Emergence of genotype C1 Enterovirus A71 and its link with antigenic variation of virus in Taiwan.

An outbreak of the hand-foot-mouth disease with severe neurological cases, mainly caused by the genotype C1 enterovirus A71 (EV-A71), occurred in Taiwan between 2018 and early 2019. In the recent decade, the most dominant EV-A71 genotypes in Taiwan were B5 and C4 but changed to C1 in 2018. Antibody-mediated immunity plays a key role in limiting the EV-A71 illness in humans. However, the level of neutralizing activities against genotype C1 virus by human polyclonal and monoclonal antibodies (MAbs) remains largely unclear. In the study, we demonstrated that that 39% (9 in 23) of post-infection sera from the genotype B5- or C4-infected patients in 2014-2017 exhibit reduced titers with the 2018-2019 genotype C1 viruses than with the earlier B5 and C4 viruses tested. This finding with polyclonal sera is confirmed with human MAbs derived from genotype B5 virus-infected individuals. The 2018-2019 genotype C1 virus is resistant to the majority of canyon-targeting human MAbs, which may be associated with the residue change near or at the bottom of the canyon region on the viral capsid. The remaining three antibodies (16-2-11B, 16-3-4D, and 17-1-12A), which target VP1 S241 on the 5-fold vertex, VP3 E81 on the 3-fold plateau and VP2 D84 on the 2-fold plateau of genotype C1 viral capsid, respectively, retained neutralizing activities with variable potencies. These neutralizing antibodies were also found to be protective against a lethal challenge of the 2018-2019 genotype C1 virus in an hSCARB2-transgenic mice model. These results indicate that the EV-A71-specific antibody response may consist of a fraction of poorly neutralizing antibodies against 2018-2019 genotype C1 viruses among a subset of previously infected individuals. Epitope mapping of protective antibodies that recognize the emerging genotype C1 virus has implications for anti-EV-A71 MAbs and the vaccine field.

Clinical features of gingivostomatitis due to primary infection of herpes simplex virus in children.

BACKGROUND: Primary herpetic gingivostomatitis (PHGS) in children, though usually self-limited, might mimic bacterial and enteroviral pharyngitis clinically. We conducted a study to define the clinical features of PHGS in children. METHODS: Between January 2012 and December 2016, 282 inpatients aged less than 19 years with cell culture-confirmed herpes simplex virus (HSV) infection in a medical center were identified from the virologic laboratory logbook. Clinical data were retrospectively collected. RESULTS: Among the 282 inpatients, 185 cases were considered as PHGS and were included for analysis. Fever was present in 99.5%. The mean duration of fever was 5.11 days (±2.24) with the longest being 17 days. Common oral manifestations included oral ulcers (84.3%), which equally resided in the anterior and posterior part of the oral cavity (65.4% vs. 63.2%), gum swelling and/or bleeding (67.6%), and exudate coated tonsils (16.8%). Leukocytosis (WBC count > 15,000/uL3) was noted in 52 patients (28.1%) and a serum C-reactive protein level > 40 mg/L in 55 patients (29.7%). Fixty-five patients (35%) were diagnosed with PHGS on admission and were significantly more likely to have ulcers over the anterior oral cavity (76.1% vs. 26.7%) and gum swelling/bleeding (76.2% vs. 7.5%, p-value all < 0.001) on admission and were significantly less likely to receive antibiotic treatment (16.9 vs. 36.7%, p-value < 0.01) than others. Forty-six patients (25%) undiagnosed as PHGS on discharge were significantly more likely to have exudate coated on the tonsils, to receive antibiotic treatment and significantly less likely to have gum swelling/bleeding and oral ulcers (all p-values < 0.01). CONCLUSIONS: Meticulously identifying specific oral manifestations of gum swelling/bleeding and ulcers over the anterior oral cavity in children can help making the diagnosis of PHGS earlier and subsequently reduce unnecessary prescription of antibiotics.

Enterovirus A71 neurologic complications and long-term sequelae.

