Missingness and algorithmic bias: an example from the United States National Outbreak Reporting System, 2009-2019.

Growing debates about algorithmic bias in public health surveillance lack specific examples. We tested a common assumption that exposure and illness periods coincide and demonstrated how algorithmic bias can arise due to missingness of critical information related to illness and exposure durations. We examined 9407 outbreaks recorded by the United States National Outbreak Reporting System (NORS) from January 1, 2009 through December 31, 2019 and detected algorithmic bias, a systematic over- or under-estimation of foodborne disease outbreak (FBDO) durations due to missing start and end dates. For 7037 (75%) FBDOs with complete date-time information, ~ 60% reported that the exposure period ended before the illness period started. For 2079 (87.7%) FBDOs with missing exposure dates, average illness durations were ~ 5.3 times longer (p < 0.001) than those with complete information, prompting the potential for algorithmic bias. Modern surveillance systems must be equipped with investigative capacities to examine and assess structural data missingness that can lead to bias.

Epidemiological characteristics of Vibrio parahaemolyticus outbreaks, Zhejiang, China, 2010-2022.

Background: Vibrio parahaemolyticus is one of the most common foodborne pathogens and poses a significant disease burden. The purpose of the study was to elucidate the epidemiological characteristics of Vibrio parahaemolyticus outbreaks in Zhejiang Province, and provide insights for the targeted prevention and control of foodborne diseases. Methods: Descriptive statistical methods were utilized to analyze the data on Vibrio parahaemolyticus outbreaks reported by all Centers for Disease Control and Prevention (CDCs) through Foodborne Disease Outbreaks Surveillance System (FDOSS) in Zhejiang Province from 2010 to 2022. Results: From 2010 to 2022, a total of 383 outbreaks caused by Vibrio parahaemolyticus were reported by 90 CDCs in 11 prefectures of Zhejiang Province, resulting in 4,382 illnesses, 326 hospitalizations and 1 death. The main symptoms of the outbreak-related cases were diarrhea (95.18%), abdominal pain (89.23%), nausea (55.64%), vomiting (50.57%), fever (24.21%), etc. The outbreaks occurring between July and September accounted for 77.54% of all outbreaks (297 out of 383). Outbreaks associated with restaurants accounted for the majority (57.96%, 222/383) of all outbreaks, followed by those linked to staff canteens (15.40%, 59/383) and rural banquets (11.23%, 43/383). 31.85% of all outbreaks were associated with the consumption of aquatic products, while ready-to-eat foods such as Chinese cold dishes and cooked meat products accounted for 12.53% of all outbreaks. Serotype O3:K6 (81.94%, 118/144) was the predominant serotype responsible for outbreaks from 2010 to 2020, while serotype O10:K4 (57.89%, 33/57) was the predominant serotype from 2021 to 2022. Conclusion: In-depth and comprehensive analysis of long-term surveillance data on Vibrio parahaemolyticus outbreaks is essential to gain insight into the epidemiological characteristics, identify long-term patterns and recent trends, and enable governments to prioritize interventions and develop targeted policies to mitigate such outbreaks.

An 11-Year Analysis of Bacterial Foodborne Disease Outbreaks in Zhejiang Province, China.

BACKGROUND: Foodborne diseases are a growing public health problem and contribute significantly to the global burden of disease and mortality. Bacteria are the most common foodborne pathogens. We aimed to explore characteristics of bacterial foodborne disease outbreaks (FBDOs) in Zhejiang Province and to provide data support for foodborne disease prevention and control. METHODS: Descriptive statistical methods were used to analyze the data reported by centers for disease control (CDCs) at all levels in Zhejiang Province through Foodborne Disease Outbreaks Surveillance System (FDOSS) during 2010-2020. RESULTS: CDCs in Zhejiang Province reported 517 bacterial FBDOs in 11 years, resulting in 7031 cases, 911 hospitalizations, and 3 deaths. Vibrio parahaemolyticus had the highest number of outbreaks, accounting for 58.41% of the total bacterial outbreaks, followed by Salmonella (18.38%). In all settings, restaurants (37.14%), staff canteens (11.99%), and households (11.80%) were responsible for the large number of outbreaks. Aquatic products (42.08%), meat and meat products (23.56%), cereals (10.81%), and flour products (9.27%) were the most common single foods reported. Further analysis showed that the settings and food vehicles of outbreaks caused by different pathogens were different. CONCLUSIONS: Bacterial outbreaks are the most common type of FBDOs in Zhejiang Province. By analyzing the epidemiological characteristics of common pathogenic bacteria, we can identify the etiology, food, and setting that the government needs to focus on, and issue relevant targeted policies to reduce the number of FBDOs.

