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1.
Journal of Preventive Medicine ; (12): 543-547, 2024.
Article in Chinese | WPRIM | ID: wpr-1038992

ABSTRACT

Objective@#To explore the effects of different concentrations of glucose solution on the survival of Aedes albopictus and Culex pipiens pallens larvae, the attraction to mosquitoes and egg-laying behaviors, so as to provide the reference for developing mosquito control technology based on sugar bait.@*Methods@#White porcelain bowls were filled with 100 mL of 3%, 5%, 8%, 10% and 15% glucose solutions. Ten of fourth instar larvae of Aedes albopictus or Culex pipiens pallens were added to each bowl, and the survival of larvae was recorded after 2, 4, 6, 24, 48 and 72 hours. Egg-laying cups containing 5%, 8% and 15% glucose solution were put in mosquito cages containing fully blooded female mosquitoes of Aedes albopictus and Culex pipiens pallens (50 mosquitoes each), and the total number of eggs laid in 72 hours was observed. The analogous site room was filled with fully blooded and starved female mosquitoes of Aedes albopictus and Culex pipiens pallens (100 mosquitoes each), and simple mosquito control buckets containing 5% and 8% glucose solution and black sticky insect plates. The number of mosquitoes and eggs was observed after 6 days. All the above experiments were repeated 3 times using dechlorinated water as the control.@*Results@#The 72 hour corrected mortality rates of Aedes albopictus and Culex pipiens pallens larvae gradually increased with the increase of glucose concentration. The glucose solution with 5% and higher concentrations was not suitable for mosquito larvae to survive. The attraction of egg-laying behaviors to Aedes albopictus and Culex pipiens pallens gradually decreased with the increase of glucose concentration. The effects were similar between 5% and 8% glucose solution, with the averages of 686.67 and 682.33 eggs for Aedes albopictus, and 3.00 and 2.33 egg rafts for Culex pipiens pallens. In analogous site room, there were 93.33, 105.00 and 130.33 adult mosquitoes captured on average in the control group, 5% and 8% glucose solution groups, respectively, with 8% glucose solution group more attractive to adult mosquitoes than the control group (F=3.283, P=0.030); there were 70.33, 55.33 and 63.00 Aedes albopictus eggs (eggs counts+larvae counts) on average, respectively, with statistically significant differences among the three groups (H=6.761, P=0.034).@*Conclusion@#Glucose solution with concentration of 5% or higher can effectively inhibit the survival of Aedes albopictus and Culex pipiens pallens larvae, and attractive to adult mosquitoes and egg-laying behavoirs.

2.
Article in Chinese | WPRIM | ID: wpr-1012651

ABSTRACT

ObjectiveTo investigate the infection and genotypes of Wolbachia in Aedes albopictus. MethodsAdult and larval samples of Aedes albopictus were collected from different residential and wild areas from 2020 to 2021, Wolbachia surface protein (wsp) gene was amplified and genotyped for wAlbA and wAlbB by PCR, and sequenced for phylogenetic analysis. The difference of detection rate among different habitats, male and female adult mosquitoes, adult and larvae was compared by χ2 analysis. ResultsThe detection rate of Wolbachia in adult and larvae of Aedes albopictus were 43.5% (77/177) and 70.4% (190/270), respectively, with a statistically significant difference (χ2=32.086,P<0.001), and wAlbA and wAlbB were mainly detected together. The detection rate of Wolbachia in female and male Aedes albopictus were 50.7% (76/150) and 3.7% (1/27), respectively, with a statistically significant difference(χ2=20.533,P<0.001). The detection rate of adult Aedes albopictus in Songjiang wild area, residential area and Hongkou residential area were 91.7% (55/60), 18.8% (22/117) and 41.7% (30/72), respectively, with a statistically significant difference (χ2=54.322,P<0.001). Genotyping and phylogenetic analysis showed that adult and larvae of Aedes albopictus infected with Wolbachia were mainly wAlb A and wAlb B. In addition, some sequences formed clades independently, and the genetic distance from other sequences was relatively large. ConclusionInfection of Wolbachia in Aedes albopictus is relatively common in Songjiang District. The main genotypes are wAlb A and wAlb B and there may be other subtypes, which are worthy of further exploration and research.

