An outbreak of norovirus-related acute gastroenteritis associated with delivery food in Guangzhou, southern China.

BACKGROUND: A large number of students at a school in Guangzhou city developed a sudden onset of symptoms of diarrhea and vomiting. To help control the outbreak, we conducted an epidemiological investigation to determine the causative agent, sources, role of transmission and risk factors of the infections. METHODS: The study population consisted of probable and confirmed cases. An active search was conducted for cases among all students, teachers and other school staff members. A case control study was carried out using standardized online questionnaires. Data were obtained regarding demographic characteristics, gastrointestinal symptoms, personal hygiene habits, history of contact with a person who had diarrhea and/or vomiting and dining locations during the past 3 days. Rectal swabs or stool samples of the cases and, food handlers, as well as environmental samples were collected to detect potential intestinal viruses and bacteria. We calculated odds ratios and 95% confidence intervals (CIs). RESULTS: A total of 157 individuals fit the definition of a probable case, including 46 with laboratory-confirmed norovirus infection between March 8 and March 22, 2018. The proportion of students who had eaten delivery food 3 days before the onset of illness in the case group was 2.69 times that in the control group (95%CI: 1.88-3.85). Intake of take-out food 3 days earlier, and exposure to similar cases 72 h before onset and case in the same dormitory were risk factors. A total of 20 rectal swab samples from students, 10 rectal swabs from food handlers and 2 environmental swab samples from the out-campus restauranttested positive for norovirus (GII, genogroup II strain). CONCLUSIONS: We investigated an outbreak of norovirus infectious diarrhea. Food handling practices carry potential risk of acute gastroenteritis outbreaks owing to a lack of surveillance and supervision. Greater attention should be paid to the monitoring and supervision of food handlers in off campus restaurant to reduce the incidence of norovirus-related acute gastroenteritis associated with delivery food.

[Sequence analysis of VP1 region of coxsackievirus A4 and coxsackievirus A10 in Guangzhou city, 2010-2012].

OBJECTIVE: To identify the enterovirus from stool samples of patients with hand, foot and mouth disease(HFMD) in Guangzhou from 2010 to 2012 and to perform phylogenetic analysis of the VP1 gene sequences of coxsackievirus A4 and coxsackievirus A10. METHODS: A total of 5 484 samples of suspected cases of HFMD which Guangzhou Center for Disease Control received from 2010 to 2012 were collected.Virus RNA was tested by nested RT-PCR method as human enterovirus 71, coxsackievirus A16, coxsackievirus A4, coxsackievirus A10 and other enteroviruses positive, and 4 111 samples were positive. Phylogenetic tree was constructed by partial VP1 gene sequences of coxsackievirus A4 and coxsackievirus A10 to perform phylogenetic analysis. RESULTS: In 4 111 enterovirus-positive samples, the positive rate of EV71, CoxA16, CoxA10 and CoxA4 was 35.1% (1 443/4 111) , 30.7% (1 261/4 111) , 2.0% (82/4 111),0.8% (31/4 111) respectively. Different enterovirus-positive rate was statistically significant (χ(2) = 148.34, P < 0.05) .Incidences of coxsackievirus A4 positive was highest in 3-year old children as 1.3% (7/534) , and that of coxsackievirus A10 positive was highest in 0-year old children as 3.7% (34/914) . The highest positive rate of diagnosed coxsackievirus A4 positive cases was admitted in April(2.6%, 12/460) , and the highest positive rate of diagnosed coxsackievirus A10 positive cases was admitted in August 4.3% (12/278). Phylogenetic analysis indicated that all the CoxA4 stains were divided into subtype A and subtype B, and the CoxA10 stains were divided into subtypes A, subtype B and subtype C. The VP1 gene nucleotide sequences of CoxA4 and CoxA10 this study measured both belonged to subtype A. CONCLUSIONS: The VP1 gene nucleotide sequences of CoxA4 and CoxA10 in Guangzhou from 2010 to 2012 both belonged to subtype A.

Circulation of Coxsackievirus A6 in hand-foot-mouth disease in Guangzhou, 2010-2012.

