of the hospital. During this period, 24 179 cases were referred to the emergency department that 10 206 of them were admitted. Of the admitted cases, 51% were male and 49% female. The majority (38%) of cases were in the age range of 21—30 years. Most (79%) of poisonings were intentional and 21% were unintentional. The most important agents of acute poisoning were drugs (69.13%) especially sedative-hypnotics followed by opioids (12.34%) and pesticides especially organophosphates (OPs) (6.21%). The mortality rate was 1.3% (318 patients). Death was mostly occurred by opioids (41.54%), followed by drugs (28%) and pesticides especially OPs (12%). The prevention and treatment of poisoning due to opioids, pesticides specially OPs and sedative-hypnotics drugs should merit high priority in the health care of the indigenous population of Tehran. Human & Experimental Toxicology (2007) 26, 753— 756

Acute Anticholinesterase Pesticide Poisoning Caused a Long-Term Mortality Increase: A Nationwide Population-Based Cohort Study

Acute anticholinesterase pesticide (organophosphate and carbamate) poisoning (ACPP) often produces severe complications, and sometimes death. We investigated the long-term mortality of patients with ACPP because it is not sufficiently understood. In this retrospective nationwide population-based cohort study, 818 patients with ACPP and 16,360 healthy comparisons from 1999 to 2010 were selected from Taiwan's National Health Insurance Research Database. They were followed until 2011. Ninety-four (11.5%) ACPP patients and 793 (4.9%) comparisons died (P < 0.01) during follow-up. The incidence rate ratios (IRRs) of death were 2.5 times higher in ACPP patients than in comparisons (P < 0.01). The risk of death was particularly high in the first month after ACPP (IRR: 92.7; 95% confidence interval [CI]: 45.0-191.0) and still high for ~6 months (IRR: 3.8; 95% CI: 1.9-7.4). After adjusting for age, gender, selected comorbidities, geographic area, and monthly income, the hazard ratio of death for ACPP patients was still 2.4 times higher than for comparisons. Older age (≥35 years), male gender, diabetes mellitus, coronary artery disease, hypertension, stroke, mental disorder, and lower monthly income also predicted death. ACPP significantly increased long-term mortality. In addition to early follow-up after acute treatment, comorbidity control and socioeconomic assistance are needed for patients with ACPP.

Paraquat prohibition and change in the suicide rate and methods in South Korea

The annual suicide rate in South Korea is the highest among the developed countries. Paraquat is a highly lethal herbicide, commonly used in South Korea as a means for suicide. We have studied the effect of the 2011 paraquat prohibition on the national suicide rate and method of suicide in South Korea. We obtained the monthly suicide rate from 2005 to 2013 in South Korea. In our analyses, we adjusted for the effects of celebrity suicides, and economic, meteorological, and seasonal factors on suicide rate. We employed change point analysis to determine the effect of paraquat prohibition on suicide rate over time, and the results were verified by structural change analysis, an alternative statistical method. After the paraquat prohibition period in South Korea, there was a significant reduction in the total suicide rate and suicide rate by poisoning with herbicides or fungicides in all age groups and in both genders. The estimated suicide rates during this period decreased by 10.0% and 46.1% for total suicides and suicides by poisoning of herbicides or fungicides, respectively. In addition, method substitution effect of paraquat prohibition was found in suicide by poisoning by carbon monoxide, which did not exceed the reduction in the suicide rate of poisoning with herbicides or fungicides. In South Korea, paraquat prohibition led to a lower rate of suicide by paraquat poisoning, as well as a reduction in the overall suicide rate. Paraquat prohibition should be considered as a national suicide prevention strategy in developing and developed countries alongside careful observation for method substitution effects.

Taking stock -- what is known about suicide in Sri Lanka: a systematic review of diverse literature

BACKGROUND

Suicide is and has been a major public health problem in Sri Lanka and has generated a wide range of literature.

AIMS

This review aimed to systematically appraise what is known about suicide in Sri Lanka. The patterns and content of articles were examined and recommendations for further research proposed.

