Application of an autoregressive integrated moving average model for predicting the incidence of hemorrhagic fever with renal syndrome.

The Box-Jenkins approach was used to fit an autoregressive integrated moving average (ARIMA) model to the incidence of hemorrhagic fever with renal Syndrome (HFRS) in China during 1986-2009. The ARIMA (0, 1, 1) × (2, 1, 0)(12) models fitted exactly with the number of cases during January 1986-December 2009. The fitted model was then used to predict HFRS incidence during 2010, and the number of cases during January-December 2010 fell within the model's confidence interval for the predicted number of cases in 2010. This finding suggests that the ARIMA model fits the fluctuations in HFRS frequency and it can be used for future forecasting when applied to HFRS prevention and control.

[Genotyping and sequence analysis on G2 segment of hantavirus carried by rat in Hebei province].

OBJECTIVE: To know the genotype and subtype of hantavirus (HV) carried by host animals in HFRS natural epidemic area of Hebei province. METHODS: According to the conservative sequence of 76-118 and R22 strains, specific primers were designed. RT-nested PCR was used to amplify partial M segments from the positive rat lungs screened by IFA. Agarose gel electrophoresis was used to identify the types. Nucleotides were assayed from partial products after purification and reclaim. Gene analysis was carried on with DNAStar package. RESULTS: 32 specimens, which were positive screened by IFA, were amplified the specific segment (418bp) and all belonged to type SEO. Sequencing results of 10 partial segments indicated that G2 segment had little variability and nucleotide homology reached to 98.0%-100.0%. Comparing with the R22 and 76-118 strains, homology was 93.3%-94.3% and 67.7%-69.0% respectively. CONCLUSION: According to G2 segment, SEO was the major type in Hebei HFRS natural epidemic area and S3 was the major subtype. HV which belonged to the same subtype had high homology and genetic materials were correspondingly stable. Different rats could carry the same subtype of HV.

[Genotype and sequence analysis on G2 segments of hantavirus from HFRS patients in Hebei Province].

OBJECTIVE: To know the genotype and subtype of hantavirus (HV) which infected persons in Hebei province. METHODS: According to G2 coding region of 76-118 and R22 strains, specific type primers were designed to detect and identity the types of HV in HFRS patients' sera with RT-nested PCR. Nucleotides were assayed from partial products after purification and reclaim. Then, gene analysis was done with DNAStar package. RESULTS: 17 out of 69 positive serum specimens were successfully detected by RT-PCR and the detection rate was 24.64%, among which, or= 14 days were 0. 17 positive specimens were all belonged to SEO. The nucleotide homology of 9 typical specimens was 92.0%-100%. Between HeB7 and other 8 specimens was 92%-95%, and they belonged to different subtypes. When HeB7 compared with R22 strain, it was 97.7%. HeB7 and R22 belonged to S1 subtype. The 8 specimens except HeB7 was 95.7%-100% and they all belonged to S3 subtype. When compared with 76-118 strain, 9 specimens' nucleotide homology was only 70.3%-72.7%, belonged to different type. CONCLUSION: SEO was the major type of HV from HFRS patients in Hebei province, S3 was the major subtype and S1 was also existed. In a certain area, the HV which belonged to the same type was correspondingly conservative, and had the characteristic of regional stability.