3.
Mem. Inst. Oswaldo Cruz ; 119: e240063, 2024. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1575304

ABSTRACT

BACKGROUND The presence of Aedes albopictus in Bolivia has been a subject of controversy, with a lack of concrete documentation. OBJECTIVES This study aimed to provide evidence of Ae. albopictus presence in Bolivia. METHODS Larval habitats were sampled in Rosario del Yata and San Agustín, Guayaramerín Municipality, Beni Department, northern Bolivia. Collected mosquito larvae were reared to the L4 and adult stages for morphological identification, with some specimens sequenced for confirmation. FINDINGS Aedes albopictus was identified in multiple larval habitats within peridomestic areas, such as buckets, canisters, and cut plastic bottles used as flower vases in both localities, confirming its establishment in the area. This represents the first concrete documentation of the species in Bolivia. The collections (larvae and adults) have been deposited in the Medical Entomology Laboratory of the Universidad Mayor de San Simón in Cochabamba, Bolivia, and the Laboratory of Entomology of the Instituto Nacional de Laboratorios de Salud of the Ministry of Health in La Paz, Bolivia. MAIN CONCLUSION Given its role as a vector for arboviruses such as dengue and Chikungunya, Ae. albopictus should be incorporated into the Bolivian National Programme of Vector Control for monitoring.

4.
Article in Chinese | WPRIM | ID: wpr-1016547

ABSTRACT

ObjectiveTo analyze the interannual fluctuation, seasonal fluctuation, habitat distribution and the correlation of the 3 monitoring indicators of Aedes albopictus in Yangpu District of Shanghai from 2017 to 2021, and to provide a scientific basis for A. albopictus control and rational use of the indicators. MethodsThe density surveillance data of A. albopictus recorded by Breteau index (BI), Path index (PI) and the mosquito ovitrap index (MOI) from 2017 to 2021 in Yangpu District, Shanghai were compared. Microsoft Excel 2019 software was used for data summary and SPSS 25.0 software was used for statistical analysis. ResultsFrom 2017 to 2021, there were two months with BI>5, and the PI were all above the density control level of Class C, and there were nine months with MOI≥5. In 2017, BI was higher than in the other four years, with statistically significant differences (all P≤0.001). MOI in 2017 and 2020 was higher than in 2019 (P=0.029, P=0.004) and 2021 (P=0.005, P=0.001), with statistical significance. MOI for different types of habitats varied significantly, with a statistically significant difference (P=0.004). A linear correlation was observed between BI and PI (r=0.462, P=0.010). ConclusionBI, PI and MOI are used simultaneously to reflect the density of A. albopictus in Yangpu District of Shanghai. However, these three monitoring indicators show poor linear correlation. Comprehensively considering the scientific aspects of monitoring methods and seasonal fluctuations of indicators, it is suggested that MOI should be used as the main index to evaluate the density of A. albopictus. In the MOI, attention should be paid to factors such as the distribution of the habitats, the standardization of operating methods, and quality control, which are essential for enhancing the reliability of the MOI.

5.
Article | IMSEAR | ID: sea-233390

ABSTRACT

Background: There are various varieties of habitats that have specific characteristics of water for the breeding of mosquito. A house-to-house cross-sectional entomological survey used to be carried out at per domestic area to become aware of larval breeding sites. Aedes aeygypti used to be primary vector and Aedes albopictus used to be predominant species in container-breeding habitats. Most breeding habitats have been category into excessive stage of larval density. Turbidity, pH, TOC, magnesium, calcium and sodium is amongst the characteristics that indicates a significant difference with larval density and species composition respectively. This study personal based entomological research and funding carried out by corresponding author. Students of zoology department of Rajshahi university involved in this research. Students were working as a research assistant for this study. Aim of this study was to assess determination of prevalence, density and breeding place of Aedes mosquito in Rajshahi city corporation. Methods: This observational study carried out 30 wards in Rajshahi city corporation areas have been surveyed in department of communicable diseases control, director general of health services, Dhaka, Bangladesh. Duration of study 3 years. Total 3 surveys were conducted in each year; pre monsoon, monsoon and post monsoon total 9 surveys conducted by this 3 years survey period. Data entered in MS excel and statistical analysis done by SPSS trial version. Results: This study shows that according to breeding area of 2020-2022. Here, total surveyed household were 8100. Total positive Wet container were 474 and positive place were 473 in these three years survey. Conclusions: Aedes aegypti and Aedes albopictus are properly established inside urban places. Meteorological variables additionally affected mosquito populations. Characteristics of mosquito breeding area can affect larval density and give impact quality of life.

