An aquaporin and an aquaglyceroporin have roles in low temperature adaptation of mosquitoes (Anopheles sinensis).

Mosquitoes (Anopheles sinensis), widely geographically distributed in Asia including China, are the primary vector of the malaria parasite Plasmodium vivax and other parasitic diseases such as Malayan filariasis. An. sinensis can survive through low winter temperatures. Aquaporin channels are found in all life forms, where they facilitate environmental adaptation by allowing rapid trans-cellular movement of water (classical aquaporins) or water and solutes such as glycerol (aquaglyceroporins). Here, we identified and characterized 2 aquaporin (AQP) homologs in An. sinensis: AsAQP2 (An. sinensis aquaglyceroporin) and AsAQP4 (An. sinensis aquaporin). When expressed in frog (Xenopus laevis) oocytes, AsAQP2 transported water, glycerol, and urea; AsAQP4 transported only water. Water permeation through AsAQP2 and AsAQP4 was inhibited by mercuric chloride. AsAQP2 expression was slightly higher in adult female mosquitoes than in males, and AsAQP4 expression was significantly higher in adult males. The 2 AsAQPs were highly expressed in Malpighian tubules and midgut. AsAQP2 and AsAQP4 expression was up-regulated by blood feeding compared with sugar feeding. At freezing point (0 °C), the AsAQP4 expression level increased and An. sinensis survival time reduced compared with those at normal temperature (26 °C). At low temperature (8 °C), the AsAQP2 and AsAQP4 expression levels decreased and survival time was significantly longer compared with those at 26 °C. These results suggest that AsAQP2 and AsAQP4 have roles in water homeostasis during blood digestion and in low temperature adaptation of A. sinensis. Together, our results show that the 2 AQPs are important for mosquito diuresis after blood feeding and when exposed to low temperatures.

Study of Township Construction Land Carrying Capacity and Spatial Pattern Matching in Loess Plateau Hilly and Gully Region: A Case of Xifeng in China.

With the acceleration of urbanization, the construction land scale of urban and rural areas is constantly expanding, which leads to contradiction and conflict between territorial development and ecological protection becoming more and more serious. Therefore, as an important unit of county (district), and even urban and rural, development, the study on land resource carrying capacity and the rationality of the development can provide some basis for developing the optimal strategies of differential territorial space. Taking Xifeng, Gansu Province, China as the research area, this study constructs the evaluation index system of township construction land carrying capacity from the three dimensions of ecological protection, natural environment, and social economy. It evaluates the suitability of township construction land by the means of a comprehensive scoring method and discusses the carrying capacity and spatial pattern matching of township construction land based on the suitability evaluation results. The results showed that: (1) the spatial difference of suitability of construction land is obvious, which is higher in the city center than in the surrounding areas; (2) the comprehensive carrying capacity of township construction land is 52.62%, and different townships range from 3.78% to 13.15%. It is different between towns; (3) on the whole, the condition of township construction land is well-developed, and the main distribution forms are flaky, banded, and dotted. (4) There is a positive correlation between spatial matching and carrying capacity. The carrying capacity should be considered in regional development to avoid overdevelopment. It can provide a basis for optimizing the territorial spatial layout, strengthening the coordinated development among townships, and improving the comprehensive township carrying capacity in the Loess Plateau hilly and gully region.

Differential metabolome responses to deltamethrin between resistant and susceptible Anopheles sinensis.

