Epidemiology of hand foot and mouth disease related onychomadesis in Hebei

Objective To understand the epidemiologic and etiologic characteristics of onychomadesis related with hand foot and mouth disease(HFMD) in the surveillance areas in Hebei province and provide scientific evidence for surveillance, prevention and control of HFMD onychomadesis. Methods A retrospective epidemiologic survey was conducted among the laboratory confirmed HFMD cases randomly selected in 5 surveillance areas in Hebei. The specimens of the HFMD cases accompanying with onychomadesis were re-detected with real time PCR and Cox A6 or Cox A10 identifications were conducted for the positive specimens of other enteroviruses. Results Onychomadesis occurred in 45 of the 1741 HFMD cases(2.6%). The male to female ratio of the cases was 1.4:1. The average age of the cases was 1.81.3 years(ranging from 0 to 6 years old). The cases in age group 1 year accounted for 51.1%. Onychomadesis occurred in the cases from 10 days before HFMD onset to 86 days after HFMD onset. The fingernail loss rate was 82.2% and the toenail loss rate was 42.2%(2=15.3, P0.01). Among the 45 HFMD related onychomadesis. 43 were infected with other enterovirusses, i.e. 41 Cox A6 infections and 2 ECHO30 infections. Conclusion Cox A6 was the major pathogen causing HFMD related onychomadesis in Hebei. Onychomadesis mainly occurred at 20 to 40 days after HFMD onset. The rate of finger-nail loss was higher than that of toenail loss.