6.
Article | IMSEAR | ID: sea-233214

ABSTRACT

Background: There are various varieties of habitats that have specific characteristics of water for the breeding of mosquito. A house-to-house cross-sectional entomological survey used to be carried out at per domestic area to become aware of larval breeding sites. Aedes aeygypti used to be primary vector and Aedes albopictus used to be predominant species in container-breeding habitats. Most breeding habitats have been category into excessive stage of larval density. Turbidity, pH, TOC, magnesium, calcium and sodium is amongst the characteristics that indicates a significant difference with larval density and species composition respectively. This study personal based entomological research and funding carried out by corresponding author. Students of zoology department of Rajshahi university involved in this research. Students were working as a research assistant for this study. Aim of this study was to assess determination of prevalence, density and breeding place of Aedes mosquito in Rajshahi city corporation. Methods: This observational study carried out 30 wards in Rajshahi city corporation areas have been surveyed in department of communicable diseases control, director general of health services, Dhaka, Bangladesh. Duration of study 3 years. Total 3 surveys were conducted in each year; pre monsoon, monsoon and post monsoon total 9 surveys conducted by this 3 years survey period. Data entered in MS excel and statistical analysis done by SPSS trial version. Results: This study shows that according to breeding area of 2020-2022. Here, total surveyed household were 8100. Total positive Wet container were 474 and positive place were 473 in these three years survey. Conclusions: Aedes aegypti and Aedes albopictus are properly established inside urban places. Meteorological variables additionally affected mosquito populations. Characteristics of mosquito breeding area can affect larval density and give impact quality of life.

7.
Article in Chinese | WPRIM | ID: wpr-965529

ABSTRACT

Objective To investigate the seasonal Aedes population fluctuation and the resistance of Aedes populations to common insecticides in Jiangsu Province in 2020, so as to provide insights into vector-borne infectious diseases control.. Methods One village was randomly sampled from each of Xinbei District of Changzhou City and Zhangjiagang County of Suzhou City in southern Jiangsu Province, Hai’an County of Nantong City and Yandu District of Yancheng City in Central Jiangsu Province, and Suining County of Xuzhou City and Sihong County of Suqian City in northern Jiangsu Province during the period between May and October, 2020. A small ponding container was sampled, and larval Aedes mosquitoes were collected using straws once each in early and late stages of each month. All larvae were bred in laboratory to adults for population identification. In addition, larval breeding were observed in all small ponding containers in and out of 30 households that were randomly sampled from six surveillance sites, and the larval mosquito density was estimated using Breteau index. Larval A. albopictus mosquitoes were sampled around Cuiyuan New Village in Jintan District of Changzhou City, and bred in laboratory to the first offspring generation, and the susceptibility of adult female mosquitoes to deltamethrin, lambda-cyhalothrin, malathion, and propoxur was tested using the filter-paper bioassay recommended by WHO. Results A total of 1 165 larval Aedes mosquitoes were captured from small ponding containers in six surveillance sites of Jiangsu Province in 2020, and all were identified as A. albopictus following eclosion. The largest number of Aedes larvae captured was found in July. A total of 1 152 households were investigated in six surveillance sites, and the mean Breteau indexes were 9.58, 13.20, 13.71, 13.20, 12.18 and 5.58 from May to October, respectively, while a high Aedes transmission risk was seen in Xinbei District of Changzhou City, with a higher Breteau index than in Suining (H = 23.667, Padjusted = 0.001) and Sihong (H = 22.500, Padjusted = 0.003) counties. The field-captured A. albopictus from Cuiyuan New Village in Jintan District of Changzhou City remained sensitive to malathion, but was resistant to propoxur, and developed high-level resistance to deltamethrin and lambda-cyhalothrin. Conclusions A. albopictus was present in southern, central and northern Jiangsu Province in 2020, and the larval density peaked in July. A. albopictus captured from Cuiyuan New Village in Jintan District of Changzhou City has developed high-level resistance to pyrethroid pesticides.

8.
Article in English | LILACS-Express | LILACS | ID: biblio-1431362

ABSTRACT

ABSTRACT Aedes (Stegomyia) albopictus (Skuse, 1854) was reported in Brazil for the first time in 1986 and has shown marked expansion throughout the Brazilian territory. During a routine activity to control dengue fever conducted by the Division of Entomology of the Municipal Health Department in Rio Branco city, adults and immatures of Culicidae were collected in a peri-urban area. The identified Culicidae forms indicated that they belonged to the species Ae. albopictus. This is the first official record of the presence of Ae. albopictus in the Acre State, confirming its current presence in all Brazilian states.