Insecticide-based vector control measures play an important role in the prevention and control of insect-borne infectious diseases such as malaria; however, insecticide resistance has become a severe global problem for vector control. To date, the metabolic mechanism by which Anopheles sinensis, the most widely distributed malaria vector in China and Asia, detoxifies insecticides is not clear. In this study, the molecular metabolite changes in both the larval and adult stages of deltamethrin susceptible (DS) and deltamethrin-resistant (DR) An. sinensis mosquitoes were analysed by using liquid chromatography tandem mass spectrometry (LC-MS/MS) after exposure to deltamethrin. There were 127 differential metabolites in larval DR An. sinensis and 168 in adults. Five metabolites (glycerophosphocholine, deoxyguanosine, DL-methionine sulfoxide, D-myo-inositol-3-phosphate and N-acetyl-alpha-D-glucosamine1-phosphate) were downregulated in both DR larvae and adults, and one metabolite (aspartyl-glutamine) was upregulated, and the ratio of down- and up-regulation of these metabolites was 5:1. The differential metabolites between the DS and DR mosquitos were mainly classified into organic oxygen compounds, carboxylic acids and their derivatives, glycerophospholipids and purine nucleotides, and the common pathway enriched in both the larval and adult DR An. sinensis was glycerophospholipid metabolism. The findings of this study provide further mechanistic understanding of insecticide resistance in An. sinensis.

The complete mitochondrial genome of major malaria vector Anopheles anthropophagus (Diptera: Culicidae) in China.

Anopheles anthropophagus (Xu and Feng 1975) is the major vector of malaria in Eastern and Southern China. The species An. anthropophagus is considered a synonym of An. lesteri (Baisas & Hu, 1936), although they differ in several key biological characteristics. Here, we report the complete mitochondrial genome of An. anthropophagus for the first time. The mitogenome of An. anthropophagus is a typical circular, double-stranded molecule with a total length of 15,413 base pairs, and contains 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and an AT-rich control region. A phylogenetic analysis of the complete mitogenomes of 16 species of Anopheles (Culicidae) revealed that An. anthropophagus is closely related to An. sinensis (Wiedemann 1828), in the family Culicidae. The An. anthropophagus mitogenome provides new data for further taxonomic and phylogenetic studies of the genus Anopheles.

[Analysis of Causes and Condition of Blood Donation Reaction Under Collective Emergency Blood Donation].

OBJECTIVE: To explore the causes and specific conditions of blood donation reaction under the collective emergency unpaid blood donation, and to provide theoretical basis and decision-making reference for drafting the collective emergency unpaid blood donation and blood donation safety. METHODS: Through a combination of prospective and retrospective models, and statistical methods were used to analyze the causes and conditions of the blood donation response of 10401 people participating in collective emergency unpaid blood donation during 2016.1-2018.8. RESULTS: A total of 10401 person-times donated blood in a sitting manner, and a total of 293 blood donation reactions occurred. By improving the blood donation services year by year, the moderate blood donation reaction during the year 2017 and 2018 was significantly lower than that in 2016 (P＜0.05). In the actual blood donation group of≤100, 200, 300 and 400 ml, the incidence of blood donation reaction was statistically significant (P＜0.05); the incidence of blood donation reaction in the blood donors for 1,2,3 and ＞3 drnations was also statistically significant (P＜0.05); the blood donation reactions rate of B antigen containers was significantly different from the donors without B antigen (P＜0.05); the incidence of blood donation reaction with related to the weight of the donor. CONCLUSION: The blood donation reaction of collective emergency unpaid blood donation closely relates with mental factors, blood donation service, blood donation frequency and body weight of the blood donor. The first blood donation is more likely to produce blood donation reaction. The blood donation volum≤ 100 ml from blood donors is resulted mostly from blood donation reactions.

[Research Progress in Acute Hemolysis and Safe Blood Transfusion of Glucose-6-Phosphate Dehydrogenase Deficiency-Review].

