Psychological and clinical-epidemiological profile of poisoning in Nepal: an institutional experience

Introduction

As per reports from the World Health Organization (WHO), about 0.3 million people die each year due to various acute poisonings.¹ The substances most commonly used in poisoning are agricultural pesticides (mostly organophosphates) in developing countries and misuse of drugs in developed countries. The common reason for most of the poisoning cases is the intention of self-harm.¹ WHO estimates that pesticide self-poisoning accounts for around 20% of global suicides.² Around 60% of the estimated annual deaths from self-harm in rural Asia are due to pesticide poisoning, and organophosphates account for around two-thirds of these deaths.³ In low and middle-income countries (LMICs) like Nepal, where 66% population is directly engaged in agriculture, pesticides have become the preferred means of suicide due to agricultural intensification and their easy availability.⁴

Limited information is available regarding the pesticide poisoning scenario in Nepal as the national routine Health Management and Information System (HMIS) doesn’t include it.⁵ Also, the psychological aspect associated with poisoning in Nepal is not addressed much in the literature although the medical aspect is given high priority.

Our study aims to address the psychological issues of poisoning with the main focus on its intent and its motives. Apart from this, the study also highlights the clinical and epidemiological profile among patients presenting to the emergency department of a hospital in Nepal following intentional or accidental poisoning.

Methods

Results

Out of 159 total poisoning cases, 71 had consumed organophosphate compounds while 63 had consumed non-organophosphate compounds like non-organophosphate pesticides, drugs, and rodenticides. Since Aluminum phosphide (n = 25) cases had unique findings (all patients being suicidal in intent and with a high case fatality rate of 84%) compared to other non-organophosphate poisoning cases, aluminum phosphide cases have been reported elsewhere as a case series. Hence they were not included in the analysis of the non-organophosphate group.

Discussions

Acute Pesticide Poisoning is a major health-care problem and a frequent medical emergency in developing countries with high case fatality.^1,5,6 This retrospective hospital-based study intends to explore various factors contributing to the exposure of poison and the outcome. Recent national, as well as international studies, suggest that younger people have emerged as a high-risk age group.^1,5–7 Our study also showed that the mean age in years in OP poisoning cases was 31.72 (±14.068). The fact that poisoning is more common among young adults reflects their vulnerability to stress, maladjustment, and immature psychological coping mechanisms at a time of life’s major stressors.^8,9

In our study, females were more involved in organophosphate poisoning as well as in other acute poisonings which was consistent with other studies conducted in different national hospitals.^5,10–12 In contrary to this finding, a study done at Liaquat University of Medical and Health Sciences, Pakistan over one year period showed only 22% were females.¹³ More vulnerability of females to suicide attempts than males in developing countries like Nepal points towards various social and cultural factors revealing inequality. Factors like early marriages, fewer opportunities for education, domestic violence, abusive spouses, problematic love and marital relationships, and unwanted pregnancies, contribute to more suicide attempts by women.^7,9,14,15 According to the Nepal Maternal Mortality and Morbidity (MMM) study 2008/09, the leading cause of death among women of reproductive age was suicide, comprising 16 percent of all deaths increasing from 10.2 percent in 1998.

This study revealed that more than 90 percent of the patients intentionally consumed the poison (self-poisoning) as a suicidal attempt. A similar study was done in Bir Hospital, Nepal which showed 97% intentional poisoning.¹² Also, a study done in Turkey revealed that deliberate self-poisoning was the most common cause of poisoning (58.6%), followed by accidental exposure (39.1%).¹⁶ A study from Nepal that examined attempted suicide showed that the commonest mode of suicide among all attempted cases was OP poisoning.¹⁷ Pesticides becoming the first choice of method of suicide in rural agricultural communities is attributed to easy availability and no restrictions on buying and selling.^5,14,15,18 To support this, we can look at the fact that in Sri Lanka, the suicide rates halved in the mid 1990s after a series of legislative activities systematically banned the most highly toxic pesticides.¹⁹ The ease of availability of lethal means of self-harm may influence patterns of suicide. Suicidal impulses are often short-lived and if we can buy some time by making the means of suicide less readily available, a proportion of suicides will be prevented.^18,20,21