9.
Article in Chinese | WPRIM | ID: wpr-1003823

ABSTRACT

ObjectiveTo develop a new mosquito trap and evaluate its effectiveness in Aedes albopictus monitoring in an urban community. MethodsThe first-round field test was conducted in a well-greened residential neighborhood with high Aedes albopictus density calculated by human landing catch in August 2022, in Minhang District, Shanghai. 65 new test containers with different designs were randomly deployed in the field. These trap containers were designed by different material, color, hole size, shape and top cover colors. The results of mosquito and its egg trapping were observed and recorded continuously for 7 days. In September 2022, the second round of experiment was conducted. After comparison, an optimized trap container was designed. 140 new trap containers were compared with 140 traditional ones to evaluate the effectiveness. SPSS 22.5 software was used for statistical analysis. ResultsThere were significant changes in the outcome of mosquito and its egg trapping on the 4th and 7th day of the pre-experiment deployment of the three kinds of containers. The 200 ml container cup with three round holes in the body had the best effect on trapping mosquitos and eggs, with a positive rate of 45.5% (5/11), while other type of contrainer cup only had a positive rate of 12% (6/50) in trapping mosquitos and eggs. Statistical significant differences (χ2=45.443,P <0.001) existed between the two tpyes of cups within the first kind of trapping container. The second kind of trapping container showed round and oval holes had better effect on mosquito trapping, with a positive rate of 55.6% (5/9). The third kind of hanging container can resist strong wind. The best mosquito trapping effect of three round holes was 66.7% (2/3). The container wall should not be made of rough material, which was easy to cause the escape of adult mosquitoes. Combined with the three types of containers, the new contariner should be top transparent, and the top 1/3 of the side should paint black with 3 round holes. The effective recovery rate of the new container was higher than that of the traditional one under the exclusion of human factors, and had the advantage of preventing rain, wind and rollover, but the effect of trapping mosquito and its egg was comparable to the traditional one(χ2D4=0.197,P=0.658; χ2D7=0.125 ,P=0.724). ConclusionThis new type of mosquito trap is worth further exploration and research, which can improve the trapping efficiency, overall recovery rate and the accurate confirmation of the mosquito density.

10.
Tropical Biomedicine ; : 320-330, 2023.
Article in English | WPRIM | ID: wpr-1006839

ABSTRACT

@#The susceptibility levels of Malaysian Aedes albopictus larvae sampled from several agricultural, fogging-free residential and dengue prone residential areas against different larvicides were evaluated using revised diagnostic doses derived from the 2xLC99 values of the reference strain. Upon 24-hour recovery period of WHO larval bioassay, incipient resistance was observed among Ae. albopictus larvae from rubber estates against fenitrothion (96.67% mortality) and permethin (97.00% mortality) while Ae. albopictus larvae from rice cultivation areas were moderately resistant to fenthion (94.33% mortality). Aedes albopictus larvae from dengue prone residential areas developed moderate to high resistance against dichlorodiphenyltrichloroethane (DDT), fenitrothion, fenthion, propoxur and permethrin (79.67% – 97.33% mortality). Moderate to high resistance were also demonstrated among all populations of Ae. albopictus larvae against temephos and chlorpyrifos (63.00% – 97.67% mortality). Except for Ae. albopictus larvae from oil palm plantations, all Ae. albopictus larval populations were also highly resistant to bendiocarb (65.67% – 89.67% mortality). Cross resistance between larvicides from similar and different insecticide classes were also revealed in this study. The use of revised diagnostic doses established from the local reference strain could reduce the possibility of underestimation or overestimation of the insecticide susceptibility status of field strain populations.