METHOD

The paper describes the systematic search, retrieval, and quality assessment of studies. Thematic analysis techniques were applied to the full text of the articles to explore the range and extent of issues covered.

RESULTS

Local authors generated a large body of evidence of the problem in early studies. The importance of the method of suicide, suicidal intention, and the high incidence of suicide were identified as key foci for publications. Neglected areas have been policy and health service research, gender analysis, and contextual issues.

CONCLUSION

The literature reviewed has produced a broad understanding of the clinical factors, size of the problem, and social aspects. However, there remains limited evidence of prevention, risk factors, health services, and policy. A wide range of solutions have been proposed, but only regulation of pesticides and improved medical management proved to be effective to date.

Pesticide use and cholinesterase inhibition in small-scale agricultural workers in southern Brazil

A controlled cross-sectional study of family growers of fruit and vegetables was conducted between October 2009 and October 2010 to characterize the use of pesticides, establish the socio-demographic profile, and analyze cholinesterase activity in small-scale agricultural workers in Southern Brazil. Data was collected for 173 workers and 179 controls. A structured questionnaire was applied collecting socio-demographic information and determining knowledge and work practices in relation to pesticide use. The benchmarks for total cholinesterase (ChEs) and butyrylcholinesterase (BuChE) were obtained from the average enzymatic activity of the occupationally unexposed group (control). The mean age of the exposed population was 40.0 ± 11.2 years. The symptoms differed significantly (p<0.05) between the exposed and unexposed populations. Forty (23.1%) workers showed symptoms associated with exposure to pesticides. The average value of enzymatic activity in the occupationally unexposed group for ChEs was 6.3 μmol/mL/min among males and 5.6 μmol/mL/min among females while for BuChE was 2.4 μmol/mL/min among males and 2.0 μmol/mL/min among females. Eight (4.6%) workers had high inhibition (>30%) of ChEs activity, whereas no workers showed high inhibition (>50%) of BuChE. Potential factors involved include gender, education, pesticide orientation, exposure, and hygiene measures.

Effects of different blood purification methods on serum cytokine levels and prognosis in patients with acute severe organophosphorus pesticide poisoning

The aim of the present study was to investigate the impact of three different blood purification methods, hemoperfusion (HP), continuous blood purification (CBP), and on-line high-volume hemodiafiltration (OL-HDF), on the survival rate of patients with acute severe organophosphorus pesticide poisoning (ASOPP), as well as on major pro-inflammatory (interleukin [IL]-1, IL-6, tumor necrosis factor-α [TNF-α]) and anti-inflammatory (IL-10) cytokines in the serum. Eighty-one ASOPP patients were randomly divided into three groups: HP (N = 23), HP + CBP (N = 26), HP + OL-HD (N = 32). Serum IL-1, IL-6, TNF-α, and IL-10 levels were assessed by ELISA before treatment and at 24 and 48 h post-treatment and survival rates were determined. Patient survival rate was significantly higher in OL-HDF and CBP treated patients compared with HP group (P < 0.05). A significantly greater clearance effect in serum IL-1, IL-6, and TNF-α levels at 24 and 48 h post-treatment was observed in CBP and OL-HDF groups compared with the HP group (P < 0.05). The levels of serum anti-inflammatory cytokine IL-10 increased significantly in CBP and OL-HDF groups compared with the HP group (P < 0.05 at 48 h post-treatment). In addition, OL-HDF treatment achieved similar changes in serum TNF-α, IL-1, IL-6 and IL-10 levels as CBP (P > 0.05). Compared with the HP method, CBP or OL-HDF combined with HP can rapidly clear inflammatory cytokines, reduce systemic inflammatory response syndrome, and improve the survival of ASOPP patients. Compared with CBP, OL-HDF is an economical and effective method to treat ASOPP with less technical difficulty and more suitability for rural areas and primary hospitals.