Surveillance for foodborne disease outbreaks in Zhejiang Province, China, 2015-2020.

BACKGROUND: Foodborne diseases are a major cause of morbidity and mortality and a major public health problem worldwide. We aim to explore characteristics of foodborne disease outbreaks (FBDOs) in Zhejiang Province and to provide data support for foodborne disease prevention and control. To our knowledge, few such analyses have been published at the provincial level. METHODS: Descriptive statistical methods were used to analyze the data reported by centers for disease control (CDC) at all levels in Zhejiang Province through Foodborne Disease Outbreaks Surveillance System (FDOSS) during 2015-2020. RESULTS: A total of 962 FBDOs were reported during this period, resulting in 8324 illnesses, 1028 hospitalizations, and 20 deaths. The number of outbreaks (410 outbreaks, 42.62%) and cases (4991 cases, 59.96%) caused by bacteria were the largest, followed by poisonous mushrooms (157 outbreaks, 587 cases), which was the main cause of death (15 deaths, 75%). The highest number of FBDOs occurred in households (381 outbreaks, 39.60%), followed by restaurants (219 outbreaks, 22.77%) and canteens (174 outbreaks, 18.08%). Animal-based foods were the most common single food reported (232 outbreaks, 24.12%), followed by poisonous mushrooms (162 outbreaks, 16.84%), and plant-based foods (133 outbreaks, 13.83%). Poisonous mushrooms took the first place in outbreaks in households (38.32%, 146/381), while bacteria took the first place in outbreaks outside households. Vibrio parahaemolyticus was responsible for the largest number of outbreaks (232 outbreaks, 24.12%), which mainly occurred in catering service units (93.10%, 216/232). Different types of bacteria tended to be found in different food categories, such as Vibrio parahaemolyticus, which was mainly found in aquatic products. CONCLUSIONS: Analysis of FBDOs can provide insight into the most important pathogens and sources of foodborne disease, helping authorities identify high-risk etiologies, high-risk foods, and high-risk settings to guide policies that would reduce FBDOs.

Etiological characteristics of an outbreak of Campylobacter foodborne disease in a middle school / 预防医学

Objective@#To analyze the etiological characteristics of an outbreak of Campylobacter foodborne disease in a middle school in Suzhou City, so as to provide insights into the identification of pathogenic factors of Campylobacter foodborne disease outbreaks.@*Methods@#Eighteen anal swabs from patients, 10 anal swabs from canteen workers, 43 food samples, 2 drinking water samples, 2 food original material samples and 31 environmental samples were collected, and the pathogens were rapidly screened using the gastrointestinal infection detection strip. The pathogens were isolated and cultured using the double-pore filtration membrane method, and cluster analysis of bacterial isolates was performed using pulsed field gel electrophoresis ( PFGE ). In addition, the susceptibility of Campylobacter isolates to antibiotics was tested using the Campylobacter agar dilution method.@*Results@#A total of 63 cases with Campylobacter infections were reported, and the major clinical symptoms included diarrhea ( 51 cases, 80.95% ) and fever ( 39 cases, 61.90% ), while no inpatients or deaths were found. Twelve Campylobacter-positive samples were detected, including 11 anal swabs sampled from patients and one food original material sample. Among the 11 positive anal swabs, there were 10 samples positive for Campylobacter jejuni and one sample positive for C. coli, and of the one positive food original material, C. coli was identified. PFGE analysis showed that 10 C. jejuni isolates of had 100.0% homology, and these 10 isolates were 100.0% resistant to naphthyridic acid, ciprofloxacin and tetracycline, appearing multidrug resistance.@*Conclusions@#This is an outbreak of foodborne disease caused by C. jejuni infections. Gastrointestinal infection detection strips, double-pore filtration membrane and PFGE typing are rapid and accurate to identify pathogenic factors.