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is one of hereditary diseases sariously influencing the human health. G6PD is characterized by wide distribution, high incidence, inducing the hemolysis, complex mechanism of hemolysis and common occurence in children and so on. The blood transfusion is most effective method for acute ouset of hemolysis, but the risk is more high, thereby it is necessary to guarante the safety of blood transfusion. In addition of the routine managementin blood transfusion and standard procedures, the basic rules and indicators of blood transfusion must be grasped, the blood preparations should be known well, the blood protection must be strengthened, and the measures of personalized psychologic interference must be drawn up carnestly and performed strictily so as to improve the therapeutic efficacy and safe of blood transfusion. Through the promotion and development of social pubbicity, elucation activities, preventive and control measures and medical levels, many patients have been freed from healthy problems as soon as possible. In this review, the research progress on acute hemolysis and safe blood transfusion in G6PD are summarized.

Monitoring of malaria vectors at the China-Myanmar border while approaching malaria elimination.

BACKGROUND: Tengchong County was one of the counties located at the China-Myanmar border with high malaria incidence in the previous decades. As the pilot county for malaria elimination at the border area, Tengchong County is aiming to be the first county to achieve malaria elimination goal. A cross-sectional entomological survey was carried out to evaluate the feasibility of elimination approach and assess the receptivity of malaria reintroduction. METHODS: Light traps associated with live baits were used to investigate the abundance of adult mosquitoes in nine villages in Tengchong County. Light traps were set to collect adult mosquitoes in both human houses and cowsheds from dusk till dawn in each site. RESULTS: A total of 4948 adult Anopheles mosquitoes were collected from May to December in two villages. Of the mosquitoes were captured, 24.2% were in human houses and 75.8% in cowsheds. The peak of abundance occurred in July for An. sinensis and in September-October for An. minimus (s.l.) Ten Anopheles species were collected, the most prevalent being An. sinensis (50.3%), An. peditaeniatus (31.6%) and An. minimus (s.l.) (15.8%), contributing to 97.6% of the sample. Potential breeding sites were also investigated and a total of 407 larvae were collected, with An. sinensis (50.1%) and An. minimus (s.l.) (46.2%) as predominant species. Ponds and rice fields were the two preferred breeding sites for Anopheles mosquitoes; however, the difference between the number of adults and larvae captured suggest other breeding sites might exist. Both An. sinensis and An. minimus (s.l.) were found zoophilic with human blood index as 0.21 and 0.26, respectively. No Plasmodium positive Anopheles specimens were found by PCR among 4,000 trapped mosquitoes. CONCLUSIONS: Although no indigenous malaria cases have been reported in Tengchong County since 2013, there is still a risk from the presence of vectors in the context of human population movements from neighboring malaria endemic areas. The presence of An. sinensis, associated to rice fields, is particularly worrying. Sustained entomological surveillance is strongly suggested even after malaria elimination certification.

Return of chloroquine sensitivity to Africa? Surveillance of African Plasmodium falciparum chloroquine resistance through malaria imported to China.

BACKGROUND: Chloroquine (CQ) was the cornerstone of anti-malarial treatment in Africa for almost 50 years, but has been widely withdrawn due to the emergence and spread of resistance. Recent reports have suggested that CQ-susceptibility may return following the cessation of CQ usage. Here, we monitor CQ sensitivity and determine the prevalence of genetic polymorphisms in the CQ resistance transporter gene (pfcrt) of Plasmodium falciparum isolates recently imported from Africa to China. METHODS: Blood samples were collected from falciparum malaria patients returning to China from various countries in Africa. Isolates were tested for their sensitivity to CQ using the SYBR Green I test ex vivo, and for a subset of samples, in vitro following culture adaptation. Mutations at positions 72-76 and codon 220 of the pfcrt gene were analyzed by sequencing and confirmed by PCR-RFLP. Correlations between drug sensitivity and pfcrt polymorphisms were investigated. RESULTS: Of 32 culture adapted isolates assayed, 17 (53.1%), 6 (18.8%) and 9 (28.1%) were classified as sensitive, moderately resistant, and highly resistant, respectively. In vitro CQ susceptibility was related to point mutations in the pfcrt gene, the results indicating a strong association between pfcrt genotype and drug sensitivity. A total of 292 isolates were typed at the pfcrt locus, and the prevalence of the wild type (CQ sensitive) haplotype CVMNK in isolates from East, South, North, West and Central Africa were 91.4%, 80.0%, 73.3%, 53.3% and 51.7%, respectively. The only mutant haplotype observed was CVIET, and this was almost always linked to an additional mutation at A220S. CONCLUSIONS: Our results suggest that a reduction in drug pressure following withdrawal of CQ as a first-line drug may lead to a resurgence in CQ sensitive parasites. The prevalence of wild-type pfcrt CQ sensitive parasites from East, South and North Africa was higher than from the West and Central areas, but this varied greatly between countries. Further surveillance is required to assess whether the prevalence of CQ resistant parasites will continue to decrease in the absence of widespread CQ usage.