Escalating chronic kidney diseases of multi-factorial origin in Sri Lanka: causes, solutions, and recommendations

During the last two decades, Sri Lanka, located close to the equator, has experienced an escalating incidence of chronic kidney disease (CKD) of unknown aetiology (CKDue) in dry zonal areas. Similar incidences of unusual CKDs have been reported in the dry zonal, agricultural areas of several other equatorial countries. In Sri Lanka, the incidence of CKDue is highest in the North Central Province (NCP), where approximately 45 % of the country's paddy fields are located. However, in recent years, the disease has spread into areas adjacent to as well as distant from the NCP. The cause of CKD in Sri Lanka is unknown, and may likely due to interactions of different potential agents; thus, CKD is of multi-factorial origin (CKD-mfo). These factors include, the negative effects from overuse of agrochemicals. Nevertheless, the potential interactions and synergism between probable agents have not been studied. This systematic review discusses the proposed hypotheses and causes of CKD-mfo in Sri Lanka, and ways to decrease the incidence of this disease and to eradicate it, and provide some recommendations. During the past decade, a number of groups have investigated this disorder using different methodologies and reported various correlations, but failed to find a cause. Research has focussed on the contamination of water with heavy metals, agrochemicals, hard water, algae, ionicity, climate change, and so forth. Nevertheless, the levels of any of the pollutants or conditions reported in water in NPC are inconsistent not correlated with the prevalence of the disease, and are too low to be the sole cause of CKD-mfo. Meanwhile, several nephrotoxins prevalent in the region, including medications, leptospirosis, toxic herbs, illicit alcohol, locally grown tobacco, and petrochemicals, as well as the effects of changed habits occured over the past four decades have not been studied to date. Taken together, the geographical distribution and overall findings indicate that combinations of factors and/or their interactions are likely to precipitate CKD-mfo, which kills more than 5,000 people annually in Sri Lanka; most victims are middle-aged male farmers. Much anecdotal evidence from this region suggests that consumption of contaminated water is the most likely source of this deadly disease. Although the aetiology is unknown, prevention of this "environmentally acquired" disease seems relatively straightforward. Solutions include (a) preventing environmental pollution, (b) stopping the irresponsible use and decreasing the usage of agrochemicals, and encouraging the use of environmentally friendly agricultural methods, (c) taking proper precautions when using agrochemicals and safe disposal of their containers, (d) changing the risky behaviour of farmers and educating them to preserve the environment, and (e) providing clean potable water to all affected regions. Implementing a well-coordinated, in-depth, region-wide, broad-based research study together with a long-term effective surveillance programme across the country is essential to curbing this disease. Unless firm actions are taken promptly, more than three million healthy people in the country, live in agricultural regions, are at risk for contracting CKD-mfo and succumb to premature deaths, which are preventable.

Escalating chronic kidney diseases of multi-factorial origin in Sri Lanka: causes, solutions, and recommendations

During the last two decades, Sri Lanka, located close to the equator, has experienced an escalating incidence of chronic kidney disease (CKD) of unknown aetiology (CKDue) in dry zonal areas. Similar incidences of unusual CKDs have been reported in the dry zonal, agricultural areas of several other equatorial countries. In Sri Lanka, the incidence of CKDue is highest in the North Central Province (NCP), where approximately 45 % of the country's paddy fields are located. However, in recent years, the disease has spread into areas adjacent to as well as distant from the NCP. The cause of CKD in Sri Lanka is unknown, and may likely due to interactions of different potential agents; thus, CKD is of multi-factorial origin (CKD-mfo). These factors include, the negative effects from overuse of agrochemicals. Nevertheless, the potential interactions and synergism between probable agents have not been studied. This systematic review discusses the proposed hypotheses and causes of CKD-mfo in Sri Lanka, and ways to decrease the incidence of this disease and to eradicate it, and provide some recommendations. During the past decade, a number of groups have investigated this disorder using different methodologies and reported various correlations, but failed to find a cause. Research has focussed on the contamination of water with heavy metals, agrochemicals, hard water, algae, ionicity, climate change, and so forth. Nevertheless, the levels of any of the pollutants or conditions reported in water in NPC are inconsistent not correlated with the prevalence of the disease, and are too low to be the sole cause of CKD-mfo. Meanwhile, several nephrotoxins prevalent in the region, including medications, leptospirosis, toxic herbs, illicit alcohol, locally grown tobacco, and petrochemicals, as well as the effects of changed habits occured over the past four decades have not been studied to date. Taken together, the geographical distribution and overall findings indicate that combinations of factors and/or their interactions are likely to precipitate CKD-mfo, which kills more than 5,000 people annually in Sri Lanka; most victims are middle-aged male farmers. Much anecdotal evidence from this region suggests that consumption of contaminated water is the most likely source of this deadly disease. Although the aetiology is unknown, prevention of this "environmentally acquired" disease seems relatively straightforward. Solutions include (a) preventing environmental pollution, (b) stopping the irresponsible use and decreasing the usage of agrochemicals, and encouraging the use of environmentally friendly agricultural methods, (c) taking proper precautions when using agrochemicals and safe disposal of their containers, (d) changing the risky behaviour of farmers and educating them to preserve the environment, and (e) providing clean potable water to all affected regions. Implementing a well-coordinated, in-depth, region-wide, broad-based research study together with a long-term effective surveillance programme across the country is essential to curbing this disease. Unless firm actions are taken promptly, more than three million healthy people in the country, live in agricultural regions, are at risk for contracting CKD-mfo and succumb to premature deaths, which are preventable.

