1. Introduction
Acute poisoning (AP) is defined as adverse health effects resulting from acute (less than 24 h), voluntary, or accidental exposure to a toxic substance, whether from industrial, environmental, chemical, or biological origin or in connection with envenomation [
1,
2]. Acute poisoning is a frequent cause of emergency department (ED) visits and hospital admissions. It accounts for 1–3% of all ED visits [
1] and up to 10% of the caseload [
3]. According to the WHO, more than 300,000 people died worldwide in 2013 because of poisoning [
4]. In the same year, French anti-poison centers recorded 168,475 cases of toxic exposure, and 43.9% of them were symptomatic [
5]. In a more recent report from the WHO published in 2019, the mortality rate attributed to unintentional poisoning (per 100,000 population) was 0.4 in high-income and 2.3 in low-income countries, and it was higher in males than in females [
6].
The causes of AP vary across regions depending on the sociodemographic and cultural characteristics of the studied population, the level of development/industrialization of the country, and the presence of a drug prescription policy [
2,
3,
7,
8]. Pesticides are the most frequent causes of poisoning in low- and middle-income countries, while household products and specialty drugs are at the top in high-income countries [
2,
3,
7,
9,
10,
11,
12]. Indeed, pesticide poisoning is a major global public health challenge predominantly impacting Southern Asia and South and Central America [
8,
13]. However, in industrialized countries, psychotropics are an increasing cause of poisoning and death [
14,
15,
16,
17]. During recent years, the rate of psychotropic agents administered increased by almost 60% [
14,
16]. This rise was followed by a subsequent increase in poisonings by these drugs. Consequently, prescription of psychotropics may play a role in this poisoning increase [
18,
19]. Also, gender and age play significant roles in the epidemiology of psychotropic drug poisoning [
20,
21]. Poisoning is considered severe when requiring close monitoring due to the intrinsic toxicity of the product and the quantity to which the patient has been exposed.
Professionals and health authorities need updated information on local AP characteristics to adapt healthcare professionals’ practices and run specific prevention campaigns [
3]. For this, most developed countries have implemented poison and toxicovigilance centers to monitor poisoning cases and advise callers based on regularly updated information. There has yet to be a reliable database of toxic substances responsible for AP in French Guiana.
Our study aimed to assess the incidence of AP among adults managed in Cayenne General Hospital in French Guiana, to depict their etiological spectra, and to describe their clinical and sociodemographic characteristics.
4. Discussion
Our study shows that AP in French Guiana involves mainly young female people with a history of psychiatric disorders. Intoxication was related to intentional self-poisoning in most cases. The main involved toxicants were psychotropic drugs, benzodiazepines, and paracetamol. Independent factors associated with mortality were paraquat poisoning, hypokalemia, and acute renal failure. These data provide insights on how to improve the medical management of and mental health care for people with AP in French Guiana. They also emphasize the need for a toxicovigilance monitoring framework to monitor the trends and profiles of acute poisoning cases and the involved toxics.
Acute poisoning is a significant public health problem worldwide. In 2018, the American Association of Poison Control Centers reported 2,099,751 cases of toxic exposure, of which 48.6% involved pharmaceutical drugs [
25]. In the United Kingdom, between 2018 and 2019, the National Poisons Information Service reported 170,000 patients hospitalized due to poisoning, representing 1% of all hospital admissions [
26]. In Germany, the incidence of AP rose from 1.2% to 1.9% between 2005 and 2012 [
27]. In France, a retrospective study using the Poison Centre Information System data in 2013 reported 168,475 exposure cases, with a peak incidence in Corsica of 39.2 cases per 100,000 inhabitants [
5]. In Martinique, a retrospective study from 2000 to 2010 reported an incidence of 7.7 severe poisoning cases/100,000 inhabitants [
2]. Our study recorded 425 adult poisoning cases over 13 years, with a decreasing incidence trend over the years.
In this study, 65.6% of patients were women, with an average age of 32 years. A history of psychiatric disorders was present in 41.9% of patients. Intentional self-poisoning was recorded in 84.2% of cases, and the most involved toxics were psychotropics, benzodiazepine, and paracetamol. These findings are in line with previous studies showing that intoxicated patients in industrialized countries are generally young women with psychiatric histories [
28,
29,
30,
31,
32]. However, this result is different from that observed in Martinique, where the male gender was recorded in 57% of AP cases [
2].
