COVID-19 Outbreak Caused by Contaminated Packaging of Imported Cold-Chain Products - Liaoning Province, China, July 2020.

What is known about this topic? Few major outbreaks of coronavirus disease 2019 (COVID-19) have occurred in China after major non-pharmaceutical interventions and vaccines have been deployed and implemented. However, sporadic outbreaks that had high possibility to be linked to cold chain products were reported in several cities of China.. What is added by this report? In July 2020, a COVID-19 outbreak occurred in Dalian, China. The investigations of this outbreak strongly suggested that the infection source was from COVID-19 virus-contaminated packaging of frozen seafood during inbound unloading personnel contact. What are the implications for public health practice? Virus contaminated paper surfaces could maintain infectivity for at least 17-24 days at -25 ℃. Exposure to COVID-19 virus-contaminated surfaces is a potential route for introducing the virus to a susceptible population. Countries with no domestic transmission of COVID-19 should consider introducing prevention strategies for both inbound travellers and imported goods. Several measures to prevent the introduction of the virus via cold-chain goods can be implemented.

Long Distance Transmission of SARS-CoV-2 from Contaminated Cold Chain Products to Humans - Qingdao City, Shandong Province, China, September 2020.

What is already known about this topic? Though coronavirus disease 2019 (COVID-19) has largely been controlled in China, several outbreaks of COVID-19 have occurred from importation of cases or of suspected virus-contaminated products. Though several outbreaks have been traced to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated on the outer packaging of cold chain products, live virus has not been obtained. What is added by this report? In September 2020, two dock workers were detected as having asymptomatic SARS-CoV-2 infection using throat swabs during routine screening in Qingdao, China. Epidemiological information showed that the two dock workers were infected after contact with contaminated outer packaging, which was confirmed by genomic sequencing. Compared to the Wuhan reference strain, the sequences from the dock workers and the package materials differed by 12-14 nucleotides. Furthermore, infectious virus from the cold chain products was isolated by cell culture, and typical SARS-CoV-2 particles were observed under electron microscopy. What are the implications for public health practice? The international community should pay close attention to SARS-CoV-2 transmission mode through cold chain, build international cooperative efforts in response, share relevant data, and call on all countries to take effective prevention and control measures to prevent virus contamination in cold-chain food production, marine fishing and processing, transportation, and other operations.

The Role of Chronic Inflammation in Various Diseases and Anti-inflammatory Therapies Containing Natural Products.

Chronic inflammation represents a long-term reaction of the body's immune system to noxious stimuli. Such a sustained inflammatory response sometimes results in lasting damage to healthy tissues and organs. In fact, chronic inflammation is implicated in the development and progression of various diseases, including cardiovascular diseases, respiratory diseases, metabolic diseases, neurodegenerative diseases, and even cancers. Targeting nonresolving inflammation thus provides new opportunities for treating relevant diseases. In this review, we will go over several chronic inflammation-associated diseases first with emphasis on the role of inflammation in their pathogenesis. Then, we will summarize a number of natural products that exhibit therapeutic effects against those diseases by acting on different markers in the inflammatory response. We envision that natural products will remain a rich resource for the discovery of new drugs treating diseases associated with chronic inflammation.

Outbreak of Haff Disease along the Yangtze River, Anhui Province, China, 2016.

We investigated a large outbreak of Haff disease that occurred along the Yangtze River in Anhui Province, China, in 2016. Of the 672 cases identified during the outbreak, 83.3% (560/672) occurred in Wuhu and Ma'anshan. Patients experienced myalgia (100%) and muscle weakness (54.7%). The mean value of myoglobin was 330 + 121.2 ng/mL and of serum creatine kinase 5,439.2 + 4,765.1 U/L. Eating crayfish was the only common exposure among all cases; 96.8% (240/248) of implicated crayfish were caught on the shores of the Yangtze River or its connected ditches. Mean incubation period was 6.2 + 3.8 hours. This case-control study demonstrated that eating the liver of crayfish and eating a large quantity of crayfish were associated with an increased risk for Haff disease. The seasonal increases in crayfish population along the Yangtze River might explain the seasonal outbreaks of Haff disease.