Maternal mortality revisited: the application of the new ICD-MM classification system in reference to maternal deaths in Sri Lanka

Background

The recently published WHO guidelines on applications of ICD-10 to deaths during pregnancy, childbirth, and the puerperium (ICD-MM) aimed at enabling a comprehensive framework for international comparison of maternal deaths, which includes maternal suicides as a direct cause of maternal deaths. At present, most developing countries do not include suicide as a maternal death.

Methods

We extracted and analysed data from the maternal death surveillance system in North Central Province of Sri Lanka for the period of 2005 to 2011, in order to identify the implications of this new classification on maternal mortality estimates. All reported deaths of pregnant women and women within 12 months of termination of pregnancy were included in this study. Causes of deaths were extracted and coded using ICD-10 reclassified according to new ICD-MM for maternal deaths.

Results

Of the 118 deaths analysed, the maternal death investigation system had classified 53 (44.9%) deaths as maternal deaths. These 53 maternal deaths included one deaths due to suicied, out of 21 (17.8%) suicide deaths among 118 reported deaths. Application of the new ICD-MM showed 83 maternal deaths which resulted in a 56.6% increase of number of maternal deaths in the province. Detailed analysis of all individual causes by ICD 10 codes showed that intentional self-poisoning by an exposure to pesticide (ICD code X63) as the leading cause of maternal deaths in NCP (n = 11, 13.3% of all maternal deaths) during this period. The estimated MMR in the study area based on the new classification in years 2009, 2010 and 2011 was 115, 103 and 88 per 100,000 live births respectively.

Conclusions

The new classification system may have an immediate effect in raising maternal mortality thresholds, making the MDG Goal 5A more elusive for many countries. However, this new approach may ultimately lead to a more accurate understanding of maternal mortality, as well as the real number of maternal deaths attributed to suicide. This more accurate accounting has implications for policymakers andpractitioners globally as they strive to meet women's needs during pregnancy, including attention to detection and treatment for maternal depression, given its close correlation with maternal suicide.

Use of OpdA, an organophosphorus (OP) hydrolase, prevents lethality in an African green monkey model of acute OP poisoning

Organophosphorus (OP) pesticides are a diverse class of acetylcholinesterase (AChE) inhibitors that are responsible for tremendous morbidity and mortality worldwide, killing approximately 300,000 people annually. Enzymatic hydrolysis of OPs is a potential therapy for acute poisoning. OpdA, an OP hydrolase isolated from Agrobacterium radiobacter, has been shown to decrease lethality in rodent models of OP poisoning. This study investigated the effects of OpdA on AChE activity, plasma concentrations of OP, and signs of toxicity after administration of dichlorvos to nonhuman primates. A dose of 75 mg/kg dichlorvos given orally caused apnea within 10 min with a progressive decrease in heart rate. Blood AChE activity decreased to zero within 10 min. Respirations and AChE activity did not recover. The mean dichlorvos concentration rose to a peak of 0.66 μg/ml. Treated monkeys received 1.2mg/kg OpdA iv immediately after poisoning with dichlorvos. In Opda-treated animals, heart and respiratory rates were unchanged from baseline over a 240-minute observation period. AChE activity slowly declined, but remained above 25% of baseline for the entire duration. Dichlorvos concentrations reached a mean peak of 0.19 μg/ml at 40 min after poisoning and decreased to a mean of 0.05 μg/ml at 240 min. These results show that OpdA hydrolyzes dichlorvos in an African green monkey model of lethal poisoning, delays AChE inhibition, and prevents lethality.