During recent 20 years, enterovirus A71 (EV-A71) has emerged as a major concern among pediatric infectious diseases, particularly in the Asia-Pacific region. The clinical manifestations of EV-A71 include uncomplicated hand, foot, and mouth disease, herpanina or febrile illness and central nervous system (CNS) involvement such as aseptic meningitis, myoclonic jerk, polio-like syndrome, encephalitis, encephalomyelitis and cardiopulmonary failure due to severe rhombencephalitis. In follow-up studies of patients with EV-A 71 CNS infection, some still have hypoventilation and need tracheostomy with ventilator support, some have dysphagia and need nasogastric tube or gastrostomy feeding, some have limb weakness/astrophy, cerebellar dysfunction, neurodevelopmental delay, lower cognition, or attention deficiency hyperactivity disorder. Long term sequelae may be related to greater severity of CNS involvement or neuron damage, hypoxia and younger age of onset.

Clinicopathologic analysis of coxsackievirus a6 new variant induced widespread mucocutaneous bullous reactions mimicking severe cutaneous adverse reactions.

BACKGROUND: The cutaneous manifestations of human enterovirus (HEV) infection are usually limited, such as hand-foot-mouth disease. By comparison, Stevens-Johnson syndrome (SJS) is a life-threatening severe cutaneous adverse reaction (SCAR), mainly caused by drugs. During the HEV outbreaks in 2010-2012 in Taiwan, we identified 21 patients who developed widespread blistering mucocutaneous reactions without any suspected drug causality. METHODS: We screened possible pathogen(s) for detecting human herpes virus (HHV1-HHV7), HEV, or Mycoplasma pneumoniae infections using throat swab virus cultures, real-time PCR, DNA sequencing, immunochemistry and electron microscopy analyses. RESULTS: Coxsackievirus A6 (CVA6) DNA was identified in the blistering skin lesions in 6 of 21 patients. Cytotoxic T lymphocytes and natural killer cells expressing granulysin predominantly infiltrated into the skin lesions, sharing the histopathological features with SJS. Intact CVA6 viral particles were identified in the blister fluids and skin lesions by electron microscopy. The phylogenetic analysis of the viral genome showed the CVA6 DNA sequence sharing higher similarity (97.6%-98.1%) to CVA6 strains reported from Finland at 2008. CONCLUSIONS: This study identifies a new variant of CVA6 as the causative agent for severe mucocutaneous blistering reactions mimicking SCAR. An awareness of this unusual presentation of HEV infection is needed in the epidemic area.

Effectiveness of case isolation and class suspension in mitigation of enterovirus transmission in children.

BACKGROUND: Appropriate mitigation strategy to minimize enterovirus (EV) transmission among children is essential to control severe EV epidemics. Scientific evidence for the effectiveness of case isolation and class suspension is lacking. METHODS: EV-infected children ≤ eight years are asked to stay at home for seven days. Classes were suspended for seven days if there are more than two classmates having an onset of herpangina or hand, foot, and mouth disease in one classroom within one week. Study subjects are divided into two groups, group A with class suspension for one week and group B without class suspension. RESULTS: Among 4153 reported EV-infected children from 1085 classes in May and June, 2015 were enrolled. Median incidence of EV infection in a class was 7% (range 3% -60%). The incidence was higher in group A (median 14%, range 3-60%) than that in group B (median 6%, range 3-80%) (P < 0.01). The median incidence is highest in day care center (20%), followed by kindergarten (8%), and primary school (4%) (P < 0.01). Most secondary cases in group A appeared within seven days after the disease onset of index case in the same class. The incidence of EV infection remained low and was similar between the two groups eight days and beyond after the disease onset of index cases. CONCLUSIONS: Targeted class suspension for seven days with case isolation for seven days is an effective measure to mitigate transmission of EV infection in children.

Clinical aspects and genetic analysis of Taiwanese patients with the phenotype of hyper-immunoglobulin E recurrent infection syndromes (HIES).

