Food Poisoning Caused by Deoxynivalenol at a School in Zhuhai, Guangdong, China, in 2019.

Deoxynivalenol (DON) or "vomitoxin" is a mycotoxin produced by Fusarium species. Few food poisoning cases caused by DON have been reported since the 1990s in China. However, on May 16, 2019, the Zhuhai Center for Disease Control and Prevention received a case report from primary school "S" that many students began vomiting after eating breakfast. To discern the cause and control the outbreak effectively, an epidemiological investigation was carried out. This retrospective cohort study defined both suspected and probable cases of food poisoning using ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry to detect 16 mycotoxins simultaneously. A total of 101 cases (14 suspected and 87 probable) were identified, with an overall attack rate of 8.1%. All cases were in grades 1-3. The main symptoms of probable cases were vomiting (100%) and nausea (63%). The average incubation time was 25 min after eating. Comparison of students who ate breakfast provided by the school with those who did not revealed the relative risk was 6.0 (95% confidence intervals [CI] = 2.2-16) among students in grades 1-3. The concentration of DON in the leftover raw breakfast noodles ranged from 6856 to 11,982 µg/kg and 878.3 to 1074.2 µg/kg in leftover cooked noodles. DON exposure was 1.3-1.6 µg/kg body weight for grades 1-2 and 1.7-2.1 µg/kg body weight for grade 3. The attack rate of grade 3 was 4.3 times higher than that for grades 1-2 (95% CI = 3.0-6.3). The food poisoning outbreak on May 16, 2019 in primary school "S" in China, was determined to be caused by DON-contaminated commercial raw noodles.

Gastroenteritis outbreaks caused by Norovirus genotype II.7 in a college in China (Zhuhai, Guangdong) in 2011.

BACKGROUND: Noroviruses are the most common cause of epidemic gastroenteritis worldwide. Noroviruses are comprised of at least five genogroups (GI-GV) and >35 genotypes. GII.7 is a nonpredominant genotype associated with Norovirus outbreaks. On November 17, 2011, Zhuhai Center for Disease Control monitored an increasing number of gastroenteritis cases at a local college. To determine the causes and control the outbreak effectively, we carried out an epidemiologic investigation. METHODS: Suspected cases were defined as those with one of the following symptoms: nausea, vomiting, abdominal pain, or diarrhea presenting on or after November 15 among the people who lived at the college. Probable cases were defined as cases with vomiting or diarrhea over three times per day on or after November 15. Confirmed cases were suspected or probable cases positive for Norovirus (nucleic acid). We conducted a case-control study to identify risk factors of the outbreak. Norovirus was tested by real-time reverse transcription-polymerase chain reaction, and Norovirus polymerase chain reaction products were further sequenced. RESULTS: In total, 63 cases were identified, which were scattered in all 14 departments of the college. The outbreak lasted for 84 h. Time distribution mode indicated a point-source outbreak. Fifty-one cases and 94 controls were contacted. Seventy-five percent of the cases compared to 19% of the controls were exposed to delicatessens (various salad and meat products) from the "Y" convenience store (odds ratio=12, 95% confidence interval 5.4-28). Laboratory tests showed 14 of the 15 cases and two asymptomatic food handlers were positive for Norovirus nucleic acid. There was 100% similarity between the cases and the food handlers when we compared the nucleotide sequences of Norovirus, which clustered with GII.7 genotype. CONCLUSIONS: Delicatessens from the "Y" convenience store were associated with the GII.7 Norovirus outbreak. We strongly recommend food supervision and quality control in convenience stores to decrease the risk of future Norovirus outbreaks.

[Step Fisher discriminant analysis on severe clinical features of hand foot and mouth disease between enterovirus (EV) 71 and other EV].

OBJECTIVE: To compare the clinical features of severe hand foot and mouth disease between enterovirus (EV) 71 and other EV to find specific diagnosis index of EV71 severe hand foot and mouth disease. METHODS: Case definition were adopted from national guideline of hand foot and mouth disease diagnose (Version 2010). Clinical data of severe hand foot and mouth disease came from case history and contents of questionnaire would include the ones between the time of onset and diagnoses being made. EV and EV71, Cox A16 nucleic acid tested were by RT-PCR in stool samples. Clinical features of severe hand foot and mouth disease between EV71 and other EV were compare. RESULTS: There appeared statistical differences between neurologic symptoms such as tremor, myoclonic jerk, listlessness, convulsion and white blood cell counts in CSF (P < 0.05). Results from the step Fisher discriminant analysis showed only tremor and white blood cell had an increase in CSF, with statistically significant differences. The discriminant equation of EV71 was Y = 3.059X(1) + 3.83X(5) - 2.742 and the equation of other EV was Y = 1.634X(1) + 1.623X(5) - 1.693. The specificity of EV71 was 91% and the specificity of other EV was 40%. CONCLUSION: The increase of clinical features of tremor and white blood cell in CSF could be used as diagnosis index of severe EV71.