A Cluster of Rhabdomyolysis Syndrome Resulting from Carp Consumption in Gongcheng Yao Autonomous County, Guangxi, 2016.

What is already known about this topic? A common food that has been associated globally with rhabdomyolysis syndrome is freshwater fish including freshwater cod, barracuda, buffalo fish, and pomfret. However, cases caused by freshwater fish have been relatively rare in China. What is added by this report? In this investigation, a cluster of five cases of rhabdomyolysis syndrome were found that were linked to consumption of carp testes and eggs, one of the first carp-related rhabdomyolysis syndrome cases reported in China. What are the implications for public health practice? To avoid similar incidents, food safety education for local residents needs to be prioritized and implemented. In addition, case monitoring of rhabdomyolysis syndrome should be strengthened through more thorough collection of epidemiological data and monitoring of pathogenic foods.

First Outbreak of Occupational Brucellosis Involving Multiple Clusters - Hubei Province, China, 2019.

WHAT IS ALREADY KNOWN ON THIS TOPIC?: Human brucellosis, a neglected zoonotic disease, causes more than 500,000 new cases each year globally. The disease is of major public health concern in China, and northern provinces are traditionally endemic areas. WHAT IS ADDED BY THIS REPORT?: This is the first published outbreak of occupational brucellosis involving multiple clusters in Hubei Province. This investigation characterizes the transmission chain of the outbreak and reveals that provinces south of the Yangtze River are faced with a series of challenges and hurdles to overcome including, but not limited to, health education, law enforcement, and occupational protection. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: In addition to measures aimed at this outbreak, the local agricultural department has issued special notices based on this investigation to adjust and strengthen local eradication program of brucellosis.

A foodborne outbreak of gastroenteritis caused by Norovirus and Bacillus cereus at a university in the Shunyi District of Beijing, China 2018: a retrospective cohort study.

BACKGROUND: On September 4, 2018, a boarding school in the Shunyi District of Beijing, China reported an outbreak of acute gastroenteritis. At least 209 suspected students caused of diarrhea and vomiting. The case was investigated, and control measures were taken to prevent further spread. METHODS: A retrospective cohort study was conducted among the school students and staff in order to test hypothesis that high risk of food served at the school canteen. We collected information on demographics, refectory records, person to person transmission by uniform epidemiological questionnaire. Risk ratios (RR) and 95% confidence intervals (CI) were calculated. Stool specimens of cases and canteen employees, retained food, water, and environmental swabs were investigated by laboratory analysis. RESULTS: We identified 209 cases (including 28 laboratory-confirmed cases) which occurred from August 29 to September 10. All cases were students, and the average age was 20, 52% were male. The outbreak lasted for 13 days, and peaked on September 5. Consumption of Drinks stall and Rice flour stall on September 1 (RR:3.4, 95%CI:1.5-7.8, and RR:7.6, 95%CI:2.8-20.2), Rice flour stall and Fish meal stall on September 2 (RR:4.0, 95%CI:1.2-13.6, and RR:4.6, 95%CI:1.7-12.5), muslim meal stall on September 4 (RR:2.7, 95%CI:1.3-5.4), Barbeque stall on September 5 (RR:3.0, 95%CI:1.2-7.0) were independently associated with increased risk of disease within the following 2 days. Among 35 specimens of rectal swabs or feces from students, 28 specimens were positive. Norovirus GI.6 alone was detected in 23 specimens, Bacillus cereus alone in 3 specimens and both norovirus GI.6 and Bacillus cereus in 2 specimens. Ten specimens of rectal swabs from canteen employees were positive for norovirus GI, and 2 specimens were positive for Bacillus cereus. Four retained food specimens were positive for Bacillus cereus, and environmental samples were negative for any viruses or bacteria. CONCLUSION: Our investigation indicated that canteen employees were infected by two pathogens (norovirus and Bacillus cereus) and transmission may have been possible due to unhygienic practices. Student consumption of food or drink at high-risk stalls was determined as the probable cause of the outbreak.

Effect of hand washing and personal hygiene on hand food mouth disease: A community intervention study.