BACKGROUND: Hyper-immunoglobulin E recurrent infection syndromes (HIES) has characteristic features and identified mutations. This study investigated clinical features and causal candidate mutations in Taiwanese patients with the HIES phenotype on referral base over 23 million inhabitants. PATIENTS AND METHODS: Clinical manifestations of the HIES phenotype, severity scoring, immunological functions and candidate genes of signal transducer and activator of transcription 3 (STAT3), tyrosine kinase 2 (TYKZ), and dedicator of cytokineses 8 (DOCK8) were analyzed. RESULTS: Between 1985 and 2009, six sporadic and two siblings met HIES criteria (onset age: 2-54 months; severity score: 31-65) out of 187 patients with primary immunodeficiencies. Five patients with the autosomal dominant (AD)-HIES phenotype presented as pneumatocoele, bronchiectasis, retained primary teeth, minor trauma fracture, scoliosis, coronary aneurysm, and lymphoma. Three with the autosomal recessive (AR)-HIES phenotype and impaired lymphocyte proliferation function had herpes simplex virus infection, molluscum contagiosum, and cerebral vasculitis. Notably in one patient with the AR-HIES phenotype, unintentional lead component in traditional application herbs for accelerating wound healing deposited in basal ganglia and aggravated involuntary movement relative to cerebral vacculitis. Those with mildly elevated memory T cells and decreased memory B cells trended to develop arteritis. Of five AD-HIES patients, three were mortalities from acute myocardial infarction, Proteus mirabilis, and Staphylococcus aureus sepsis. Only one had de novo novel STAT3 (Gln 469 Arg) mutation with "relative" lower HIES STAT3 score. CONCLUSIONS: Known genetic defects responsible for the HIES phenotype are not so common in Taiwan. This may infer genetic variations in different ethnicities although selection bias and under-diagnosis for HIES with known genetic defects could be contribution factors.

Neurodevelopment and cognition in children after enterovirus 71 infection.

BACKGROUND: Enterovirus 71 is a common cause of hand, foot, and mouth disease and encephalitis in Asia and elsewhere. The long-term neurologic and psychiatric effects of this viral infection on the central nervous system (CNS) are not well understood. METHODS: We conducted long-term follow-up of 142 children after enterovirus 71 infection with CNS involvement - 61 who had aseptic meningitis, 53 who had severe CNS involvement, and 28 who had cardiopulmonary failure after CNS involvement. At a median follow-up of 2.9 years (range, 1.0 to 7.4) after infection, the children received physical and neurologic examinations. We administered the Denver Developmental Screening Test (DDST II) to children 6 years of age or younger and the Wechsler intelligence test to children 4 years of age or older. RESULTS: Nine of the 16 patients with a poliomyelitis-like syndrome (56%) and 1 of the 5 patients with encephalomyelitis (20%) had sequelae involving limb weakness and atrophy. Eighteen of the 28 patients with cardiopulmonary failure after CNS involvement (64%) had limb weakness and atrophy, 17 (61%) required tube feeding, and 16 (57%) required ventilator support. Among patients who underwent DDST II assessment, delayed neurodevelopment was found in only 1 of 20 patients (5%) with severe CNS involvement and in 21 of 28 patients (75%) with cardiopulmonary failure (P<0.001 for the overall comparison). Children with cardiopulmonary failure after CNS involvement scored lower on intelligence tests than did children with CNS involvement alone (P=0.003). CONCLUSIONS: Enterovirus 71 infection with CNS involvement and cardiopulmonary failure may be associated with neurologic sequelae, delayed neurodevelopment, and reduced cognitive functioning. Children with CNS involvement without cardiopulmonary failure did well on neurodevelopment tests. (ClinicalTrials.gov number, NCT00172393 [ClinicalTrials.gov].).

Epitope-associated and specificity-focused features of EV71-neutralizing antibody repertoires from plasmablasts of infected children.

Protective antibody levels are critical for protection from severe enterovirus 71 infection. However, little is known about the specificities and functional properties of the enterovirus 71-specific antibodies induced by natural infection in humans. Here we characterize 191 plasmablast-derived monoclonal antibodies from three enterovirus 71-infected children, each of whom shows a distinct serological response. Of the 84 enterovirus 71-specific antibodies, neutralizing antibodies that target the rims and floor of the capsid canyon exhibit broad and potent activities at the nanogram level against viruses isolated in 1998-2016. We also find a subset of infected children whose enterovirus 71-specific antibodies are focused on the 3- and 2-fold plateau epitopes localized at the margin of pentamers, and this type of antibody response is associated with lower serum titers against recently circulating strains. Our data provide new insights into the enterovirus 71-specific antibodies induced by natural infection at the serological and clonal levels.Enterovirus 71 is a leading cause of hand-foot-and-mouth disease and herpangina. Here, the authors characterize a large panel of plasmablast-derived IgG mAbs that target the capsid of EV71 to identify neutralizing antibodies induced by natural infection.

