Objective To analyze the genetic characteristics of measles virus strains causing two outbreaks in Guizhou province from November 2014 to March 2015. Methods Throat swab samples collect-ed from measles cases in two outbreaks were inoculated into Vero/SLAM cells. Viral RNAs were extracted from positive cultures. Nucleoprotein genes were amplified by using reverse transcription-polymerase chain reaction ( RT-PCR) and the PCR products were sequenced and analyzed. Results Eleven strains of wild-type measles virus were isolated from the two measles outbreaks and all of them belonged to H1a sub-geno-type. Phylogenetic analysis showed that those strains were clustered into two distinct branches. Differences in nucleotide and amino acid genetic distances between the 11 strains of measles virus and the WHO reference strain of H1a sub-genotype (Chin9322) were 1. 1%-1. 6% and 0. 7%-3. 4%, respectively. Compared with the reference strain Chin9322 and Guizhou epidemic strains in recent years, six strains showed amino acid sequence mutations in 47 ( G to S) , 82 ( S to G) and 122 ( R to K) sites and two strains had a mutation in 98 ( P-L) site. Conclusion H1a sub-genotype measles virus was the predominant pathogen causing two measles outbreaks in Guizhou province during 2014 to 2015. Moreover, it was also a predominant sub-geno-type circulating in China and Guizhou province. Different measles virus strains of H1a sub-genotype contin-ued to be prevalent in Guizhou province. This study provided some scientific data for the control and elimina-tion of measles in Guizhou province.

Objective To identify the rubella virus circulated in Guizhou province in 2012 ,and confirm the genotype and analyze the genetic characterization of rubella virus isolated .Methods The throat swab samples were collected from suspected rubella cases during the rubella outbreak and sporadic in 2012 .Rubella virus isolation was performed using Vero/SLAM cells .The presence of vi-ral RNA was detected using real-time RT-PCR after RNA extraction from infected tissue culture cells .Fragments of 944 nucleotides of E1 genes of the isolates were amplified by RT-PCR ,the PCR products were directly sequenced and analyzed .The phylogenetic trees based on the 739 nucleotide sequences 1E was conducted with the rubella viruses isolated in Guizhou province in 2012 and 32 WHO reference sequences representing 13 genotypes .Results 5 rubella virus strains were isolated in Guizhou province for the first time .The results of phylogenetic analysis showed that all 5 rubella virus isolates belong to genotype 1E .The nucleotide acid and a-mino acid homology among 5 rubella virus isolates were 99 .8% -100 .0% and 100 .0% respectively .Compared with the WHO ref-erence strain (Chinese strain T14-CH-02) ,the nucleotide acid and amino acid homology were 98 .7% -98 .9% and 100 .0% respec-tively ;while compared with another WHO reference strain (Malaysia strains M1-MAL-01) ,the nucleotide acid and amino acid ho-mology were 97 .5% -97 .6% and 99 .5% .Conclusion Genotype 1E rubella virus was the predominant genotype in Guizhou prov-ince in 2012 ,which was similar to the other provinces .This study accumulated the molecular epidemiological baseline date in Guizhou province .

Objective To observe the changes of abdominal oxygen saturation in very low birth weight infants (VLBWI)with feeding intolerance (FI)within 1 4 days after birth monitored by near infrared spectroscopy (NIRS).Methods VLBWI fitting entry criteria were enrolled into this study.NIRS monitoring was carried out to detect cerebral oxygen saturation (ScO2 )and abdominal oxygen saturation (SsO2 ).Data were analyzed between FI infants and feeding tolerance (FT)infants.FI was defined as follows:gastric residual of more than 50% of the previous feeding volume;emesis or abdominal distention or both;decrease,delay or discontinuation of enteral feedings. Results 93 VLBWI were enrolled.52 cases(55.91 %)presented with FI,including 29 cases(31 .1 9%)of gastric residual increasing and 23 cases(24.73%)of emesis with or without abdominal distention within 1 4 days after birth. The levels of SsO2 and SsO2 /ScO2 showed no differences in infants with FT and with FI within 24h after birth (P >0.05).The change rates of the median of SsO2 and SsO2 /ScO2 in FT infants were similar during 1 4 days (P >0.05).While both the change rates of SsO2 and SsO2 /ScO2 were markedly decreased 1 day before and the day of FI (P <0.01 ).The decreasing degree of SsO2 was similar between infants with gastric residual increasing and infants with emesis with or without abdominal distention[(1 6.2 ±5.1 )vs (1 7.4 ±3.6)%,t =0.733,P =0.476]. Conclusion Abdominal oxygen saturation measured by NIRS may be a useful method for infants adjusting the feeding plan.