Applied clinical pharmacology and public health in rural Asia--preventing deaths from organophosphorus pesticide and yellow oleander poisoning

Self-poisoning with pesticides or plants is a major clinical problem in rural Asia, killing several hundred thousand people every year. Over the last 17 years, our clinical toxicology and pharmacology group has carried out clinical studies in the North Central Province of Sri Lanka to improve treatment and reduce deaths. Studies have looked at the effectiveness of anti-digoxin Fab in cardiac glycoside plant poisoning, multiple dose activated charcoal in all poisoning, and pralidoxime in moderate toxicity organophosphorus insecticide poisoning. More recently, using a Haddon matrix as a guide, we have started conducting public health and animal studies to find strategies that may work outside of the hospital. Based on the 2009 GSK Research in Clinical Pharmacology prize lecture, this review shows the evolution of the group's research from a clinical pharmacology approach to one that studies possible interventions at multiple levels, including the patient, the community and government legislation.

Characteristics of non-fatal self-poisoning in Sri Lanka: a systematic review

Background

The rate of non-fatal self-poisoning in Sri Lanka has increased in recent years, with associated morbidity and economic cost to the country. This review examines the published literature for the characteristics and factors associated with non-fatal self-poisoning in Sri Lanka.

Methods

Electronic searches were conducted in Psychinfo, Proquest, Medline and Cochrane databases from inception to October 2011.

Results

26 publications (representing 23 studies) were eligible to be included in the review. A majority of studies reported non-fatal self-poisoning to be more common among males, with a peak age range of 10–30 years. Pesticide ingestion was the most commonly used method of non-fatal self-poisoning. However three studies conducted within the last ten years, in urban areas of the country, reported non-fatal self-poisoning by medicinal overdose to be more common, and also reported non-fatal self-poisoning to be more common among females. Interpersonal conflict was the most commonly reported short-term stressor associated with self-poisoning. Alcohol misuse was reported among males who self-poisoned, and data regarding other psychiatric morbidity was limited.

Conclusions

The findings indicate that pesticide ingestion is the commonest method of non-fatal self-poisoning in Sri Lanka, and it is more common among young males, similar to other Asian countries. However there appears to be an emerging pattern of increasing medicinal overdoses, paralleled by a gender shift towards increased female non-fatal self-poisoning in urban areas.

Many non-fatal self-poisoning attempts appear to occur in the context of acute interpersonal stress, with short premeditation, and associated with alcohol misuse in males. Similar to other Asian countries, strategies to reduce non-fatal self-poisoning in Sri Lanka require integrated intervention programs with several key aspects, including culturally appropriate interventions to develop interpersonal skills in young people, community based programs to reduce alcohol misuse, and screening for and specific management of those at high risk of repetition following an attempt of self-poisoning.

Changing epidemiologic patterns of deliberate self poisoning in a rural district of Sri Lanka

Background

Acute poisoning is a major public health issue in many parts of the world. The epidemiology and the mortality rate is higher in low and middle income countries, including Sri Lanka. The aim of this study was to provide details about the epidemiology of acute poisoning in a rural Sri Lankan district and to identify the changing patterns and epidemiology of poisoning.

Methods

A prospective study was conducted from September 2008 to January 2010 in all hospitals with inpatient facilities in Anuradhapura district of North Central Province of Sri Lanka. Acute poisoning data was extracted from patient charts. Selected data were compared to the data collected from a 2005 study in 28 hospitals.

