National Outbreak Research Articles

Update: Characteristics of Patients in a National Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injuries - United States, October 2019.

CDC, the Food and Drug Administration, state and local health departments, and other public health and clinical stakeholders are investigating a national outbreak of electronic-cigarette (e-cigarette), or vaping, product use-associated lung injury (EVALI) (1). As of October 22, 2019, 49 states, the District of Columbia (DC), and the U.S. Virgin Islands have reported 1,604 cases of EVALI to CDC, including 34 (2.1%) EVALI-associated deaths in 24 states. Based on data collected as of October 15, 2019, this report updates data on patient characteristics and substances used in e-cigarette, or vaping, products (2) and describes characteristics of EVALI-associated deaths. The median age of EVALI patients who survived was 23 years, and the median age of EVALI patients who died was 45 years. Among 867 (54%) EVALI patients with available data on use of specific e-cigarette, or vaping, products in the 3 months preceding symptom onset, 86% reported any use of tetrahydrocannabinol (THC)-containing products, 64% reported any use of nicotine-containing products, and 52% reported use of both. Exclusive use of THC-containing products was reported by 34% of patients and exclusive use of nicotine-containing products by 11%, and for 2% of patients, no use of either THC- or nicotine-containing products was reported. Among 19 EVALI patients who died and for whom substance use data were available, 84% reported any use of THC-containing products, including 63% who reported exclusive use of THC-containing products; 37% reported any use of nicotine-containing products, including 16% who reported exclusive use of nicotine-containing products. To date, no single compound or ingredient used in e-cigarette, or vaping, products has emerged as the cause of EVALI, and there might be more than one cause. Because most patients reported using THC-containing products before symptom onset, CDC recommends that persons should not use e-cigarette, or vaping, products that contain THC. In addition, because the specific compound or ingredient causing lung injury is not yet known, and while the investigation continues, persons should consider refraining from the use of all e-cigarette, or vaping, products.

Paediatric hospitalizations due to whooping cough in Spain (1997–2017)

This epidemiological survey estimates the burden of whooping cough in infants up to 12 months old in Spain during a twenty-one-year period (1997–2017). The survey was conducted by reviewing data from the Spanish Surveillance System for Hospital Data. All hospitalizations due to whooping cough for infants, reported during the 1997–2017 period, were analysed. Codes were selected from the International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes 033.0–033.9. To explore the latest national outbreak and the implementation of vaccination in pregnant women, analyses were stratified to compare the following periods: 1997–2010, 2011–2015 and 2016–2017. A total of 13,352 hospital discharges for whooping cough in infants up to 12 months old were reported. A total of 6850 discharges in the period 1997–2010, 5271 in the period 2011–2015 and 1231 in 2016–2017 were identified. The annual hospitalization rate prior to 2011 was 131.02 cases per 100,000 infants; in 2011–2015, the rate was significantly higher (250.13 cases per 100,000 infants) and in 2016–2017 it decreased (157.69 cases per 100,000 infants). Most of the cases (n = 11,446) occurred in infants under 4 months of age, with hospitalization rates of 328.80, 670.81 and 385.84 cases per 100,000 infants up to 4 months of age in the periods 1997–2010, 2011–2015 and 2016–17, respectively. Thirty-four deaths occurred in the period 1997–2010, 36 in the period 2011–2015 and 4 in 2016–2017. All of the deaths occurred in infants under 4 months old. The case fatality rate did not vary significantly across the study periods. Whooping cough infections concentrate in infants up to 4 months of age in Spain. Public health measures such as vaccination of pregnant women, caregivers, health care professionals and relatives, especially young parents, could reduce the hospitalization burden during the current outbreak.

Use of a case-control study and control bank to investigate an outbreak of locally acquired cyclosporiasis in Canada, 2016.

