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*

The research of 108 patients taken organophosphate to kill oneself who were treated by the new regimen in which, pralidoxime (PAM) were indicated according to poisoning level and adjusted by two factors: the change of plasma ChE and the adjustment of essential atropine dose. The results were compared with control groups including 54 patients treated by old regimen. Age, sex and ChE activity characteristics in 2 groups when hospitalized were the same. Compared with control group, the patients of study group received higher doses of PAM. The doses are very different between the patients depending on poisoning level. Therefore, predictive indicators in patient group were better than controlled group, especially the mortality rate (1.85% vs. 13%). The regimen achieved good results
Phosphoric Acid Esters ; Mortality ; Phosphoric Acid Esters ; Poisoning

Animals ; Chromatography, Thin Layer ; Dichlorvos ; blood ; Dimethoate ; blood ; Insecticides ; blood ; Methyl Parathion ; blood ; Mice ; Organothiophosphorus Compounds ; blood

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

The workers in insecticide factory generally are exposed to organophosphate insecticide chemicals while working in the plants. We have investigated the effects of organophosphate insecticides on the activities of some erythrocyte antioxidant enzymes, total antioxidant status and lipid peroxidation in the blood of the insecticide producing workers. The results: (1) erythrocyte superoxide dismutase (SOD) and glutathione reductase (GR) activities were significantly depressed by 37.64% and 28.55%, respectively while serum cholinesterase (ChE) activity was only depressed by 13.47% as compared with an unexposed group; (2) erythrocyte glutathione peroxidase (GPx) was increased significantly; (3) serum total antioxidant status (TAS) was depressed by 9.86% (p>0.05). This preliminary study suggests that erythrocyte SOD may be a sensitive indicator of exposure to organophosphate insecticides.
Phosphoric Acid Esters ; Insecticides ; Erythrocytes ; Antioxidants

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

OBJECTIVETo observe the treatments on the patients with acute methamidophos dichlorvos (DDV) and omethoate poisoning and provide the reliable basis for the rational treatments on these three organophosphorus pesticides poisoning.

METHODS101 patients with AOPP in 7 hospitals were divided into three groups: Group A, 59 patients with acute methamidophos poisoning, Group B, 32 patients with acute DDV/dipterex (DEP) poisoning, Group C, 10 patients with acute omethoate/dimethoate poisoning. The levels of erythrocyte AChE and the therapeutic efficacies of pralidoxime chloride (PAM-Cl) were compared among the three groups.

RESULTSThe AChE activities of all the three groups were inhibited on level of (9.12 +/- 7.99) U/g Hb (group A), 7.32 +/- 4.62 U/g Hb (group B) and (12.01 +/- 9.53) U/g Hb (group C), among which no significant difference was found (P > 0.05). All the patients recovered from acute cholinergic excitation or crisis after the treatment of PAM-Cl. The erythrocyte AChE activities were obviously reactivated in group A three hours later after admission to hospital, each on level of (11.37 +/- 8.67) U/g Hb, (12.51 +/- 6.98) U/g Hb, (15.90 +/- 7.31) U/g Hb, (18.33 +/- 4.78) U/g Hb and (18.91 +/- 7.00) U/g Hb at the 12th, 24th, 48th, 72nd hour and discharge (P < 0.05), and the upgrade tendency was continuous. AChE activities in group B were also reactivated after treatment, each on level of (8.91 +/- 5.89) U/g Hb, (1.31 +/- 6.61) U/g Hb, (13.00 +/- 7.55) U/g Hb, (14.22 +/- 7.80) U/g Hb, (12.78 +/- 7.07) U/g Hb and (16.87 +/- 7.06) U/g Hb at the 3rd, 12th, 24th, 48th, 72nd hour and discharge, but the upgrade tendency turned slowly after 12 hours, the inhibited AChE activities were not reactivated in group C from the beginning to the end.

CONCLUSIONAfter the treatment of PAM-Cl, the AChE activities of the patients with acute methamidophos poisoning could be continuously reactivated, the AChE activities of the patients with acute DDV/DEP poisoning could also be reactivated in 12 hours, and then keep stable, but the AChE activities of the patients with acute omethoate/dimethoate poisoning could not be reactivated. However, PAM-Cl has therapeutic efficacy against acute toxicity of all the three organophosphorus pesticides. Oximes should be vigorously used in the treatment of AOPP, including acute omethoate/dimethoate poisoning.

