Insectivorous animal is one of the oldest and most primitive mammals, which is widely distributed throughout the world. Hantavirus is one of the most important zoonotic pathogens, causing hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). In recent years, 23 types of hantaviruses have been found in insectivorous animals. The typing, phylogenetic, co-evolution or cross-species transmission of hantaviruses associated with insectivorous animals were reviewed in this paper.

Bat is important reservoir hosts of emerging viruses. It has been confirmed that bats in nature in China were infected by many emerging viruses, such as SARS - like coronaviruse, MERS - related betacoronavirus and another coronaviruses as well as novel Rotavirus, Orthohepadnavirus, Hantavirus, Adenovirus, Reovirus etc. In addition, antibodies against Ebola and Nipah viruses were detected in bats in China. This paper presente a review about the emerging viruses infection in bats in China.

Objective To analyze the epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) in Yunnan province, China and to provide reference for the prevention and control of HFRS. Methods The data on HFRS cases in Yunnan were collected to establish a database using Excel 2003. Statistical analysis was performed using SPSS 13.0 to evaluate the incidence and mortality of HFRS, as well as the geographical, seasonal, and population distributions of the cases; analysis of variance was used to determine the regional differences in incidence, and linear correlation analysis was used to determine the population distribution of HFRS. Results From 1976 to 2012, a total of 876 cases of HFRS were reported in Yunnan province, and 50 cases were fatal; the average annual incidence was 0.058/100 000, the average annual mortality rate was 0.0042/100 000, and the fatality was 5.71%. Two epidemic peaks occurred in 1984-1987 and 1998-2006. The cases of HFRS were reported in 75 county-level regions (counties, cities, or districts) of 14 prefecture-level regions (prefectures or cities) in Yunnan. There were significant differences in the incidence of HFRS among the prefecture-level regions. The main epidemic areas (prefecture-level regions) were Kunming, Honghe, Chuxiong, and Dali, where 80.48% of all cases occurred, and particularly 35.50% of all cases were reported in Kunming. The epidemic areas were distributed in the central and northwestern regions at 1500-2500 m elevation; few cases were reported in the mountainous areas (>2500 m elevation) and low-elevation areas (<1500 m elevation) in the southwestern region. The incidence of this disease was found through the whole year, and the epidemic peak was in spring and summer. Young and middle-aged male farmers were the main affected population. Conclusion HFRS cases are widely distributed in Yunnan province, and the central and northwestern basin areas at 1600-2000 m elevation are the main epidemic areas. The surveillance and control of HFRS should be strengthened in the main epidemic areas.

Objective To investigate the distribution profiles of mosquitoes and arboviruses in Xishuangbanna,Yunnan province, China, and to provide evidence for prevention and control of arbovirus diseases. Methods Mosquito samples were collected in Xishuangbanna and then used for virus isolation by cell culture. RT-PCR was used to identify arbovirus. Serum and cerebrospinal fluid samples were collected from fever patients, and the common encephalitis virus IgM antibodies were detected by ELISA. Results A total of 13 337 mosquitoes, belonging to 29 species and 5 genera, were collected. The main mosquitoes were Culex tritaeniorhynchus (79.98%, 10 667/13 337), followed by Anopheles sinensis (7.95%, 1060/13 337) and An. peditaeniatus (7.38%, 984/13 337). Several specific primers for Japanese encephalitis virus (JEV), Banna virus, alphavirus, and circovirus were used for PCR detection in 214 batches of mosquitoes, and no virus was isolated from the mosquitoes. Also, no virus was found in isolation using several types of cells. A total of 52 serum samples and 54 cerebrospinal fluid samples were collected from patients in acute stage by kits for encephalitis viruses and then subject to ELISA. There were 16 cases with JEV IgM, 4 cases with Herpes simplex virus IgM, 13 cases with mumps virus IgM, 3 cases with ECHO virus IgM, and 1 case with dengue virus IgM. Conclusion No JEV, BAV, and circovirus were detected from mosquitoes collected in Xishuangbanna,Yunnan province, China in 2011. However, serological results indicated that local fever patients were infected with several viruses such as JEV.

Objective To investigate the distribution patterns of mosquito-borne viruses in Mile county, Honghe prefecture, Yunnan province, China, and to provide evidence for prevention and control of mosquito-borne diseases. Methods Mosquito samples were collected in Mile county during July 2009. Viruses were isolated from the samples through cell culture and then identified by molecular biology techniques. Results Nine virus strains were isolated from the mosquito samples including 4400 individuals of Culex tritaeniorhynchus and 2200 individuals of Anopheles sinensis. Seven strains, which were from Cx. tritaeniorhynchus, were identified as Japanese encephalitis virus (JEV), and 2 strains, which were from Cx. tritaeniorhynchus and An. sinensis, were identified as Cx. pipiens pallens densovirus (CppDNV). Conclusion JEV was first isolated from Mile county, Honghe prefecture, demonstrating that Mile county is an endemic area of JE from the etiological aspect. The prevalent JEV strain was confirmed to be genotypeⅠ, according to homology and phylogenetic analysis, and was first isolated in the southeast area in Yunnan province, China.