Elevated expression of circulating miR876-5p is a specific response to severe EV71 infections.

Human enterovirus 71 (EV71) is a major causative agent of hand, foot, and, mouth disease, accounting for more than 65% of recent outbreaks. Following enteroviral infection, the host responses are crucial indicators for the development of a diagnosis regarding the clinical severity of EV71 infections. In this study, we implemented NanoString nCounter technology to characterize the responses of serum microRNA (miRNA) profiles to various EV71 infection diseases. Upon EV71 infection, 44 miRNAs were observed in patients with EV71 infections, with at least a 2-fold elevation and 133 miRNAs with a 2-fold reduction compared with the same miRNAs in healthy controls. Further detailed work with miR876-5p, a 9.5-fold change of upregulated miR-876-5p expression was observed in cases with severe EV71 symptoms, revealed that in vitro and in vivo knockdown of miR876-5p reduced viral RNA in cultured cells, and attenuated the severity of symptoms in EV71-infected mice. Altogether, we demonstrated that the elevated expression of circulating miR876-5p is a specific response to severe EV71 infections.

Proteome demonstration of alpha-1-acid glycoprotein and alpha-1-antichymotrypsin candidate biomarkers for diagnosis of enterovirus 71 infection.

BACKGROUND: Human enterovirus 71 (EV71) is the major causative agents of hand-foot-and-mouth disease and frequently associated with severe complications such as encephalitis and death. Understanding the host response following enteroviral infection may facilitate the development of biomarkers for EV71 infections. METHODS: We implemented two-dimensional gel electrophoresis technology on proteins prepared from serum obtained from 4 mild and 4 severe cases of EV71 infections and 4 healthy control children, to investigate the differentially expressed proteins. The differential expressed proteins were further identified with liquid chromatography-mass spectrometry/mass spectrometry analysis and western blotting validation. RESULTS: A total of 27 differentially expressed proteins were picked and identified with liquid chromatography-mass spectrometry/mass spectrometry. Of the 27 identified proteins, 6 proteins were up-regulated in the mild-infected and severe EV71-infected patients in comparison to the healthy control group. Two proteins, alpha-1-acid-glycoprotein (AGP1) and alpha-antichymotrypsin (AACT), were not detected in the EV71-infected patients, but appeared in the control patient. Western blotting analysis demonstrated that AGP1 and AACT proteins were negatively associated with the clinical severity of EV71 infection. Similarly, both of the proteins were not detected in the secretion medium from the EV71-infected neuroblastoma cells, but detected in the mock-infected cells, suggesting that differentially expressed AGP1/AACT protein levels are in response to EV71 infections. CONCLUSIONS: Two candidate proteins AGP1 and AACT, whose expression levels were reduced under the EV71 infection pathological condition, provide useful source of information for potential diagnostic biomarkers of EV71 infection in children.

Use of molecular assay in diagnosis of hand, foot and mouth disease caused by enterovirus 71 or coxsackievirus A 16.

Hand, foot and mouth disease is a common illness in children and is usually caused by coxsackievirus A 16 and enterovirus 71. It has been noted that enterovirus 71 infection is more severe with significantly greater frequency of serious complications and fatality than coxsackievirus A 16. Therefore, it is important to develop a rapid and specific assay for discriminating coxsackievirus A 16 and enterovirus 71 in hand, foot and mouth disease outbreaks. In this study we designed two sets of RT-PCR primers specific for coxsackievirus A 16 and enterovirus 71. One hundred and eighty-nine viruses were evaluated for this molecular diagnosis assay. Among 110 enterovirus 71 strains, the enterovirus 71 specific primers gave clear signal for 107 clinical enterovirus 71 isolates and three reference enterovirus 71 strains. None of coxsackievirus A 16, other enteroviruses or non-enteroviruses show signal for enterovirus 71-specific primers. On the other hand, among 28 coxsackievirus A 16 strains, the coxsackievirus A 16-specific primers detect 27 clinical isolates and one reference strain but show no cross-reaction with other viruses. The molecular assay developed in this study provides a sensitive and specific way to distinguish coxsackievirus A 16 and enterovirus 71 induced hand, foot and mouth disease, which will be a useful rapid diagnostic method in future outbreaks.

