Sampling survey of disability in 0-6 year-old children in China.

OBJECTIVE: To investigate the current status of disabled children and prevalence of disabilities in children aged 0-6 years and their risk factors, and to provide scientific evidence for making relevant policies for disabled children. METHODS: In a community-based cross-sectional study, multi-phase, stratified, unequal proportional and cluster sampling was adopted to survey 60 124 children aged 0-6 years. All the investigated children were screened for disabilities, and those with positive screening tests were further diagnosed by various specialties. RESULTS: A total of 819 children were diagnosed as disabled with an overall prevalence of 1.362%, 0.155% for hearing disability, 0.160% for visual disability, 0.931% for intelligent disability, 0.424% for limb disability, and 0.101% for mental disability. Prevalence of disability in children was higher in rural areas, and in families with two or more children, low educational level or in divorced families. CONCLUSION: The prevalence of disability can be reduced by economic development, improvement of health care and quality of population, as well as harmonious familial relationship, early prevention of disability, and preschool education for disabled children.

[Study on the coinfection of three tick-borne infectious diseases in China using polymerase chain reaction method].

OBJECTIVE: To study the existence of Ehrluichiosis, lyme disease and tick-borne spotted fever coinfection in some areas in China. METHODS: Using polymerase chain reaction (PCR), B. burgdorferi sensu lato, spotted fever group (SFG) Rickettsiae and human granulocytic ehrlichia (HGE), Ehrlichia chaffeensis (EC) were detected in ticks and mouse samples collected from Inner Mogolia autonomous region, Heilongjiang province, Beijing and Fujian province. RESULTS: 408 Ixodes persulcatus collected from Inner Mogolia autonomous region, HGE and B. burgdorferi sensu lato and SFG Rickettsiae were detected positive, with rates as 6.8%, 7.8%, 45.6%, respectively. 5 (5/408) were coinfection with HGE and B. burgdorferi sensu lato while 1 (1/408) was coinfection with HGE and SFG Rickettsiae. 46 Ixodes persulcatus collected from Helongjiang province were determined positive, with rates as 6.5%, 10.8% and 34.8%, respectively including 1 (1/46) coinfected with HGE and B. burgdorferi sensu lato. 2 of 922 ticks collected from Beijing were detected positive with B. burgdorferi sensu lato. Among 283 groups of Haemaphysalis yeni ticks (3/group) and from 38 rodent samples collected from Ninghua county of Fujian province HCE and B. burgdorferi sensu lato and SFG Rickettsiae were detected. Out of them, 25 groups were positive with EC and the minimal positive rate was 3.8% while 21 rodent samples were positive with EC with a positive rate of 56.4%. 2 ticks and 1 rodent sample were detected positive with EC and spotted fever group. CONCLUSION: Coinfection of HGE and B. burgdorferi sensu lato or spotted fever group Richi did exist in Ixodes persulcatus collected from Inner Mogolia autonomous region and Heilongjiang province. Coinfection of EC and spotted fever group Richi was found in the ticks and rodents collected from Fujian province.

[Typing of hemorrhagic fever with renal syndrome by cluster analysis].

OBJECTIVE: To make an inquiry into method of typing of hemorrhagic fever with renal syndrome (HFRS). METHOD: Average monthly rates were calculated on the basis of data from 1995 to 1999, then cluster analysis was carried out to type out endemic areas. RESULTS: Compared with the results of 36 surveillance spots from 1980 to 1992, twenty-four surveillance spots had the same results (66.7%). Twenty-three surveillance spots had the same results with the original data in 1999 (82.1%). CONCLUSION: HFRS incidences increased in spring or in summer, but decreased in autumn or in winter. Cluster analysis seemed to be a supplementary method in distinguishing the epidemic types for HFRS.

[A case-control study on the vitamin D receptor gene polymorphisms and susceptibility to pulmonary tuberculosis].