As far as the implicated toxic agents are concerned, an Australian study showed that tricyclic antidepressants, benzodiazepines, and ethanol were the most involved toxics, and multidrug AP was present in 65% of cases [
30]. Conversely, pesticide poisoning, mainly organophosphate poisoning, was the leading toxic cause in developing countries [
3,
33,
34]. An Ethiopian study showed organophosphates (45%) and sodium hypochlorite (22.5%) as the most involved toxics [
3]. It is noteworthy that etiologies of AP have experienced notable shifts in recent years, requiring close monitoring of the involved toxics [
1,
35,
36,
37]. Also, healthcare professionals managing AP must have advanced skills in clinical toxicology to provide tailored care according to the toxic and the patient’s characteristics [
38]. Furthermore, the management strategy must incorporate the pharmacokinetic/pharmacodynamic properties of the involved toxic and consider the availability of specific investigations, antidotes, and rescue techniques [
38]. Lastly, healthcare professionals, policymakers, and health authorities must focus on preventive programs based on the most involved toxics and patient characteristics.
Regarding AP outcomes, mortality rates secondary to AP vary considerably among studies and depend essentially on the type of the predominant toxicant and access to care [
28,
39,
40,
41]. The rate was 0.9% in South Africa, 1.9% in Sweden, and up to 10% in Martinique [
2,
28,
39]. While lethality from AP in Martinique was the highest in the literature, it may be explained by the inclusion of severely intoxicated patients and the involvement of combined pesticides and pharmaceutical drugs [
2]. A multi-source study carried out in Paris in 2010 and 2011, including the Paris Poison Control Centre (CAP); the Lariboisière ED and ICU, which are part of the Organization of Coordinated Emergency Surveillance (OSCOUR) network; the Île-de-France regional pharmacovigilance co-ordination unit; and two toxicology laboratories involved in forensic assessments after lethal intoxication, recorded 9520 cases of intoxication (sex ratio M/F = 0.77), with a mortality rate of 2.18% [
42]. Factors associated with mortality were male gender, organ failure, metabolic acidosis, hypokalemia, rhabdomyolysis, and hepatic cytolysis. In our study, the mortality rate was 3.9%, in line with most international references. However, the most lethal toxic in our region was paraquat. Additionally, the toxics associated with severe poisoning were chloroquine, neuroleptics, and paraquat.
According to the WHO, more than 77% of suicides occurred in low- and middle-income countries in 2019. Also, 20% of suicides involved pesticide poisoning and occur mainly in rural areas [
43]. In Suriname, half of the suicides and attempted suicides involved pesticides, mainly paraquat [
44]. In French Guiana, suicides caused by paraquat generally occurred in remote areas [
45]. Paraquat (1,1 dimethyl 4,4′ bipyridylium dichloride) is a harmful non-selective herbicide [
45,
46]. Despite its high toxicity, it is still widely used worldwide, as are many other plant protection products like glyphosate and organophosphates [
46,
47]. Given its high toxicity to humans (50–90% mortality following ingestion), Europe banned its use in July 2007 [
48,
49,
50]. However, it remained available in neighboring countries and is illegally imported into French Guiana. In France, in 2008, the “Ecophyto” plan banned 30 active substances contained in pesticides (including paraquat) [
51,
52]. Despite this prohibition, 23.8% of calls to French Anti-Poison Centers concerning pesticide poisonings between 2012–2016 involved paraquat [
51]. The lethal ingested dose of paraquat is 35 mg/kg. Note that a 20 mL sip of Gramoxone
® (the commercial paraquat name) equals 57 mg/kg in a 70 kg adult [
53]. French Guiana has the highest incidence of Paraquat-induced AP in the EU, with 3.8 cases/100,000 inhabitants/year [
45]. Various avenues, therefore, need to be explored, including educating the public and improving product safety (addition of an emetic, a laxative, and an alginate: Gramoxone INTEON) [
53,
54,
55]. In South Korea, paraquat prohibition has led to a 46.1% drop in paraquat AP [
56]. In 2020, Brazil banned paraquat because of its acute and chronic toxicity [
57]. Accordingly, banning Paraquat in Suriname would be an option due to its harmful effect on the environment, human, and animal health [
58]. A One Health approach can help to optimize the net benefits and risks from pesticides and paraquat use on plants, people, animals, and ecosystems [
59].
