Objective To understand the epidemiological and clinical characteristics of 25 imported Zika cases in Mainland China, and to provide reference for the prevention and control of Zika disease. Methods Collect the information of 25 imported Zika cases in mainland China, and use descriptive study to analyze the characteristics of demography, epidemiology, clinic, and laboratory. Results Among 25 imported Zika cases, 17 cases (68.0%) came from Venezuela, the median age of all cases was 30, the ratio of male to female was 1.5:1, and half the number of cases (12/25, 48.0%) engaged in commercial services. The border quarantine and health follow-up were the main methods to discover the imported cases (each found 9 cases). All cases had skin rash, and the proportion of conjunctivitis and fever was 64.0% and 52.0%, respectively. In laboratory test, the positive rate of urine sample was 92.0%, followed by saliva sample (80.0%) and blood sample (60.0%). Conclusion Strengthening the health education for people who will enter the Americas and other epidemic countries, and consolidating the border screening and inspection of travelers from the Zika epidemic areas will help to prevent and control Zika in China. Skin rash and positive result of urine sample can be considered as important references to the diagnoses of Zika disease.

Objective To investigate the pathogen harborage in small mammals in Beijing area. Methods Night trapping method was used to capture the small mammals in Beijing area and the organ tissue was obtained from the trapped small mammals. PCR and Real-time PCR methods were used to detect the specific gene of Orientia tsutsugamushi, Borrelia burgdorferi and Babesia in the small mammals tissue. Results In 500 samples obtained from Beijing area in 2013, the positive rate of O. tsutsugamushi was 2.40% which was distributed in 6 districts, and the highest was 21.43% in Haidian district. The positive rate of Babesia was 6.40% which was distributed in 11 districts, and the highest was 21.43% in Haidian district. Four samples were coinfected with O. tsutsugamushi and Babesia, and the coninfection rate was 0.80%. The B. burgdorferi was not detected in any of the rodents. Conclusion The O. tsutsugamushi harborage in small mammals in Beijing was not restricted in the area where the human cases were reported, and the surveillance of human cases, animal hosts and vectors should be reinforced in Beijing. The Babesia harborage was higher than O. tsutsugamushi both in distribution and infection rate, therefore the training of the fundamental medical practitioners and the surveillance and health education of the high risk group should be carried out in time.

Objective To learn the epidemic status of scrub typhus in suburban districts in Beijing, providing the basis for prevention and control of scrub typhus. Methods A total of 4 362 serum samples were collected from the residents in Pinggu, Miyun, Huairou and Mentougou districts of Beijing during April 2012 and December 2013. Scrub typhus IgG antibody was tested by ELISA method, and the seroepidemiological investigation was carried out. Results Among 4 362 samples, 460 were positive of scrub typhus IgG, the positive rate was 10.55%. The positive rate was 11.66% in Pinggu district, 9.47% in Miyun, 8.73% in Huairou and 2.26% in Mentougou district. The difference between Mentougou and other districts was statistically significant (P < 0.01). Conclusion The infection of scrub typhus exists in Pinggu, Miyun, Huairou and Mentougou districts. The infection rate in Pinggu was the highest. Miyun and Huairou also had high infection rate, and the surveillance, prevention and control of scrub typhus should be strengthened in these areas.

Objective To map the land coverage by remote sensing, and to investigate the relationship between land coverage and the species diversity and density of small mammals in Beijing. Methods The 2009 land coverage for Beijing was provided by the MODIS Land Cover Type product (MCD12Q1) from NASA. Small beasts were captured using the trap-at-night method during 2009-2011 for species identification and density calculation. Results According to plant functional type (PFT) scheme, the proportion of urban and construction land was 12.19%, and the proportion of cropland was 39.24%. Natural vegetation accounted for 48.27%, of which 31.28% was covered by broadleaf forests, 10.91% by shrubs, and 3.68% by coniferous forests. The area of grass was relatively small, making up only 2.40% of the total area. Eight hundred and eighty one small mammals belonging to 10 species were captured with trap-at-night method. Of which 871 (98.86%) belonged to nine species of rodents and 10 belonged to one species of insectivores. The species compositions were statistically different in three different habitats including broadleaf forest, shrub, and cropland. The dominant rodents in broadleaf forest and cropland were Niviventer confucianus and Apodemus peninsulae, whereas N. confucianus and Rattus norvegicus were dominant in shrub. Conclusion The major hosts of plague confirmed in China could not adapt to the vegetation landscape with high proportion of trees and shrubs and low proportion of grasses in Beijing. Although the dominant rodents could be infected by Yersinia pestis, there is a small chance of natural foci of plague emerging in Beijing.

Objective To investigate distribution of mosquito density from 2009 to 2011 in Shunyi district and provide data for scientific elimination of malaria in 2015. Methods According to GB/23797-2009, capture method of light-traps was adopted in mosquito surveillance. Epidemiological analysis was carried out on mosquito density monitoring from 2009 to 2011 in Shunyi district. Analysis of variance was adopted in statistic analysis. Results Culex pipiens pallens was the dominant mosquito species (99.57%). Mosquito densities were not significantly different among 2009, 2010 and 2011 ( F=0.214, P=0.807). The mosquito number caught on July and August was 58.63% of total number. Mosquito density of public parks was 2.88 per hour and significantly higher than those of residential areas and hospitals ( F=34.55, P<0.01). Multivariate analysis showed that month and place of investigation were influence factors on mosquito density and their effects can be compounded. Conclusion The risk on spread native malaria was low and the compounded effect of month and place on mosquito density should be paid attention to

Objective To analyze the epidemiological characteristics of dengue fever cases from 2006 to 2010 for determination of the risk of dengue fever outbreaks in Beijing. Methods Data of the reported dengue fever cases in Beijing were collected and analyzed for their epidemiological characteristics with SPSS software. CO₂ trapping lamp method was used to monitor the constituent ratio and density of mosquitoes. Results A total of 23 imported dengue fever cases were confirmed, of which 95.65% (22/23) of the cases were at the age of 25-59 years. The male-female ratio was 4.75∶1. Among them, 69.57% (16/ 23) were office clerks. The constituent ratio and density of Aedes albopictus showed 25.71 times and 6.00 times increase in 2010 than in 2007, respectively. Conclusion The density of subdominant mosquito species (Ae. albopictus) has increased in recent years. Vector monitoring and control measures should be implemented effectively to reduce the outbreak risk.

【Abstract】 Objective To understand the situation of the reservoir hosts and vectors infected by Borrelia burgdorferi, the distribution of the reservoir hosts and the seasonal fluctuation of ticks in Miyun area.  Methods Ticks were caught with flag method, which were identified by Inverted microscope. The night trapping method was used to catch rats.  The pathogen from ticks and rodents was isolated with BSKⅡculture. The nested PCR was used to do etiological detection. The antibody of B.burgdorferi from goat serum was tested by indirect immunofluorescence. Results Ticks caught in Miyun area were all Haemaphysalis longicornis, which growth curve was obviously seasonal. The rate of ticks bearing pathogen was 10.16% after detection by nested PCR. Apodemus agrarius and Niniventer confucianus were the dominant species in the area, and the rate of rodents bearing pathogen was  4.26%.  The  positive  rate  of  goats  stocked  in  the  local  was  12.00%.  Conclusion The  specific fragment of B.burgdorferi was found in ticks and rodents, which showed that Miyun area maybe one of the epidemic focus of Lyme disease.