OBJECTIVE: To investigate the association between the genetic polymorphisms of VDR gene and susceptibility to pulmonary tuberculosis. METHODS: Case-control study was conducted. PCR-RFLP technique was used to detect the C/T polymorphism in VDR gene. Information on related factors of tuberculosis was collected using a pre-tested questionnaire. Univariate and multivariate logistic analyses were conducted with SPSS software package. RESULTS: A sample of 76 cases and 171 controls was studied. The genotype frequencies of VDR-FF, VDR-Ff and VDR-ff were 38.2%, 44.7%, 17.1% and 52.6%, 40.9%, 6.4% respectively. VDR-ff was significantly overrepresented in case group, the OR (95% CI) was 3.668 (1.483 - 9.071) when comparing with FF genotype. The significant association remained after adjusting BCG immunization and smoking, the OR (95% CI) was 3.036 (1.117 - 8.253). CONCLUSION: The VDR-ff genotype might be associated with the susceptibility to pulmonary tuberculosis in Chinese Han population.

[Study on the application of geographic information system in spatial distribution of hemorrhage fever with renal syndrome in China].

OBJECTIVE: To analyze the spatial distribution of hemorrhagic fever with renal syndrome (HFRS) in China by geographic information system, and to draw up a map on HRFS risk areas. METHODS: A set of database was set up using the information collected and linked to electronic maps of China in a software ArcGIS 8.01 from 41 HFRS surveillance sites during 1995 - 1998. A HFRS spatial distribution model was developed using inverse distance weighted interpolation of ArcGIS's spatial analysis method. The normalized difference vegetation index (NDVI) in each HFRS surveillance site was extracted from SPOT4 satellite vegetation imagery. Correlation analysis was performed through SPSS 10.0 to analyze the association between NDVI and HFRS incidence, HFRS risk areas were mapped under different colors. RESULTS: Spatial distribution model from HFRS surveillance sites showed that HFRS foci mainly presented in the Heilongjiang River drainage, the middle and lower reaches of the Yellow River, the middle and lower reaches of the Yangtze River, and the Jinghang grant Canal-Huaihe River drainage. It was consistent with HFRS distribution map derived from national infectious disease reporting system. Correlation analysis indicated that HFRS incidence rates were significantly associated with NDVI (r = 0.417, P < 0.01). The HFRS risk areas was mapped according to NDVI of each surveillance site. CONCLUSION: It is promising to apply GIS technology in predication of the distribution of HFRS by establishing this prediction model.

Prevalence of Anaplasma phagocytophila and Borrelia burgdorferi in Ixodes persulcatus ticks from northeastern China.

A total of 1,345 Ixodes persulcatus ticks collected from northeastern China were investigated for the presence of Anaplasma phagocytophila and Borrelia burgdorferi by a nested polymerase chain reaction (PCR). Sixty-two (4.6%) ticks were positive for A. phagocytophila and 454 (33.8%) were positive for B. burgdorferi. Seven (0.5%) were coinfected with both agents. Sequence analysis of 919-basepair PCR amplicons revealed three types of A. phagocytophila. Type 1 was identical to the published sequences of A. phagocytophilas responsible for human granulocytic ehrlichiosis (HGE). The other two variants differed from the HGE agent sequence at one and four positions, respectively. These findings imply that infection with A. phagocytophila poses a potential health threat to both humans and animals in northeastern China, and that ehrlichiosis should be considered in the differential diagnosis of febrile patients with a history of tick bite, particularly when clinical manifestations are atypical for Lyme disease.

[A new type of spotted fever group Rickttsiaes detected in the area of Changbai mountain, Jilin province].

OBJECTIVE: In order to find out the current situation of tick-borne spotted fever in the area of Changbai mountain, Jilin province. METHODS: In this study, a polymerase chain reaction (PCR) method was developed with primers R. rOmpA 190.70p and R. rOmpA 190.701n designed on the basis of rOmpA gene, which is specific for examining spotted fever group Rickttsiaes (SFGR). Six hundred nighty-three ticks were tested and a positive PCR product amplified from D. silvarum specimen (named JL-02) was cloned and sequenced. RESULTS: The SFGR DNA was detected from D. silvarum, Haemaphysalis concinna with the positive rates were 53.81% and 7.41% respectively. Its nucleotide sequence of 587 bp rOmpA and derived amino-acids showed 100.00% similarity with nucleotide sequence of DnS 14 and 99.00% with DnS 28 from the Former Soviet Union according to the result of BLUST and CLUSTAL, which was differential from the DNA sequences of strains previously detected in China. CONCLUSION: The natural focus of tick-borne spotted fever did exist in the area of Changbai mountain. The DNA sequence of SFGR was similar to that of DnS 14, which was first reported in China.