11.
J Vector Borne Dis ; 2022 Jul; 59(3): 198-205
Article | IMSEAR | ID: sea-216887

ABSTRACT

Background & objectives: Recently, the incidences of chikungunya, dengue and Zika infections have increased due to globalization and urbanization. It is vital that reliable detection tools become available to assess the viral prevalence within mosquito populations. Methods: Based on the previous publications on clinical diagnosis in human infections, for the first time, we described a customized triplex RT-qPCR protocol for simultaneous detection of chikungunya virus (CHIKV), dengue virus serotypes 1-4 (DENV1-4) and Zika virus (ZIKV) in mosquitoes. Results: In preliminary assessment to determine the specificity and sensitivity of primers and probes, all six targets were detected individually with the following thresholds as indicated by calculated pfu equivalents: 3.96x100 for CHIKV, 3.80x101 for DENV1, 3.20x101 for DENV2, 8.00x10-1 for DENV3, 1.58x100 for DENV4, and 6.20x100 for ZIKV. When tested in a full combination of six targets (CDZ mix), CHIKV, DENV1-4 mix or ZIKV were all detected with the thresholds of 1.32x100 for CHIKV, 3.79x100 for DENV1-4 and 2.06x100 for ZIKV. All targets, individually or in full combination were detected in the mixtures of Aedes aegypti (L.) homogenate and viral lysates. A robust evaluation with three replicates in each of three plates for CHIKV, DENV1-4 and ZIKV individually or in full combination was conducted. In individual assays, CHIKV was detected to 3.96x10-1, DENV1-4 to 1.14x100 and ZIKV to 3.20x100 . In full combination assays, CHIKV was detected to 1.32x10-1, DENV1-4 to 3.79x101 and ZIKV to 1.07x100 . Interpretation & conclusion: This triplex RT-qPCR assay appears to consistently detect all six targets and does not cross react with Ae. aegypti homogenate, making it a feasible, practical, and immediately adoptable protocol for use among vector control and other entities, particularly in the endemic areas of CHIKV, DENVs and ZIKV.

12.
J Vector Borne Dis ; 2022 Jan; 59(1): 37-44
Article | IMSEAR | ID: sea-216863

ABSTRACT

Zika virus disease is a great concern in different parts of the world, and it has become a Public Health Emergency of International Concern. The global pandemic of ZIKV in 2015 prompted concern among scientific community. Zika is a flavivirus of the family Flaviviridae transmitted by mosquitoes. Natural vertical transmission is an ecological strategy that arboviruses adopt to ensure their survival inside the mosquito vector during harsh conditions or interepidemic periods when horizontal transmission is difficult. ZIKV is vertically transmitted from infected females to its offspring. This review has concluded various studies regarding the vertical transmission ability of different mosquito species for ZIKV. Previously Aedes aegypti was considered to be a major vector, however Aedes albopictus and Culex quinquifasciatus are discovered to have the similar vertical transmission potential. Different studies shown that natural vertical transmission has been detected in mosquito species which are not implicated as possible vectors. It leads to the possibility that many other mosquito species may be potential ZIKV vectors.

13.
China Tropical Medicine ; (12): 1142-2022.
Article in Chinese | WPRIM | ID: wpr-971804

ABSTRACT

@#Abstract: Objective To understand the density changes and seasonal fluctuation of larvae and adults of Aedes albopictus in Hainan Province from 2017 to 2021, and to provide a scientific basis for the prevention and control of dengue fever and other vector-borne diseases in Hainan Province. Methods The Breteau index method was used to monitor the larvae of Aedes mosquitoes, and the breeding sites of all small indoor and outdoor water containers and their larvae was checked and recorded. The adult mosquitoes were monitored by double lamination and light trap. Results A total of 1 962 adult female Aedes albopictus mosquitoes were captured in Hainan Province from 2017 to 2021, accounting for 2.17% of the total captured mosquitoes. There were significant differences in mosquito species composition in different habitats in different years (χ2=312.258, P<0.01). In 2017, the density of mosquitoes in livestock sheds was the highest (9.71 per lamp·night), but the composition ratio of Aedes albopictus was the lowest (1.29%). In 2020, the mosquito density in hospitals was the lowest (2.22 mosquitoes per lamp·night), and in 2019, the proportion of Aedes albopictus in residential areas and hospitals was the highest (3.27% on average).The mosquito density in different habitats was the lowest in 2020. The proportion of Aedes albopictus in residential areas and livestock sheds showed an increasing trend from 2017 to 2021, while the proportion of other habitats showed significant fluctuations. The proportion of Aedes albopictus in hospitals showed an obvious decreasing trend in 2020. From 2017 to 2021, the average mosquito density was 5.97, 4.26, 3.82, 3.39 and 3.68 mosquitoes per lamp·night, respectively, showing a decreasing trend year by year except 2021. Except for 2019, the lure index also showed a decreasing trend, with an average value of 1.5/(hour·net), showing a decreasing trend year by year. From 2017 to 2021, the annual average density of Aedes albopictus in Hainan Province was 0.09 mosquitoes per lamp·night, showing obvious seasonal fluctuation. The Breteau index showed a slow decline from 2017 to 2021, and its annual peak was between June and August, which was 1-2 months later than the peak of adult mosquito density. Conclusions The population density of Aedes albopictus in Hainan shows obvious seasonal characteristics. Mosquito control activities should be carried out according to the seasonal characteristics of mosquitoes to reduce the risk of dengue fever and other infectious diseases.