Cyclospora is an intestinal parasite that is not endemic in Canada. However, national outbreaks of locally acquired cases have been reported since 2013. These outbreaks were suspected to be associated with consumption of produce imported from countries where Cyclospora is endemic. Identification of the source can be challenging because of reporting delays and limited traceability of produce. To report on a national outbreak of locally acquired cyclosporiasis, highlight the challenges of investigating these outbreaks and document the first time use of a control bank to recruit controls for a national outbreak case-control study in Canada. Cases of cyclosporiasis were identified through provincial laboratory testing and reported through provinces to the national level. Cases were interviewed about food exposures using a questionnaire and food exposures reported by cases were compared to Foodbook reference values. To narrow down the food items of interest, a matched case-control study was conducted. Controls for the study were recruited primarily from a control bank, that is, a list of individuals who had previously agreed to participate in public health-related surveys. In total, 87 cases of locally acquired cyclosporiasis with onset or report dates between May 19, 2016 and August 10, 2016 were reported by four provinces. Comparing case exposures to Foodbook reference values identified several food items of interest, including blackberries, other berries, herbs and leafy greens. The case-control study identified only blackberries and mesclun greens as significantly more frequently consumed by cases than controls. Due to lack of product details for blackberries and mesclun greens, the source of the outbreak was not conclusively identified. Blackberries were the primary food item of interest, but could not be identified as the conclusive source due to lack of traceability. The control bank was found to be a useful tool for control recruitment.

Cryptosporidiosis outbreaks — United States, 2009–2017

Cryptosporidium is a parasite that causes cryptosporidiosis, a profuse, watery diarrhea that can last up to 3 weeks in immunocompetent patients and can lead to life-threatening malnutrition and wasting in immunocompromised patients.* Fecal-oral transmission can occur by ingestion of contaminated recreational water, drinking water, or food, or through contact with infected persons or animals. For the period 2009-2017, public health officials from 40 states and Puerto Rico voluntarily reported 444 cryptosporidiosis outbreaks resulting in 7,465 cases. Exposure to treated recreational water (e.g., in pools and water playgrounds) was associated with 156 (35.1%) outbreaks resulting in 4,232 (56.7%) cases. Other predominant outbreak exposures included contact with cattle (65 outbreaks; 14.6%) and contact with infected persons in child care settings (57; 12.8%). The annual number of reported cryptosporidiosis outbreaks overall increased an average of approximately 13% per year over time. Reversing this trend will require dissemination of prevention messages to discourage swimming or attending child care while ill with diarrhea and encourage hand washing after contact with animals. Prevention and control measures can be optimized by improving understanding of Cryptosporidium transmission through regular analysis of systematically collected epidemiologic and molecular characterization data.

Emerging Novel GII.P16 Noroviruses Associated with Multiple Capsid Genotypes.

Noroviruses evolve by antigenic drift and recombination, which occurs most frequently at the junction between the non-structural and structural protein coding genomic regions. In 2015, a novel GII.P16-GII.4 Sydney recombinant strain emerged, replacing the predominance of GII.Pe-GII.4 Sydney among US outbreaks. Distinct from GII.P16 polymerases detected since 2010, this novel GII.P16 was subsequently detected among GII.1, GII.2, GII.3, GII.10 and GII.12 viruses, prompting an investigation on the unique characteristics of these viruses. Norovirus positive samples (n = 1807) were dual-typed, of which a subset (n = 124) was sequenced to yield near-complete genomes. CaliciNet and National Outbreak Reporting System (NORS) records were matched to link outbreak characteristics and case outcomes to molecular data and GenBank was mined for contextualization. Recombination with the novel GII.P16 polymerase extended GII.4 Sydney predominance and increased the number of GII.2 outbreaks in the US. Introduction of the novel GII.P16 noroviruses occurred without unique amino acid changes in VP1, more severe case outcomes, or differences in affected population. However, unique changes were found among NS1/2, NS4 and VP2 proteins, which have immune antagonistic functions, and the RdRp. Multiple polymerase-capsid combinations were detected among GII viruses including 11 involving GII.P16. Molecular surveillance of protein sequences from norovirus genomes can inform the functional importance of amino acid changes in emerging recombinant viruses and aid in vaccine and antiviral formulation.

