Tracking investigating of the carriage status of virus among HFMD patients with EV71 and their close contacts

Objective To investigate the carriage status among HFMD patients with EV71 and their close contacts,and explore affecting factors for continuing circulation of EV71 ;in order to provide evidence for prevention and control of HFMD.Methods Serial samples of 18 definitely diagnosed HFMD cluster cases and their 50 close contacts,were traced and collected within the interval of 1 to 2 weeks,respectively.RD cells were used for enterovirus isolation and real-time RT-PCR for EV71 specific nucleotide.Results live EV71 have been detected in feces from 38.89％ (7/18) cases within 3rd ～6th weeks after onset,the longest excretion time of live EV71 through stool was 39 days post-onset.22.00％ (11/50) close contacts through 1st ～3rd weeks after the two-week kindergarten suspension,showed also live EV71 in samples,the longest duration of shedding for fecal specimens observed was 49 days since the date of onset for first case in their class.Conclusions EV71 may result in large proportion of asymptomatic infections,and may continuously shed from feces of HFMD patients after recovery for a relatively long period.The intervention effectivehess of “two-week kindergarten suspension” is limited in controlling transmission of EV71.