14.
Ginecol. obstet. Méx ; Ginecol. obstet. Méx;90(4): 364-370, ene. 2022. graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1385034

ABSTRACT

Resumen INTRODUCCION: El dengue es causado por un virus perteneciente a la familia Flaviviridae; existen cuatro serotipos relacionados: DENV-1, DENV-2, DENV-3, DENV-4 trasmitidos por picadura del mosquito hembra de las especies Aedes aegypti y Aedes albopictus. CASO CLÍNICO: Paciente de 19 años, con 36 semanas de embarazo por fecha de la última menstruación y diagnóstico de dengue por serología positiva (Ag-NS1) y trombocitopenia (68,000/mm3). El padecimiento se inició con fiebre de 38.0°C, de tres días de evolución acompañado de artralgias, mialgias, dolor retro ocular y contracciones uterinas. La paciente se ingresó al área de terapia intensiva debido a insuficiencia respiratoria (que ameritó ventilación mecánica invasiva), insuficiencia renal aguda y hematológica, posterior a cesárea. Ameritó reintervención quirúrgica por sangrado intrabdominal por trastornos de la coagulación. Durante su estancia hospitalaria requirió 50 concentrados plaquetarios, 8 concentrados eritrocitarios, 14 plasmas frescos y 4 aféresis plaquetarias. Después de 14 días de estancia hospitalaria se dio de alta por mejoría clínica. CONCLUSIÓN: Si no se actúa inmediatamente, el dengue grave es una causa de desenlace fatal madre-hijo. La identificación oportuna de las complicaciones agregadas a esta enfermedad en la embarazada denota la importancia de la prevención, el diagnóstico temprano y su tratamiento. De igual manera, es importante que en pacientes embarazadas con esta comorbilidad el servicio de Obstetricia intervenga oportunamente en la vigilancia pre y posquirúrgica.


Abstract BACKGROUND: Dengue is caused by a virus belonging to the Flaviviridae family, there are four related serotypes: DENV-1, DENV-2, DENV-3, DENV-4 transmitted by the bite of the female mosquito of the species Aedes aegypti and Aedes albopictus. CLINICAL CASE: 19-year-old female patient, 36 weeks pregnant by date of last menstrual period and diagnosed with dengue due to positive serology (Ag-NS1) and thrombocytopenia (68,000/mm3). The illness started with fever of 38.0°C, of three days of evolution accompanied by arthralgias, myalgias, retro ocular pain and uterine contractions. The patient was admitted to the intensive care unit due to respiratory failure (which required invasive mechanical ventilation), acute renal and hematologic failure, following cesarean section. She required surgical reintervention for intra-abdominal bleeding due to coagulation disorders. During her hospital stay she required 50 platelet concentrates, 8 erythrocyte concentrates, 14 fresh plasmas and 4 platelet apheresis. After 14 days of hospital stay he was discharged due to clinical improvement. CONCLUSION: If no immediate action is taken, severe dengue is a cause of fatal mother-child outcome. The timely identification of the complications associated with this disease in pregnant women highlights the importance of prevention, early diagnosis and treatment. Similarly, it is important that in pregnant patients with this comorbidity, the obstetrics service should intervene in a timely manner in pre- and post-surgical surveillance.

15.
Article in Chinese | WPRIM | ID: wpr-920779

ABSTRACT

Objective Based on mosq-ovitrap monitoring method of Aedes albopictus, to determine the spatial and temporal distribution of Aedes albopictus in Songjiang District and provide scientific evidence for prevention and control of mosquito-borne diseases. Methods From May to October, 2018‒2020, density of Aedes albopictus was monitored by using the mosq-ovitrap method. Sub-districts and towns were used as the monitoring units and the difference in mosquito ovitrap index (MOI) was compared by seasons, years and habitats. Results The total number of positive mosquito ovitraps was 1049 in 2018‒2020, and the average MOI was 8.10. Four sub-districts/towns in the urban area and the northern area had the relatively high MOIs. Moreover, MOIs in residential and external environments were higher than other habitats. In addition, MOI of Aedes albopictus decreased over years from 2018 to 2020. Conclusion Aedes albopictus is widely distributed in Songjiang District. Although the number of mosquito decreased over years after the implementation of mosquito control measures, reproduction of mosquito remains excessive in some areas and seasons. It is necessary to perform targeted control measures based on comprehensive monitoring methods.