BACKGROUND: Hand, foot and mouth disease (HFMD) is usually caused by Enterovirus 71(EV71), and Coxsackievirus A16 (CV-A16) in Guangzhou, the biggest city of South China. However, Coxsackievirus A6 (CV-A6) were observed increased dramatically from 2010-2012. METHODS: In order to understand and to describe the epidemiologic and genetic characteristics of CV-A6, specimens of 5482 suspected HFMD cases were collected and examined by real-time fluorescence PCR. All samples positive for enteroviruses were analyzed by descriptive statistics. Phylogenetic analysis of CV-A6 based on the VP1 sequences was performed to investigate molecular and evolutionary characteristics. RESULTS: Coxsackievirus A6 increased dramatically from 9.04% in 2010 to 23.21% in 2012 and became one of the main causative agents of HFMD in Guangzhou. CV-A6 attack rates were highest in one to two year olds (33.14%). Typical clinic symptoms of CV-A6 HFMD include fever (589/720, 81.81%), maculopopular rash and vesicular exanthema around the perioral area (408/720, 56.66%), intraoral (545/720, 75.69%), the buttock (395/720, 54.86%), the trunk (244/720, 33.89%), the knee (188/720, 26.11%), and the dorsal aspects of hands (437/720, 60.69%). Phylogenetic analysis showed the CV-A6 isolates in this study belonged to Cluster A1 and were similar to those found in Shanghai in 2011 and 2012 (JX495148, KC414735), Shenzhen in 2011 (JX473394), Japan in 2011 (AB649243, AB649246), France in 2010(HE572928), Thailand in 2012(JX556564) and Israel in 2012 and 2013(.KF991010, KF991012).

[An investigation on a case of hand-foot-mouth disease caused by coxsackie-virus A6 associated with a vaccine-derived poliovirus co-infection].

OBJECTIVE: To identify the pathogen and characteristics on a case of hand-foot-mouth disease (HFMD) caused by coxsackie-virus A6 (CA6) associated with vaccine-derived poliovirus (VDPV) co-infection. METHODS: Field epidemiological study at the epidemic area was conducted and 16 stool samples including from the patient and close contacts were collected for isolation and identification of the enterovirus (EV). 21 stool samples from patients diagnosed as HFMD were collected in the same hospital at the same month to detect CA16,EV71, CA6 and PV by real-time RT-PCR or RT-PCR. The VP1 gene of the CA6 was amplified by RT-PCR and PCR products were sequenced and analyzed. RESULTS: The patient showed only HFMD symptoms, but no symptoms related to acute flaccid paralysis (AFP). No EVs were isolated from 16 samples collected from the patient and close contacts. And no AFP cases were found by an active search. A total of 21 samples from patients diagnosed as HFMD were collected in the same hospital at the same month and 4 were found to be EV71, 2 were CA16 and 15 (include the patient)were CA6. Only this patient was found to have had VDPV II infection. The CA6 VP1 gene was amplified from the HFMD patient and 9 other cases from the same hospital at the same month. Nucleotide sequences of the VP1 gene among the 9 strains shared 98.9%-100.0% in homology and 96.0%-100.0% in the deduced amino acid sequences. Phylogenetic analysis of the VP1 sequences categorized the 9 strains into the same branch. There were 6 nucleotides changes including U2909A between the VP1 region of the VDPV strain of the case and Sabin II. Results from phylogenetic analysis on the VP1 sequences indicated that the VDPV strain of the case was different from other VDPVs strains isolated in the world. CONCLUSION: This case was a HFMD which caused by CA6 co-infection with VDPV II and the VDPV was newly discovered. HFMD symptoms of the case were caused by CA6. The reason why this case did not have AFP symptoms was probably due the protective effect of IPV vaccine. No AFP cases were found by the active search for AFP cases conducted in the area, which indicated that VDPV did not cause virus circulation in this area.

[An epidemiological investigation on a food-born outbreak of noroviru caused by Sydney 2012 G II.4 strain].

OBJECTIVE: To identify the source of infection, route of transmission and risk factors related to a cluster of acute gastroenteritis cases in a university of Guangzhou. METHODS: Cases were identified according to the definition. Descriptive epidemiological approaches and case-control study designs were employed in the analysis. All the samples were tested for norovirus by RT-PCR. Positive samples were subjected to both nucleotide sequence and homology analysis. RESULTS: A total of 141 cases related to norovirus gastroenteritis were identified in January 8 to 21, 2013, with the attack rate as 8.5 per thousand (141/16,600). The peak in morbidity was seen on January 8 to 9. No clustering was found in different classes or dormitories. Results from the case-control study revealed that early cases were infected in Restaurant A (OR = 3.46, 95% CI: 1.07-11.16) and the cold shredded chicken set meal (OR = 17.82, 95% CI: 4.46-78.17) served at lunch (OR = 4.34, 95% CI: 1.18 -17.37) on January 7 was under suspicion. A total of 266 samples, including rectal swabs from the patients and kitchen wokers, leftover food and environmental swabs, were collected. Twenty-one samples (collected from 17 persons) were positive for norovirus by RT-PCR. About 29.6% (8/27) of the kitchen workers in the Restaurant A were tested positive for the virus. The pathogen was identified as the new norovirus genotype II.4 variant, termed Sydney 2012. The virus strains isolated from the patients among student and staff and the kitchen workers were 100% identical in their nucleotide sequence. CONCLUSION: This was the first reported acute gastroenteritis outbreak caused by the new norovirus genotype II.4 variant, Sydney 2012, which showed that the food was contaminated by the asymptomatic kitchen workers who carried the virus.

