**14. Prognosis**

There are cases where spontaneous recoveries do not occur and neurological symptoms per‐ sist. A retrospective study of 105 patients from 1966 to 1972, with documented enterovirus infection and CNS complications, revealed that half, 9 out of 18, of the children not lost to follow up still displayed signs after 1-5 years [78]. Magnetic resonance imaging of two cases with neurological sequelae demonstrated hypointense lesions on T1-weighted images and hyperintense lesions on T2-weighted images, implying tissue destruction [61]. In a more re‐ cent retrospective study of 177 cases with enterovirus isolated via throat swab or stool speci‐ men, 92 patients (52%) had nervous system involvement, out of which 13 patients (7%) had persistent neurological deficits at discharge [19]. Out of the 92 patients with neurological in‐ volvement, 67 (73%) had EV71 isolated and of the 13 patients with deficits at discharge, 11 (85%) had EV71 isolated. The persistent neurological deficits ranged from dysphagia and weakness to lack of regular, spontaneous respiration despite presence of brain function [19]. Studies have also linked EV71 CNS infections to increased symptoms of inattention, hyper‐ activity, oppositional defiance, internalizing problems, and greater likelihood of the diagno‐ sis of attention deficit hyperactivity disorder [115].

Overall, mortality rates for HFMD is reported to be at 0.05% in China [19]. In the aforemen‐ tioned retrospective study of 177 cases, 5 mortalities were reported and in all these 5 cases, EV71 was isolated [19]. Of the 5 mortalities, 2 were attributed to neurogenic pulmonary ede‐ ma, 2 to shock and 1 to brain-death. Mortalities in EV71 infection is generally due to neuro‐ genic pulmonary edema secondary to medulla destruction [13, 80, 116, 117]. In Taiwan, the Department of Health has recorded a decrease of incidence in recent years, however the mortality rate is still high (9 deaths in 1999, 41 deaths in 2000, 58 deaths in 2001) [60].