Ludwig's angina following herpetic gingivostomatitis in a toddler with tetralogy of Fallot.

Ludwig's angina is a rare but potentially lethal cellulitis of the submandibular space that occurs most often in young adults with predisposing odontogenic infection. In contrast to adult cases, most children with Ludwig's angina have no initiating factor. We report a case of Ludwig's angina in a 15-month-old boy which developed after an episode of herpetic gingivostomatitis. Under close monitoring of respiratory status, the condition was successfully managed with antibiotic treatment. This case illustrates that Ludwig's angina can develop in association with herpetic gingivostomatitis, which is a common and usually self-limited disease in pediatric patients. Prompt recognition and aggressive management of this rare and severe secondary bacterial infection are the keys to avoiding unnecessary morbidity and mortality.

Transmission and clinical features of enterovirus 71 infections in household contacts in Taiwan.

CONTEXT: Although enterovirus 71 has caused epidemics associated with significant morbidity and mortality, its transmission has not been thoroughly investigated. OBJECTIVES: To investigate enterovirus 71 transmission and determine clinical outcomes within households. DESIGN, SETTING, AND PARTICIPANTS: Prospective family cohort study to investigate patients at a children's hospital in Taiwan and family members of these patients who had signs and symptoms suggestive of enterovirus 71 between February 2001 and August 2002. Patients and household members underwent clinical evaluations, virological studies, questionnaire-based interviews, and were followed up for 6 months. MAIN OUTCOME MEASURES: Enterovirus 71 infection, defined as a positive viral culture from a throat or rectal swab, or the presence of IgM or a 4-fold increase in neutralizing antibody in serum; and clinical syndromes, defined as asymptomatic; uncomplicated symptomatic; and complicated; with unfavorable outcomes of sequelae or death. RESULTS: Ninety-four families (433 family members) had at least 1 family member with evidence of enterovirus 71 infection. The overall enterovirus 71 transmission rate to household contacts was 52% (176/339 household contacts). Transmission rates were 84% for siblings (70/83); 83%, cousins (19/23); 41%, parents (72/175); 28%, grandparents (10/36); and 26%, uncles and aunts (5/19). Of 183 infected children, 11 (6%) were asymptomatic and 133 (73%) had uncomplicated illnesses (hand, foot, and mouth disease, herpangina, nonspecific febrile illness, upper respiratory tract infection, enteritis, or viral exanthema). Twenty-one percent (39/183) experienced complicated syndromes including the central nervous system or cardiopulmonary failure. During the 6-month follow-up, 10 died and 13 had long-term sequelae consisting of dysfunction in swallowing, cranial nerve palsies, central hypoventilation, or limb weakness and atrophy. Age younger than 3 years was the most significant factor associated with an unfavorable outcome in children (P =.004). Among 87 infected adults, 46 (53%) were asymptomatic, 34 (39%) had nonspecific illnesses of fever, sore throat, or gastrointestinal discomfort, and 7 (8%) had hand, foot, and mouth disease. There were no complicated cases in adults. CONCLUSIONS: Enterovirus 71 household transmission rates were high for children in Taiwan and severe disease with serious complications, sequelae, and death occurred frequently. In contrast, adults had a much lower rate of acquisition of the infection and much less adverse sequelae.

Bedside immunochromatographic test for enterovirus 71 infection in children.

