OBJECTIVETo evaluate the susceptibility of Aedes albopictus and Culex pipiens quinquefasciatus to oral infection with bat Japanese encephalitis virus isolates (GD1 and HN2 strains).

METHODSAedes albopictus and Culex pipiens quinquefasciatus were infected orally by GD1 and HN2 strains of bat Japanese encephalitis virus. TaqMan real-time PCR was used to detect the virus and monitor the changes in the viral loads in Aedes albopictus and Culex pipiens quinquefasciatus at a 2-day interval, starting from 4 days till 20 days after the infection.

RESULTSThe infected Aedes albopictus and Culex pipiens quinquefasciatus were found positive for the Japanese encephalitis virus from day 4 to day 20. Both Aedes albopictus and Culex pipiens quinquefasciatus were susceptible to infection by GD1 and HN2 strains, but the latter showed a greater susceptibility. The HN2 strain virus appeared to have a greater virulence than the GD1 strain.

CONCLUSIONAedes albopictus and Culex pipiens quinquefasciatus can carry GD1 and HN2 strains of bat Japanese encephalitis virus isolates.

Aedes ; virology ; Animals ; Chiroptera ; virology ; Culex ; virology ; Disease Susceptibility ; Encephalitis Virus, Japanese ; isolation & purification

Since Zika virus (ZIKV) has firstly been isolated in 1947, Uganda, outbreaks of Zika fever have been reported in many areas such as in Africa, Southeast Asia and America. Imported cases in China also have been reported. Zika virus belongs to the family Flaviviridae, genus Flavivirus, and include Africa subtype and Asia subtype. It is a mosquito-borne virus primarily transmitted by Aedes aegypti mosquitoes. Sexual transmission, Blood transmission and mother-to-fetus transmission were also reported. Zika virus can go though blood-brain barrier and infect central nervous system. Symptoms are generally mild and self-limited, but recent evidence suggests a possible association between maternal Zika virus infection and adverse fetal outcomes, such as congenital microcephaly, as well as a possible association with Guillain-Barré syndrome. Laboratorial Diagnosis includes nucleic acid detection, Serological test, and isolation of virus. Currently, no vaccine or medication exists to prevent or treat Zika virus infection. Preventive measures against Zika virus infection should be taken through prevention of mosquito bites and surveillance in epidemic area.
Aedes ; physiology ; virology ; Animals ; Humans ; Insect Vectors ; physiology ; virology ; Zika Virus ; genetics ; physiology ; Zika Virus Infection ; transmission ; virology

No abstract available.
Aedes/virology ; Animals ; Global Health ; Humans ; Travel ; Zika Virus/isolation & purification ; Zika Virus Infection/epidemiology/*pathology

Aedes ; virology ; Animals ; Dengue Virus ; classification ; isolation & purification ; Genome, Viral ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo screen DENV-2 binding proteins from Aedes albopictus and Culex. quinquefasciatus.

METHODSThe total proteins of Aedes albopictus and Culex. quinquefasciatus in different developmental stages were prepared and analyzed with SDS-12% polyacrylamide gel. After electrophoresis the proteins were transferred using Mini Trans-Blot Electrophoretic Transfer Cell (Bio-Rad ) to a nitrocellulose membrane. Virus overlay protein-binding assay (VOPBA) was carried out using anti-dengue virus 1-4 monoclonal antibody.

RESULTSIn Aedes albopictus, VOPBA detected DEN-2 binding molecules of 25 000, 35 000, and 50 000 in larvae samples, molecules of 35 000 and 50 000 in pupae samples, a 50 000 molecule in male mosquito samples, and molecules of 35 000 and 50 000 in female mosquito samples. DENV-2 binding protein of 35 000 was found in the larvae, pupae, and female mosquitoes, but not in male mosquitoes. In Culex. Quinquefasciatus, VOPBA detected a molecule of 100 000 in larvae samples, molecules of 40 000, 100 000, and around 50 000 (48 000 and 60 000) in pupae samples, and molecules of 40 000 and 100 000 in male mosquitoes and female mosquito samples.

CONCLUSIONSeveral proteins capable of binding DENV are found in Aedes albopictus and Culex. quinquefasciatus in different development stages. The 35 000 molecule expressed in Aedes albopictus as a putative receptor protein may be related to virus tropism in mosquito tissues.

Aedes ; virology ; Animals ; Culex ; virology ; Dengue Virus ; Female ; Insect Proteins ; isolation & purification ; Larva ; Male ; Pupa ; Receptors, Virus ; isolation & purification

BACKGROUND: International Health Regulations controls international travel including human movement, disease vector, and imported items to prevent the spread of dengue, especially in seaports, airports, and border crossing posts. This study aimed to determine dengue Transovarial Transmission Index (TTI) and distribution of dengue virus in the areas around Adisucipto Airport of Yogyakarta, Indonesia. METHODS: The study was a descriptive analytic study with cross sectional design, conducted by mapping the spread of the dengue virus and identifying TTI in Adisucipto Airport. A total of 145 ovitraps were installed in both perimeter and buffer areas of the airport. Positive Ovitrap Index (OI), TTI, and serotype of dengue virus were examined. The TTI was identified using immunocytochemistry immunoperoxidase streptavidin biotin complex (IISBC) method in mosquito head squash preparations. RESULTS: OI in the buffer area was 32 (45.1%), whereas OI in the perimeter area was 24 (32.4%). The TTI in the buffer and perimeter areas were 21 (18.3%) and 11 (18.9%), respectively. The TTI was found greater in the Aedes aegypti population compared to the Aedes albopictus population, both in the perimeter area (20% versus 16.7%) and the buffer area (20.3% versus 16.1%). Dengue virus serotype-2 (DENV-2) and dengue virus serotype-3 (DENV-3) were predominantly found in Ae. aegypti and Ae. albopictus. CONCLUSIONS Buffer areas of Adisucipto Airport of Yogyakarta have higher risk as breeding sites for Aedes spp., predominantly DENV-2 and DENV-3 serotypes. High OI shows that the areas are likely to have higher risk of developing dengue outbreak.
Aedes ; virology ; Air Travel ; Airports ; Animals ; Cross-Sectional Studies ; Dengue ; transmission ; virology ; Dengue Virus ; classification ; isolation & purification ; Female ; Indonesia ; Mosquito Vectors ; virology ; Ovum ; virology ; Serotyping

OBJECTIVETo screen the molecules binding dengue II virus expressed in Aedes albopictus C6/36 cells and characterize their biological functions.