Epidemiological features of foodborne disease outbreaks in Shanghai 2010 to 2020 / 上海预防医学

ObjectiveTo analyze the epidemiological features of foodborne disease outbreaks in Shanghai and to find the risk factors. MethodsWe collected the data of foodborne disease outbreaks occurred in Shanghai between 2010 and 2020， analyzed the characteristics of outbreaks， including time and geographic distribution， pathogenic factors and possible reasons caused outbreaks. ResultsBetween 2010 and 2020， there were 108 foodborne disease outbreaks with 1 736 cases， 45 inpatient cases and 1 death. May to September was the epidemic period， with about 64.81% of the outbreak occurrence. 39.81% outbreaks occurred in Pudong， Songjiang and Chongming Districts. Most outbreaks occurred in small restaurants （25%） and most foodborne cases were in staff canteen outbreaks （27.53%）. The main possible reasons caused outbreaks were improper food storage （19.44%）， cross-contamination （14.81%） and improper cooking （12.04%）. The major pathogenic factor was biological， caused 75.92% outbreaks and 77.59% cases. Methanol poisoning caused 1 death. The main contaminated food caused outbreaks was meat （17.59%）， multiple food （12.04%） and aquatic products （11.11%）. ConclusionThe foodborne disease outbreaks in Shanghai caused inpatient cases and death. We should pay more attention to foodborne disease outbreaks and we can control the risk factors by strengthening supervision and carrying out health education to reduce foodborne disease outbreaks.

Analysis on Foodborne Disease Outbreaks in Yunnan Province From 2013 to 2017 / 昆明医科大学学报

Objective To provide a besis of the control measures for foodborne disease outbreaks by analysing the laws and the popular features of foodlorne disease outbreaks in yunnan from 2013 to 2017.Methods The data of epidemic situation and field investigation of foodborne disease outbreaks from 2013 to 2017 in Yunnan province was analyzed. Results From 2013 to 2017,a total of 2 519 cases of foodborne disease outbreaks were repeatedin Yunnan Province,Among 18681 cases, 257 patients died with mortality 1.38% . Foodborne disease outbreaks occur in the third quarters.Outbreaking and outbreaking from a few number of households, followed by the work unit Employer Unit; outbreaking deaths in the family is also the most. Primary causal factor is plant. Pathogen the pathogenic bacteria main pathogen are Salmonella (38.89%), Bacillus cereus intoxication bacillus (38.89%),staphylococcus aureus (11.11%), Diarrheagenic escherichia coli (5.56%), Proteus Proteus species Proteus vulgaris (5.56%),et al. Conclusion From 2013 to 2017,foodborne disease outbreaking in yunnan is mainly due to plants and micro－organisms and mosty oceurs at home and canteens. It is necessary to strengthen the food hygiene management at home and canteens,to avoid foodborne disease outbreaking incidents.

Challenging Investigation of a Norovirus Foodborne Disease Outbreak During a Military Deployment in Central African Republic.

In January 2016, a large-scale outbreak of acute gastroenteritis was reported among French armed forces deployed in the Central African Republic. Challenging investigations, conducted from France, made it possible to identify a norovirus genogroup II in both stool and food samples, confirming a norovirus foodborne disease outbreak. Infected food handler management is discussed.

Characterization of the Salmonella enterica Serotype Isangi Isolated from Patients for the First Time in China.

No studies have reported the isolation of serotype Salmonella Isangi from cases of salmonellosis in mainland China. We investigated an outbreak of foodborne disease with salmonella and collected the samples from the patients and surplus foods. Salmonella strains were isolated and the serotype was identified according to the Kauffmann-White scheme. The relatedness of the isolates was determined using pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Antimicrobial susceptibility was conducted by the broth microdilution method. There were 74 diners in the case, 33 of which got ill, with an attack rate of 44.6% (33/74). A total of 24 samples were collected from the outbreak cases, six Salmonella Isangi strains were isolated and susceptible to all tested drugs. PFGE and WGS analysis suggested that the pathogen dissemination through a single or limited vector(s), the steamed fish and mixed food (fry spicy chicken, braised pork ribs, and goose leg), may be the source of infection or be cross-contaminated. We first report the characteristics of an outbreak and molecular strain relatedness of Salmonella Isangi in mainland China.