BACKGROUND: Enterovirus 71 (EV71) causes frequent outbreaks worldwide, particularly in the Asia-Pacific area. Its quick spread is a critical challenge for public health and timely preventive measures and clinical management therefore rely on early detection. There is a need for a rapid, easy-to-use, and reliable method for detecting EV71 infections. OBJECTIVE: The study aimed to evaluate a bedside immunochromatography (ICT) kit for diagnosing acute EV71 infection in children. STUDY DESIGN: Pediatric patients with herpangina or hand-foot-mouth disease were randomly and prospectively enrolled from hospitals across Taiwan. Throat or rectal swabs were collected for viral culture and reverse-transcriptase polymerase chain reaction (RTPCR). For the ICT kit, whole blood was obtained by ear piercing, finger-sticking, or venipuncture. The results of ICT, virus isolation and RTPCR in clinical samples were compared. RESULTS: Of the 156 patients enrolled, 91 (58%), 64 (41%) and 72 (46%) had positive results of the ICT kit, viral culture and RTPCR, respectively. Laboratory-confirmed infection with either positive EV71 culture or RTPCR was used as the diagnostic standard. The sensitivity and specificity of the ICT kit was 84% and 77%, respectively. The viral culture and RTPCR had relatively lower sensitivity but higher specificity. The patient's age did not affect the performance of the ICT, viral culture and RTPCR. However, a low sensitivity of ICT kit was noted before the second day of disease onset. CONCLUSIONS: The ICT kit may serve as a simple, quick and reliable method for the bedside diagnosis of acute EV71 infection in children.

Herpetic gingivostomatitis with severe hepatitis in a previously healthy child.

A previously healthy boy aged 9 years and 11 months was admitted due to herpetic gingivostomatitis with poor intake. He also had fever, neutropenia, and elevated serum aminotransferase level (> 1000 IU/mL). Prolonged prothrombin time, mild gastrointestinal hemorrhage and transient decreased conscious level were noted during hospital days 2 and 3. Intravenous acyclovir therapy commenced on hospital day 2 and his serum aminotransferase level peaked (> 4000 IU/mL) on hospital day 3 and then improved gradually. A throat swab was positive for human herpes simplex virus (HSV)-1, serological test was positive for acute primary HSV-1 infection, and a blood specimen was also strongly positive for HSV-1 by polymerase chain reaction. He received a 14-day course of intravenous acyclovir and recovered uneventfully. Herpetic gingivostomatitis, although mostly benign and self-limited, may be complicated with severe hepatitis, even in immunocompetent hosts.

Comparative genomic analysis of coxsackievirus A6 strains of different clinical disease entities.

BACKGROUND: Studies regarding coxsackievirus A6 (CVA6) infection were limited. In Taiwan, outbreaks of CVA6 occurred in 2009 and 2010, respectively, but the clinical manifestations were markedly different. We conducted a study to compare the clinical features and genomic sequence between the two years. METHODOLOGY/PRINCIPAL FINDINGS: In 2009 and 2010, 205 patients with coxsackievirus A6 (CVA6) infection were treated at Chang Gung Memorial Hospital. Detailed clinical features were obtained from 126 inpatients, 62 in 2009 and 64 in 2010. Between the inpatients in 2009 and 2010, no statistically significant difference was noted in terms of demographics, length of hospital stay and laboratory data. Significantly more patients in 2009 presented with herpangina (82%) while more patients in 2010 presented with hand-foot-mouth disease (HFMD; 67%) and skin rash beyond the typical sites for HFMD. Complete genomic sequences were determined and compared for three isolates from patients with herpangina in 2009 and three isolates from patients with HFMD in 2010. The complete sequences showed that 2009 and 2010 CVA6 isolates were indistinguishable by partial VP1 genes, but there were 5 unique nucleotide changes in 3' UTR, and 23 out of 2201 (1%) amino acids were different. 2010 viruses underwent the largest number of amino acid changes in 3CD protein, which is the precursor of both 3C protease and 3D polymerase. CONCLUSIONS: Since 2008 in Finland, outbreaks of HFMD due to CVA6 were noted internationally. CVA6 of different genetic background may cause different clinical manifestations such as herpangina and HFMD.

Clinical and epidemiologic features of Coxsackievirus A6 infection in children in northern Taiwan between 2004 and 2009.