16.
Article in Chinese | WPRIM | ID: wpr-920780

ABSTRACT

Objective To determine the seasonal fluctuation and population distribution of Aedes albopictus in Jiading District, and provide scientific evidence for the prevention and control of dengue fever and other Aedes-borne diseases. Methods In 2020, the mosq-ovitrap method and mosq-ovitrap index (MOI) were used to monitor and evaluate the density of Aedes albopictus in Jiading District. Spatial and temporal distribution of Aedes albopictus was determined. Chi-square test was used for statistical analysis. Results In 2020, the annual average MOI was determined to be 4.10, which was under safety threshold. The seasonal fluctuations showed a unimodal distribution, which peaked in July. The fluctuation trend in urban area was similar to the overall trend, while that in the non-urban area showed a bimodal distribution with peaks in June and August. The density of Aedes albopictus at different monitoring sites varied widely,with the highest MOI (6.64) at Anting town and the lowest MOI (2.09) at Huating town. The distribution of Aedes albopictus in different habitats also varied widely; the highest density was observed in environments as waste collection stations and construction sites, with the highest MOI 33.33 in waste collection stations in peak season. The MOI value of Aedes albopictus in residential areas was significantly higher than that in non-residential areas (χ2 = 6.082, P = 0.014). Conclusion Aedes albopictus is quite common in Jiading District. In certain areas, Aedes density may exceed the safety threshold from May to September. More targeted mosquito control measures should be implemented in waste collection stations, construction sites and residential areas.

17.
Article in Chinese | WPRIM | ID: wpr-920781

ABSTRACT

Objective To investigate the resistance development of Aedes albopictus to commonly used insecticides in Yangpu District of Shanghai, China, and to provide scientific bases for the control of A. albopictus and the emergency treatment of dengue fever. Methods The larva immersion method recommended by WHO was used to assay the median lethal concentration (LC50) of A. albopictus larva. SPSS 25.0 was used to calculate the toxicity baselines of insecticides. Results A. albopictus kept a medium resistance to beta-cypermethrin, and the resistance ratios were 14.44, 10.00, 17.78, respectively, in 2015, 2017, 2019. The mosquitos kept a high resistance to permethrin, and the resistance ratios were 54.00, 140.00, 52.00 respectively, in 2015, 2017, 2019. Besides, A. albopictus also kept a medium resistance to propoxur, and the resistance ratios were 15.34, 13.06, 10.83 respectively, in 2015, 2017, 2019. To deltamethrin, A. albopictus showed high resistance in 2015 and medium resistance in 2017, the resistance ratios were 40.00 and 35.00. To temephos, A. albopictus showed low resistance in 2015, with the resistance ratio of 9.38. Conclusion A. albopictus has developed high resistance to permethrin in Yangpu District of Shanghai, and cautious and reduced use of permethrin is suggested. It is necessary to implement and adopt the strategy of comprehensive management, in order to establish the long-term mechanism for mosquito control and prevention.

18.
Article in Chinese | WPRIM | ID: wpr-920782

ABSTRACT

Objective To investigate the type and consumption of sanitary insecticides used in Putuo District of Shanghai, determine the current resistance of Aedes albopictus to the insecticides, and explore the causes of regional variations in insecticide resistance spectrum. Methods Public and private institutions of pest control operation were investigated on the use of sanitary insecticides. Dipping method and tube method were used to measure the insecticide resistance of Aedes albopictus, including larvae and adults. Results The main insecticides used in residential areas and governmental units was β-cypermethrin, while that in markets and public environment was propoxur. In addition, and the insecticides in dengue control program was λ-cyhalothrin. Aedes albopictus larvae had medium resistance to parathion, and were sensitive to propoxur, with insignificant change within three years. Their resistance to permethrin and deltamethrin was medium and high, respectively. Moreover, resistance to β-cypermethrin increased over years. In contrast, resistance of adult Aedes albopictus differed by area, except consistently being sensitive to fenitrothion. Conclusion Multiple sanitary insecticides have been used in Putuo District. In addition, Aedes albopictus has different resistance to these insecticides by area. It suggests that resistance surveillance should be promoted, which may be crucial for scientific application of insecticides and impede the development of potential resistance.

