BACKGROUND: Yeoncheon is an endemic region for hemorrhagic fever with renal syndrome (HFRS) and has been reporting HFRS cases intermittently in other seasons, including autumn. This study was conducted to determine whether a seasonal variation pattern of HFRS exists in Yeoncheon. MATERIALS AND METHODS: From 2002 to 2016, raw data of the number of patients with HFRS in Yeoncheon and nationwide was collected from the Korea Center for Disease Control and Prevention. On the basis of the raw data, the incidence per 100,000 population was calculated for each month of the year. The twelve months were divided into four quarters, and the proportion of the disease by each quarter was calculated. The effects of sex, age, quarter, and time on HFRS occurrence were analyzed by Poisson regression analysis. RESULTS: A total of 6,132 HFRS cases occurred nationwide, and 62 cases occurred in Yeoncheon. The incidence of the disease in Yeoncheon (9.07/100,000) was statistically higher than that nationwide (0.81/100,000). The quarterly incidence showed that occurrence proportion of HFRS was high in the third and fourth quarters (12.9%, 67.5%) nationwide, whereas it was relatively similar in all quarters in Yeoncheon (17.7%, 21.0%, 25.8%, 35.5%). The Poisson regression model showed that the relative risk of HFRS nationwide was 1.322 in the third quarter and 6.903 in the fourth quarter, but Yeoncheon had no risk increase by quarter. CONCLUSION: In this study, HFRS in Yeoncheon demonstrated no seasonal variation pattern compared to that in nationwide Korea, which may be considered a regional characteristic. Furthermore, in other regions where HFRS is endemic, like Yeoncheon, HFRS may arise regardless of seasonal variations.
Centers for Disease Control and Prevention (U.S.) ; Endemic Diseases ; Epidemiology ; Hemorrhagic Fever with Renal Syndrome* ; Humans ; Incidence ; Korea* ; Seasons*

BACKGROUND: Yeoncheon is an endemic region for hemorrhagic fever with renal syndrome (HFRS) and has been reporting HFRS cases intermittently in other seasons, including autumn. This study was conducted to determine whether a seasonal variation pattern of HFRS exists in Yeoncheon. MATERIALS AND METHODS: From 2002 to 2016, raw data of the number of patients with HFRS in Yeoncheon and nationwide was collected from the Korea Center for Disease Control and Prevention. On the basis of the raw data, the incidence per 100,000 population was calculated for each month of the year. The twelve months were divided into four quarters, and the proportion of the disease by each quarter was calculated. The effects of sex, age, quarter, and time on HFRS occurrence were analyzed by Poisson regression analysis. RESULTS: A total of 6,132 HFRS cases occurred nationwide, and 62 cases occurred in Yeoncheon. The incidence of the disease in Yeoncheon (9.07/100,000) was statistically higher than that nationwide (0.81/100,000). The quarterly incidence showed that occurrence proportion of HFRS was high in the third and fourth quarters (12.9%, 67.5%) nationwide, whereas it was relatively similar in all quarters in Yeoncheon (17.7%, 21.0%, 25.8%, 35.5%). The Poisson regression model showed that the relative risk of HFRS nationwide was 1.322 in the third quarter and 6.903 in the fourth quarter, but Yeoncheon had no risk increase by quarter. CONCLUSION: In this study, HFRS in Yeoncheon demonstrated no seasonal variation pattern compared to that in nationwide Korea, which may be considered a regional characteristic. Furthermore, in other regions where HFRS is endemic, like Yeoncheon, HFRS may arise regardless of seasonal variations.
Centers for Disease Control and Prevention (U.S.) ; Endemic Diseases ; Epidemiology ; Hemorrhagic Fever with Renal Syndrome* ; Humans ; Incidence ; Korea* ; Seasons*

OBJECTIVETo establish an early-warning indicator system on outbreak of hemorrhagic fever with renal syndrome by Delphi method seeking expert advices.

METHODSFirstly, the literature review and the experts meeting method were used to formulate the initiator frame work and indicators. A two-round consultation was used to filter indicators, discuss the boundary of indicators and determine the weighting coefficient among 25 experts from 14 provinces, municipalities and autonomous regions. The relative weightiless of indicators was determined by the weight coefficients method.