An analysis on epidemiological characteristics of foodborne disease outbreak occurred in Zhejiang Province,2015 / 预防医学

Objective To learn the epidemiological characteristics of foodborne disease outbreak in 2015,Zhejiang Province,and to provide evidences for the prevention and control of foodborne disease outbreak.Methods Descriptive epidemiological analysis using ArcGIS 10.2 and SPSS 19.0 was conducted on geographical country data,information of permanent resident population and the incidence data of foodborne disease outbreak reported through foodborne disease outbreak reporting information system in 2015.Results There were 116 foodborne disease events reported in Zhejiang in 2015,resulting in 1 009 persons attacked,115 hospitalization and 10 deaths.The proportion of unknown pathogenic factor for events was 29.31%.The events appearance sporadic,there were some local hotspots in Jiaxing.The vibrio parahaemolyticus was the most common pathogen (32.76%),and poisonous mushrooms(8.62%)come the second.Most foodborne disease incidents occurred during June to November.Restaurants ,family and rural feasts were the major places where the foodborne disease occurred.The proportion of family foodborne disease events because of mistaken and misuse poisonous substances increased,and the hospitalization rate and mortality of events of which were the highest (33.9% and 7.63% respectively).Conclusion The food safety management and of restaurants and rural feasts should be strengthened in summer and autumn,as well as foodborne disease prediction and forewarning to reduce the foodborne disease incidents caused by microorganism contamination and poisonous muchnooms.It is necessary to conduct public risk cognition research for foodborne disease in Zhejiang,which could provide evidence for preventing and controlling family foodborne disease.

Surveillance for foodborne disease outbreaks in Iran, 2006-2011.

BACKGROUND: The outbreaks of foodborne diseases is a major health problem and occur daily in all countries, from the most to the least developed. This study is the first report of foodborne outbreaks in Iran that carried out from 2006 to 2011. METHODS: A retrospective, longitudinal study carried out using foodborne disease national surveillance system data from 2006-2011, which have been reported by all provincial health centers to the Center for Communicable Disease Control. Collected data were analyzed using SPSS version 18 software. RESULTS: Since 2006 to 2011, a total of 2250 outbreaks were reported in Iran. Analyzed data showed that the outbreak rate has increased from 0.07/100000 in 2006 to 1.38/100000 population in 2011. Khuzestan, Kermanshah and Qazvin were three provinces that reported more outbreaks than nationally expected outbreak incidence rate during 2011. Analysis of epidemiological characteristics of foodborne outbreaks during 2011 indicated that the numbers of outbreaks were highest in warm months, e.g. 17.8% of total outbreaks was just reported in August. Females and age group of 16-30 years old were more affected and 55% of cases occurred in rural area. Among 684 human samples which have been tested, E. coli, Shigella, Hepatitis A and Vibrio cholera were predominant etiologic agents respectively. CONCLUSION: Increasing the detection rate of foodborne outbreaks imply the expansion of surveillance activities and improved primary health care in Iran in recent years. Foodborne disease surveillance system is a new program in Iran that should be continued and strengthened including diagnostic laboratory capacities.

Escherichia coli O157:H7 infections associated with consumption of locally grown strawberries contaminated by deer.