BACKGROUND: Isolates of Coxsackievirus A6 (Cox A6) is increasing clinically in 2009 in Taiwan but detailed clinical features of Cox A6 infections in children have not been reported. This study is to define clinical manifestations and laboratory findings of Cox A6 infection in children. METHODS: From January 2004 to December 2009, a total of 4,664 children with enterovirus infections, based on throat virus culture, were treated in Chang Gung Children's hospital. Two hundred and ninety-six (6.3%) patients positive for Cox A6 infection were included in this study. One hundred and forty-one (47.6%) inpatients were further analyzed for clinical presentations, laboratory findings, and clinical diagnoses. RESULTS: There were two peaks of Cox A6 infection in 2007 and 2009 during the study period, especially during the warm season. The proportion of Cox A6 among total enterovirus isolates was 15.5% in 2007 and up to 22.2% in 2009. The mean age of inpatients was 2.42 ± 0.14 years. The mean hospitalization duration was 4.21 ± 0.11 days. The most common symptoms were fever (100%), oral ulcers (90.8%), and decreased oral intake (89.4%). The mean duration of fever was 2.78 ± 1 days (range, 1-7 days). Seventy-seven (54.6%) patients had fever more than 3 days. The mean leukocyte count was 14,850/mm(3), and 63 (45%) patients had leukocytosis (>15,000/mm(3)). The mean serum C-reactive protein (CRP) level was 44.1 ± 3.3 mg/L (normal, <10 mg/L) and 62 (44%) had a CRP level >40 mg/L. One hundred and eight (76.6%) inpatients were diagnosed as herpangina and 18 (12.8%) hand-foot-mouth disease. Three patients had complications, including aseptic meningitis in one and encephalitis in two. All 141 inpatients recovered uneventfully. CONCLUSIONS: Cox A6 is among the major serotypes of enteroviruses in Taiwan and most cases presented as herpangina and hand-foot-mouth disease. Nearly half of the cases may have leukocytosis and elevated CRP levels. Outcomes are usually good.

Comparison of clinical features between coxsackievirus A2 and enterovirus 71 during the enterovirus outbreak in Taiwan, 2008: a children's hospital experience.

BACKGROUND/PURPOSE: Coxsackievirus A2 (Cox A2) was the predominant serotype in the enterovirus outbreak in Taiwan, 2008. However, detailed clinical features of Cox A2 infection have not been reported. In this study, we compared Cox A2 with enterovirus 71 (EV71) in terms of clinical manifestation and epidemiology during the 2008 enterovirus outbreak in Taiwan. METHODS: A total of 280 hospitalized patients (97 with culture-proven EV71 infection and 183 with culture-proven Cox A2 infection) in 2008 at the Chang Gung Children's Medical Center were enrolled in this study. Epidemiologic data, clinical manifestations, and outcomes for these patients were collected and compared. RESULTS: Both Cox A2 and EV71 serotypes peaked in June and declined soon afterwards. Seventy-one percent of the patients were younger than 3 years of age. Both groups had the same male-to-female ratio of 1.6:1. Patients with EV71 infection had a significantly longer hospitalization period (4.1 vs. 3.0 days, p< 0.001). Fever, fever for more than 3 days with a temperature above 39 degrees C, lethargy, poor activity, poor appetite and a myoclonic jerk were significantly associated with EV71 infection. Fever, or fever with a temperature above 39 degrees C, febrile seizure, elevated white cell counts, and elevated serum C-reactive protein concentrations were significantly associated with Cox A2 infection. Most patients with EV71 infection presented with hand-foot-mouth disease (78.3%), while most Cox A2-infected patients presented with herpangina (83.6%). Central nervous system complications were found in 18.6% of EV71-infected children, but only in 1.1% of Cox A2-infected children. All the patients with Cox A2 infection showed total recovery. One patient with EV71 infection died from encephalitis with cardiopulmonary failure, and 6.2% of EV71-infected children had neurologic sequelae. CONCLUSION: Both Cox A2 and EV71 serotypes accounted for the enterovirus outbreak in Taiwanese children in 2008. Compared with those infected by EV71, the children with Cox A2 infection mostly presented with herpangina, had fewer central nervous system complications, and had better overall outcome.