Most of the suicidal cases were impulsive in nature and the main triggering factor for attempting suicide was found to be interpersonal conflict (family disputes) in our study. In many other studies, interpersonal conflicts involving domestic problems are the main precipitating factors.^22–24 However, various studies done in India, Sri Lanka, and other countries showed that psychiatric illnesses like depression are associated with high-risk attempts.^25–27 It was not significant in our study due to inadequate data and incomplete history provided by the patient’s party. Since we relied completely on the history given by patients for psychiatric illness, its prevalence among them cannot be verified and can be more than what is reported. Evidence also suggests that there is a lesser prevalence of psychiatric disorders in individuals involved in suicidal behavior in LMICs. It may reflect the suicide methods used in LMICs (e.g., pesticide ingestion) which are mostly impulsive acts with low suicidal intent.²⁸

As is commonly observed in different studies, organophosphorus compounds are common mode of poisoning in our study followed by drugs and rodenticides.^5,10,29 However, some studies showed a higher percentage of rodenticides compared to drugs.^11,30 Among different organophosphorus compounds, our study showed the combination of chlorpyrifos and cypermethrin to be the most common. Previous studies from Nepal and other countries report methyl parathion and dichlorvos as the commonest causes of OP poisoning.¹¹ But contrary to these studies and as mentioned by the National Forensic Science Laboratory,²⁹ the use of a combination of chlorpyrifos and cypermethrin seems to be increasing. This might be because compounds like methyl parathion and dichlorvos, previously very common compounds of poisoning, have been banned from the country.

In our study 77.5 percent of patients fall under mild severity as per POP score. It has been shown by Senanayeke et al. that the severity, morbidity, and mortality of OP poisoned patients can be predicted through the POP score.³¹ Perhaps we can conclude the pertinent factor for improved survival in our study was the mild severity status of the patients at presentation. A previous study from Karachi also showed a similar relation between POP score and severity.³²

In this study, 26.86 per cent of all poisoning cases developed complications, very similar to one of the studies from Central Nepal.¹⁰ This shows that the majority of the patients recovered completely without any complications and sequelae which might be because of various reasons like adequate and proper management, ingestion of low doses, and induction of vomiting at home as seen in this study as well. Aspiration pneumonia was the commonest complication in the OP group with bradycardia being common in the Non-OP group. Other studies are also found in favor of these findings.^10,33 The intermediate syndrome was also found in a good percentage (5 per cent) among the OP group similar to the findings of a study from eastern Nepal³ but significantly low compared to a study from India (29.4 percent).³⁴

90 per cent of patients with OP poisoning were recovered while 100 percent of patients recovered with other Non-OP poisoning. The case fatality was 4.4 percent among OP poisoning patients excluding the cases whose outcome couldn’t be evaluated such as referred cases and LAMA. The fatality rate was lower as compared to various studies done in Nepal and other South Asian countries.^10,35,36

The study being retrospective and hospital based, some data were missing. Although the study has been conducted over the period of three years, the seasonal variation couldn’t be elicited because of lack of data. Also, the domestic conflict could not be further elaborated because of inadequate data but it still gives a prominent and a larger view of how the family dispute is a major cause. The severity of the patient is only based on POP score, but different toxicological parameters could have contributed to the complications.

Conclusion

Pesticides, commonly organophosphate compounds are used as the major means of self-poisoning. Our study showed that young adults and females are mostly involved in poisoning with the intent of suicide. Disputes with family members were found to be the main reason. Short-term suicidal impulses and the easy availability of pesticides also contributed to suicides. Limitations of a hospital-based study like ours can be overcome by a population-based study, which will provide true reflection about the problem of pesticide exposure and self-poisoning. Easy access to pesticides should be restricted with strong regulatory mechanisms and implementation of rules and regulations for pesticide handling. Early psychiatric consultation and identification of psychiatric disorders will help to reduce the incidence of self-harm. So, preventive strategies and mental health awareness programs should be conducted for high-risk populations.

Data availability