Observation on intestinal viral shedding time of hand, foot and mouth disease induced by coxsackievirus A6

Abstract

Objective: To observe the intestinal viral shedding time in patients with hand, food and mouth disease (HFMD) induced by coxsackievirus A6 (CA6). Method: Throat swab specimens and stool specimens of HFMD children were collected from those admitted to Hangzhou Children's Hospital between May and October 2015, while fluorescence quantitative PCR was used to detect the viral load.Eeighteen cases of HFMD children were followed up, who were confirmed as CA6 infection via laboratory tests.Stool specimen was collected every 4-7 days, and fluorescence PCR was used for virus nucleic acid detection until the stool viral nucleic acids of infected children turned to be negative.The intestinal virus shedding time of CA6-infected HFMD was compared with the intestinal virus shedding time of 65 children with enterovirus 71 (EV71) infection and 44 children with coxsackievirus A16 (CA16) infection of the previous studies (from May to September 2012). Result: The median stool viral load was 25×10(5) copies/ml (55×10(4) copies/mL, 9×10(6) copies/ml) in CA6-infected children.The numbers of stool virus nucleic acid turning negative were 0 case, 4 cases, 9 cases, 3 cases and 2 cases in 18 children at 1st, 2nd, 3rd, 4th, 5th weeks. At 5th week, the stool virus nucleic acid of children in CA6 group all turned to be negative.The positive rates of stool virus nucleic acid in EV71 group and CA16 group at the 5th week, however, were 31% and 27% respectively.There were statistically significant differences in distribution of positive rate of stool virus nucleic acid between CA6 infected children with EV71 and CA16 infected children (χ(2)=13.894, 10.698, P<0.05). Conclusion: The longest intestinal virus shedding time for CA6-infected HFMD children was 5 weeks, which is obviously shorter than that of EV71- infected children and CA16-infected children.