A two-year surveillance of 2009 pandemic influenza A (H1N1) in Guangzhou, China: from pandemic to seasonal influenza?

In this two-years surveillance of 2009 pandemic influenza A (H1N1) (pH1N1) in Guangzhou, China, we reported here that the scale and duration of pH1N1 outbreaks, severe disease and fatality rates of pH1N1 patients were significantly lower or shorter in the second epidemic year (May 2010-April 2011) than those in the first epidemic year (May 2009-April 2010) (P<0.05), but similar to those of seasonal influenza (P>0.05). Similar to seasonal influenza, pre-existing chronic pulmonary diseases was a risk factor associated with fatal cases of pH1N1 influenza. Different from seasonal influenza, which occurred in spring/summer seasons annually, pH1N1 influenza mainly occurred in autumn/winter seasons in the first epidemic year, but prolonged to winter/spring season in the second epidemic year. The information suggests a tendency that the epidemics of pH1N1 influenza may probably further shift to spring/summer seasons and become a predominant subtype of seasonal influenza in coming years in Guangzhou, China.

Factors affecting the long-term results of hypospadias repairs.

PURPOSE: The aim of this study was to explore the relationships between the short- and long-term results of hypospadias repair and identify the factors that could affect the long-term results of hypospadias repair. MATERIALS AND METHODS: Between 1982 and 1988, 142 patients were operated for hypospadias and completed their treatment at Tongji Hospital (Wuhan, China). Their records were analyzed retrospectively, and a detailed questionnaire was mailed to them. RESULTS: One hundred two patients returned the questionnaire. Patients in the proximal hypospadias group, those using Denis-Browne technique, and those with early complications were markedly dissatisfied with the overall results of hypospadias repair and penile appearance. Moreover, their dissatisfaction grew with the number of operations they had. Thirty-nine (95.1%) of 41 patients using the Denis-Browne technique had voiding problems. Forty-nine (48%) of 102 patients felt inhibited in seeking girlfriends or sexual contacts. Moreover, there was a positive correlation between the level of sexual inhibition and operation times. A highly positive correlation was found between the age at the time hypospadias surgery was completed and the extent of being sexually inhibited. The patients in proximal hypospadias group had more erection and ejaculation problems. CONCLUSIONS: The short-term results of hypospadias repair could affect the long-term results significantly, and good short-term results also predict long-term ones. The types of hypospadias, procedures, and complications have significant influences on predicting the long-term results of hypospadias repairs.

The treatment of high and intermediate anorectal malformations: one stage or three procedures?

BACKGROUND/PURPOSE: The aim of this study was to examine the safety, feasibility, and the long-term outcome of complete 1-stage repair of high and intermediate anorectal malformation using posterior sagittal anorectoplasty (PSARP) in a neonate. METHODS: One hundred thirteen patients with high-type and intermediate-type anorectal malformations (ARM) underwent follow-up. Of 113 cases, 48 cases entailed a divided colostomy, definitive operation, and colostomy closure (group I); the other 65 patients underwent 1-stage PSARP (group II). Anorectal function was measured by the modified Wingspread scoring, including "excellent," "good," "fair," and "poor." In barium enema studies, anorectal angulation was judged as "clear," "unclear," and "not present," and leakage of barium was observed in the meantime. For anorectal manometric studies, anal resting pressure (ARP), anal squeezing pressure (ASP), and positive anorectal reflex (PAR) were measured. RESULTS: In group I, the rate of excellent and good scores was 58.3% (28 of 48). In the barium enema examination, 85.4% (41 of 48) was clear and 14.6%(7 of 48) unclear or not present. The rate of barium leakage was 10.4% (5 of 48). In group II, the rate of excellent and good was 53.8% (35 of 65). Anorectal angulations were clear in 83.1% of patients (54 of 65). Barium leakage happened in 7.69% of patients (5 of 65). Early operative complications occurred in 56.3% (27 of 48) of patients in group I and 29.2% (19 of 65) in group II. The incidence of colostomy complications in group I was 39.6% (19 of 48). Soiling and constipation were the major complications after the PSARP operation. The respective rates of constipation in the 2 groups were 47.9% (23 of 48) and 44.6% (29 of 65), and the respective rates of soiling were 47.9% (23 of 48) and 50.8% (33 of 65). There was no significant difference in the mean ARP between the 2 groups. CONCLUSIONS: The 1-stage PSARP procedure in the neonate not only achieves the same long-term outcome as the conventional PSARP procedure but also involves fewer short-term complications. Complete 1-stage repair using the PSARP to treat high-type and intermediate-type anorectal malformations is safe and feasible.