19.
Article in Chinese | WPRIM | ID: wpr-920783

ABSTRACT

Objective To investigate the resistance level of adult Aedes albopictus to commonly used insecticides in urban areas of Huzhou City, and analyze the trend of insecticide resistance. Methods Aedes albopictus larvae were collected from different urban areas of Huzhou City in 2019 and 2020. The larvae were reared to adults for determining resistance using the WHO standard test kits by contact tube method. Results The mortality was 97.06%‒100.00% in adult Aedes albopictus mosquitoes exposed to 0.4% beta-cypermethrin, 0.1% deltamethrin, 0.5% malathion, 0.05% propoxur and 3% permethrin in 2019. While the adult mosquitoes exposed to 0.4% beta Cypermethrin, 0.08% beta Cypermethrin, 0.03% deltamethrin, 0.4% permethrin, 0.5% malathion and 0.02% propoxur in 2020, the adjusted mortality were 98.58%, 89.09%, 85.64%, 91.34%, 91.43% and 100% respectively . When the insecticide doses on medicated paper were high, the Huzhou populations of Aedes albopictus were sensitive to beta-cypermethrin, deltamethrin, malathion and propoxur, and showed suspected resistance to permethrin. While the Aedes albopictus were exposed to low testing dose, they showed suspected resistance to beta-cypermethrin, deltamethrin, permethrin and malathion, but remained to be sensitive to propoxur. Conclusion The adult Aedes albopictus in Huzhou City from 2019 to 2020 was still sensitive to propoxur, but their resistance to malathion changes from sensitive to resistant. When the contact tube method is used for insecticide resistance, it is suggested that the accurate diagnostic dose should be obtained first before conducting further insecticide resistance tests.

20.
China Tropical Medicine ; (12): 866-2022.
Article in Chinese | WPRIM | ID: wpr-980032

ABSTRACT

@#Abstract: Objective  To investigate the population densities composition and seasonal change of mosquitoes, and resistance of Culex pipiens quinquefasciatus and Aedes albopictus several commonly used insecticides in Zigong, so as to provide a theoretical basis for guiding the scientific rational selection and use of chemical insecticides, as well as the prevention and control of mosquito-borne diseases. Methods The surveillance data on mosquitoes by traps were collected from 2018 to 2020 in Zigong. The wild Culex pipiens quinquefasciatus and Aedes albopictus were collected throughout the city and reared to F1 generation in lab. The resistance of adult Culex pipiens quinquefasciatus and Aedes albopictus to these commonly insecticides was detected by contact tube method recommended. The statistical analysis on the monitoring results was used by Excel 2010. Results The annual average mosquito densities of monitoring sites were 1.11, 10.71, and 4.81 mosquitoes/(lamp·h), respectively from 2018 to 2020. The seasonal density of mosquitoes showed a single peak curve distribution throughout the year from 2018 to 2020 in Zigong, with the highest in July. There were obvious differences in mosquito density between different habitats, with the highest density of mosquitoes in barn. The 24 h mortality of Aedes albopictus and Culex pipiens quinquefasciatus to beta-cypermethrin, lambda-cyhalothrin, deltamethrin, permethrin, malathion, fenitrothion, chlorpyrifos, propoxur, and bendiocarb were 70.71% and 3.85%, 26.53% and 1.68%, 19.79% and 1.94%, 40.80% and 0.81%, 97.98% and 3.85%, 100.00% and 7.52%, 100.00% and 66.34%, 96.15% and 33.60%, 100.00% and 71.43%, respectively. The adult Aedes albopictus larvae in Zigong was sensitive to fenitrothion, chlorpyrifos, bendiocarb, showed resistance to beta-cypermethrin, lambda-cyhalothrin, deltamethrin, permethrin, and showed resistance dubiously to malathion and propoxur. The adult Culex pipiens quinquefasciatus larvae in Zigong have developed certain resistance to these commonly insecticides. Conclusion Both Culex pipiens quinquefasciatus and Aedes albopictus had high resistance to pyrethroid insecticides, which suggested that we should strengthen the patriotic hygiene campaigns, reduce pyrethroid insecticides, use alternately different types of insecticides for delay the development of resistance and better mosquito prevention and control.

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