BACKGROUND: An outbreak of Escherichia coli O157:H7 was identified in Oregon through an increase in Shiga toxin-producing E. coli cases with an indistinguishable, novel pulsed-field gel electrophoresis (PFGE) subtyping pattern. METHODS: We defined confirmed cases as persons from whom E. coli O157:H7 with the outbreak PFGE pattern was cultured during July-August 2011, and presumptive cases as persons having a household relationship with a case testing positive for E. coli O157:H7 and coincident diarrheal illness. We conducted an investigation that included structured hypothesis-generating interviews, a matched case-control study, and environmental and traceback investigations. RESULTS: We identified 15 cases. Six cases were hospitalized, including 4 with hemolytic uremic syndrome (HUS). Two cases with HUS died. Illness was significantly associated with strawberry consumption from roadside stands or farmers' markets (matched odds ratio, 19.6; 95% confidence interval, 2.9-∞). A single farm was identified as the source of contaminated strawberries. Ten of 111 (9%) initial environmental samples from farm A were positive for E. coli O157:H7. All samples testing positive for E. coli O157:H7 contained deer feces, and 5 tested farm fields had ≥ 1 sample positive with the outbreak PFGE pattern. CONCLUSIONS: The investigation identified fresh strawberries as a novel vehicle for E. coli O157:H7 infection, implicated deer feces as the source of contamination, and highlights problems concerning produce contamination by wildlife and regulatory exemptions for locally grown produce. A comprehensive hypothesis-generating questionnaire enabled rapid identification of the implicated product. Good agricultural practices are key barriers to wildlife fecal contamination of produce.

Brote de enfermedad alimentaria en la localidad de El Huecú, provincia de Neuquén / Foodborne disease outbreak in El Huecú community, province of Neuquén

En febrero de 2006 ocurrió un brote epidémico de gastroenteritis aguda de origen alimentario, en ocasión de un festejo popular en una pequeña localidad de la provincia de Neuquén, Argentina. Aproximadamente 800 personas participaron de un almuerzo en las instalaciones del Gimnasio Municipal, y unas tres horas después de finalizado, cerca de 150 asistentes consultaron al hospital local, afectados por síndrome gastroentérico agudo. Se realizó una investigación epidemiológica caso-control a través de un muestreo representativo no probabilístico. Los resultados epidemiológicos establecieron un brote de ETA a fuente común, con una relación caso-control de 1:1,8. Los principales síntomas fueron cólicos abdominales (88%), vómitos (73,5%) y diarrea (60%). La torta que se sirvió en ese evento fue identificada como el alimento causal (OR 9,79; IC 95%; 2,66-36,00; valor p = 0,0001), sujeto a condiciones higiénico-sanitarias insatisfactorias en los diferentes procesos de elaboración, conservación y manipulación. De una porción de la torta se aisló una cepa de Staphylococcus aureus subespecie aureus, coagulasa positiva, enterotoxigénica, con un recuento de 2,4x10(6) UFC/g, y también se aisló este microorganismo de tres muestras de manos y narinas de personas involucradas en la preparación y el servicio. Las cepas aisladas de un operador y de la torta portaron el gen sea y presentaron el mismo patrón de SmaI-PFGE. Se atribuyó el brote de ETA a la contaminación durante el proceso de preparación de la torta consumida durante ese almuerzo popular, lo que podría estar relacionado con deficiencias en aspectos higiénicos y con la falta de refrigeración y de mantenimiento de la cadena de frío.

In the summer of 2006, an epidemic outbreak of acute gastrointestinal illness related to food consumption occurred in a small town in the province of Neuquén, Argentina. During a popular feast, approximately 800 local residents attended lunch held in the facilities of the Municipal Gymnasium. About three hours later, nearly 150 attendees sought medical assistance at the local hospital due to acute gastroenteritis. A case-control epidemiological investigation was conducted using representative non-probability sampling. The epidemiological investigation showed a common-source foodborne disease outbreak with a case-control ratio of 1:1.8. The main symptoms were abdominal cramps (88%), vomiting (73.5%) and diarrhea (60%). The cake was identified as the source of infection (OR 9.79; IC 95%, 2.66-36.00; p = 0.0001), and unsatisfactory hygienic conditions in food production, conservation and handling steps were identified. Coagulase positive, enterotoxigenic Staphylococcus aureus, subspecies aureus was detected in a piece of cake, with a count of 2.4x10(6) CFU/g, and in samples from the hands and nostrils of three people involved in food preparation and service. The strains isolated from both the cake and one of the food handlers carried the sea gene, and presented the same SmaI-PFGE pattern. The foodborne disease outbreak was considered to be due to contamination in the preparation process of the cake consumed at the feast, which was related to inadequate hygienic conditions, lack of refrigeration and cold chain disruption.