OBJECTIVE: To analyze the density, distribution and insecticide resistance of Aedes albopictus in Ningbo City in 2021, so as to provide insights into formulation of dengue fever control strategies. METHODS: Four administrative villages were randomly selected from each county (district) in Ningbo City from April to November, 2021, to investigate the indoor population density of Aedes larvae, and the Breteau index (BI) was calculated. The population density of adult mosquitoes was investigated in residential areas, parks/bamboo forests, waste tire stacking sites/waste stations/construction sites in each county (district). On June 2021, larvae of the natural strain A. albopictus were collected from epidemic sites of dengue fever in Ningbo City in 2018, and raised in laboratory. Then, larvae and female mosquitoes without blood feeding were selected for insecticide resistance bioassays, while insecticide-sensitive strains of A. albopictus served as controls. The resistance of A. albopictus larvae to deltamethrin, beta-cypermethrin, propoxur, temephos and dichlorvos using the impregnation method, and the medium lethal concentration (LC₅₀) and resistance ratio (RR) were calculated. The resistance of adult A. albopictus to beta-cypermethrin, permethrin, deltamethrin, propoxur and malathion was determined using the tube bioassay, and the mosquito mortality was calculated. RESULTS: A total of 10 072 small water containers from 9 935 households were investigated in Ningbo City in 2021, and there were 1 276 containers with Aedes larvae detected, with an average BI of 12.89. Totally 1 422 mosquito nets were allocated and 954 female A. albopictus were captured, with an average net trapping index of 1.34 mosquitoes/(net·hour). Both larval and adult A. albopictus mosquitoes were found from April to November, and the density of larval A. albopictus peaked in September (BI = 21.21), while the density of adult A. albopictus peaked in August, with a net trapping index of 2.38 mosquitoes/(net·hour). The LC₅₀ values of delta-methrin, beta-cypermethrin, propoxur, temephos and dichlorvos were 0.017 4, 0.000 9, 0.364 1, 0.038 1 mg/L and 0.001 6 mg/L against larvae of natural strains of A. albopicchus, with RRs of 49.66, 25.53, 9.65, 2.24 and 6.06, and the mortality rates of adult mosquitoes were 66.00% (66/100), 69.39% (68/98), 25.00% (25/100), 98.97% (96/97) and 100.00% (98/98) 24 hours post-treatment with 0.08% beta-cypermethrin, 0.03% deltamethrin, 0.4% permethrin, 0.05% propoxur, and 0.5% malathion for 24 h, respectively. CONCLUSIONS A. albopictus is widely distributed in Ningbo City, with a high population density and presents high-level resistance to common pyrethroid insecticides. The population density and insecticide resistance of A. albopictus requires to be reinforced.
Animals ; Female ; Malathion ; Temefos ; Aedes ; Propoxur ; Permethrin ; Dichlorvos ; Mosquito Vectors ; Larva ; Dengue/prevention & control*

Poisoning may result from self-injection. Previous reports have described acute cholinergic crisis, intermediate syndrome, and delayed toxicity resulting from parenteral organophosphate administration. These complications have been managed with antidotal and conservative treatment. Acute kidney injury was not listed among the complications. We report a case of acute kidney injury after intravenous injection with an unknown liquid. After chemical composition analysis, organophosphate dichlorvos has been identified as the injected liquid substance. A 50-year-old man injected this into his left arm. He visited the emergency department with a mental change accompanied by seizure. During admission, there were no typical cholinergic symptoms or intermediate syndrome; however, there was a development of acute oliguric kidney injury. The patient was treated successfully with a combination of hemodialysis, hemoperfusion, and conservative management. The manifested seizure, altered mental state, and acute kidney injury could have been caused by several types of poisoning. Based on patient history, which was obtained during the early treatment period, there was no information of what the injected material may have been, and there were no signs of a typical organophosphate toxidrome. However, the patient was successfully treated with rapid initiation of renal replacement treatment, without the use of antidotes. Poisoning by unknown causative substances poses a diagnostic challenge to emergency physicians. In many cases, treatment may be delayed while the physician tries to identify the toxin. However, the basic toxicology principle of focusing on the patient treatment rather than the poisonous substance should not be forgotten.
Acute Kidney Injury* ; Antidotes ; Arm ; Dichlorvos ; Emergencies ; Emergency Service, Hospital ; Hemoperfusion ; Humans ; Injections, Intravenous* ; Kidney ; Middle Aged ; Organophosphates ; Poisoning ; Renal Dialysis ; Seizures ; Toxicology

OBJECTIVETo investigate the characteristics of pesticide poisoning in Jiangsu Province, China, and to provide a scientific basis for developing effective intervention measures and prevention strategies.

