[Study on kdr allele mutation of Culex pipiens pallens in Zichuan District, Zibo City, Shandong Province].

OBJECTIVE: To study the seasonal dynamics of Culex pipiens pallens and the distribution of knockdown resistance (kdr) gene related sodium channel gene polymorphism in Zichuan District, Zibo City, Shandong Province. METHODS: Cx. pipiens pallens mosquitoes were collected in Zichuan District during the peak period of mosquito vector activity from 2017 to 2018. The DNA from Cx. pipiens pallens was extracted, and the genotypes and frequencies of kdr allele mutation were detected by polymerase chain reaction. RESULTS: Totally 830 mosquitoes belonging to six species, including Cx. pipiens pallens, Armigeres subalbatus, Aedes albopictus, Ae. vexans, Anopheles sinensis, and Cx. tritaeniorhchus were collected in this study. The number of Cx. pipiens pallens accounted for 83.13% in total, with the density of 12.32 per lamp per night. The annual density monitoring curve of Cx. pipiens pallens showed a bimodal trend, and the peaks were observed in June and September respectively. In this study, five kdr alleles were detected at the 1 014 locus of kdr gene, with TTA (75.71%), TTT (10.00%), CTA (5.71%), TCA (4.29%), and TTC (4.29%). Two nonsynonymous nucleotide mutations were detected at site 1 014 of kdr gene, namely leucine (L1014) mutated to phenylalanine (L1014F) and serine (L1014S). The kdr gene mutation frequency (%) of Cx. pipiens pallens in Luochun Town and Taihe Town was 10.53% and 40.63%, respectively, and the difference was statistically significant ( χ2 = 8.559, P = 0.003). CONCLUSIONS: Cx. pipiens pallens is the dominant mosquito species in Zichuan District. In addition, two novel mutations, CTA and TTC, are identified in the voltage-dependent sodium channel gene of Cx. pipiens pallens. The kdr genotype of Cx. pipiens pallens in Zichuan area was polymorphic.

Study on kdr allele mutation of Culex pipiens pallens in Zichuan District, Zibo City, Shandong Province / 中国血吸虫病防治杂志

Objective To study the seasonal dynamics of Culex pipiens pallens and the distribution of knockdown resistance (kdr) gene related sodium channel gene polymorphism in Zichuan District, Zibo City, Shandong Province. Methods Cx. pipiens pallens mosquitoes were collected in Zichuan District during the peak period of mosquito vector activity from 2017 to 2018. The DNA from Cx. pipiens pallens was extracted, and the genotypes and frequencies of kdr allele mutation were detected by polymerase chain reaction. Results Totally 830 mosquitoes belonging to six species, including Cx. pipiens pallens, Armigeres subalbatus, Aedes albopictus, Ae. vexans, Anopheles sinensis, and Cx. tritaeniorhchus were collected in this study. The number of Cx. pipiens pallens accounted for 83.13% in total, with the density of 12.32 per lamp per night. The annual density monitoring curve of Cx. pipiens pallens showed a bimodal trend, and the peaks were observed in June and September respectively. In this study, five kdr alleles were detected at the 1 014 locus of kdr gene, with TTA (75.71%), TTT (10.00%), CTA (5.71%), TCA (4.29%), and TTC (4.29%). Two nonsynonymous nucleotide mutations were detected at site 1 014 of kdr gene, namely leucine (L1014) mutated to phenylalanine (L1014F) and serine (L1014S). The kdr gene mutation frequency (%) of Cx. pipiens pallens in Luochun Town and Taihe Town was 10.53% and 40.63%, respectively, and the difference was statistically significant ( χ2 = 8.559, P = 0.003). Conclusions Cx. pipiens pallens is the dominant mosquito species in Zichuan District. In addition, two novel mutations, CTA and TTC, are identified in the voltage-dependent sodium channel gene of Cx. pipiens pallens. The kdr genotype of Cx. pipiens pallens in Zichuan area was polymorphic.

Study on kdr allele mutation of Culex pipiens pallens in Zichuan District, Zibo City, Shandong Province / 中国血吸虫病防治杂志

Objective To study the seasonal dynamics of Culex pipiens pallens and the distribution of knockdown resistance (kdr) gene related sodium channel gene polymorphism in Zichuan District, Zibo City, Shandong Province. Methods Cx. pipiens pallens mosquitoes were collected in Zichuan District during the peak period of mosquito vector activity from 2017 to 2018. The DNA from Cx. pipiens pallens was extracted, and the genotypes and frequencies of kdr allele mutation were detected by polymerase chain reaction. Results Totally 830 mosquitoes belonging to six species, including Cx. pipiens pallens, Armigeres subalbatus, Aedes albopictus, Ae. vexans, Anopheles sinensis, and Cx. tritaeniorhchus were collected in this study. The number of Cx. pipiens pallens accounted for 83.13% in total, with the density of 12.32 per lamp per night. The annual density monitoring curve of Cx. pipiens pallens showed a bimodal trend, and the peaks were observed in June and September respectively. In this study, five kdr alleles were detected at the 1 014 locus of kdr gene, with TTA (75.71%), TTT (10.00%), CTA (5.71%), TCA (4.29%), and TTC (4.29%). Two nonsynonymous nucleotide mutations were detected at site 1 014 of kdr gene, namely leucine (L1014) mutated to phenylalanine (L1014F) and serine (L1014S). The kdr gene mutation frequency (%) of Cx. pipiens pallens in Luochun Town and Taihe Town was 10.53% and 40.63%, respectively, and the difference was statistically significant ( χ2 = 8.559, P = 0.003). Conclusions Cx. pipiens pallens is the dominant mosquito species in Zichuan District. In addition, two novel mutations, CTA and TTC, are identified in the voltage-dependent sodium channel gene of Cx. pipiens pallens. The kdr genotype of Cx. pipiens pallens in Zichuan area was polymorphic.

