Acute Imidacloprid Poisoning in Thailand

Figures & data

Figure 1 Number of reported imidacloprid (IM) exposures between all and single (IM-only) exposure, and the incidence rate (per 100,000 population). The total population in Thailand from 2010 to 2018 was 63,701,703–65,406,320 people.

Table 1 Demographic and Exposure Characteristics of Patients with Acute Imidacloprid Exposure

Characteristics	Number of Cases (%)
Sex
Male	91 (55.8)
Female	72 (44.2)
Age in years, mean ± SD (min-max)	41.3 ± 22.2 (2–88)
Region of exposure
Northeast	57 (35.0)
Central	48 (29.5)
North	22 (13.5)
East	14 (8.6)
West	12 (7.4)
South	10 (6.1)
Route of exposure
Oral	152 (93.3)
Inhalation	7 (4.3)
Dermal	2 (1.2)
Ocular	1 (0.6)
Dermal and inhalation	1 (0.6)
Concentrations and formulations
70% WG/WS	80 (49.0)
10% w/v SL	31 (19.0)
5% w/v EC	8 (4.9)
35% w/v EC	3 (1.8)
10% WG	3 (1.8)
0.5% w/w	3 (1.8)
20% w/v EC	1 (0.6)
0.03% w/v	1 (0.6)
Unknown	33 (20.2)
^aEstimated amount in grams, median (IQR);	2.5 (1.4–5.0)
- Intentional exposure	2.5 (1.4–5.6)
- Accidental exposure	2.5 (1.4–3.75)
^bTime to hospital in hours, median (IQR)	1 (0.5–2.7)
Admitted to the hospital
No	28 (17.2)
Yes	135 (82.8)
Length of stay in days, median (IQR)	1 (1–2)

Notes: ^aData on estimated amount of ingestion were available for 68 patients; intentional exposure for 55 patients, accidental exposure for 13 patients. ^bDuration from exposure to arrival at healthcare facility.

Abbreviations: WG/WS, water-dispersible granules/powders; w/v, weight by volume; SL, soluble concentrates; w/w, weight by weight; EC, emulsifiable concentrates.

Table 2 Medical Outcome by Severity of Initial Signs and Symptoms

Initial Severity	Medical Outcome Number of Cases (%)				Total Number of Cases (%)
	No Effects	Minor	Moderate	Death
No effects	30 (75)	8 (20)	2 (5)	0	40 (24.5)
Mild	0	116 (97.5)	1 (0.8)	2 (1.7)	119 (73)
Moderate	0	0	1 (50)	1 (50)	2 (1.2)
Severe	0	0	0	2 (100)	2 (1.2)
Total	30 (18.4)	124 (76.1)	4 (2.5)	5 (3.1)^a	163 (100)

Note: ^aThe mortality rate was 3.1%.

Table 3 Details of Fatal Cases

Patient No.	Sex/Age (Year)	Formulation	Dose Ingested (Grams)	Time^a to Hospital (Hours)	Initial Severity	Clinical Manifestations	Time^b to Death
1	Male/47	Unknown	NA	2	Severe	Coma and cardiopulmonary arrest	2 days
2	Male/52	70% WG	20	NA	Severe	Nausea/vomiting, diaphoresis, hypotension, tachycardia, progressive coma, cardiovascular collapse.	5 hours after arrival
3	Female/64	10% w/v SL	NA	8	Moderate	Dizziness, dyspnea, tachycardia and hypertension, respiratory failure and cardiac arrest	13 hours
4	Male/88	35% w/v EC	70	1	Mild	Tachypnea, diaphoresis, mental status changes, hypotension, tachycardia, and prolonged shock	22 hours
5	Female/49	10% w/v SL	40	6	Mild	Nausea/vomiting, burning sensation of throat, dyspnea, confusion, and cardiopulmonary arrest	2 days

Notes: ^aDuration from exposure to arrival at healthcare facility. ^b Time until patient died after ingestion.

Abbreviations: NA, not applicable; WG, water-dispersible granules; w/v, weight by volume; SL, soluble concentrates; EC, emulsifiable concentrates.

Table 4 Subgroup Analysis of Clinical Manifestations Between Patients Who Survived and Those Who Died

Clinical Manifestations	Survived (n = 158)	Died (n = 5)	p-value*
Number (%) male to female	88:70 (55.7:44.3)	3:2 (60:40)	1.00
Age in years, mean ± SD (min-max)	40.7 ± 22.1(2–86)	60 ± 16.9(47–88)	0.056
Number (%) of age in years			0.496
Less than 5 years	18(11.4)	0
6–12 years	2 (1.3)	0
13–19 years	7 (4.4)	0
20–39 years	43(27.2)	0
40–59 years	54(34.2)	3 (60)
More than 60 years	34 (21.5)	2 (40)
Time to hospital in hours, median (min-max); data available for 160 patients	1 (0.17–72) n = 156	4 (1–8) n = 4	0.064
Estimated ingestion amount in grams, median (min-max); data available for 68 patients	2.5 (0.1–30) n = 65	40 (14–87.5) n = 3	0.004**
Number (%) of initial signs and symptoms^a
Gastrointestinal:	98 (62.0)	2 (40)	0.376
Nausea/vomiting	84 (53.2)	2 (40)	0.668
Abdominal pain	33 (20.9)	0	0.584
Burning sensation in    throat	11 (7.0)	1 (20)	0.321
Cardiovascular:	13 (8.2)	3 (60)	0.007**
Tachycardia	3 (1.9)	3 (60)	<0.001**
Bradycardia	1 (0.6)	0 (0)	1.000
Hypertension	8 (5.1)	1 (20)	0.250
Hypotension	2 (1.3)	1 (20)	0.090
Cardiac arrest	0	1 (20)	0.031**
Central nervous system:	5 (3.2)	3 (60)	0.001**
Dizziness	20 (12.7)	1 (20)	0.503
Drowsiness	5 (3.2)	1 (20)	0.173
Headache	4 (2.5)	0	1.000
Coma	0	1 (20)	0.031**
Respiratory:
Dyspnea	0	2 (40)	0.001**
Other:
Muscle twitching^b	2 (1.3)	0	1.000
Diaphoresis	4 (2.5)	2 (40)	0.011**
Salivation	6 (3.8)	0 (0)	1.000
Paresthesia^b	3 (1.9)	0 (0)	1.000

Notes: ^aData from all routes of exposure. ^bSymptoms occurred only after dermal or inhalational exposures. * Comparisons between-group were performed by Student’s t-test if the data were normally distributed and by the Mann–Whitney U-test if they were not normally distributed. Differences in categorical variables were evaluated by chi-squared analysis and Fisher’s exact test. ** Statistically significant.