METHODSThe data from report cards of pesticide poisoning in Jiangsu Province from 2006 to 2013 were arranged using EXCEL tables, and assessed. Statistical analysis was applied to the epidemiological data using SPSS.

RESULTSFrom 2006 to 2013, a total of 32672 cases of pesticide poisoning were reported in Jiangsu Province. Most of the cases were caused by non-occupational poisoning (life poisoning) (72.78%). A majority of patients with pesticide poisoning were 35-54 years old (40.85%) or older than 65 years (15.69%). There were more female patients (58.22%) than male patients (41.78%). Among patients with occupational poisoning, male patients (50.90%) were more than female patients. Among patients with non-occupational poisoning, female patients were more than male patients (38.37%). Pesticide poisoning mainly occurred from July to September. The case-fatality rate of occupational poisoning (0.47%) was lower than that of non-occupational poisoning (7.10%). All 13 cities in Jiangsu Province reported cases of pesticide poisoning. There were more cases in the northern regions than in the southern regions. Pesticide poisoning was mainly caused by organophosphorus insecticides including methamidophos, dichlorvos, dimethoate, omethoate, and parathion, which accounted for 65.58%of all cases. Paraquat had the highest case-fatality rate (10.06%) among all pesticides, followed by tetramine (10.00%), dimethoate or omethoate (7.85%), methamidophos (7.79%), and dimehypo (7.68%).

CONCLUSIONPesticide poisoning cannot be ignored. The management and control should be improved in production and usage of highly toxic pesticides including organophosphorus insecticides, rodenticides, and herbicides. More attention should be paid to the protection of vulnerable groups including women, children, and the elderly.

Adult ; Age Distribution ; Aged ; China ; epidemiology ; Cities ; Dichlorvos ; Dimethoate ; analogs & derivatives ; Environmental Exposure ; prevention & control ; statistics & numerical data ; Female ; Herbicides ; poisoning ; Humans ; Insecticides ; poisoning ; Male ; Middle Aged ; Organothiophosphorus Compounds ; Paraquat ; Pesticides ; poisoning ; Poisoning ; epidemiology ; prevention & control ; Rodenticides

Dichlorvos ; toxicity ; Disseminated Intravascular Coagulation ; complications ; Humans ; Organophosphate Poisoning ; complications

In organophosphate intoxication, the neurotransmitter acetylcholine accumulates in synapses, causing excessive stimulation of nicotinic and muscarinic receptors, producing various signs and symptoms. Organophosphates are highly toxic compounds that are readily absorbed through the skin, mucous membranes, and gastrointestinal and respiratory tracts. Organophosphate intoxication leads to many well defined complications, including cholinergic crisis, intermediate syndrome, and acute pancreatitis. However, parotitis caused by organophosphate intoxication is very rare. We experienced such a case of a 55 year old woman who visited the emergency center because of organophosphate intoxication. The next day, she complained of left facial redness, swelling, and pain. We checked serum lipase, amylase, and amylase-isoenzymes, and found elevation of salivary type amylase only. The mechanism of parotitis due to organophosphate intoxication is assumed to be similar to that of pancreatitis caused by organophosphate. In patients with elevated amylase caused by organophosphate intoxication, the possibility of parotitis must be considered.
Acetylcholine ; Amylases ; Dichlorvos ; Emergencies ; Female ; Humans ; Lipase ; Mucous Membrane ; Neurotransmitter Agents ; Organophosphates ; Pancreatitis ; Parotitis ; Poisoning* ; Receptors, Muscarinic ; Respiratory System ; Skin ; Synapses

BACKGROUNDOrganophosphate poisoning is an important health problem in developing countries which causes death mainly by inducing acute lung injury. In this study, we examined the effects of penehyclidine hydrochloride (PHC), a selective M-receptor inhibitor, on dichlorvos-induced acute lung injury in swine.

METHODSTwenty-two female swines were randomly divided into control (n = 5), dichlorvos (n = 6), atropine (n = 6), and PHC (n = 5) groups. Hemodynamic data, extravascular lung water index (EVLWI), and pulmonary vascular permeability index (PVPI) were monitored; blood gas analysis and acetylcholinesterase (AchE) levels were measured. PaO2/FiO2, cardiac index (CI), and pulmonary vascular resistance indices (PVRI) were calculated. At termination of the study, pulmonary tissue was collected for ATPase activity determination and wet to dry weight ratio (W/D) testing 6 hours post-poisoning. TUNEL assay, and Bax, Bcl-2, and caspase-3 expression were applied to pulmonary tissue, and histopathology was observed.

