Molecular identification of non-polio enteroviruses in acute flaccid paralysis cases in Henan Province of China in 2019 / 中华微生物学和免疫学杂志

Objective:To investigate the types and distribution of non-polio enterovirus (NPEV) in acute flaccid paralysis (AFP) cases in Henan Province in 2019.Methods:A total of 513 cases of AFP were reported in Henan Province in 2019. Two stool specimens were collected from each case for virus isolation. The VP1 gene of NPEV-positive strains was amplified and sequenced. Sequence alignment and construction of the phylogenetic tree were completed by MEGA5.1 software. The epidemiological data of NPEV-positive strains were statistically analyzed by Excel 2016 and SPSS19 software.Results:A total of 39 NPEV strains were isolated from 513 AFP cases, with an isolation rate of 7.60% (39/513). Among them, 18 strains were group A viruses and 21 strains were group B viruses. Both group A and group B viruses contained seven serotypes. No viruses of group C and group D was isolated. Coxsackievirus A type 4 (CVA4) and CVA16 were the predominant types in group A, and echovirus type 11 (Echo11) was the predominant type in group B. The nucleotide identity between the NPEV-positive strains was 67.4%-100.0%, and their nucleotide identity with the prototype strain was 71.4%-85.6%. NPEV was mainly detected in scattered children under 7 years old with an isolation rate of 84.62% (33/39), and the ratio of male to female was 2.07∶1. No statistically significant difference in the isolation rate was found between different age groups or between different sexes ( P>0.05). Among the group A viruses, CVA2, CVA4 and CVA16 were widely distributed. Echo3, Echo11 and Echo30 were the widely distributed group B viruses. NPEV could be isolated throughout the year except for January. Group A virus infections mainly occurred from April to July, accounting for 66.67% (12/18) of the whole year. Group B virus infections mainly occurred in September, accounting for 28.57% (6/21) of the whole year. Conclusions:The main serotype of NPEV isolated in Henan Province in 2019 was Echo11. The pathogen spectrum and regional distribution of NPEV as well as the isolation rate in different age groups changed significantly compared with those in 2018. Therefore, it was necessary to strengthen monitoring and conduct targeted prevention and control to effectively reduce the occurrence of AFP.

Typing and identification of non-polio enterovirus from acute flaccid paralysis cases in Ningxia,1997-2011 / 中华流行病学杂志

Objective To identify the serotype of 73 non-polio enterovirus (NPEV) strains from acute flaccid paralysis (AFP) cases in Ningxia province,during 1997-2011.Methods Partial sequencing of the VP1 region was amplified by RT-PCR with degenerate primers and sequenced while sequences were compared with the database of GenBank by the BLAST algorithm.Evolution was analyzed by constructing phylogenetic tree using Mega 5.1.Results In this study,a total of 73 NPEVs were analyzed,including 4 strains un-typed,69 strains typed by RT-PCR.A total of 27 serotypes were identified,including 8 serotypes of human enterovirus (HEV)-A,19 serotypes of HEV-B.The HEV-B group (46/69,66.7％) constituted the largest proportion of isolates,followed by HEV-A (23/69,33.3％),but no strains were found that belonged to HEV-C or HEV-D group.In the 69 strains,enterovirus 71 was the most frequently seen isolates,followed by coxsackie-virus A4,16,9 and echovirus 24,6.Conclusion HEV-B was the most predominant (46/69,66.7％) serotype of NPEV in Ningxia during the AFP surveillance,in 1997-2011.

Development of a new method for diagnosis of Group B Coxsackie genome by reverse transcription loop-mediated isothermal amplification.

Background: Coxsackie B viruses (genus, Enterovirus; family, Picornaviridae) can cause aseptic meningitis, encephalitis, pleurodynia, and fatal myocarditis, and are implicated in the pathogenesis of dilated cardiomyopathy. The differentiation of the group B Coxsackieviruses into their subtypes has potential clinical and epidemiological implications. Objective: In this study, we developed a one-step, single-tube genogroup-specific reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of group B Coxsackie genomes targeting 5′ UTR region. Materials and Methods: The amplification can be obtained in less than 1 hour by incubating all the reagents in a single tube with reverse transcriptase and Bst DNA polymerase at 63°C. Detection of gene amplification could be accomplished by agarose gel electrophoresis and the monitoring of gene amplification can also be visualised with the naked eye by using SYBR green I fluorescent dye. Results: A total of 40 samples comprising 31 positive samples and 9 negative samples were used in this study for comparative evaluation. The results were compared with those from Real-Time Polymerase Chain Reaction (RT-PCR). None of the RT-PCR-positive samples were missed by RT-LAMP, thereby indicating a higher sensitivity of the RT-LAMP assay. Conclusion: Thus, due to easy operation without a requirement of sophisticated equipment and skilled personnel, the RT-LAMP assay reported here is extremely rapid, cost-effective, highly sensitive, and specific and has potential usefulness for rapid detection of non-polio enterovirus (NPEV) not only by well-equipped laboratories but also by peripheral diagnostic laboratories with limited financial resources in developing countries.

Clinical study of 15 children with hand foot and month disease and acute flaccid paralysis / 中华急诊医学杂志

Objective To discuss the clinical characteristics and prognosis of 15 children with hand foot and mouth disease (HFMD) and acute flaccid paralysis (AFP) who were admitted to Beijing Ditan Hospital during the outbreak of HFMD in 2008. Method The epidemiology, clinical manifestations, cerebrospinal fluid (CSF),magnetic resonance imaging and prognosis of 15 children with HFMD and AFP were retrospectively reviewed. The recovery of the patients' affected extremities were monitored for 4 weeks. Results The mean age of these patients was (22.47 ± 20.68) months (range: 5～72 months). Acute paralysis developed (3.47 ± 1.68) days after the onset of fever and progressed to maximum severity within (1～2) days. Poliomyelitis-like syndrome was observed in all cases. Of the 15 cases, 10 had monoplegia of lower limbs, two had paraplegia, one had monoplegia of upper limbs and two had quadriplegia. In these cases, the muscle power varied from level 0 to level 4, and six even showed no muscle power in their affected extremities. Thirteen cases developed neurologic complications (encephalitis, meningitis or ataxia) and three had transient urinary retention. Cerebrospinal MRI examination in eight cases showed hyperintense lesions on T2-weighted images, predominantly in the impaired anterior horn regions of the spinal cord (C2～C7 for cases with upper extremity impairments and T12～L1 for cases with lower extremity impairments), and displayed long T1 signals and long T2 signals. In addition, the midbrain, brain-stem or medulla was also involved in four cases who also contracted encephalitis or meningitis. The muscle strength in 11 patients with single lower extremity impairment showed improvements in the distal limb muscles within 4～8 days, and the other cases showed recovery 2～3 weeks later. Conclusions HFMD in combination with AFP most commonly occurs in children aged less than 2 years old. Acute paralysis develops during the early stage of infection and progresses to a maximum severity within 2 days. In most cases described here, paralysis occurred in a single lower extremity and recovered more rapidly than those with all four limbs affected or with single upper extremity impairment . MRI examination is particularly valuable for the diagnosis and prognosis of AFP because of its high sensitivity and accuracy.