Results

There were 3813 poisoned patients admitted to the hospitals in the Anuradhapura district over 17 months. The annual population incidence was 447 poisoning cases per 100,000 population. The total number of male and female patients was approximately similar, but the age distribution differed by gender. There was a very high incidence of poisoning in females aged 15–19, with an estimated cumulative incidence of 6% over these five years. Although, pesticides are still the most common type of poison, medicinal drug poisonings are now 21% of the total and have increased 1.6 fold since 2005.

Conclusions

Acute poisoning remains a major public health problem in rural Sri Lanka and pesticide poisoning remains the most important poison. However, cases of medicinal drug poisoning have recently dramatically increased. Youth in these rural communities remain very vulnerable to acute poisoning and the problem is so common that school-based primary prevention programs may be worthwhile.

Lalith Senarathna, Shaluka F Jayamanna, Patrick J Kelly, Nick A Buckley,michael J Dibley, Andrew H Dawson. These authors contributed equally to this work.

Validity of referral hospitals for the toxicovigilance of acute poisoning in Sri Lanka

OBJECTIVE

To identify the hospital admission data set that best captures the incidence of acute poisoning in rural Sri Lanka.

METHODS

Data were collected on all acute poisoning cases admitted to 34 primary and 1 referral hospital in Anuradhapura district from September 2008 to January 2010. Three admission data sets were compared with the "true" incidence of acute poisoning to determine the systematic bias inherent to each data set. "True" incidence was calculated by adding all direct admissions (not transfers) to primary hospitals and to the referral hospital. The three data sets were: (i) all admissions to primary hospitals only; (ii) all admissions to the referral hospital only (direct and referrals), and (iii) all admissions to both primary hospitals and the referral hospital ("all admissions"). The third is the government's routine statistical method but counts transfers twice, so for the study transferred patients were counted only once through data linkage.

FINDINGS

Of 3813 patients admitted for poisoning, 3111 first presented to a primary hospital and 2287 (73.5%) were later transferred to the referral hospital, where most deaths (161/177) occurred. All data sets were representative demographically and in poisoning type, but referral hospital data yielded a more accurate case-fatality rate than primary hospital data or "all admissions" data. Admissions to primary hospitals only or to the referral hospital only underestimated the incidence of acute poisoning by about 20%, and data on "all admissions" overestimated it by 60%.

CONCLUSION

Admission data from referral hospitals are easily obtainable and accurately reflect the true poisoning incidence.

Patterns of female suicidal behavior in Ghana

The suicidal behavior of African females is a rarely explored topic. The present study is a descriptive analysis of fatal and nonfatal female suicidal behavior in Ghana. Patterns of both fatal and nonfatal female suicidal behavior recorded by the Ghana Police Service during 2006-2008 are examined and described in depth. The data show that during the 3-yr. period, there were 11 fatal and 4 nonfatal suicidal acts by females, out of the total 243 fatal and 44 nonfatal suicidal acts found in the official data. The author describes the ages and occupations of the women and girls who engaged in fatal and nonfatal suicidal behavior, as well as the suicide method, location, circumstances, and police-assigned motives for the suicidal acts. The author concludes that additional research on female suicidal behavior in Africa and other non-Western societies is warranted to develop a more precise understanding of suicidality.

Knowledge, attitude and practices of pesticide use and acetylcholinesterase depression among farm workers in Nepal

Assessing erythrocyte acetylcholinesterase (AChE) activity in farm workers across agricultural seasons can be used to monitor risks of pesticide exposure. We surveyed a total of 403 households in Nepal and adopted the Test-mate ChE Cholinesterase Test System to monitor AChE activity across season on the 127 individuals of the sampled households. The study aims to (i) document knowledge and practices of pesticide use among farmers and (ii) present the relationship between farmers' reported acute health symptoms and erythrocyte acetylcholinesterase depression. We found low levels of pesticide use hygiene and high levels of individuals' knowledge on the local environmental impacts of pesticide use. Safety measures taken against potential risks of pesticides exposure were inadequate. Exposure to organophosphates significantly reduced AChE activity across season, but was not sufficient enough to claim clinical symptoms whereas exposure to the pyrethroid insecticides and fungicides were sufficient enough to claim acute symptoms of poisoning.

