Korean Hemorrhagic Fever was recognized during the Korean War (1950-1953) and intensive studies have been done especially in early 1950's. However, the etiologic agent, vector, and reservoir are not known conclusively. The occurrence has two peak seasons in spring and autumn, and is not limited to military personnel in front lines but also civilians are attacked. Still the study is going on.
Diagnosis, Differential ; Hemorrhagic Fever with Renal Syndrome/epidemiology* ; Hemorrhagic Fever with Renal Syndrome/pathology ; Hemorrhagic Fever with Renal Syndrome/transmission ; Human ; Korea

OBJECTIVETo realize the influence of climatic changes on the transmission of hemorrhagic fever with renal syndrome (HFRS), and to explore the adoption of climatic factors in warning HFRS.

METHODSA total of 2171 cases of HFRS and the synchronous climatic data in Changsha from 2000 to 2009 were collected to a climate-based forecasting model for HFRS transmission. The Cochran-Armitage trend test was employed to explore the variation trend of the annual incidence of HFRS. Cross-correlations analysis was then adopted to assess the time-lag period between the climatic factors, including monthly average temperature, relative humidity, rainfall and Multivariate Elño-Southern Oscillation Index (MEI) and the monthly HFRS cases. Finally the time-series Poisson regression model was constructed to analyze the influence of different climatic factors on the HFRS transmission.

RESULTSThe annual incidence of HFRS in Changsha between 2000 - 2009 was 13.09/100 000 (755 cases), 9.92/100 000 (578 cases), 5.02/100 000 (294 cases), 2.55/100 000 (150 cases), 1.13/100 000 (67 cases), 1.16/100 000 (70 cases), 0.95/100 000 (58 cases), 1.40/100 000 (87 cases), 0.75/100 000 (47 cases) and 1.02/100 000 (65 cases), respectively. The incidence showed a decline during these years (Z = -5.78, P < 0.01). The results of Poisson regression model indicated that the monthly average temperature (18.00°C, r = 0.26, P < 0.01, 1-month lag period; IRR = 1.02, 95%CI: 1.00 - 1.03, P < 0.01), relative humidity (75.50%, r = 0.62, P < 0.01, 3-month lag period; IRR = 1.03, 95%CI: 1.02 - 1.04, P < 0.01), rainfall (112.40 mm, r = 0.25, P < 0.01, 6-month lag period; IRR = 1.01, 95CI: 1.01 - 1.02, P = 0.02), and MEI (r = 0.31, P < 0.01, 3-month lag period; IRR = 0.77, 95CI: 0.67 - 0.88, P < 0.01) were closely associated with monthly HFRS cases (18.10 cases).

CONCLUSIONClimate factors significantly influence the incidence of HFRS. If the influence of variable-autocorrelation, seasonality, and long-term trend were controlled, the accuracy of forecasting by the time-series Poisson regression model in Changsha would be comparatively high, and we could forecast the incidence of HFRS in advance.

China ; epidemiology ; Climate Change ; Forecasting ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; transmission ; Humans ; Humidity ; Incidence ; Models, Theoretical ; Seasons ; Temperature

OBJECTIVETo explore the influence of landscape elements on the transmission of hemorrhagic fever with renal syndrome (HFRS) in Changsha.

METHODSA total of 327 cases of HFRS diagnosed between year 2005 - 2009 were recruited in the study. Based on the demographic data, meteorological data and the data of second national land survey during the same period, a GIS landscape elements database of HFRS at the township scale of Changsha was established. Spatial-temporal cluster analysis methods were adopted to explore the influence of landscape elements on the spatial-temporal distribution of HFRS in Changsha during the year of 2005 - 2009.

RESULTSThe annual incidences of HFRS in Changsha between year 2005 - 2009 were 1.16/100 000 (70 cases), 0.95/100 000 (58 cases), 1.40/100 000(87 cases), 0.75/100 000(47 cases) and 1.02/100 000(65 cases) respectively. The results of poisson regression model analysis of principal component showed that the incidence of HFRS was positively correlated with farmland area (M = 29.00 km2) and urban and rural area (M = 6.12 km2; incidence rate ratios (IRR) = 1.34, 95% CI: 1.27 - 1.41); but negatively correlated with forestland area (M = 39.00 km2; IRR = 0.67, 95% CI: 0.55 - 0.81) and garden plot area (M = 0.99 km2; IRR = 0.74, 95% CI: 0.63 - 0.86). A significant cluster of the spatial-temporal distribution of HFRS cases was found in the study. The primary cluster (28.9 N, 113.37 E, radius at 22.22 km, RR = 5.23, log likelihood ratio (LLR) = 51.61, P <0.01, 67 cases of HFRS and incidence at 4.4/100 000) was found between year 2006 and 2007; and the secondary cluster (28.2 N, 113.6 E, RR = 10.77, LLR = 16.01, P < 0.01, 11 cases of HFRS and the incidence at 10.6/100 000) was found between year 2008 and 2009.