RESULTSAfter poisoning, PHC markedly decreased PVRI, increased CI more effectively than atropine. Anticholinergic treatment reduced W/D, apoptosis index (AI), and mitigated injury to the structure of lung; however, PHC reduced AI and caspase-3 expression and improved Bcl-2/Bax more effectively than atropine. Atropine and PHC improved ATPase activities; a significant difference between groups was observed in Ca(2+)-ATPase activity, but not Na(+)-K(+)-ATPase activity.

CONCLUSIONSThe PHC group showed mild impairment in pathology, less apoptotic cells, and little impact on cardiac function compared with the atropine group in dichlorvos-induced acute lung injury.

Acute Lung Injury ; chemically induced ; drug therapy ; Animals ; Dichlorvos ; toxicity ; Female ; Quinuclidines ; therapeutic use ; Swine

OBJECTIVETo develop a method for determining the concentration of dichlorvos in serum by gas chromatography and to provide a basis for clinical diagnosis and monitoring of dichlorvos poisoning.

METHODSThe serum (0.5 ml)collected from patients with dichlorvos poisoning was mixed with ethyl acetate (2.0 ml) and underwent shaking/extraction; the obtained liquid was subjected to standing (5 min) and centrifuging (4000 rpm); the obtained supernatant was collected and blow-dried with nitrogen and was then dissolved in ethanol (50 µl); 1.0 µl of the obtained liquid was collected and loaded into a glass-packed column; gas chromatography was performed using a nitrogen-phosphorus detector.

RESULTSA linear relationship was found when the concentration of dichlorvos in serum was 5.0 ∼ 50.0 µg/ml, with a regression equation of y = 804.13x-691.8 (r = 0.9992). The minimum detectable concentration was 2.0 µg/ml, the recovery rate was 86.8% ∼ 94.5%, the relative standard deviation (RSD) was 4.6% ∼ 5.5%, with an intra-day RSD of 4.52% ∼ 5.21% and an inter-day RSD of 3.56% ∼ 5.52%.

CONCLUSIONThis determination method is easy to operate, efficient, and accurate, and can be used for quickly diagnosing dichlorvos poisoning and quantitatively evaluating treatment outcome.

Chromatography, Gas ; methods ; Dichlorvos ; blood ; Humans ; Serum

BACKGROUNDRespiratory failure is the main cause of death in acute organophosphorus pesticide poisoning. In this study, a pulse-induced contour cardiac output monitor was used to evaluate the respiratory status in a pig model of acute dichlorvos poisoning.

METHODSTwenty female pigs were randomly allocated to dichlorvos (n = 7), atropine (n = 7), and control (n = 6) groups. In the dichlorvos group, pigs were administered 80% emulsifiable dichlorvos (100 mg/kg) via a gastric tube. In the atropine group, pigs were similarly administered dichlorvos, and 0.5 hours later, atropine was injected to attain and maintain atropinization. The control group was administered saline solution. Arterial blood gas was measured at 0, 0.5, 1, 2, 4, and 6 hours post-injection. The extravascular lung water index and pulmonary vascular permeability index were recorded by the pulse-induced contour cardiac output monitor. At termination of the study, the animals were euthanized, the lung wet-to-dry weight ratio was determined, and histopathology was observed.

RESULTSIn the dichlorvos group, the extravascular lung water index and pulmonary vascular permeability index were substantially increased from 0.5 hours and were particularly high within 1 hour. In the atropine group, these indices increased initially, but decreased from the 1-hour mark. The control group exhibited no obvious changes. In both the dichlorvos and atropine groups, the extravascular lung water index was negatively correlated with partial pressure of oxygen/fraction of inspiration oxygen (PO2/FiO2) and positively correlated with the pulmonary vascular permeability index. Compared with the control group, the lung wet-to-dry weight ratio markedly increased and the histopathological findings obviously changed in the dichlorvos group, but only mildly increased and changed, respectively, in the atropine group.

CONCLUSIONThe extravascular lung water index is an appropriate and valuable parameter for assessment of respiratory function in acute dichlorvos poisoning.