There are no specific treatment drugs and vaccine for Hand Foot and Mouth Disease (HFMD). Taking effective preventive measures is particularly important for control of HFMD infection. The objective of this study is to evaluate the effect of intervention of intensive education on hand hygiene on HFMD.We randomized 64 villages into intervention and control groups in Handan, Hebei province, China. Parents and caregivers of children 6 to 40 months age group in intervention villages received intensive education on hand hygiene. Control group received general education. The intervention period was from April 1 to July 31, 2011 and April 1 to July 31, 2012. We measured and compare the knowledge and incidences of HFMD between 2 groups.We collected 6484 questionnaires, including 3583 in the intervention group [response rate: 96% (3583/3726)] and 2901 in the control group [response rate: 90% (2901/3224)]. We observed that hand washing habit of children and parent, knowledge of HFMD of parents, children's daily cleaning habits scores improved in the intervention group and higher than that in the control group at both the end of year 1 (April 1-July 31, 2011)and year 2 (April 1-July 31, 2012). The incidence of HFMD (2.1%) in intervention group was significantly lower than that in control group (4.2%) at year 2 (χ = 22.138, P <.001). The positive percent of coli-form on the hand swabs in intervention group (2.00%) were significantly lower than that in control group (9.45%) at the end of year 2.The intervention of intensive education on hand hygiene effectively improved the personal hygiene both of children and parents, as well as reduced the incidence of HFMD. We suggested expanding the intervention measures in community to prevent HFMD.

Zika virus infection in travelers returning from countries with local transmission, Guangdong, China, 2016.

BACKGROUND: Zika virus (ZIKV) is a mosquito-borne virus spreading rapidly in the Americas, Africa, and Asia. No indigenous ZIKV infection had been seen in China. We monitored ZIKV infection among travelers returning to Enping county from ZIKV transmitting countries from 1 March to 10 April 2016. METHODS: We analyzed data including interviews; conducted laboratory test on blood, urine, saliva, conjunctival swab or semen specimens for evidence of ZIKV infection; evaluated household for presence of Aedes mosquitoes or larvae. RESULTS: A total of 925 individuals were screened, 507 (54.8%) were interviewed, 400 (43.2%) provided samples, of which 13 (3.3%) tested positive for ZIKV including 3 asymptomatic. Rash, conjunctivitis, sore throat, fever were the common symptoms; rash was more pronounced in adults than in children. ZIKV RNA was detected for 1-4 days in blood, but longer in urine and saliva (3-32 days and 2-10 days). Among interviewed, 57.0% had good knowledge about ZIKV, 45.8% were worried about ZIKV, 99.2% would go to hospital if they had infection. Aedes mosquitoes or larvae were detected in townships of infected returners. CONCLUSIONS: ZIKV was imported to China. Screening by symptoms alone is inadequate for detecting ZIKV infection. ZIKV surveillance, health-education, and vector control are necessary to decrease risk of ZIKV transmission.

Rubella outbreak and outbreak management in a school setting, China, 2014.

BACKGROUND: An active response to a rubella outbreak may interrupt disease transmission, and outbreak response immunization (ORI) can increase immunity among persons who might otherwise not be protected. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China. We conducted an investigation to assess impact of a policy of exclusion of cases from school and of ORI. METHODS: Active surveillance was used to find cases of rubella. Investigators interviewed teachers and reviewed the absentee records to determine implementation details of school exclusion. ORI was recommended on 2 occasions during the outbreak, one small-scale and one large-scale. Laboratory confirmation tests included serum IgM and IgG measurements to distinguish between acute infection and immunity. A serological survey in 4 classes was used to determine immunity status and identify symptomatic and asymptomatic cases. RESULTS: From February 17 to May 23, 2014, 162 rubella cases (24 laboratory-confirmed and 138 epidemiologically linked) were detected among 1,621 students. Cases ultimately occurred in 27 classes (72.97%) across 37 classes. In 11 classes in which exclusion from school was delayed by 1 or more days, the secondary attack rate was 12.30%, compared with 2.35% in 15 classes with immediate exclusion. ORI increased vaccine coverage from 25.83 % to 86.92%, and the final case of the epidemic was reported one month later. A serological survey of 91 students in 4 classes identified 15 cases, 6 of which were asymptomatic. CONCLUSIONS: The outbreak happened in school with low rubella-containing vaccination coverage. Exclusion from school upon rash/fever onset was associated with lowering the secondary attack rate, but school exclusion alone was not able to stop this outbreak - a large ORI was needed. Assuring complete vaccination upon entry to school is likely to be necessary to ensure coverage is above the herd immunity threshold and prevent outbreaks from happening.