CONCLUSIONThe landscape elements were found to be closely related to the prevalence and transmission of HFRS.

China ; epidemiology ; Climate ; Geographic Information Systems ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; transmission ; Humans ; Regression Analysis ; Space-Time Clustering

OBJECTIVETo investigate whether Leptotrombidium scutellare could be naturally infected by both Hantaan virus (HV) and Orientia tsutsugamushi (OT) and transmission status by stinging.

METHODS3459 Leptotrombidium scutellares from mice bodies and 3265 which were free were collected in the epidemic area of hemorrhagic fever with renal syndrome (HFRS) and tsutsugamushi disease.15 days later, the suspensions of lung and spleen of mice with 6 in a group stung by 1, 5 or 10 infected mites were injected intra-cerebrally into other mice for the detection of HV and OT in the next 6 generations of the mice, with immunofluorescent antibody technique (IFAT) and Giemsa staining technique. The passages of Vero-E6 cells inoculated on the aseptic filtrations from different number of infected mites were used to detect HV and OT pathogens. HV-RNA and OT-DNA were detected by PCR.

RESULTSAfter passage, HV positive mouse body mite group out of both 5 and 10 mites in the sixth generation, OT positive mouse body mite group out of the 10 mites in the sixth generation, both HV and OT positive mouse body mite group out of 1 mite in the fifth and sixth generation, both HV and OT positive mouse body mite group out of 5 and 10 mites in the sixth generation, and free mites group out of 1, 5 and 10 mites in the sixth generation, were found one mouse infected by both HV and OT, respectively. Out of the fourth generation of Vero-E6 cells, one sample was found both HV and OT positive out of 5 and 10 HV and OT mouse body mite group, respectively. In the sixth generation, both HV and OT positive cells were detected in one mouse mite group and the 1, 5, 10 free mite groups, respectively. HV-RNA and OT-DNA were all detected by PCR.

CONCLUSIONBoth HV and OT could be coexisted in wild Leptotrombidium scutellare and transmitted by stinging.

Animals ; Hantaan virus ; Hemorrhagic Fever with Renal Syndrome ; transmission ; Insect Bites and Stings ; Mice ; Mice, Inbred Strains ; Mites ; parasitology ; virology ; Murinae ; Orientia tsutsugamushi ; Scrub Typhus ; transmission ; Trombiculidae

Animals ; China ; epidemiology ; Disease Reservoirs ; Hantaan virus ; immunology ; isolation & purification ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; transmission ; Humans ; Prevalence ; Vaccination ; Vaccines, Inactivated ; Viral Vaccines ; immunology

OBJECTIVETo analyze the incidence rate, animal hosts, and human inapparent infection rate from surveillance data collected in Jiangsu province from 1996 to 2000 and the risk factors of hemorrhagic fever with renal syndrome (HFRS).

METHODSData on the incidence rate was collected from the whole province to describe the epidemiologic characteristics of HFRS. Data on the density of rats, proportion of rats with virus, index of rats with virus and the human inapparent infection rate were collected in special areas according to the standardised protocol in the project.

RESULTSThe incidence rate of HFRS reduced continuously in Jiangsu province, with a 42.17% reduction from 1996 to 2000. The ratio between the incidence rate of autumn-winter peak and spring peak had also reduced. The main host in spring was Rattus norvegicus (with a density of 3.07%), while that in autumn was Apodemus agrarius (with a density of 4.64%). The density of main hosts and mixed species of rats had all reduced during the five years of observation. The proportions of Rattus norvegicus, Apodemus agrarius, Mus musculus with virus were relatively high in spring and autumn. The index of Rattus norvegicus and Mus musculus with virus in spring were 0.025 5 and 0.028 4 respectively, while that of Apodemus agrarius with virus in autumn was 0.030 2. The average human inapparent infection rate was 4.73% in the five years.

