[Clinical analysis of 555 outpatients with hand, foot and mouth diseases caused by different enteroviruses]

Objective: To study the clinical characteristics of outpatients with hand, foot and mouth disease (HFMD) caused by different serotypes of enteroviruses. Methods: This was a prospective study. From February 2017 to March 2018, 563 outpatients with HFMD were enrolled by systematic sampling in the Department of Infectious Diseases, Henan Children's Hospital. Throat swabs were collected to determine the serotypes via PCR. Demographic, clinical, and laboratory data were collected by standard questionnaire. All cases were followed up twice at 2 and 9 weeks after the initial outpatient visit through telephone interview. A total of 563 cases were enrolled and 555 (98.6%) cases were positive for human enteroviruses, including 338 (60.9%) males. Analyses were stratified by enterovirus serotypes, Chi square test or Fisher's exact test, Rank sum test was used for comparison among different groups. Results: The age of 555 cases was 24.2 (16.4, 41.3) months. Among them 44.0% (224 cases) were identified as coxsackievirus (CV)-A6, while 189 cases, 35 cases, 14 cases and 73 cases were identified as CV-A16, enterovirus (EV)-A71, CV-A10 and other serotypes, respectively. Fever (≥37.5 ℃) was present in 51.4% (285/555) of laboratory confirmed cases. The proportions of fever in cases of CV-A6 (68.9%(168/244)) and CV-A10 (12/14) were significantly higher than those in cases of CV-A16 (31.7%(60/189),χ(2)=57.344,14.313,both P=0.000), other serotypes (43.8%(32/73),χ(2)=15.101 and 8.242, P=0.000 and 0.004) and EV-A71 (37.1%(13/35), χ(2)=13.506 and 9.441, P=0.000 and 0.002) respectively. There was no significant difference between CV-A6 and CV-A10 in presentation of fever (χ(2)=1.785, P=0.182). There were 359 cases (64.7%) with eruptions in mouth, hands, feet and buttocks. Cases infected with EV-A71 had the highest proportions (74.3%(26/35)) of rash emerging simultaneously in mouth, hands, feet, and buttocks. The proportion in cases of CV-A16, CV-A6, CVA10 and other serotype were 73.5% (139/189), 61.9% (151/244), 7/14 and 49.3% (36/73), respectively. The proportion of rash on other parts of body, such as face, limbs or torso in cases infected with CV-A6 (16.8% (41/244)) was the higherest and the proportion in cases of CV-A16, EV-A71, CV-A10 or other serotypes were 8.5% (16/189) , 5.7% (2/35) , 1/14, 6.8% (5/73) , respectively. None of these cases developed serious complications. Desquamation occurred in 45.5% (179/393) cases 7.5 (5.0, 9.0) days after disease onset and 13.5% (53/393) cases showed onychomadesis 31.0 (18.0, 33.5) days after disease onset. The proportion of desquamation and onychomadesis associated with CV-A6 (64.2% (95/148) and 31.8% (47/148)) was significantly higher than CV-A16 (31.8% (49/154) and 1.3% (2/154), χ(2)=33.601 and 52.482, both P=0.000) and other serotypes (38.0%(19/50) and 6.0%(3/50),χ(2)=10.236 and 12.988, P=0.001 and 0.000). Desquamation appeared more in cases of CV-A6 than in cases of CV-A10 (2/11,χ(2)=9.386, P=0.002), with the proportion of onychomadesis higher in CV-A6 than in EV-A71 (3.3% (1/30),χ(2)=11.088, P=0.001). Conclusion: Clinical manifestation such as fever, rash emerging parts, desquamation and onychomadesis are different among outpatient HFMD cases infected with CV-A16, CV-A6, EV-A71, CV-A10 and other enteroviruses.