West Nile virus (WNV) is a positive, single strand RNA virus belonging to Flavivridae that causes infectious West Nile fever (WNF) in human beings. Birds are the main host of WNV, and mosquitoes the main transmitting vector. WNF has been endemic in the Europe and middle-west Asia for decades. The outbreak of WNF in the United States in 1999 and subsequent epidemics in North America in the following years have caused great concerns. Moreover, greater concerns have arisen from other transmitting routes besides mosquito bites, such as blood transfusion, organ transplantation and vertical transmission. As there is no vaccine available for prevention of WNF, the condition is associated with significant threat to public health and life security due to the high infection rate, the increasing number of severe cases and high mortality rate. This paper unfolds a comprehensive discussion about the etiology, epidemiology clinical, lab diagnosis, prevention and surveillance of WNF.

Objective To investigate the distribution patterns of mosquitoes and mosquito-borne viruses in Yunnan province to provide evidence for prevention and control of mosquito-borne diseases. Methods In 2009, mosquito samples were collected from 6 counties of Yunnan province. Mosquitoes were first classified, followed by cell culturing for viral isolation for molecular identification. Positive isolates were identified using SDS-PAGE and RT-PCR. The genomes of isolates were also, sequenced for phylogenetic analysis. Results A total of 18 562 mosquitos of 4 genera (Culex, Anopheles, Armigeres, Aedes) and 24 species were collected. Cx. tritaeniorhynchus and An. sinensis were the major species, comprising 58.37% and 28.45% of the total population, respectively. Fifteen strains of viruses were isolated from the mosquito pools. RT-PCR and phylogenetic analysis revealed two viral strains from Cx. tritaeniorhynchus, identified as Japanese encephalitis virus (JEV, GenotypeⅠ). One strain isolated from An. sinensis was identified as Banna virus. Twelve vrial strains were identified as Cx. pipiens pallens densovirus (CppDNV), of these, nine strains were isolated from Cx. tritaeniorhynchus, and three strains from An. sinensis. Conclusion Cx. tritaeniorhynchus and An. sinensis were the predominant species in the investigated areas. JEV, Banna virus and CppDNV were isolated. In northeast Yunnan, JEV was isolated for the first time.

Objective To evaluate the specificity and sensitivity of the newly developed colloidal gold reagent for tsutsugamushi antibody detection. Methods A micro?indirect immunofluorescent assay (IFA) was performed to measure the tstsugamushi IgG antibody level in the serum samples of febrile patients, and 242 negative and strongly positive serum samples were drawn for determination of IgM, IgG and total antibody levels of Orientia tsutsugamushi using three colloidal gold reagent strips. If the control group was eligibly founded, the presence of red bands was indicative of positive results. Statistical analysis of the above results was then conducted. Results The sensitivity of the colloidal gold immunochromatographic assay for tsutsugamushi IgM, IgG and total antibody was 62.25%, 30.12% and 93.98%, respectively; the specificity was 98.11%, 98.74% and 96.23%, respectively. The results of IgM and IgG levels were statistically different from the IFA measurements, whereas that of total antibody was not (P＜0.05, P＜0.05 and P＞0.05, respectively). Conclusion Statistically significant differences were shown between the results of IgG and IgM antibody reagent strips and that of the IFA, whereas no significant difference was shown between the results of total antibody. Therefore, the newly developed assay could be a substitute for the IFA in tsutsugamushi antibody detection.

【Abstract】 Objective To analyze the distribution characteristics of mosquito in Yunnan province and its relationship with the arborvirus such as Japanese encephalitis (JE), and provide the scientific basis for its prevention and control. Methods Mosquitoes were collected from the residential areas and the stables of livestocks in villages at night, and bamboo forests in the day. Results A total of 158 909 adult female mosquitoes were collected, which belonged to 88 species 10 Genera, and were mainly Culex，Anopheles and Aedes, accounting for 56.66%, 25.35% and 13.88% respectively. Among them, as many as 132 081 adult mosquitoes belonging to 63 species 7 Genera were caught in the residential areas at night, in which Cx.triaeniorhynchus has the highest proportion (42.12%), followed by An.sinensis (23.31%). And 26 828 adult mosquitoes belonging to 48 species 5 Genera were caught in the field by day, and the proportion of Ae.albopictu was highest (31.89%), followed by Ae.annandalei（20.21%）. A total of 131 538 female mosquitoes that belonged to 29 species of 8 Genera were divided into 3957 groups. As a result, 81 strains of JE virus were isolated from mosquitoes (17 species 5 Genera). The virus strains isolated from Culex were the most（59 strains）accounting for 72.84%, followed by Anopheles (8 strains ) accounting for 9.88%, and Aedes (9 strains) accounting for 11.11%. Only two  strains  were  isolated  from  Armigeres  and  Mansonia,  accounting   for  2.47%.  About  27  strains  JE  were  isolated  from Cx.triaeniorhynchus, accounting  for   33.33%  of  the  total.  Conclusion The  dominant  species  in  the  residential areas  are  Cx.triaeniorhynchus, An. sinensis,  Cx.fuscocephalus, Cx.whitmorei, Cx.pseudovishnui and An.vagus  at  night,  while  Ae.albopictus,  Ae.pseudalbopict,  Ae.annandalei,  Ae.vexans  and  Ar.subalbatus  were   the  dominant  species  in  the  field  by  daytime. Cx.triaeniorhynchus  and  Ae.albopictus are the main vectors of JE and Dengue fever in Yunnan province, respectively.