Objective: To analyze the genetic characteristics of rubella virus isolated from 2012 to 2015 in Guizhou province. Methods: A total of 390 cases of suspected measles were collected from Guizhou measles network laboratory from 2012 to 2015 and 25 cases of rubella cases were diagnosed. Rubella virus isolation was performed using Vero/SLAM cells. The presence of rubella viral RNA was detected using Real-time RT-PCR after RNA extraction from infected tissue culture cells. Fragments of 480 bp and 633 bp nucleotides of E1 genes of the isolates were amplified by RT-PCR and the PCR products were sequenced and spliced. The phylogenetic tree was conducted based on the 739 bp nucleotide sequences of E1 genes and gene characteristic analysis was performed. Results: There were 19 cases of rubella outbreaks and 6 cases of rubella sporadic cases in 25 cases of suspected rubella cases. There were 11 males (44.0%) and 14 females (56.0%). The mean age and standard deviation were (12.3±3.9) years. A total of 10 rubella strains were isolated. The results of phylogenetic analysis showed that 7 strains of rubella virus isolates belonged to genotype 1E and the other belonged to genotype 2B. The nucleotide acid and amino acid homology among 7 strains 1E genotype were 99.0%-100% and 100% respectively. 2B genotype of 3 strains of nucleotide and amino acid homology were 99.4%-100% and 99.5%-100% respectively. Ten strains of rubella virus were not mutated in the E1 glycoprotein gene, Asn 177 and Asn 209 N-type glycosylation sites and E1 antigen epitopes between 213 and 285aa.Among them, 7 strains of 1E genotype had a mutation from leucine to phenylalanine in 338 amino acid, 2 strains of 2B genotype at 377 amino acids from valine to alanine. Conclusion Rubella virus epidemic was caused by 1E and 2B genotypes in Guizhou from 2012 to 2015.Ten strains of rubella virus were highly conserved in nucleotide and amino acid sequences and there was no variation of important functional sites.

Objective:To analyze the viral nucleic acid and cytokines in 12 children with 2019-nCoV infection.Methods:Clinical and laboratory data of the children diagnosed with 2019-nCoV infection in Guangzhou Women and Children′s Medical Center from January to April 2020 were retrospectively analyzed. Throat and anal swabs were collected on alternate days for the detection of 2019-nCoV nucleic acid by fluorescence quantitative PCR. Flow cytometry was used to detect serum cytokines including IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-17F, IL-22, TNF-α and TNF-β during the early (both throat and anal swab tests were positive), the intermediate (throat swab test was negative, while anal swab test remained positive), and the convalescence (both throat and anal swab tests were negative) stages of infection.Results:A total of 12 children were enrolled in this study. The male-to-female ratio was 5∶1. The average age was (7.0±4.3) years. There were two asymptomatic, five mild and five common cases. No severe or critical cases were involved. Initially, throat and anal swab nucleic acid tests were simultaneously positive in nine children newly diagnosed in our hospital and the median time of viral shedding in throat swab was longer than that in throat swab [32 (4.5, 45.0) d vs 3 (2, 9) d, Z=11.0, P=0.010]. The median difference of viral shedding time between anal swab and pharyngeal swab was 25.5 (1.5, 42.8) d. The overall levels of serum cytokines IL-17A, IL -4 and IL-5 in different stages of the disease (early, intermediate and convalescence stage) were statistically different ( Z or F, P values were 8.33, 0.016; 5.36, 0.010 and 6.56, 0.004, respectively), and a significant increase was observed in the intermediate stage of infection. IL-17F, IL-2 and IL-22 were all increased during the infection, but there was no significant statistical difference among the three stages ( P>0.05). Conclusions:It was noted that intestinal viral shedding needed a longer time. Although the infectivity has not been determined, higher requirements have been put forward for disease prevention and control. Cytokines secreted by Th2 and Th17 cells were involved in the immune response in children with non-severe 2019-nCoV infection. Monitoring viral shedding and cytokine changes in pediatric patients would be conducive to disease assessment.

Objective: To investigate the clinical manifestations, diagnosis, and treatment of H1N1 influenza A-associated encephalopathy (IAE) in children. Methods: The clinical manifestations, laboratory tests, cranial magnetic resonance imaging (MRI), electroencephalography (EEG) examinations and treatments of seven children with H1N1 IAE hospitalized in Guangzhou Women and Children′s Medical Center from December 2018 to January 2019 were retrospectively analyzed. Results: Five of the seven children with H1N1 IAE were female. The age at admission was 4 years and 5 months (range 7 months-9 years). Neurological symptoms occurred simultaneously or early (0-3 days) after the flu-like symptom appeared. The main clinical manifestations of neurological symptoms were seizures (repeated seizures in five cases and status convulsion in two cases, including one case of unexpected fever and repeated seizures in a nine-year old girl) accompanied with altered consciousness (drowsiness in five cases and coma in two cases). Cranial MRI in three cases displayed multifocal lesions, mainly in the bilateral thalamus, brainstem and cerebellar hemisphere. MRI also showed reversible splenial lesion in the corpus callusumin in three cases. EEG tracings were characterized by diffuse slow wave activity in four cases, and status epilepticus was monitored in one case. All the 7 cases were treated with oral oseltamivir. Three cases were treated with pulsed methylprednisolone and intravenous immunoglobulin. One case was treated with intravenous immunoglobulin alone and all the patients received oral oseltamivir. All the patients survived, with three patients had minor neurological sequelae at discharge. Conclusions The main clinical manifestations of H1N1 IAE are seizures and altered consciousness. Cranial MRI combined with EEG is helpful for early diagnosis. Intravenous immunoglobulin and (or) methylprednisolone should be considered for severe cases.