The increasing importance of Plasmodium ovale and Plasmodium malariae in a malaria elimination setting: an observational study of imported cases in Jiangsu Province, China, 2011-2014.

BACKGROUND: Following initiation of China's National Malaria Elimination Action Plan in 2010, indigenous malaria infections in Jiangsu Province decreased significantly. Meanwhile imported Plasmodium infections have increased substantially, particularly Plasmodium ovale and Plasmodium malariae. Given the risk for malaria resurgence, there is an urgent need to understand the increase in imported P. ovale and P. malariae infections as China works to achieve national malaria elimination. METHODS: An observational study of imported malaria cases in Jiangsu Province, China was carried out for the period of 2011-2014. RESULTS: A total of 1268 malaria cases were reported in Jiangsu Province from 2011 to 2014. Although imported Plasmodium falciparum cases (n = 1058) accounted for 83.4 % of all reported cases in Jiangsu, P. ovale cases (14, 19, 30, and 46) and their proportion (3.7, 9.6, 8.8, and 13.0 %) of all malaria cases increased over the 4 years. Similarly, P. malariae cases (seven, two, nine, and 10) and proportion (1.9, 1.0, 2.6, and 2.8 %) of all malaria cases increased slightly during this time. A total of 98 cases of Plasmodium ovale curtisi (47/98, 48 %) and Plasmodium ovale wallikeri (51/98, 52 %) were identified as well. Latency periods were significant among these Plasmodium infections (p = 0.00). Also, this study found that the latency periods of P. ovale sp., P. malariae and Plasmodium vivax were significantly longer than P. falciparum. However, for both P. ovale curtisi and P. ovale wallikeri infections, the latency period analysis was not significant (p = 0.81). Misdiagnosis of both P. ovale and P. malariae was greater than 71.5 and 71.4 %, respectively. The P. ovale cases were misdiagnosed as P. falciparum (35 cases, 32.1 %), P. vivax (43 cases, 39.4 %) by lower levels of CDCs or hospitals. And, the P. malariae cases were misdiagnosed as P. falciparum (ten cases, 35.7 %), P. vivax (nine cases, 32.1 %) and P. ovale sp. (one case, 3.6 %). Geographic distribution of imported P. ovale sp. and P. malariae cases in Jiangsu Province mainly originated from sub-Saharan Africa such as Equatorial Guinea, Nigeria, and Angola. CONCLUSIONS: Although the vast majority of imported malaria cases were due to P. falciparum, the increase in other rare Plasmodium species originating from sub-Saharan Africa and Southeast Asia should be closely monitored at all levels of health providers focusing on diagnosis and treatment of malaria. In addition to a receptive vector environment, long latency periods and misdiagnosis of P. malariae and P. ovale sp. increase the risk of re-introduction of malaria in China.

[Effect of different temperatures on development of Aedes albopictus].