CONCLUSIONThe incidence rate of HFRS in Jiangsu reduced significantly from 1996 to 2000, but the risk factors still widely existed. Suggesting that the surveillance program needs to be carried out steadily in Jiangsu.

Adult ; Animals ; Antibodies, Viral ; blood ; China ; epidemiology ; Disease Reservoirs ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; transmission ; Humans ; Incidence ; Middle Aged ; Muridae ; virology ; Rats ; virology ; Risk Factors ; Seasons ; Time Factors

OBJECTIVETo find out the status of intrauterine infection with hemorrhagic fever with renal syndrome virus (HFRSV).

METHODSThe blood of mothers and the umbilical cords were examined by using anti-HFRSV-IgG at labor of mothers infected with HFRSV. The venous blood of naturally delivered babies were examined for anti-HFRSV-Ig M, HI test was used to type the HFRSV.

RESULTSMothers blood showed positive reaction for anti-HFRSV-IgG. Twenty-three of 27 cases of the fetal death were umbilical cords blood positive two out of twelve of umbilical cord blood that the babies were born naturally after their mothers recovered showed positive for anti-HFRSV -IgG but negative for anti-HFRSV-IgM, 14 babies born naturally normally.

CONCLUSIONSHFRSV can cause intrauterine infection, and lead to fetal death, but no post natal deformity was observed in the babies born naturally.

Female ; Fetal Blood ; immunology ; Fetal Diseases ; virology ; Follow-Up Studies ; Hantaan virus ; immunology ; Hemorrhagic Fever with Renal Syndrome ; blood ; transmission ; Humans ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; Pregnancy ; Pregnancy Complications, Infectious ; blood ; virology

OBJECTIVETo summarize and analyze the epidemic situation of hantaviruses including geographic distribution, types and prevalent intensity of epidemic areas of hantavirus for the last 30 years in China, and to discuss relative preventive measures.

METHODSCollecting and analyzing the data of hantaviruses epidemics in China.

RESULTSThe annual number of cases of hantavirus disease rapidly increased from 3295 in 1970 to 115,804 in 1986 then sustained between 40,000 and 60,000 cases annually in the 1990's, and then decreased thereafter. The epidemic areas existed in all provinces except Qinhai and Xinjiang and there were the hospitalized cases of hantavirus disease reported in other provinces. In recent years, the prevalence of hantavirus infection had increased in some cities, and the seasonal distribution of the cases changed as well.

CONCLUSIONData suggested that the new epidemic characteristics of hantaviruses had emerged in China suggesting that it was necessary to strengthen surveillance programs and to take comprehensive preventive measures for the control and prevention of hantaviruses in China.

Animals ; China ; epidemiology ; Disease Reservoirs ; Female ; Hantaan virus ; immunology ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; transmission ; Humans ; Male ; Mice ; Population Surveillance ; Prevalence ; Rats ; Rodent Control ; Vaccination ; Vaccines, Inactivated ; immunology

OBJECTIVETo explore the relations between different areas on hemorrhagic fever with renal syndrome (HFRS) in Guizhou.

METHODSVarious forms of infectious areas were surveyed continuously through epidemiologic surveillance system.

RESULTSIn fixed areas under surveillance system, the mean positive rate of HFRSV among Apodemus agrarius was 3.39%, comparing with Rattus norvegicus 1.61% in Apodemus infectious areas of Zunyi county, 3.19% in Rattus norvegicus, but no HFRSV of Apodemus agrarius was identified in Rattus infectious area of Shiqian county. Both Apodemus and Rattus infectious areas were relatively stabilized. In both banks of Luowang river, Kaiyang county, which had been identified as areas of infections for Apodemus in the eastern part, Rattus infectious area in the west, slow change was noticed. In 1983 - 1984 was not found in Apodemus agrarius HFRSV, however the infectious rate of HFRSV in Apodemus agrarius was 13.85% (Ag 1/65, Ab 8/65) in the western part of the province in 1995 - 1998.

CONCLUSIONBoth Apodemus and Rattus infectious areas were stabilized but changed slowly. Mixed type and the result of mutual penetration were noticed.

Animals ; Antigens, Viral ; blood ; China ; epidemiology ; Disease Reservoirs ; Female ; Hantaan virus ; immunology ; isolation & purification ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; transmission ; Humans ; Incidence ; Male ; Muridae ; virology ; Rats ; Risk Factors ; Seasons ; Sentinel Surveillance ; Time Factors