A community-based cluster randomised trial of safe storage to reduce pesticide self-poisoning in rural Sri Lanka: study protocol

Background

The WHO recognises pesticide poisoning to be the single most important means of suicide globally. Pesticide self-poisoning is a major public health and clinical problem in rural Asia, where it has led to case fatality ratios 20-30 times higher than self-poisoning in the developed world. One approach to reducing access to pesticides is for households to store pesticides in lockable "safe-storage" containers. However, before this approach can be promoted, evidence is required on its effectiveness and safety.

Methods/Design

A community-based cluster randomised controlled trial has been set up in 44,000 households in the North Central Province, Sri Lanka. A census is being performed, collecting baseline demographic data, socio-economic status, pesticide usage, self-harm and alcohol. Participating villages are then randomised and eligible households in the intervention arm given a lockable safe storage container for agrochemicals.

The primary outcome will be incidence of pesticide self-poisoning over three years amongst individuals aged 14 years and over. 217,944 person years of follow-up are required in each arm to detect a 33% reduction in pesticide self-poisoning with 80% power at the 5% significance level. Secondary outcomes will include the incidence of all pesticide poisoning and total self-harm.

Discussion

This paper describes a large effectiveness study of a community intervention to reduce the burden of intentional poisoning in rural Sri Lanka. The study builds on a strong partnership between provincial health services, local and international researchers, and local communities. We discuss issues in relation to randomisation and contamination, engaging control villages, the intervention, and strategies to improve adherence.

Trial Registritation

The trial is registered on ClinicalTrials.gov ref: NCT1146496 (http://clinicaltrialsfeeds.org/clinical-trials/show/NCT01146496).

Toxicologists in public health--Following the path of Louis Roche (based on the Louis Roche lecture "An accidental toxicologist in public health", Bordeaux, 2010)

BACKGROUND

The global burden of clinical toxicology suggests a natural partnership with public health. This article reflects the content of a Louis Roche lecture given in 2010. HISTORICAL CONTEXT: Our practice and research in clinical toxicology has evolved from clinical cases to toxico-epidemiology to public health. This evolution in practice was initially unplanned but gained momentum and impact as we placed it more formally in a public health framework. This perspective is implicit in Louis Roche's call to "examine all aspects of the poisoning problem" and still provides a valuable starting point for any clinical toxicologist.

DISCUSSION

Clinical toxicology has always had a patient centered focus but its greatest successes have been related to public health interventions. Our early failures and later success in pubic health toxicology correlated with our understanding of the importance of partnerships outside our field. The most rapid dissemination and implementation of information derived from research occur through apriori partnerships with other agencies and international partners.

CONCLUSION

Addressing both local and global need has a number of bilateral synergies. Repositioning clinical toxicology into a public health framework increases access to strategic partnerships, research funds, and policy implementation while still addressing questions that are important to clinical practice.

Oximes for acute organophosphate pesticide poisoning

BACKGROUND

Acute organophosphorus pesticide poisoning causes tens of thousands of deaths each year across the developing world. Standard treatment involves administration of intravenous atropine and oxime to reactivate inhibited acetylcholinesterase. The clinical usefulness of oximes, such as pralidoxime and obidoxime, has been challenged over the past 20 years by physicians in many parts of the world.

OBJECTIVES

To quantify the effectiveness and safety of the administration of oximes in acute organophosphorus pesticide-poisoned patients.

SEARCH STRATEGY

We searched both English and Chinese databases: Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE (Ovid SP), EMBASE (Ovid SP), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S) and the Chinese language databases CNKI and WANGFANG. All searches were run in September 2009.

SELECTION CRITERIA

Articles that could possibly be RCTs were retrieved to determine if they were randomised.

DATA COLLECTION AND ANALYSIS

The published methodology of three RCTs was not clear. We contacted the principal authors of these, but did not obtain further information.