OBJECTIVE: To explore the effect of different temperatures on the different development stages of Aedes albopictus. METHODS: The changes at different development stages of mosquitoes (egg, larva, pupae) and gonotrophic cycle were observed at different temperature conditions of 10, 15, 20, 25, 30, 35 °C and 40 °C. The full developmental cycles were compared during different temperatures. RESULTS: All the stages of the mosquitoes could not develop at 10 °C. Under the different temperatures of 15, 20, 25, 30, 35 °C and 40 °C, the hatchabilities of the mosquitoes were 0, 32%, 82%, 83%, 82% and 59% respectively; the pupation rates of the mosquitoes were 38%, 53%, 84%, 88%, 72% and 42% respectively; and the emergence rates of the mosquitoes were 92%, 95%, 97%, 97%, 83% and 17% respectively. The mosquitoes could well develop at 20, 25, 30 °C and 35 °C, the development time was 37.73, 18.50, 16.92 and 13.66 days respectively. CONCLUSION: The development time of Aedes albopictus is shorter at the higher temperature. The optimum temperature for the mosquitoes to develop is between 25-30 °C, and higher or lower the temperatures will suppress the development of the mosquitoes.

Risk factors for hepatitis B and C infection among blood donors in five Chinese blood centers.

BACKGROUND: Few studies were conducted on hepatitis B and C virus (HBV and HCV, respectively) risk factors among Chinese blood donors in recent years since voluntary donors replaced commercial donors. STUDY DESIGN AND METHODS: A case-control survey was conducted in HBV- or HCV-positive and -negative donors from five blood centers in China between September 2009 and April 2011. Case status was defined by having a reactive result on Monolisa HBsAg Ultra (Bio-Rad) for HBV and Ortho anti-HCV EIA 3.0 (Johnson & Johnson) for HCV. Controls were randomly selected qualified blood donors matched to cases by donation month and blood center. Specific test-seeking, medical-related, and behavioral risk factors were compared by HBV and HCV status using chi-square tests or Fisher's exact tests with Bonferroni correction. RESULTS: A total of 364 HBV cases, 174 HCV cases, and 689 controls completed the survey; response rates were 66.2, 47.3, and 82%, respectively. HCV-positive donors were significantly more likely to report having a blood transfusion history (23.4% vs. 3.0%, p < 0.0001) and ever living with a person with illegal drug injection (6.0% vs. 0.5%, p < 0.0001) than controls. Having intravenous and intramuscular injections in the past 12 months and ever having a tattoo are marginal risk factors for HCV (p values < 0.01). No specific risk factor for HBV was identified. CONCLUSION: History of previous transfusion and living with illegal drug users are risk factors for HCV infection among Chinese blood donors from five regions. Test-seeking behavior is not associated with HBV or HCV infections.

[Surveillance of malaria in provincial surveillance sites in Jiangsu Province, 2013].

OBJECTIVE: To understand the epidemic situation and influencing factors of malaria in Jiangsu Province and grasp its epidemic regularity and trend. METHODS: According to the malaria prevalence in Jiangsu Province, 6 counties (city, district) including Yixing, Suining, Wujin, Hai'an, Ganyu and Xuyi were selected as provincial surveillance sites to survey malaria epidemic conditions. The basic information, blood test results of fever patients, case investigation, information of malaria patients, monitoring data of investigation and disposition of the malaria focus were collected and analyzed. RESULTS: In 2013, the blood tests of 66 723 fever patients were performed, the average blood smear checking rate was 1.10%, and the average positive rate was 0.08% (52 plasmodium positive individuals) in the 6 areas. For these 52 plasmodium positive individuals, the blood retests and case investigations were completed within 3 days after these cases were reported by the network system, and the investigation confirmed that they were foreign imported malaria cases. The malaria focus investigation and disposition were finished within 1 week and the data were reported by the Parasitic Diseases Information System. Four of 52 cases were recrudescence during the follow-up. Among the 52 cases, 20 people went abroad themselves and 4 were labors of private enterprises, 21 people came back without the accompanied. CONCLUSIONS: With the development of the malaria elimination program in Jiangsu Province, the eliminating malaria "targeted 1-3-7" working pattern has been comprehensively implemented. The personnel monitoring for labors who returned from overseas working will be a key in the future.

