The laboratory test procedure to confirm rotavirus vaccine infection in severe complex immunodeficiency patients

The rotavirus vaccine is a live vaccine, and there is a possibility of infection by the virus strain used in the vaccine. We investigated the process of determining whether an infection was caused by the vaccine strain in a severe complex immunodeficiency (SCID) patient with rotavirus infection. The patient was vaccinated with RotaTeq prior to being diagnosed with SCID. The testing process was conducted in the following order: confirming rotavirus infection, determining its genotype, and confirming the vaccine strain. Rotavirus infection was confirmed through enzyme immunoassay and VP6 gene detection. G1 and P[8] were identified by multiplex polymerase chain reaction for the genotype, and G3 was further identified using a single primer. By detecting the fingerprint gene (WC3) of RotaTeq, it was confirmed that the detected virus was the vaccine strain. Genotypes G1 and P[8] were identified, and the infection was suspected of having been caused by rotavirus G1P[8]. G1P[8] is the most commonly detected genotype worldwide and is not included in the recombinant strains used in vaccines. Therefore, the infection was confirmed to have been caused by the vaccine strain by analyzing the genetic relationship between VP4 and VP7. Rotavirus infection by the vaccine strain can be identified through genotyping and fingerprint gene detection. However, genetic linkage analysis will also help to identify vaccine strains.

The laboratory test procedure to confirm rotavirus vaccine infection in severe complex immunodeficiency patients

The rotavirus vaccine is a live vaccine, and there is a possibility of infection by the virus strain used in the vaccine. We investigated the process of determining whether an infection was caused by the vaccine strain in a severe complex immunodeficiency (SCID) patient with rotavirus infection. The patient was vaccinated with RotaTeq prior to being diagnosed with SCID. The testing process was conducted in the following order: confirming rotavirus infection, determining its genotype, and confirming the vaccine strain. Rotavirus infection was confirmed through enzyme immunoassay and VP6 gene detection. G1 and P[8] were identified by multiplex polymerase chain reaction for the genotype, and G3 was further identified using a single primer. By detecting the fingerprint gene (WC3) of RotaTeq, it was confirmed that the detected virus was the vaccine strain. Genotypes G1 and P[8] were identified, and the infection was suspected of having been caused by rotavirus G1P[8]. G1P[8] is the most commonly detected genotype worldwide and is not included in the recombinant strains used in vaccines. Therefore, the infection was confirmed to have been caused by the vaccine strain by analyzing the genetic relationship between VP4 and VP7. Rotavirus infection by the vaccine strain can be identified through genotyping and fingerprint gene detection. However, genetic linkage analysis will also help to identify vaccine strains.

An Outbreak Associated with Sapovirus GI.3 in an Elementary School in Gyeonggi-do, Korea

On October 4, 2018, an outbreak of gastroenteritis associated with sapovirus occurred among elementary school students in Gyeonggi-do, Korea. Epidemiologic studies were conducted in a retrospective cohort approach. Using self-administered questionnaires, we collected information on symptoms and food items consumed. Of the 999 subjects, 17 developed patients that met the case definition. The main symptom was vomiting (100%), and the symptomatic age was 6-12 years. Positive samples were identified by conventional reverse transcription polymerase chain reaction for sequencing. They were classified into genotype GI.3 by phylogenetic analysis. This is the first report of an outbreak associated with sapovirus GI.3 in Korea.

Outbreak associated with Rotavirus G11,P25 in Korea in 2018 / 감염과화학요법

We here report the first outbreak caused by rotavirus G11,P[25] in Korea in 2018, representing a case of re-assortment with pig-derived rotavirus. The genotype constellation was identical to the virus identified in Korea in 2012 as G11-P[25] -I12-R1-C1-M1-A1-N1-T1-E1-H1. The infection source was not known exactly but it must be considered infection from swine.

Outbreak associated with Rotavirus G11,P25 in Korea in 2018 / 감염과화학요법

We here report the first outbreak caused by rotavirus G11,P[25] in Korea in 2018, representing a case of re-assortment with pig-derived rotavirus. The genotype constellation was identical to the virus identified in Korea in 2012 as G11-P[25] -I12-R1-C1-M1-A1-N1-T1-E1-H1. The infection source was not known exactly but it must be considered infection from swine.