Acetylcholinesterase ; metabolism ; Acute Disease ; Adult ; Cholinesterase Reactivators ; therapeutic use ; Dichlorvos ; poisoning ; Dimethoate ; analogs & derivatives ; poisoning ; Female ; Humans ; Male ; Middle Aged ; Organophosphate Poisoning ; Organothiophosphorus Compounds ; poisoning ; Pralidoxime Compounds ; therapeutic use ; Retrospective Studies

A modified electrometric method was described and validated for measurement of plasma and erythrocyte cholinesterase activities in 6~18 months old goats. The enzymatic reaction mixture contained 3 ml distilled water, 3 ml barbital-phosphate buffer (pH 8.1), 0.2 ml plasma or erythrocytes and 0.1 ml acetylthiocholine iodide (7.5%) as a substrate. The mixture was incubated at 37 degrees C for 40 minutes. The pH of the reaction mixture was determined by a pH meter before and after the incubation. The initial pH was measured before the substrate addition. The enzyme activity was expressed as deltapH/40 min. The coefficients of variation of the described method in measuring plasma and erythrocyte cholinesterase activities were 4 and 2%, respectively. Preliminary reference values (n = 14) of the mean cholinesterase activity (deltapH/40 min) and 95% confidence interval in the plasma were 0.194 and 0.184~ 0.204, respectively, and those of the erythrocytes were 0.416 and 0.396~0.436, respectively. The pseudocholinesterase activity of the plasma cholinesterase was 63.5% as determined by quinidine sulfate inhibition. The organophosphorus insecticides dichlorvos and diazinon at 0.5~4 micrometer and the carbamate insecticide carbaryl at 5~20 micrometer in the reaction mixture significantly inhibited plasma (13.7~85.5%) and erythrocyte (16.4~71.9%) cholinesterases in vitro in a concentration-dependent manner. The results suggest that the described electrometric method is simple, precise and efficient in measuring blood cholinesterase activity in goats.
Acid-Base Equilibrium/physiology ; Animals ; Carbaryl/pharmacology ; Cholinesterase Inhibitors/pharmacology ; Cholinesterases/*blood/drug effects ; Diazinon/pharmacology ; Dichlorvos/pharmacology ; Enzyme Activation/drug effects/physiology ; Erythrocytes/metabolism ; Goats/*blood ; Plasma/metabolism

This study was carried out to obtain the basic data for the preverition of chronic poisoning by organic phosphate pesticides. 6 sprayers who participated in the summer pest control programs of Jeonju city were chosen as the subjects in this study. Pesticides which were spread in the period of study are DDVP (1.09%), dursban (1.8%) and dibrom (1.9%). And from May 16, 1983 to Aug. 22, 1983, plasma cholinesterase activity, hematological and biochemical parameters were measured with several physical examinations for each sprayers and controls. Majors findings are as following; 1. Before pesticides were sprayed, plasma cholinesterase were 7.32+/-6 microM/20microliter/hr. in sprayers and 7.13+/-1.39 microM/20 microliter/hr. in the control group(p>0.05). 2. At 60th day of spraying, plasma cholinesterase activity of sprayers was 6.78+/-2.01 microM/20 microliter/hr. Which is significantly decreased from the pre-exposed value(p<0.01), but plasma cholinesterase activity in the control group was not changed. 3. The specific findings which suggested to organophosphorous poisoning were not found through the period of study. 4. Hematological and bichemical parameters were not significantly changed in the both groups.
Chlorpyrifos ; Cholinesterases* ; Dichlorvos ; Jeollabuk-do ; Naled ; Occupations* ; Pest Control ; Pesticides* ; Physical Examination ; Plasma* ; Poisoning

The aquatic quality of the Naktong river after two of three months in June, 1991 with phenol spillage from a electrical factory in Kumi was investigated. The samples were collected at six sites of the Naktong river basin and Kachang and Kongsan lakes. Phenol was not detected from all water samples. Turbidity was very much increased to the down stream in the Naktong river. The BOD and COD values exceeded the 2nd grade(3 mg/l) of the Korean standard quality of Environmental Water Act at the all sampling sites of the Naktong river. Especially, the value of COD at Kaejin (12.5 mg/l) was poorly classified as to the 5th grade of water class for the environmental quality standards. Organophosphorous pesticides such as parathion, malathion, fenitrothion and diazinon were investigated but not detected. Diazinon was only detected at the Ilson bridge(1.42 ppb), Okkye stream(6.95 ppb), Waekwan bridge(0.32 ppb), Gangjung reservior(0.13 ppb), Kaejin(0.05 ppb). Of the carbamates such as carbanyl, isoprocarb and cabofuran, the carbofuran was detected all sites except tap water, and Kachang and Kongsan lakes. The content of heavy metals such ans Cd, Pb, Zn, Fe, Mn, Hg were not exceeding for drinking water standards at the all sampling region, but only mecury was detected from Okkye stream(0.018ppb) and Kaejin(0.09ppb). In the regions of Kachang and Kongsan lakes, the content of heavy metals were lower than that of reservoir of Naktong river.
Carbamates ; Carbofuran ; Diazinon ; Drinking Water ; Fenitrothion ; Gyeongsangbuk-do* ; Korea* ; Lakes ; Malathion ; Metals, Heavy ; Parathion ; Pesticides ; Phenol* ; Rivers* ; Water ; Water Quality