Clinico-epidemiology of diuron poisoning in Ratnapura: A cross-sectional study

Abstract

Intentional self-poisoning is a significant public health problem in Sri Lanka. Recently, diuron, a herbicide widely used for weed and grass control in agriculture, has emerged as a potential poisoning agent. The objective of this study was to describe the epidemiological and clinical features of diuron poisoning in Ratnapura. A prospective observational clinical study was conducted in the medical wards of the Teaching Hospital, Ratnapura, over two years from July 2021, taking patients with a history of diuron ingestion into account. Data were collected using an interviewer-administered questionnaire. A total of 21 patients with diuron poisoning were identified, comprising 17 (81%) males and 4 (19%) females, with a mean age of 37.7 years (range: 17–66 years). Most patients were from Ratnapura (4; 19%), followed by Lellopitiya (3; 14%). The most affected occupational groups were labourers (5; 23.8%), gem miners (3; 14%), and three-wheel drivers (3; 14%). Eleven patients (52.4%) were direct admissions, while 10 (47.6%) were transfers from peripheral hospitals. The median hospital stay was 3 days (IQR 3–4.5; range 2–12 days). Vomiting was the most common presenting symptom (19; 90.5%), followed by nausea and dyspnoea (11; 52.4% each). Methaemoglobinaemia was detected in 11 (52.4%) patients, all of whom required intensive care due to respiratory failure. Of these, 8 (38.1%) required intubation and mechanical ventilation. Other complications included hypotension (10;47.6%) and aspiration pneumonia (3;14.3%). Methylene blue was administered to all patients with methemoglobinemia (11;52.4%). Gastrointestinal decontamination was carried out in 17 (81%) patients, including activated charcoal in 17 (81%) and gastric lavage in 12 (57%). Fourteen patients (66.7%) recovered completely, while 7 (33.3%) died. The high morbidity and mortality rate in diuron poisoning was mainly attributed to severe methaemoglobinaemia and its complications, such as subsequent hypoxemia.