MAIN RESULTS

Seven pralidoxime RCTs were found. Three RCTs including 366 patients studied pralidoxime vs placebo and four RCTs including 479 patients compared two or more different doses. These trials found quite disparate results with treatment effects ranging from benefit to harm. However, many studies did not take into account several issues important for outcomes. In particular, baseline characteristics were not balanced, oxime doses varied widely, there were substantial delays to treatment, and the type of organophosphate was not taken into account. Only one RCT compared the World Health Organization (WHO) recommended doses with placebo. This trial showed no clinical benefits and a trend towards harm in all sub-groups, despite clear evidence that these doses reactivated acetylcholinesterase in the blood.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to indicate whether oximes are harmful or beneficial. The WHO recommended regimen (30 mg/kg pralidoxime chloride bolus followed by 8 mg/kg/hr infusion) is not supported. Further RCTs are required to examine other strategies and regimens. There are many theoretical and practical reasons why oximes may not be useful, particularly for late presentations of dimethyl OP and those with a large excess of OP that simply re-inhibits reactivated enzymes. Future studies should screen for patient sub-groups that may benefit and may need flexible dosing strategies as clinical effectiveness and doses may depend on the type of OP.

A study on poisoning cases in a tertiary care hospital

Acute poisoning with various substance is common everywhere. The earlier the initial resuscitations, gastric decontamination and use of specific antidotes, the better the outcome. The aim of this study was to characterize the poisoning cases admitted to the tertiary care hospital, Warangal district, Andhra Pradesh, Southern India. All cases admitted to the emergency department of the hospital between the months of January and December, 2007, were evaluated retrospectively. We reviewed data obtained from the hospital medical records and included the following factors: socio-demographic characteristics, agents and route of intake and time of admission of the poisoned patients. During the outbreak in 2007, 2,226 patients were admitted to the hospital with different poisonings; the overall case fatality rate was 8.3% (n = 186). More detailed data from 2007 reveals that two-third of the patients were 21-30 years old, 5.12% (n = 114) were male and 3.23% (n = 72) were female, who had intentionally poisoned themselves. In summary, the tertiary care hospitals of the Telangana region, Warangal, indicate that significant opportunities for reducing mortality are achieved by better medical management and further sales restrictions on the most toxic pesticides. This study highlighted the lacunae in the services of tertiary care hospitals and the need to establish a poison information center for the better management and prevention of poisoning cases.

Knowledge and practices of pesticide use among farm workers in the West Bank, Palestine: safety implications

OBJECTIVES

The objectives of this study were to assess the knowledge and practices associated with pesticide use in an agricultural community in Palestine, and to determine the prevalence of self-reported health symptoms related to pesticide exposure.

METHODS

In this cross-sectional questionnaire study, agricultural farm workers in Nablus district, Palestine, were interviewed on their knowledge and practices of pesticide use. Comparisons of knowledge and practices of pesticide use between various groups were performed using the Mann-Whitney U-test or the Kruskal-Wallis rank test of variance. The program of the Statistical Package for Social Sciences (SPSS) version 15 was used for data analysis.

RESULTS

The questionnaire was completed by 381 farm workers. The mean age ± SD of the participants was 38.8 ± 11.8 years. The majority (97.9%) of the participants were male. The mean participant scores for knowledge and safety procedures were 2.8 ± 3.2 out of 8 and 9.8 ± 2.4 out of 15, respectively. There was a significant positive correlation (r = 0.323; P < 0.001) between the knowledge and safety procedure scores. Unsafe behaviors were identified as the storage of pesticide products at home, the preparation of pesticides in the kitchen, inadequate disposal of empty pesticide containers, eating and drinking during pesticide application, and using inadequate protective clothing. The most frequent self-reported toxicity symptoms associated with pesticide use were skin rash (37.5%), headache (37%), excessive sweating (24.9%), and diarrhea (21.3%). There was a strong significant negative correlation (r = -0.83; P < 0.001) between self-reported toxicity symptoms and scores for protective measures.

CONCLUSION

The results of this study indicate that most farm workers in this district need more educational programs regarding the safety and use of pesticides. Legislation promoting the use of safer pesticides is also needed.