METHODSAedes albopictus C6/36 cells were infected with dengue II virus, and the virus were collected and purified. The total and membrane proteins of C6/36 cells were extracted and analyzed using 12% SDS-polyacrylamide gel (PAGE). After electrophoresis, the proteins were transferred to a nitrocellulose membrane, and virus overlay protein-binding assay (VOPBA) was carried out using an anti-dengue virus 1-4 monoclonal antibody.

RESULTSTwo specific bands of 67 000 and 30 000 occurred after VOPBA of the proteins from the cells incubated with the virus, while the negative control group did not show these specific bands.

CONCLUSIONTwo putative dengue virus receptor molecules of 67 000 and 30000 have been obtained from C6/36 cells using VOPBA, and their functional identification is in progress.

Aedes ; cytology ; virology ; Animals ; Cells, Cultured ; Dengue Virus ; isolation & purification ; Membrane Proteins ; Receptors, Virus ; isolation & purification ; metabolism ; Virus Attachment

OBJECTIVETo compare the sequences of cytochrome C oxidase subunit I gene (COI) in Aedes albopictus from different geographic strains in China and to discuss the differences in susceptibility among different geographic strains to dengue virus (DV).

METHODSCOI was amplified with polymerase chain reaction method and sequenced from its genomic DNA. Molecular phylogenetic trees were constructed with Neighbor-Joining method.

RESULTSSequence length of COI fragment in each geographic strains was 415 bp. The rates of shift and reverse of base pairs in Simao strain were 1.93% and 0.24% respectively. The rate of shift in Mawei and Nanning strains was 0.48%. The analyses of phylogenetic of COI sequences showed that there was close relationship between Simao strain in Yunnan and Mawei strain in Guizhou and between Mawei strain and Nanning strain in Guangxi.

CONCLUSIONSThe susceptibility was widely related to many factors including genetic and environmental ones. COI in Aedes albopictus from different geographic strains in China belonged to the same gene type. There were no direct correlations between COI gene type in different geographic strains and susceptibility to DV.

Aedes ; genetics ; virology ; Animals ; Dengue ; transmission ; Electron Transport Complex IV ; genetics ; Genotype ; Insect Vectors ; Polymerase Chain Reaction

OBJECTIVETo explore the spatial distribution character of dengue fever and the change of Aedes' population, so as to provide macroscopical decision-making evidences of prevention and supervision on dengue fever.

METHODS(1) Collecting data on morbidity of dengue and supervision on vector's population in the corresponding period. (2) Drawing digitized map of Chaozhou in scale of 1:50,000, including elements of boundary, residential areas, road and traffic, altitude, water systems etc. (3) Measuring the latitude and longitude of center position of surveillance safes on the scene. (4) Processing spatial analysis by the ArcGIS 8.5 software.

RESULTSDistribution of Aedes showed spatial cluster in Chaozhou, while its density was related to the distance to the watersides. The closer to the watersides, the higher the density was. Map on spatial distribution showed that although the Aedes epidemic situation changed yearly, but primarily be kept in high, middle, low regions. Cross-validation effects of the distribution maps were satisfactory.

CONCLUSIONGeographic information system was promising in analyzing data on dengue fever, and better than other routine research methods.

Aedes ; Animals ; China ; Dengue ; prevention & control ; Dengue Virus ; Ecology ; Geographic Information Systems ; standards ; statistics & numerical data ; Geography ; Insect Vectors ; virology

OBJECTIVEImpact of climate warming in winter on the potential epidemics of dengue fever in Hainan was assessed.

METHODSBased on historic data of mean monthly temperature in January from 8 weather observation stations, tendency and amplitude of variation were analyzed. Using 21 degrees C as lowest limit of temperature suitable for dengue fever transmission, impact caused by climate warming on dengue fever epidemic was estimated by means of geography information system (GIS), insect vector and epidemiological features.

RESULTSTemperature in winter in Hainan province had shown an obvious increase. The maximum amplitude of increase appeared in Dongfang which was 1.4 degrees C and the minimum 0.5 degrees C in Shanhudao, but the increase amplitude in the other stations was varied from 0.7 to 1.3 degrees C. By the year of 2050, 21 degrees C contour will have moved 190 km or so northward, nearly spanned 6/7 of distance from south to north in Hainan province and under the condition of daily fraction surviving of Aedes aegypti as P = 0.89, Qionghai city which stands north in Hainan province will probably have become epidemic area of dengue fever all year round.

CONCLUSIONClimate warming in winter will probably make half or more of the areas in Hainan province with temperature that permitting transmission of dengue fever by 2050. Monitoring and prevention of dengue fever in winter should be emphasized.

Aedes ; physiology ; virology ; Animals ; China ; epidemiology ; Climate ; Dengue ; epidemiology ; Dengue Virus ; isolation & purification ; Geographic Information Systems ; Humans ; Insect Vectors ; virology ; Seasons ; Temperature