RESULTSThe experts' average length of service in prevention and control of hemorrhagic fever with renal syndrome was (23.80 ± 11.70) years. The positivity coefficients of the two-round experts were 100% and 72%. Kendall's coefficients of the two-round consultation were 0.50 (χ(2)(R) = 148.95, P < 0.01) and 0.54 (χ(2)(R) = 212.63, P < 0.01) and opinions among experts became consistent and the consultation had achieved the need of forecast. Four first-class indicators (host animals, risk population, social environment and case-related indicators) and 14 second-class indicators were filtered to develop the indicators system. The weight coefficients of the first-class indicators were 0.28, 0.23, 0.23 and 0.26.

CONCLUSIONThe early-warning index system of hemorrhagic fever with renal syndrome has been established and it could provide a reference for the forest and warning of HFRS outbreak.

Animals ; Disease Notification ; Disease Outbreaks ; prevention & control ; Early Diagnosis ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; Humans

Adolescent ; Adult ; Child ; China ; epidemiology ; Female ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; Humans ; Incidence ; Male ; Middle Aged

Adult ; China ; epidemiology ; Female ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; Humans ; Male ; Middle Aged ; Prevalence ; Seasons ; Vaccination ; Viral Vaccines ; immunology ; Weather

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

We conducted an epidemiologic study to understand temporal and spatial patterns of hemorrhagic fever with renal syndrome (HFRS) in the Republic of Korea (ROK). We estimated the incidence among civilians in endemic areas through the active surveillance system during the major epidemic periods, from September to December, between 1996 and 1998. We also estimated the prevalence among Korean military personnel from 1995 to 1998. In addition, we assessed seroprevalence, subclinical infection rate, and vaccination rates in both civilians and military personnel. The incidence in civilians ranged from 2.1 to 6.6 per 100, 000 person-months. The annual prevalence in the military personnel was 40-64 per 100, 000 military populations, and remained generally constant throughout the study period with seasonal variation. This is the prospective epidemiologic data set on HFRS in the ROK since the inactivated Hantaan virus vaccine was licensed for use in the late 1990s. These results will be invaluable in establishing a national immunization program against HFRS.
Vaccination/statistics & numerical data ; Seroepidemiologic Studies ; Seasons ; Population Surveillance ; Military Personnel ; Korea ; Incidence ; Humans ; Hemorrhagic Fever with Renal Syndrome/*epidemiology/prevention & control ; Disease Outbreaks/*statistics & numerical data

OBJECTIVETo compare the differences between the direct immuno-fluorescent assay (DFA) and real-time quantitative PCR in detecting the Hantavirus (HV) in rat lungs.

METHODSFrom April to October in 2012, a total of 479 rats were caught by mouse-trap in residential or wild areas in Huxian, Jingyang, and Meixian of Shaanxi province, where haemorrhagic fever with renal syndrome (HFRS) was highly prevalent. The rats were dissected to take the two lungs, one was frozen and applied immuno-fluorescent assay to detect HV antigen while the other one was extracted its RNA and detected HV nucleic acid by real-time quantitative PCR. Then we compared the positive rate of the two methods.

RESULTSOut of the 479 rats, 105 were caught from residential areas and the other 374 were caught from wild areas. Among the 105 rats caught from residential areas, no HV were detected out neither by DFA nor by real-time quantitative PCR. Among the 374 wild rats, 13.1% (49/374) were detected HV positive by DFA and 14.7% (55/374) were detected HV positive by real-time quantitative PCR. The difference showed no statistical significance (χ(2) = 0.402, P = 0.526). When detecting each lung sample, the HV positive rate was 10.2% (49/479) under the detection by DFA while the HV positive rate was 11.5% (55/479) under the detection by real-time quantitative PCR. The difference had no statistical significance (χ(2) = 1.286, P = 0.257) and the consistency coefficient was 68.2% under the paired chi-square test analysis, which showed high consistency (u = 11.759, P < 0.05). The sensitivity of real-time quantitative PCR to detect HV was 77.6% (38/49) comparing with DFA as standard, and the specificity was 96.1% (413/430). Out of the 9 suspected HV positive sample detected by DFA, 6 were confirmed positive by real-time quantitative PCR and 3 were denied.

