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 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.

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.

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.

Measles outbreak on a college campus transmitted through internet cafés.

BACKGROUND: During March 2008, a college in Urumqi, capital of Xinjiang Uygur Autonomous Region in China, reported a measles outbreak, amid a city-wide outbreak involving >2700 cases. METHODS: Suspected case patients were defined as patients with onset of fever (≥38°) and rash between 7 March and 30 April 2008. Probable case patients were defined as suspected case patients with >3 days of rash or known exposure to someone with laboratory-confirmed measles. Confirmed case patients were defined as suspected or probable case patients with Koplik spots or positive titer for immunoglobulin M antibody. We conducted a case-control investigation to identify risk factors for transmission. RESULTS: We identified 162 suspected (attack rate, 1.9%), 99 probable, and 62 confirmed case patients. The epidemic curve indicated a point source initially, followed by person-to-person transmission. Approximately 63% of 90 probable case patients and 27% of 150 asymptomatic student controls randomly selected among classmates of student case patients visited internet cafés during the exposure period (odds ratio [OR], 4.5; 95% confidence interval [CI], 2.6-8.0); 66% of case patients and 45% of student controls reported close contact with a measles case patient (OR, 2.3; 95% CI, 1.3-3.9). In stratified analysis, visiting internet cafés (OR, 4.0; 95% CI, 1.5-11) remained significantly associated with disease, but contact with case patients (OR, 1.9; 95% CI, .79-4.4) became nonsignificant. CONCLUSIONS: This measles outbreak was transmitted in internet cafés, followed by secondary transmission. Chinese universities should require proof of immunity or 2 doses of measles vaccine at college entry.

Early use of glucocorticoids was a risk factor for critical disease and death from pH1N1 infection.

BACKGROUND: Glucocorticoids increase the risk of developing critical disease from viral infections. However, primary care practitioners in China use them as antipyretics, potentially exposing hundreds of millions to this risk. METHODS: We enrolled all patients with confirmed pandemic influenza A (pH1N1) virus infection aged ≥3 years with available medical records at 4 Shenyang City hospitals from 20 October to 30 November 2009. A critical patient was any confirmed, hospitalized pH1N1 patient who developed ≥1 of the following: death, respiratory failure, septic shock, failure or insufficiency of ≥2 nonpulmonary organs, mechanical ventilation, or ICU admission. In a retrospective cohort study, we evaluated the risk of developing critical illness in relation to early (≤72 hours of influenza-like illness [ILI] onset) glucocorticoids treatment. RESULTS: Of the 83 hospitalized case-patients, 46% developed critical illness, 17% died, and 37% recovered and were discharged. Critically ill and other patients did not differ by underlying conditions and severity, median temperature at first clinic visit, and other measured risk factors. Of 17 patients who received early glucocorticoid treatment, 71% subsequently developed critical disease compared with 39% of 66 patients who received late (>72 hours) or no glucocorticoid treatment (RR(M-H) = 1.8, 95% CI = 1.2-2.8, after adjusting for 2 summary variables; ie, presence of underlying diseases and presence of underlying risk factors). Proportional hazards modeling showed that use of glucocorticoids tripled the hazard of developing critical disease (hazard ratio [HR] = 2.9, 95% CI = 1.3-6.2, after adjusting for the same summary variables). CONCLUSIONS: Early use of parenteral glucocorticoids therapy for fever reduction and pneumonia prevention increases the risk for critical disease or death from pH1N1 infection. We recommend that guidelines on glucocorticoid use be established and enforced.

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.

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.

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.

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.

Lack of airborne transmission during outbreak of pandemic (H1N1) 2009 among tour group members, China, June 2009.

During June 2-8, 2009, an outbreak of influenza A pandemic (H1N1) 2009 occurred among 31 members of a tour group in China. To identify the mode of transmission and risk factors, we conducted a retrospective cohort investigation. The index case-patient was a female tourist from the United States. Secondary cases developed in 9 (30%) tour group members who had talked with the index case-patient and in 1 airline passenger (not a tour group member) who had sat within 2 rows of her. None of the 14 tour group members who had not talked with the index case-patient became ill. This outbreak was apparently caused by droplet transmission during coughing or talking. That airborne transmission was not a factor is supported by lack of secondary cases among fellow bus and air travelers. Our findings highlight the need to prevent transmission by droplets and fomites during a pandemic.

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.

A cluster-randomized controlled trial evaluating the effect of a handwashing-promotion program in Chinese primary schools.

Intensive handwashing promotion can reduce diarrheal and respiratory disease incidence. To determine whether less intensive, more scalable interventions can improve health, we evaluated a school-based handwashing program. We randomized 87 Chinese schools to usual practices: standard intervention (handwashing program) or expanded intervention (handwashing program, soap for school sinks, and peer hygiene monitors). We compared student absence rates, adjusting for cluster design. In control schools, children experienced a median 2.0 episodes (median 2.6 days) of absence per 100 student-weeks. In standard intervention schools, there were a median 1.2 episodes (P = 0.08) and 1.9 days (P = 0.14) of absence per 100 student-weeks. Children in expanded intervention schools experienced a median 1.2 episodes (P = 0.03) and 1.2 days (P = 0.03) of absence per 100 student-weeks. Provision of a large-scale handwashing promotion program and soap was associated with significantly reduced absenteeism. Similar programs could improve the health of children worldwide.

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.