Utility of RT-PCR-based Dot-blot Hybridization for Detecting and Genotyping Echoviruses

We attempted to detect and identify virus types quickly by improving an RT-PCR-based dot-blot hybridization test for echoviruses, important human pathogens mainly causing aseptic meningitis. This test was applied to reference viruses of seven echovirus serotypes prevalent in Korea (E6, 7, 9, 11, 13, 25, and 30) and seventy isolates of echovirus isolated in Korea between 2002 and 2004. The primers for target DNA and hybridization probes (25mer, 50mer, and 70mer) were designed within the VP1 region of the echovirus. In RT-PCR, a nonradioactive digoxigenin-DNA labeling mix was added instead of dNTP to initiate PCR. The PCR product was then hybridized against 25mer, 50mer, and 70mer probe DNA spotted on nylon membranes and the reaction was observed. To investigate the optimal conditions for hybridization, various concentrations of target DNA (0.1, 1, 10, and 100 ng/micron l), size of probe DNA (25mer, 50mer, and 70mer), concentrations of probe DNA (10~50 pM), and reaction time were included. In the test zone, the optimal condition in terms of time and cost was a reaction time of 1 h with 10 ng/micron l target DNA concentration and 10 pM of a 50mer probe. We found 100% diagnosis of the serotypes for seven reference echoviruses and 90% (63/70) sensitivity for clinical isolates. Also, tests with this probe for reactivity with seven reference echoviruses by using DNA chips showed that diagnostic identification was possible without other serotype cross-reactivity. Therefore, efficiency analysis of probe and target DNA on clinical specimens by using dot-blot analysis indicated that this system can be applied to the prestages of the DNA chip and that the dot blot analysis itself can be used in applications to develop a tool for diagnosing specific viral serotypes.

Updates on Enterovirus Surveillance in Korea / 감염과화학요법

PURPOSE: We identified the causative viruses from patients with aseptic meningitis, acute hemorrhagic conjunctivitis and other enterovirus-related diseases to understand the epidemiological patterns and prevailing strains of enterovirus infections each year. MATERIALS AND METHODS: During 1999-2003, we examined 3,260 specimens from 2,939 patients with aseptic meningitis or other clinical manifestations for the presence of enteroviruses by using both cell culture/ neutralisation test and reverse transcription-polymerse chain reaction-sequencing. To investigate the etiological agents which caused an epidemic of acute haemorrhagic conjunctivitis, conjunctival swab samples from acute haemorrhagic conjunctivitis patients showing cytopathic effects in HEp2 cells were tested by enteroviral specific PCR. RESULTS: We identified 603 isolates of enteroviruses (20.5%) among 2,939 cases and 22 serotypes of human enteroviruses were isolated during this 5 year period. Echovirus 13 and coxsackievirus A24 in 2002 and coxsackievirus A9 in 2003 were the first enterovirus to be indentified in Korea since we began the enterovirus surveillance in 1993. While an epidemic of echovirus 13 infection in Korea began in Gwangju and Jeolla province in 2002 and spread to Seoul, Gyunggi, Busan, Ulsan and other regions, echovirus 6 isolates in 2002 were mainly detected in Busan specimens and some Gwangju samples. From the nucleotide sequencing of enteroviral PCR products of conjunctival swab specimens, we found 85% nucleotide homology to coxsackievirus A24 (D90457). CONCLUSIONS: We isolated 603 enteroviral isolates among 2939 cases during 1999-2003. Echovirus 13 and coxsackievirus A24 were the first enterovirus to be identified in Korea and caused nationwide epidemics in 2002.

Updates on Enterovirus Surveillance in Korea / 감염과화학요법

PURPOSE: We identified the causative viruses from patients with aseptic meningitis, acute hemorrhagic conjunctivitis and other enterovirus-related diseases to understand the epidemiological patterns and prevailing strains of enterovirus infections each year. MATERIALS AND METHODS: During 1999-2003, we examined 3,260 specimens from 2,939 patients with aseptic meningitis or other clinical manifestations for the presence of enteroviruses by using both cell culture/ neutralisation test and reverse transcription-polymerse chain reaction-sequencing. To investigate the etiological agents which caused an epidemic of acute haemorrhagic conjunctivitis, conjunctival swab samples from acute haemorrhagic conjunctivitis patients showing cytopathic effects in HEp2 cells were tested by enteroviral specific PCR. RESULTS: We identified 603 isolates of enteroviruses (20.5%) among 2,939 cases and 22 serotypes of human enteroviruses were isolated during this 5 year period. Echovirus 13 and coxsackievirus A24 in 2002 and coxsackievirus A9 in 2003 were the first enterovirus to be indentified in Korea since we began the enterovirus surveillance in 1993. While an epidemic of echovirus 13 infection in Korea began in Gwangju and Jeolla province in 2002 and spread to Seoul, Gyunggi, Busan, Ulsan and other regions, echovirus 6 isolates in 2002 were mainly detected in Busan specimens and some Gwangju samples. From the nucleotide sequencing of enteroviral PCR products of conjunctival swab specimens, we found 85% nucleotide homology to coxsackievirus A24 (D90457). CONCLUSIONS: We isolated 603 enteroviral isolates among 2939 cases during 1999-2003. Echovirus 13 and coxsackievirus A24 were the first enterovirus to be identified in Korea and caused nationwide epidemics in 2002.