Protective Effect of Hand-Washing and Good Hygienic Habits Against Seasonal Influenza: A Case-Control Study.

Previous observational studies have reported protective effects of hand-washing in reducing upper respiratory infections, little is known about the associations between hand-washing and good hygienic habits and seasonal influenza infection. We conducted a case-control study to test whether the risk of influenza transmission associated with self-reported hand-washing and unhealthy hygienic habits among residents in Fujian Province, southeastern China.Laboratory confirmed seasonal influenza cases were consecutively included in the study as case-patients (n = 100). For each case, we selected 1 control person matched for age and city of residence. Telephone interview was used to collect information on hand-washing and hygienic habits. The associations were analyzed using conditional logistic regression. Compared with the poorest hand-washing score of 0 to 3, odds ratios of influenza infection decreased progressively from 0.26 to 0.029 as hand-washing score increased from 4 to the maximum of 9 (P < 0.001). Compared with the poorest hygienic habit score of 0 to 2, odds ratios of influenza infection decreased from 0.10 to 0.015 with improving score of hygienic habits (P < 0.001). Independent protective factors against influenza infection included good hygienic habits, higher hand-washing score, providing soap or hand cleaner beside the hand-washing basin, and receiving influenza vaccine. Regular hand-washing and good hygienic habits were associated with a reduced risk of influenza infection. These findings support the general recommendation for nonpharmaceutical interventions against influenza.

Epidemiological Feature of Visceral Leishmaniasis in China, 2004-2012.

BACKGROUND: Visceral leishmaniasis (VL) remains an important public health problem in China. It is essential to elucidate the current epidemiological characteristics of VL for designing control policy. METHODS: The data were obtained from China Disease Prevention and Control Information System from 2004 to 2012. Characteristics by major variables, such as age, gender, season and geography were analyzed using SPSS13.0. RESULTS: The incidence of VL in China remained at a lower level in recent years. The outbreak appeared in xinjiang kashgar region in 2008. A total of 3337 VL cases were reported in China from 2004 to 2012, 97.03% of cases were concentrated in Xinjiang, Gansu and Sichuan provinces. The cases under 5 year-old accounted for 59.21%. concentrated in 3 ~ 5 months each year and annual December to January of next year The ratio of males to females was 1.67:1(2088:1249). The lag time between symptom onset and diagnosis of VL appeared a marked decrease after 2008, and were shorter in endemic provinces of Xinjiang, Gansu and Sichuan than non-endemic provinces. The case fatality rate was 2.99% (10/3337) during the study period. CONCLUSION: The reported cases of VL were concentrated in Xinjiang, Gansu, Sichuan provinces in China, 2004-2012. The onset was given priority to children. The lag time between symptom onset and diagnosis of VL were difference among years and provinces. Therefore, prevention and control measures should be focused on improving awareness and capacities of diagnosis and treatment, targeting high-risk people in high-risk areas.

Effectiveness of Rubella vaccine in a rubella outbreak in Guangzhou city, China, 2014.