Acetylcholinesterase ; blood ; Acute Disease ; Animals ; Dichlorvos ; toxicity ; Extravascular Lung Water ; drug effects ; Female ; Insecticides ; poisoning ; Lung ; pathology ; Respiratory Insufficiency ; chemically induced ; pathology ; Swine

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease involving the motor neuron of the cerebrum, brain stem, and spinal cord. It has been suggested that various occupational or environmental agents could be a cause of ALS. We report upon a case of a person contracting ALS who experienced a long-time exposure to pesticides, implying that pesticides are probable causal agents of ALS. CASE REPORTS: The patient has been experiencing shoulder pain and limitation of movement that started abruptly about three years ago. Over time, these symptoms have become aggravated despite ongoing therapies including medication. After two years, he was diagnosed with ALS through electromyography, nerve conduction velocity and many laboratory tests at a university hospital in Seoul. His social and medical history was non-specific. The patient had worked for about 15 years at a waste disposal site and mainly destroyed glass bottles containing pesticides. During this period, his respiratory tract and skin were exposed to various raw pesticides without appropriate personal protective equipment. He did this job one or two times a week and worked for two or more hours without a break. Through an investigation into the patient's working environment, significant levels of dichlorvos, one of the organophosphates, were detected. CONCLUSIONS: The study results revealed that the patient was exposed to considerable doses of pesticides as opposed to men spraying pesticides. Although controversial, pesticide exposures have been associated with ALS. However, we suggest that in this case the possibility that these pesticide exposures acted as a causal agent for the diagnosed ALS based on plausible biological mechanisms and epidemiologic data.
Amyotrophic Lateral Sclerosis ; Brain Stem ; Cerebrum ; Contracts ; Dichlorvos ; Electromyography ; Glass ; Humans ; Male ; Motor Neurons ; Neural Conduction ; Neurodegenerative Diseases ; Occupational Exposure ; Organophosphates ; Pesticides ; Respiratory System ; Shoulder Pain ; Skin ; Spinal Cord

OBJECTIVETo evaluate the reproduction toxicity of the mixture composed of dichlorvos, dimethoate and malathion synergistic effect on male mice, and further explore its possible mechanisms.

METHODSThe 105 male mice were divided into 7 groups, including control (0 mg/kg), mix low (10.8 mg/kg), mix medium (21.5 mg/kg), mix high dose (43.0 mg/kg), dichlorvos (5.1 mg/kg), dimethoate (12.6 mg/kg) and malathion (25.3 mg/kg) group. The oral gavage for successive 35 days, and the mice were sacrificed on the 36(th) day. The body weight, and the quantity, activity and morphology of sperms were examined. The levels of sexual hormone were measured, including testosterone (T), follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)). Pathological changes of testicle and epididymis were observed by morphology, pathology and electron microscope.

RESULTSAfter 14 days exposure, the body weights of the mice were lower in the mix-high dose group ((22.40 ± 3.07) g) than those in control group ((26.73 ± 2.82) g) (P < 0.05). After 28 days exposure, the body weights of the mice were also lower in the mix-medium dose group ((30.00 ± 4.93) g) than those in control group ((33.13 ± 3.29) g) (P < 0.05). The sperm counts and sperm motility decreased significantly as the toxic concentration arised. Comparing to control group ((373.33 ± 14.65)×10(6)/g weight of epididymis and (75.17 ± 7.68)%), the spermatozoa count and sperm motility had decreased in mix-medium and mix-high dose groups ((321.17 ± 18.19)×10(6)/g weight of epididymis, (225.00 ± 19.67)×10(6)/g weight of epididymis, and (64.67 ± 9.91)%, (57.83 ± 9.66)%), and the sperm abnormality rates were higher in mix-medium and mix-high groups ((43.33 ± 8.66)‰ and (55.00 ± 13.80)‰) comparing to those in control group ((32.67 ± 8.17)‰). Compared to those in control group (FSH (1.41 ± 0.20), E(2)(17.32 ± 2.72), LH (8.75 ± 1.32) and T (3.45 ± 0.80) nmol/L), the serum level of FSH (3.14 ± 0.62) and (3.85 ± 0.37) nmol/L, E(2) (36.81 ± 6.68) and (43.76 ± 9.82) nmol/L in mix-medium and mix-high dose group increased (P < 0.01), while the level of LH (5.21 ± 1.23) and (4.27 ± 1.09) nmol/L and T (1.37 ± 0.38) and (0.73 ± 0.18) nmol/L decreased (P < 0.01). The morphological and ultramicrostructure results of testicle and epididymis indicated that the mature sperm numbers were decreased, and the cacoplastic sperm head and the tail of spermatozoon were observed in mix-high dose groups.

CONCLUSIONThe dichlorvos, dimethoate and malathion mixture had synergistic reproductive toxicity to the testicle and epididymis structure and function, and thus leading to the process of generation cell cytopoiesis abnormalities, simultaneously the hypothalamus-pituitary-gonad axis were also affected and thus resulted in parasecretion.

Animals ; Body Weight ; Dichlorvos ; toxicity ; Dimethoate ; toxicity ; Malathion ; toxicity ; Male ; Mice ; Mice, Inbred ICR ; Organ Size ; Sperm Count ; Sperm Motility ; Spermatozoa ; drug effects ; Toxicity Tests