The colonization of pyrethroid resistant strain from wild Anopheles sinensis, the major Asian malaria vector.

BACKGROUND: Anopheles sinensis is one of the most important malaria vectors in Asian countries. The rapid spread of insecticide resistance has become a major obstacle for insecticide-based strategies for vector control. Therefore, it is necessary to prepare an insecticide-resistant strain of An. sinensis to further understand the insecticide resistance mechanisms in this species to facilitate genetic approaches to targeting the insecticide-resistant population of this important malaria vector. METHODS: An. sinensis mosquitoes were collected from regions where pyrethroid resistance had been reported. The mosquitoes were subjected to continuous pyrethroid selection after species confirmation, and the forced copulation method was used to increase the mating rate. In addition, the knockdown-resistance (kdr) mutation frequencies of each generation of An. sinensis were measured; and the metabolic enzyme activities of cytochrome P450 monoxygenases (P450s) and glutathione S-transferases (GSTs) were detected. RESULTS: The identification of field-captured An. sinensis was confirmed by both morphological and molecular methods. The population of An. sinensis exhibited stable resistance to pyrethroid after continuous generations of pyrethroid selection in the laboratory with high kdr mutation frequencies; and elevated levels of both P450s and GSTs were significantly found in field selected populations comparing with the laboratory susceptible strain. So far, the colonised strain has reached its eleventh generation and culturing well in the laboratory. CONCLUSIONS: We colonised a pyrethroid-resistant population of An. sinensis in the laboratory, which provides a fundamental model for genetic studies of this important malaria vector.

Development and application of an AllGlo probe-based qPCR assay for detecting knockdown resistance (kdr) mutations in Anopheles sinensis.

BACKGROUND: Anopheles sinensis is one of the most important malaria vectors in China and other Southeast Asian countries. High levels of resistance have been reported in this species due to the long-term use of insecticides, especially pyrethroids, for public health and agricultural purposes. Knockdown resistance (kdr) caused by a single base pair mutation in the gene encoding the sodium channel is strongly associated with pyrethroid insecticide resistance in many Anopheles mosquitoes. There are few methods currently available for detecting kdr mutations in An. sinensis. METHODS: A novel AllGlo probe-based qPCR (AllGlo-qPCR) method was developed to screen for the predominant kdr mutations in An. sinensis mosquitoes from the Jiangsu Province. The results from AllGlo-qPCR, allele-specific PCR (AS-PCR), and TaqMan-MGB probe-based qPCR (TaqMan-qPCR) were compared. A comparative analysis of the equipment required, ease of use and cost of the available methods was also performed. Finally, the AllGlo-qPCR method was used to detect the frequencies of kdr mutations from the other four provinces in central China. RESULTS: Six kdr genotypes were detected in An. sinensis from the Jiangsu Province by DNA sequencing. The AllGlo-qPCR method detected all of the kdr genotypes with a high level of accuracy (97% sensitivity and 98% specificity). AllGlo-qPCR correctly determined the kdr genotypes of 98.73% of 158 An. sinensis samples, whereas TaqMan-qPCR and AS-PCR correctly identified 96.84% and 88.61% of mutations, respectively. Furthermore, the AllGlo-qPCR method is simpler to perform, requires less equipment, and exhibits a moderate expense cost comparing with the other tested methods of kdr mutation detection. Samples collected from four of the other provinces in central China showed a high frequency of kdr mutation in An. sinensis, as detected by the established AllGlo-qPCR method. CONCLUSION: The novel AllGlo-qPCR method developed for kdr mutation detection in An. sinensis exhibits greater specificity and sensitivity than currently available methods and is more cost-effective; therefore, it represents a useful tool for entomological surveillance.

Transcriptome profiling of pyrethroid resistant and susceptible mosquitoes in the malaria vector, Anopheles sinensis.