CONCLUSIONCompared with the DFA, real-time quantitative PCR could also be used to detect the infection of HV in rats, and the result might be more stable.

Animals ; Fluorescent Antibody Technique, Direct ; Hantavirus ; isolation & purification ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; Lung ; virology ; Rats ; Real-Time Polymerase Chain Reaction

OBJECTIVETo study the comprehensive monitoring mechanism of mouse and the effect of hemorrhagic fever with renal syndrome (HFRS) vaccine in the high prevalence areas of natural focus infectious disease of Zhejiang province in 1994 - 2010.

METHODSThe night trapping method was used to monitor the population proportion, density and the rate of hantavirus (HV) carriers in mice in Xikou township Longyou county in August and September from 1994 to 2010. The healthy residents in Xikou township aged 16 to 60 years were recruited. The subjects were randomly selected as vaccination group and control group according to age, sex, occupational distribution (10 178 in intervention group and 16 159 in control group). Intervention group was given purified and inactivated vaccine from suckling mouse brain, while the control group received no intervention. The prevention effect was evaluated by protective rate of vaccine.

RESULTSThe mouse population was stable in the sixteen years and the apodemus agrarius was the main type (76.5% (564/737)). The average density of mouse was 4.73% (1170/24 727). The average rate of virus carrier of mouse was 3.87% (41/1033). In 1994 - 1995, the density of mouse was 22.82% (186/815) and the rate of virus carrier was 7.0% (10/143). In 2009 - 2010, the density of mouse decreased to 2.75% (119/4330) and the rate of virus carrier was 5.5% (13/237). The average antibody positive rate of mouse from 2005 to 2010 was 4.8% (35/728) and the rate was 4.4% (6/138), 0.0% (0/113), 11.8% (16/136), 1.0% (1/104), 3.7% (4/109) and 6.3% (8/128) in each year (P < 0.01). The protective rate of HFRS vaccine was 96.2% (1 case in intervention group and 41 cases in control group).

CONCLUSIONThe density of mouse decreased significantly in Zhejiang province. The rate of virus carrier of mouse is stable. The vaccine is effective.

Adolescent ; Adult ; Animals ; China ; epidemiology ; Disease Reservoirs ; Environmental Monitoring ; Female ; Hantavirus ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; Humans ; Male ; Middle Aged ; Muridae ; Vaccination ; Viral Vaccines ; therapeutic use ; Young Adult

OBJECTIVETo observe the serological and epidemiological efficacy of hemorrhagic fever renal syndrome (HFRS) vaccine in Zhejiang province.

METHODSImmunofluorescent antibody assay and Mcro-CPE method were used to test specific IgG antibody and the titer of neutralizing antibody.

RESULTSTwo weeks after the injection of the third dose, the sero-conversion rates by both immunofluorescent antibody test (IgG) and neutralization test were 100.0% (67/67) (95% CI: 96.3 - 100.0) and 44.4% (8/18)(95% CI: 22.0 - 69.0) with geometric mean titers (GMTs) 72.1 and 4.6 respectively. The rates of seroconversion of immunofluorescent antibody by immunofluorescence antibody assay (IFA) were 28.6%, 83.3%, 75.0%, 53.1%, 22.6%, 10.0% and 55.0% before reinforcement, two weeks, one year, one year and a half years, two years, three years and five years after reinforcement. The rates of neutralizing antibody seroconversion by the Mcro-CPE method were found as 14.8%, 55.6%, 35.0%, 31.3%, 26.0%, 10.0% and 50.0% respectively. We found some antibody dependent immunization enhancement phenomenon among the inoculated population, but further observation was needed.

CONCLUSIONHFRS vaccine was immunologically effective and the duration of serous antibody last long.

Adolescent ; Adult ; Antibodies, Viral ; blood ; China ; epidemiology ; Fluorescent Antibody Technique ; Hantaan virus ; immunology ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; prevention & control ; Humans ; Immunization Schedule ; Immunoglobulin G ; blood ; Male ; Middle Aged ; Neutralization Tests ; Vaccination ; Viral Vaccines ; immunology