An investigation of epidemic enterovirus 71 infection in Taiwan, 2008: clinical, virologic, and serologic features.

BACKGROUND: Enterovirus 71 (EV71) is causing life-threatening hand-foot-mouth disease in Asia. In Taiwan, EV71 epidemics with different predominant genotypes occurred in 1998 (C2), 2000-2001 (B4), and 2004-2005 (C4). This genotype replacement may have important implications for vaccine development and prediction of epidemics. A nationwide EV71 outbreak occurred again in 2008, which provided a unique opportunity to characterize clinical, virologic, and serologic features of this epidemic. METHODS: We analyzed clinical and virologic data of 111 EV71 patients hospitalized in 2008 and prospectively conducted follow-ups of healthy children from June 2006 to December 2008. RESULTS: Among the 111 EV71 inpatients, 21 (19%) developed complications. Among the 21 complicated cases, 15 had central nervous system complication only, 2 had acute heart failure, and 4 had central nervous system and pulmonary complications. In the prospective study, 11 symptomatic infections and 4 asymptomatic infections were detected. Twenty-two EV71 isolates were genotyped, and 21 of them belong to genotype B5, which is phylogenetically close to B5 viruses circulating in Southeast Asia. Serologic tests show that children infected with B5 viruses have lower geometric mean titers of neutralizing antibody against genotype C4 than those against genotype B5 (P = 0.004, t test). CONCLUSIONS: The 2008 nationwide EV71 epidemic was caused by genotype B5 that was likely introduced to Taiwan from Southeast Asia. Clinical features of the 2008 epidemic were not different from those observed before in Taiwan. Potential antigenic variations between genotype C4 and B5 viruses could be detected and its long-term epidemiologic significance needs further investigation to clarify.

Risk factors of enterovirus 71 infection and associated hand, foot, and mouth disease/herpangina in children during an epidemic in Taiwan.

OBJECTIVE: In 1998, an enterovirus 71 (EV71) epidemic in Taiwan was associated with hand, foot, and mouth disease (HFMD)/herpangina and involved 78 fatal cases. We measured EV71 seroprevalence rates before and after the epidemic and investigated risk factors associated with EV71 infection and illness. METHODS: Neutralizing antibodies to EV71 were assayed for 539 people before the epidemic and 4619 people of similar ages after the epidemic. Questionnaires, which were completed during household interviews after the epidemic, solicited demographic variables, exposure history, and clinical manifestations. RESULTS: A total of 129 106 cases of HFMD were reported during the epidemic. Age-specific pre-epidemic EV71 seroprevalence rates were inversely related to age-specific periepidemic mortality rates (r = -0.82) or severe case rates (r = -0.93). Higher postepidemic EV71 seropositive rates among children who were younger than 3 years positively correlated with higher mortality rates in different areas (r = 0.88). After the epidemic, 51 (56%) of 91 younger siblings of elder siblings who were EV71-seropositive were EV71-seropositive; otherwise, 2.2% (4 of 186) of younger siblings were EV71-seropositive (matched odds ratio [OR]: 10; 95% confidence interval [CI]: 3.4-29). Stepwise multiple logistic regression revealed other factors associated with EV71 infection to be older age (adjusted OR: 2.5; 95% CI: 1.9-3.4), attendance at kindergartens/child care centers (adjusted OR: 1.8; 95% CI: 1.3-2.5), contact with HFMD/herpangina (adjusted OR: 1.6; 95% CI: 1.2-2.1), greater number of children in a family (adjusted OR: 1.4; 95% CI: 1.1-1.7), and rural residence (adjusted OR: 1.4; 95% CI: 1.2-1.6). Twenty-nine percent of preschool children who were infected with EV71 developed HFMD/herpangina. Younger age and contact with HFMD/herpangina were significant factors for the development of EV71-related HFMD/herpangina in these children. CONCLUSIONS: An increased incidence of EV71 infection in young children occurred more often in geographic areas with increased mortality rates. Intrafamilial and kindergarten transmissions among preschool children were major modes of disease transmission during the widespread EV71 epidemic in Taiwan in 1998.