Utility of Droplet Digital PCR Assay for Quantitative Detection of Norovirus in Shellfish, from Production to Consumption in Guangxi, China.

OBJECTIVE: Shellfish are recognized as important vehicles of norovirus-associated gastroenteritis. The present study aimed to monitor norovirus contamination in oysters along the farm-to-fork continuum in Guangxi, a major oyster production area in Southwestern China. METHODS: Oyster samples were collected monthly from farms, markets, and restaurants, from January to December 2016. Norovirus was detected and quantified by one-step reverse transcription-droplet digital polymerase chain reaction (RT-ddPCR). RESULTS: A total of 480 oyster samples were collected and tested for norovirus genogroups I and II. Norovirus was detected in 20.7% of samples, with genogroup II predominating. No significant difference was observed in norovirus prevalence among different sampling sites. The norovirus levels varied widely, with a geometric mean of 19,300 copies/g in digestive glands. Both norovirus prevalence and viral loads showed obvious seasonality, with a strong winter bias. CONCLUSION: This study provides a systematic analysis of norovirus contamination 'from the farm to the fork' in Guangxi. RT-ddPCR can be a useful tool for detection and quantification of low amounts of norovirus in the presence of inhibitors found particularly in foodstuffs. This approach will contribute to the development of strategies for controlling and reducing the risk of human illness resulting from shellfish consumption.

Risk factors for measles in children younger than age 8 months: A case-control study during an outbreak in Guangxi, China, 2013.

BACKGROUND: Following a period (2009-2012) during which zero measles cases were reported, a measles outbreak occurred in 2013 in Bama County, Guangxi, China, that involved more than 100 children younger than age 8 months. We aimed to identify the pitfalls and risk factors while implementing the control measures. METHODS: An outbreak investigation and a case-control study was conducted among children younger than age 8 months. The serum specimens of the study subjects and their mothers were tested for measles immunoglobulin M and immunoglobulin G. RESULTS: The attack rate was 2.3/1,000 population. The median (interquartile range) age was 18.6 months (7.9-52.8 months). The coverage of 2-dose measles-containing vaccine was only 34%. The case-control study revealed 2 independent risk factors: low education level of main caregiver (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.31-6.22) and visiting a hospital 7-21 days before the date of symptoms onset (OR, 9.84; 95% CI, 4.27-22.67). The population attributable fraction of the latter was 52.8%. The mothers of the cases had nonsignificantly higher levels of immunoglobulin M and were significantly more likely to have protective levels of immunoglobulin G than those of the controls. This suggests a reactive rather than protective role of the antibody to the child's infection. CONCLUSIONS: In a near-elimination but low measles-containing vaccine coverage community, supplementary immunization activities should be emphasized for children and women who are potential future mothers. The minimum age of measles-containing vaccine should be further reduced. Hospital measles transmission must also be strictly prevented.

Spatio-temporal clustering of hand, foot, and mouth disease at the county level in Guangxi, China.

BACKGROUND: Amid numerous outbreaks of hand, foot and mouth disease (HFMD) in Asia over the past decade, studies on spatio-temporal clustering are limited. Without this information the distribution of severe cases assumed to be sporadic. We analyzed surveillance data with onset dates between 1 May 2008 to 31 October 2013 with the aim to document the spatio-temporal clustering of HFMD cases and severe cases at the county level. METHODS: Purely temporal and purely spatial descriptive analyses were done. These were followed by a space-time scan statistic for the whole study period and by year to detect the high risk clusters based on a discrete Poisson model. RESULTS: The annual incidence rate of HFMD in Guangxi increased whereas the severe cases peaked in 2010 and 2012. EV71 and CoxA16 were alternating viruses. Both HFMD cases and severe cases had a seasonal peak in April to July. The spatio-temporal cluster of HFMD cases were mainly detected in the northeastern, central and southwestern regions, among which three clusters were observed in Nanning, Liuzhou, Guilin city and their neighbouring areas lasting from 1.2 to 2.5 years. The clusters of severe cases were less consistent in location and included around 40-70% of all severe cases in each year. CONCLUSIONS: Both HFMD cases and severe cases occur in spatio-temporal clusters. The continuous epidemic in Nanning, Liuzhou, Guilin cities and their neighbouring areas and the clusters of severe cases indicate the need for further intensive surveillance.

Comparison of dexmedetomidine and sufentanil for conscious sedation in patients undergoing awake fibreoptic nasotracheal intubation: a prospective, randomised and controlled clinical trial.

INTRODUCTION: Fibreoptic intubation is a valuable technique for difficult airway management in which conscious sedation is paramount. OBJECTIVES: To investigate the efficacy and safety of dexmedetomidine (DEX) and sufentanil (SUF) for conscious sedation during awake nasotracheal intubation under vision by a fibreoptic bronchoscope. METHODS: Forty patients with anticipated difficult airways of American Society of Anesthesiologists I-II scheduled for awake fibreoptic nasotracheal intubation were randomised into two groups each containing 20 subjects. DEX group received DEX at a dose of 1.0 µg/kg over 10 min followed by a continuous infusion of 0.5 µg/kg per hour, while SUF group received SUF target controlled infusion in which the target plasma concentration was 0.3 ng/mL. The nasotracheal intubation conditions and the tolerance to nasotracheal intubation were observed; the occurrence of adverse events including hypertension, bradycardia and respiratory depression during nasotracheal intubation and post-surgical throat pain and hoarseness, and post-surgical memory score were recorded. RESULTS: Better nasotracheal intubation conditions and higher tolerance to intubation were observed in DEX group than those in SUF group (P < 0.05). The incidence rates of hypertension, respiratory depression during intubation and throat pain after surgery were lower in DEX group than those in SUF group; however, the incidence of bradycardia was higher in DEX group than that in SUF group. CONCLUSIONS: DEX provides better nasotracheal intubation conditions, improves patients' tolerance to intubation and leads to lower occurrence of hypertension, respiratory depression and throat pain and post-surgical memory score for sedation during awake fibreoptic nasotracheal intubation.

[Surveillance and research on acute meningitis, encephalitis syndrome in Guangxi, China].

OBJECTIVE: To estimate disease burden and epidemiological characteristics of acute meningitis/encephalitis, and provide the basis for the disease control strategy development. METHODS: A syndrome surveillance system was established in Guigang city with a population of 5 020 000. For the suspected cases, serum and CSF were collected, and bacterial culture, latex agglutination test, real-time PCR and ELISA tests were carried out. All involved cases were identified to 6 categories according to WHO case definition. RESULTS: 1424 suspected cases were evaluated in a surveillance of 30 months, yielding the incidence, mortality and mortality of 11.35/100 000 (1424/12 546 500 person years), 0.43/100 000 (54/12 546 500 person years), 3.79% (54/1424) respectively. A total of 103 and 51 cases were confirmed for JE, bacterial meningitis, with a incidence of 0.82/100 000 (103/12 546 500 person years), 0.41/100 000 (51/12 546 500 person years). 96.10% (99/103) of JE cases and 37.30% (19/51) bacterial meningitis cases occurred in < 10 years old children and < 5 years old children. A clinical misdiagnosis rate of 19.42% (20/103) and 15.69% (8/51) were observed for JE and bacterial meningitis. CONCLUSION: Acute encephalitis, meningitis syndrome can cause a higher burden of disease, of which the main components of viral encephalitis. Most of syndrome is occurred in summer and autumn, mainly reported in children of younger than 10 years old. A quite misdiagnosis would be made among meningitis and encephalitis syndrome cases.