BACKGROUND: Anopheles sinensis is a major malaria vector in China and other Southeast Asian countries, and it is becoming increasingly resistant to the insecticides used for agriculture, net impregnation, and indoor residual spray. Very limited genomic information on this species is available, which has hindered the development of new tools for resistance surveillance and vector control. We used the 454 GS FLX system and generated expressed sequence tag (EST) databases of various life stages of An. sinensis, and we determined the transcriptional differences between deltamethrin resistant and susceptible mosquitoes. RESULTS: The 454 GS FLX transcriptome sequencing yielded a total of 624,559 reads (average length of 290 bp) with the pooled An. sinensis mosquitoes across various development stages. The de novo assembly generated 33,411 contigs with average length of 493 bp. A total of 8,057 ESTs were generated with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. A total of 2,131 ESTs were differentially expressed between deltamethrin resistant and susceptible mosquitoes collected from the same field site in Jiangsu, China. Among these differentially expressed ESTs, a total of 294 pathways were mapped to the KEGG database, with the predominant ESTs belonging to metabolic pathways. Furthermore, a total of 2,408 microsatellites and 15,496 single nucleotide polymorphisms (SNPs) were identified. CONCLUSIONS: The annotated EST and transcriptome databases provide a valuable genomic resource for further genetic studies of this important malaria vector species. The differentially expressed ESTs associated with insecticide resistance identified in this study lay an important foundation for further functional analysis. The identified microsatellite and SNP markers will provide useful tools for future population genetic and comparative genomic analyses of malaria vectors.

[Experimental observation of toxic effect of Bacillus thuringiensis var. israelensis against Aedes, Culex and Anopheles larvae].

OBJECTIVE: To evaluate the toxic effect of Bacillus thuringiensis var. israelensis (Bti) wettable powder against Aedes, Culex and Anopheles larvae. METHODS: The biological assay was applied to test the lethal concentration of 50% (LC50) of Bti wettable powder against Aedes, Culex and Anopheles larvae. RESULTS: The LC50(s) of Bti wettable powder against Aedes albopictus, Culex pipiens pallens and Anopheles sinensis larvae were 0.104, 0.160 microg/ml and 0.324 microg/ml, respectively; its biological potencies against them were 0.125, 0.192 IU/ml and 0.389 IU/ml, respectively. The LC50(s) of continuous contact of Bti wettable powder with An. sinensis stage III larvae for 1, 2 d and 3 d were 0.324, 0.092 microg/ml and 0.032 microg/ml, respectively, and its biological potencies were 0.389, 0.110 IU/ml and 0.038 IU/ml, respectively. The LC50(s) of the bacteria against An. sinensis stage I , II, III, IV were 0.024, 0.137, 0.324 microg/ml and 0.450 microg/ml, respectively, and the biological potencies were 0.029, 0.164, 0.389 IU/ml and 0.540 IU/ml, respectively. CONCLUSION: Bti wettable powder has a good toxicity to Aedes, Culex and Anopheles larvae, especially for the latter two. It is better to apply the bacteria at the early stage of mosquito larvae.

[Study on TaqMan-MGB real-time fluorescence quantitative PCR to detect gene mutation of kdr from Anopheles sinensis].

OBJECTIVE: To establish a Real-time Fluorescence Quantitative PCR to detect the kdr gene mutation in Anopheles sinensis. METHODS: One pair of primers and three TaqMan-MGB probes were designed based on kdr gene and its L1014 locus mutations of A. sinensis. After optimization, the Real-time Fluorescence Quantitative PCR was verified by using 6 types of A. sinensis samples with different kdr gene types. Additionally, 50 laboratory samples and 113 field samples were tested by this method. RESULTS: The established Real-time Fluorescence Quantitative PCR could identify 6 different kdr gene types in A. sinensis. The mutation could be detected by single-tube Fluorescence Quantitative PCR, and the detail mutation type could be further identified by double-tube Fluorescence Quantitative PCR. By using this method, 50 laboratory samples were confirmed as wild type homozygotes. Among 113 field samples, 12 were wild type homozygotes, others were L1014F or L1014C mutations, and the total mutation frequency was 87.61%. CONCLUSION: The new established TaqMan-MGB Real-time Fluorescence Quantitative PCR can be used to detect the kdr gene L1014 mutations of A. sinensis.