BACKGROUND: WHO recommends the use of rubella-containing vaccine (RCVs) to prevent rubella and congenital rubella syndrome (CRS). Most licensed rubella vaccines in use globally are based on RA27/3 strains and have estimated vaccine effectiveness (VE) rates of 95-100%. In contrast, China uses a BRD-II strain-based rubella vaccine. Few field studies have been conducted that estimate VE of China's RCV. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China. We conducted an investigation to understand reasons for the outbreak, and we used that investigation to estimate vaccine effectiveness of China's rubella vaccine. METHODS: To identify cases, investigators reviewed records kept by the school doctor and absentee records kept by teachers. Self-administered questionnaires were sent to parents of all students to collect information about the students' symptoms, the results of any physician consultation, and disease history. We obtained demographic information and illness information for all students in the school; vaccination status was determined by inspection of official, parent-held vaccination records. A retrospective cohort study was conducted in 13 classes that had secondary cases of rubella. Using the secondary attack rates, we evaluated VE by the number of RCV doses received and age at vaccination. RESULTS: During the period February 17-May 23, 2014, 162 students (50 suspected cases, 88 probable cases, 24 confirmed cases) were diagnosed with rubella, yielding an overall attack rate of 10% (162/1621). Cases occurred in 27 classes (73%) of 37 classrooms. Secondary cases occurred in 13 classes (35%) of 37 classrooms. A total of 1130 students (69.7%) have vaccination certificates; 419 (37%) students were record-confirmed to have received RCV. For those vaccinated using BRD-II strain vaccine, vaccine effectiveness (VE) was 94% (95%CI: 75-98). VE for measles, mumps, and rubella (MMR) vaccine which is based on either BRD-II or RA27/3 strain was 89% (95%CI: 56-97). VE of a single dose of domestic monovalent rubella vaccine that used BRD-II strain vaccine was 93% (95%CI: 73-98). VE for those who received the vaccine between 1 and 2 years of age was 95% (95% CI: 67-99) while the VE was 100% for those vaccinated after 2 years of age. VE among those who received RCV <12 years ago was 100% while VE among those who received RCV ≥12 years ago was 92% (95%CI: 70-98). CONCLUSIONS: The rubella vaccines used in China that are based on the BRD-II rubella vaccine strain have VE of 94%, which is similar to the more commonly used RA27/3-based RCVs. Low vaccination coverage contributed to this outbreak; early reporting of an outbreak is necessary for effective outbreak response immunization.

[Investigation on the causes of increased hepatitis E cases reported in Guizhou province].

OBJECTIVE: To analyze causes of growing hepatitis E (HE) cases reported in Guizhou province, and probe into existing problems faced by medical institutions in diagnosis of clinical and laboratory-confirmed cases, for the purpose of improving the quality of HE surveillance system. METHODS: Six hospitals reporting greater HE cases from 2007 to 2011 were pinpointed, whose reported cases rose suddenly in 2011. Such cases were investigated by means of impatient medical record review, results of laboratory test and clinician interview. RESULTS: 136 of the 354 reported HE cases investigated were found compliant with the diagnostic criteria of HE with an accordance rate of 38.42%. Difference of the HE diagnostic accordance rate among individual years, hospitals and reporting departments was statistically significant. Such rate of hospital reports was found to be the lowest in 2011, ranging from 0 to 18.18% respectively; HE cases reported by non-infectious departments accounted for 61.30% of total cases reported, with its accordance rate considerably below the infectious departments (8.29%). HE positive cases and HE positive rate in 2011 were significantly higher than that of preceding years. CONCLUSION: Such increase of reported HE cases in 2011 in the province was mostly attributable to more HE laboratory tests made by the hospitals, yet the accordance rates were lower than satisfactory. In this regard, the medical institutions in question were advised to enhance their competency training for HE diagnosis and case report quality.

Outbreak of pulmonary tuberculosis in a Chinese high school, 2009-2010.

BACKGROUND: In February 2009, a high school student was diagnosed with sputum-smear positive pulmonary tuberculosis (TB). One year later, 2 other students in the same grade developed sputum-smear positive TB. METHODS: We used tuberculin skin testing (TST), chest radiography, sputum smear, and symptomatology for case identification. We defined latent TB infection (LTBI) as a TST induration of 15 mm or larger, probable TB as a chest radiograph indicative of TB plus productive cough/hemoptysis for at least 2 weeks or TST induration of 15 mm or larger, and confirmed TB as 2 or more positive sputum smears or 1 positive sputum smear plus a chest radiograph indicative of TB. RESULTS: Of students in the same grade as the primary case-student, 26% (122/476) had LTBI and 4.8% (23/476) had probable/confirmed TB. Of teachers, 43% (18/42) had LTBI and none had probable/confirmed TB. Sharing a classroom with the primary case-student increased risk for LTBI (rate ratio = 2.5; 95% CI: 1.9-3.4) and probable/confirmed TB (rate ratio = 17, 95% CI: 7.8-39). Of students with LTBI in February 2009 who refused prophylaxis, 50% (11/22) had probable/confirmed TB in April 2010. CONCLUSIONS: This TB outbreak was likely started by delayed diagnosis of TB in the case-student and was facilitated by lack of post-exposure chemoprophylaxis. Post-exposure prophylaxis is strongly recommended for all TST-positive students.

