[Epidemiological investigation of hand-foot-and-mouth disease in children and exposed population in Hangzhou city].

OBJECTIVE: To investigate the epidemic characteristics of hand-foot-and-mouth disease (HFMD) in children and exposed population in Hangzhou city. METHODS: The throat swab or stool samples from children with HFMD admitted in Hangzhou Children's Hospital were collected. The HFMD pathogens were detected by real-time fluorescent quantitative PCR. The distribution of different HFMD pathogens in HFMD patients was subsequently determined. Human enteric virus type-71 (HEV71) in stool samples from subjects, who had close or general contact to 54 severe HFMD children with positive HEV71, was detected, and these contact persons were followed-up for one month. The diversity of predominant pathogens of HFMD in the area during 2011-2013 was investigated. RESULTS: In 641 HFMD children, the male/female ratio was 1.4:1 and 80.3% was 1-3 years old. HEV71 was detected in 24.3% HFMD children (156/641), while coxsackievirus group-A type-16 (CVA16) and other enteroviruses were detected in 4.7% (30/641) and 71.0% (455/641) of the cases, respectively. 75.6% (118/156) of HEV71-infected cases were diagnosed as severe HFMD cases, while those for CVA16-infected and other HFMD viruses-infected were 13.3% (4/30) and 6.2% (28/455) respectively (Χ(2)=43.28, P<0.05). HEV71 was the predominant HFMD pathogens during 2011-2012, while the predominant HFMD pathogens in 2013 were the other HFMD viruses. In the 54 close contact persons or 54 general contact persons, 9 or 10 persons were detectable for HEV71, but no clinical symptoms of HFMD were presented. CONCLUSION: There are no marked changes of epidemic seasons, favorable age and gender ratio of HFMD in Hangzhou area in 2013. The infection of HEV71 tends to cause the severe HFMD but the other enteroviruses have substituted HEV71 as the predominant pathogens of HFMD.

[The development and in vitro experiment study of a bio-type root canal filling sealer using calcium phosphate cement].

PURPOSE: The purpose of this study is to develop a novel root canal filling sealers based on calcium phosphate cement (CPC), and to evaluate its physical-chemical properties and in vitro antibacterial activity on the predominant bacteria infecting root canal. METHODS: The fluidity and the setting time of the sealer were tested according to ISO 6876:2001(E) standards. The crystal size of the final product was determined. Its opacification with different composition were measured. The in vitro antibacterial property of the sealer was tested according to the Antimicrobial Susceptibility Testing of Anaerobes recommended by National Committee for Clinical Laboratory Standards (NCCLs). The involved bacteria included Actinomyces naeslundii(A. naeslundii), Peptostreptococcus anaerobius (P. anaerobius), Porphyromonas gingivalis (P. gingivalis), Porphyromonas endodpntalis (P. endodpntalis) and Fusobacterium nucleatum (F. nucleatum). Twenty single-rooted human extracted teeth were selected to evaluate the sealing ability using dye microleakage technology. Dye penetration was measured and the results were statistically analyzed using SPSS12.0 software package. RESULTS: The new root canal filling sealer was primarily composed of hydroxyapatite in 279 nm after setting. Its liquidity was suitable, the operating time was over 30 minutes, and the controlled setting time was (1.0+/-0.5) hours. The opacification was acceptable. MIC