[Diffusion, population dynamics and potential distribution of Armigeres subalbatus].

OBJECTIVE: To investigate the diffusion trend of Armigeres subalbatus and analyze its potential geographic distribution in China. METHODS: The trend analysis of diffusion and population dynamics were carried out based on three aspects including literature reports, information of museum specimens and new collection records from our field survey. To compare the potential geographic distribution, two ecological niche models were constructed by Maxent software based on the geographic presence occurrence data and 20 environmental variables. The final models were evaluated with the receiver operating characteristics curve (ROC). The analyses of variable contributions were confirmed by using the Jackknife method. RESULTS: The populations in Weifang and Weihai, Shandong Province were reported for the first time. The results showed that this species was spread to the Palaearctic Northern Region and reached 42° north latitude regions. In some areas, it gradually developed into a dominant species. A total of 294 georeferenced occurrence points of A. subalbatus were found out. Two predictions of Maxent models were established based on the presence occurrence data in 2000 and 2016, respectively. The results showed that the current distribution range of A. subalbatus had been significantly northward expanded compared with 2000. It means that the potential suitable area gradually spread northward. The ROC analysis results showed the AUC values were 0.980 and 0.982, and it indicated that the models had a high reliability. The Jackknife method displayed that the precipitation of warmest quarter, precipitation of wettest month and precipitation of wettest quarter were the dominant environmental variables that mainly contributed to the distribution of A. subalbatus. CONCLUSIONS: A. subalbatus distribution gradually spreads northward, and climate warming is probably the main reason for the diffusion. It could affect the local mosquito species composition and increase the risk of mosquito-borne disease transmission.

[Investigation of tick bites in outpatients with fever from health care facilities in Tengchong County].

OBJECTIVE: To study the prevalence of tick bites and relative factors of outpatients with fever from health care facilities in Tengchong County. METHODS: From July to August, 2014, the outpatients with fever in five health care facilities namely Tengchong Center for Disease Control and Prevention, Hehua Health Center, Jietou Health Center, Qushi Health Center and Xinhua Health Center were investigated by questionnaires. The factors related to tick bites were explored with the univariate analysis and multiple regression models. RESULTS: Totally 884 effect questionnaires were acquired. Among the 884 participants, 85 (9.6%) had experienced tick bites. The frequency of tick bites was associated with locations, gender, age group, ownership of cattle, working at foreign country, firewood cutting and lumbering in the forest (all P < 0.05). The multiple regression revealed that the male and people raising cattle, working at foreign country, engaging in firewood cutting and lumbering in the forest had a more risk for tick bites. CONCLUSIONS: Tick bites are common in the residents of Tengchong County. The risk of being bitten varies in different populations. The local health departments should promote health education in the high-risk population to reduce the risk of infecting tick-borne diseases.

Public health situation and needs assessment after Wenchuan earthquake in Anxian, Sichuan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the public health situation and needs in Anxian after Wenchuan earthquake so as to make an effective strategy for disease control and prevention.</p><p><b>METHODS</b>69 concentrated settlements with 100 residents were investigated. Probability proportion to size was adopted for sampling of 2200 residents from 687 scattered households (about 440 000 scattered residents). The content of this survey included drinking water, food hygiene, environment sanitation, planning immunity and medical health service, disease surveillance and so on. SPSS 16.0 was used for data analysis, and statistical interpretation was used to describe the results.</p><p><b>RESULTS</b>90.9% (31/66) resettled residents in Anxian lived in tents, 7.6% (5/66) lived in the movable-plate house, 93.3% (621/666) scattered households lived in tents and 71.9% (446/621) of them lived in tents which were built by residents themselves; the rate of drinking water disinfection in resettlement sites and scattered households were 97.1% (66/68) and 94.6% (650/687); 12.8% scattered residents had mouldy or food; 50% of resettlement sites raised animals; 43.6% (17/39) medical station didn't have bacterin inoculation service; 66.7% (10/15) lacked sufficient disinfection equipment; register rate was 50.0% (33/66) and report rate of symptoms and infectious diseases was 56.1% (37/66).</p><p><b>CONCLUSION</b>There was still some risk of enteric and vector-borne diseases in Anxian, therefore, some tailored measures should be very important.</p>

Mental health assessment among scattered residents after Wenchuan earthquake in Anxian, Sichuan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the mental health status of residents scattered living in Anxian after Wenchuan earthquake so as to provide scientific basis for further mental health intervention.</p><p><b>METHODS</b>A face to face interview was conducted among the scattered residents with designed questionnaire, which had three parts of the physical and emotional reaction, the relax methods and the social care and supports expected. Two-stage probability proportional to size (PPS) sample method was performed to sample 2184 from 0.44 million scattered residents in Anxian. On the basis of statistical description, mental health of different characteristics groups was compared.</p><p><b>RESULTS</b>Three main symptoms of posttraumatic stress disorders in 2184 residents (11.23+/-3.44) were higher than the 103 fire victims in Hunan in 2003 (10.06+/-3.26), three factor scores of SCL-90 (5.76+/-1.74) were higher than normal in 1998 repair mode (n=23 891) (4.72+/-1.44), and the statistical difference was observed (t=10.77, P<0.05; t=706.04, P<0.05). Comparing the mental health of different groups, some significant differences were found by age, gender and education background.</p><p><b>CONCLUSION</b>The earthquake disaster brought prevalent physical and emotional reaction. Elderly people, female, junior students need mental intervention immediately. Therefore, strengthen the mental education and assistance (especially in high risk groups) would be of more significance.</p>