In our study, 41.9% of patients suffered from psychiatric disorders, raising the issue of mental health in the context of AP. Also, there was a close link between mental disorders and intentional self-poisoning (84.2%), as is similar to a Spanish report (83.2%) [
60]. One of the leading causes of AP is suicide attempts. In an Indian study, 64% of APs were related to a suicide attempt [
33]. In 2018, Santé Publique France reported that intentional drug intoxication was the most frequent mode of suicide (87% of hospital admissions for suicide in women and 75% in men) [
61]. In the United States, in 2000, 80% of suicide attempts were associated with AP [
62]. The WHO reported 877,000 deaths by suicide in 2003 [
63]. In French Guiana, the overall suicide rate is estimated at 7 per 100,000 inhabitants/year, which is lower than in mainland France (16/100,000 inhabitants/year). Still, most cases of suicide are reported in the Amerindian communities of Camopi and Trois-Sauts (113 and 137 deaths/100,000 inhabitants/year). The most frequently used methods are hanging (72%) and AP (18%). Also, voluntary AP accounted for 50% of hospital stays for suicide attempts recorded between 2015 and 2017 in French Guiana [
64]. Women account for two-thirds of suicide attempts, with a 3.7 times higher incidence of AP than men. In the Maripasoula municipality, the rate of suicide attempts by paraquat absorption was the highest, at 46% [
64]. Albano et al. [
8], in a systematic review of toxicological findings of self-poisoning suicidal deaths, found that the most involved substances in low- and middle-income countries with significant agricultural areas were pesticides such as organophosphates and carbamates. In contrast, in high-income countries, the use of illicit drugs and medicines for suicide was more frequent. Collados-Ros et al. [
65] reported that most suicides were associated with drug abuse, mainly psychopharmaceuticals. In this study, the authors highlight the vital role of toxic substances in suicidal behaviors. In 2016, an “Equality and Citizenship” bill on the fight against suicide among the young Guyanese population was proposed to the government to create a regional suicide observatory [
66]. In 2020, the Regional Agency for Health in French Guiana set up the “Centre Ressource Prévention du Suicide” and the “VigilanS” system. This original and unique platform in France combines monitoring, crisis intervention, recidivism prevention, and training. The “Well-being of the Populations of the Interior of French Guiana,” called the “BEPI program,” complements this policy. In addition to these devices, involving mental health specialists in the emergency care teams could play a crucial role in assessing and managing at-risk and poisoned patients.
The scientific literature reflects the sociodemographic, cultural, geographical, and spatial–temporal variability of APs [
64,
67,
68,
69]. All these parameters and the prevalence of APs observed in our study highlight the need for a toxicovigilance center (TVC) dedicated to French Guiana. The aim of toxicovigilance is to monitor the acute or chronic toxic effects to humans of exposure to a natural or synthetic mixture or substance available on the market or found in the environment in order to undertake alert and prevention actions, as stated in the L. 1340-2 article of the French Public Health Code. This activity covers collecting and analyzing information and alerting the public to enable preventive action, according to the R.1341-16 article of the French Public Health Code. Toxicovigilance in France is organized nationally and regionally based on the network of 13 Acute Poisoning and Toxicovigilance Centers (APTVCs) spread throughout the country. The APTVCs respond 24/7 to any request for risk assessment or advice on the diagnosis, prognosis, and treatment of human intoxication. Each call is entered into a database. The latter can be used for toxicovigilance by assessing the involved toxins and proposing appropriate action. Accordingly, TVCs organize thematic networks at the local level and joint surveillance with the Health Monitoring Institute (InVS) at the national level. It contributes as an investigation reporter or data producer. Thereafter, data are analyzed by the “Cellule interrégionale d’épidémiologie” (CIRE).
Overall, there is an urgent need for a dedicated toxicovigilance monitoring framework in the French overseas departments [
2]. The French West Indies and French Guiana depend on the APTVC in Paris, while Réunion Island and Mayotte depend on the APTVC in Marseille. In addition, there have been attempts to develop local and regional structures, with the Indian Ocean Toxicovigilance System (IO-TVS) in 2006, which allowed the epidemiological situation of pesticide-induced AP in Reunion Island to be described. In 2009, a joint mission by the InVS, the “CIRE Antilles-Guyane,” the Anti-Poison Center in Paris, and the TVC in Grenoble recommended setting up a TVC in the French West Indies departments. Its implementation in 2014 enabled the identification of specific intoxications in Guadeloupe. These examples demonstrate the value of implementing a TVC in French Guiana for the purpose of improving knowledge of APs and developing activities targeting toxicological themes. It is a priority in French Guiana to investigate traditional medicine’s beneficial or harmful effects, as well as intoxications by herbicides (Paraquat) and those attributable to local fauna. Moreover, no regional or inter-regional register exists to identify APs or to enable descriptive analyses. Furthermore, AP poses a significant public health challenge in the French Territories in the Americas (FTA), which experience a notable prevalence of rural and domestic poisonings. Consequently, it is imperative to establish dedicated Poison and Toxicovigilance Centers within these departments to enhance the quality of care and facilitate the prompt identification of individuals affected by toxic substances. Moreover, a deeper understanding of the impact of pesticide use in French Guiana and the FTA on human, animal and environment is needed within the One Health concept.
Our study has several limitations due to its retrospective, monocentric design, and focuses mainly on symptomatic patients. However, Cayenne Hospital is the referral healthcare facility in French Guiana, managing more than 50% of ED visits and most severe poisoning cases. Furthermore, this is the first large-scale epidemiological study shedding light on the peculiarities of AP in the adult population in French Guiana. It confirms the burden of AP as a neglected public health problem and the urgent need to set up a dedicated toxicovigilance monitoring framework in French Amazonia and an antipoison center in the French Territories in the Americas.