[Establishment of malaria early warning system in Jiangsu Province II application of digital earth system in malaria epidemic management and surveillance].

OBJECTIVES: To explore a new mode of malaria elimination through the application of digital earth system in malaria epidemic management and surveillance. METHODS: While we investigated the malaria cases and deal with the epidemic areas in Jiangsu Province in 2011, we used JISIBAO UniStrong G330 GIS data acquisition unit (GPS) to collect the latitude and longitude of the cases located, and then established a landmark library about early-warning areas and an image management system by using Google Earth Free 6.2 and its image processing software. RESULTS: A total of 374 malaria cases were reported in Jiangsu Province in 2011. Among them, there were 13 local vivax malaria cases, 11 imported vivax malaria cases from other provinces, 20 abroad imported vivax malaria cases, 309 abroad imported falciparum malaria cases, 7 abroad imported quartan malaria cases (Plasmodium malaria infection), and 14 abroad imported ovale malaria cases (P. ovale infection). Through the analysis of Google Earth Mapping system, these malaria cases showed a certain degree of aggregation except the abroad imported quartan malaria cases which were highly sporadic. The local vivax malaria cases mainly concentrated in Sihong County, the imported vivax malaria cases from other provinces mainly concentrated in Suzhou City and Wuxi City, the abroad imported vivax malaria cases concentrated in Nanjing City, the abroad imported falciparum malaria cases clustered in the middle parts of Jiangsu Province, and the abroad imported ovale malaria cases clustered in Liyang City. CONCLUSION: The operation of Google Earth Free 6.2 is simple, convenient and quick, which could help the public health authority to make the decision of malaria prevention and control, including the use of funds and other health resources.

The persistence of hepatitis C virus transmission risk in China despite serologic screening of blood donations.

BACKGROUND: A total of 2%-2.9% of the population in China is infected with hepatitis C virus (HCV). This study estimated the prevalence and incidence of HCV among Chinese blood donors. STUDY DESIGN AND METHODS: We examined whole blood and apheresis platelet donations at five Chinese blood centers in 2008 to 2010. All donations were screened using two rounds of testing for alanine aminotransferase, antibody to human immunodeficiency virus Types 1 and 2, hepatitis B surface antigen, anti-HCV, and syphilis. Screening reactivity is defined by a reactive result in one or both rounds of screening tests. Confirmatory tests (Ortho third-generation HCV enzyme immunoassay, Johnson & Johnson) were performed on anti-HCV screening-reactive samples. Confirmatory positive rates among first-time donors (prevalence) and repeat donors (incidence) were calculated by blood center and demographic categories. Donor characteristics associated with HCV confirmatory status among first-time donors were examined using trend test and multivariable logistic regression analysis. RESULTS: Among 821,314 donations, 40% came from repeat donors. The overall anti-HCV screening-reactive rate was 0.48%. Estimated HCV prevalence was 235 per 100,000 first-time donors; incidence was 10 per 100,000 person-years in repeat donors. In multivariable logistic regression analysis, first-time donors older than 25 years displayed higher HCV prevalence than the younger donors. Less education is associated with higher HCV prevalence. Donors 26 to 35 years old and those above 45 years displayed the highest incidence rate. CONCLUSION: High prevalence and incidence in donors indicate high residual risks for transfusion-transmitted HCV in Chinese patients. Implementation of minipool nucleic acid testing in routine donation screening may prevent a substantial number of transfusion-transmitted HCV infections.