Epidemic of measles following the nationwide mass immunization campaign.

BACKGROUND: A prolonged measles epidemic occurred in Wenzhou City, China after a nationwide measles mass immunization campaign (MMIC) in 2010. We conducted an investigation to identify factors contributing to this epidemic and to provide evidence-based recommendations for measles elimination strategies in China. METHODS: Measles was diagnosed using the national standard case-definitions. We estimated the population vaccination coverage based on the proportion of measles patients that had been vaccinated. In a case-control investigation, all measles patients who received treatment in The Second Affiliated Hospital of Wenzhou Medical College (Hospital S) during November 1 to December 31, 2010 served as cases; controls were randomly selected among all other patients who received treatment in Hospital S during the same time period, frequency matched by month of hospital visit. We reviewed medical records of case- and control-patients to compare their exposure history at Hospital S and to its intravenous rehydration room (IV room) during the incubation period (7-21 days before their illness onset). RESULTS: The attack rate of measles in Wenzhou City was 3.3/100,000 during September 1, 2010 to January 11, 2011. Children aged 8-11 m had the highest attack rate (171/100,000) of all age groups. In children not age-eligible for the MMIC but should have been routinely vaccinated after the MMIC, the vaccination rate was only 52%. In the case-control investigation, 60% (25/42) of case-patients compared with 21% (35/168) of control-patients had visited Hospital S (adjusted ORM-H = 5.5, 95% CI = 2.7-11). Among unvaccinated children who had received treatment in Hospital S, 84% (21/25) of case-patients compared 38% (11/29) of control-patients had visited the IV room (adjusted ORM-H = 9.2, 95% CI = 1.5-59). CONCLUSION: Relaxed routine measles vaccination among children after the MMIC was the main factor responsible for this epidemic. Exposure in the IV room at Hospital S facilitated the epidemic. To reach the goal of measles elimination, the Chinese public health authorities should make greater efforts to improve timely routine measles vaccination, and to reduce nosocomial transmission.

[Epidemiological features of typhoid/paratyphoid fever in provinces with high incidence rate and in the whole country, in 2012].

OBJECTIVE: Through analyzing the national statutory reporting data on typhoid, paratyphoid fever in 2012, we were trying to understand the whole picture of typhoid, paratyphoid fever at the national level as well as to understand the trends and characteristics of typhoid and paratyphoid fever in provinces with high incidence rate, so as to the development of prevention and control strategies of the diseases in those high-incidence rate provinces. METHODS: We descriptively analyzed the national typhoid and paratyphoid fever statutory reporting data which was reported through disease surveillance information reporting system in 2012. RESULTS: 11 998 cases with typhoid and paratyphoid fever were reported with 3 fatal ones, in 2012 in the whole country. The incidence rate was 0.89 per 100 000. Compared to the data gathered in 2011, the incidence rates of typhoid/ paratyphoid fever increased by 1.20%. The total number of the confirmed cases on typhoid and paratyphoid fever was 6522 and was accounted for 54.36% of the total cases, in which paratyphoid fever accounted for 36.86%. Cases were mainly involved farmers and followed by students and children. Incidence rates of typhoid and paratyphoid fever in children aged 0-4 years old appeared the highest (respectively 1.31/100 000 and 0.46/100 000). Yunnan,Guizhou,Guangdong,Guangxi, Zhejiang, Hunan and Xinjiang provinces (autonomous regions)were identified as provinces with high-incidence rates of typhoid and paratyphoid fever. During 2005-2012, the incidence rates in most of the above high-incidence provinces showed a downward trend, except for in Guangdong which had only showed a slight change. There were variations on peak period and highly-hit population in seven high-incidence provinces. CONCLUSION: The incidence rate of typhoid/paratyphoid fever was in a relatively low level in China. Prevention and control strategies on the diseases in children under 5 years old remained a challenge, warranted more work to be done. The epidemiological situation is still severe in some high-incidence rate provinces.