Acute Hepatitis A Infection and Vaccination in the Veterans Health Administration

Acute Hepatitis A Infection and Vaccination in the Veterans Health Administration

Acute Hepatitis A Infections among Veterans in Outbreak States, 2016-2018

ObjectiveTo conduct surveillance for acute Hepatitis A virus (HAV) infections in Veterans from states reporting outbreaks among high-risk individuals beginning in fiscal year (FY) 2017.IntroductionAlthough cases of acute HAV have declined in recent years, elevated numbers of HAV infections began to be reported by California and Michigan in the fall of 2016.1,2 Since this time, associated outbreaks have been reported in 9 additional states (Arizona, Utah, Kentucky, Missouri, Tennessee, Indiana, Ohio, Arkansas, and West Virginia).3 No common source of food, beverages or drugs have been identified and transmission appears to be primarily person-to-person with high-risk individuals including people experiencing homelessness, those who use illicit drugs and their close direct contacts. In June 2018, CDC issued a Health Alert Network Advisory providing additional guidance on identification and prevention of HAV and updates on the outbreaks.4 This prompted our office to more closely review our HAV surveillance, to identify Veterans who may be part of these outbreaks, and assess risk factors and outcomes of HAV infection.MethodsWe queried VA data sources starting in FY 2017 (October 1, 2016 – June 30, 2018) for HAV IgM laboratory tests and HAV-coded outpatient encounters and hospitalizations (ICD-10-CM: B15) to identify potential case patients. We performed a detailed chart review on all HAV IgM positive Veterans residing in or treated in an outbreak state during the identified outbreak time frame as reported by each state health department. Data elements collected included: (1) demographics; (2) risk factors, exposures and Hepatitis A vaccination status; (3) treatment locations (i.e. outpatient, Emergency Department, inpatient, intensive care unit); (4) presenting signs and symptoms; (5) laboratory data (including liver function tests (LFTs) and hepatitis testing); and (6) outcomes (i.e. deaths). County-level rates for positive HAV IgM test results were calculated using total unique users of VHA care for matching fiscal year time frames in each county as denominators.ResultsA total of 247 HAV IgM positive individuals were identified among 136,970 HAV IgM tests performed during the study period. Among these, 67 individuals resided in an outbreak state and were identified for further chart review. Additional laboratory review revealed that 5 of the 67 were positive for HAV Total Ab with no HAV IgM performed (all five patients came from a single facility and were asymptomatic at the time of testing). Based on review of clinical data for the remaining 62 HAV IgM positive patients, 22 (35%) did not meet the CSTE clinical case definition criteria5 of having signs or symptoms consistent with acute viral hepatitis plus either jaundice or elevated ALT/AST levels. These patients were either asymptomatic or had relevant symptoms that could be explained by other diagnoses. None had documented jaundice and only 4 had any LFT elevation, which was mild (ALT: 60-83 IU/L, AST: 36-103 IU/L). There was often no mention of the positive HAV IgM test result in the patient visit records. In the cases where the results were documented, it was thought to be a false positive or cross reactivity, related to recent receipt of HAV vaccination, or prolonged persistence of HAV IgM from a prior infection. Patient characteristics of the 40 patients meeting the case definition are summarized in Table 1. None of confirmed cases had documentation of HAV vaccination prior to their acute infection. The top 5 counties of residence among confirmed cases were Jefferson, KY (7, 18%), San Diego, CA (6, 15%), Wayne, MO (4, 10%), Butler, MO (3, 8%) and Macomb, MI (3, 8%). Additionally, the top three counties (Jefferson, San Diego and Wayne) were each noted to have clustering of cases of acute HAV with risk factors of homelessness, substance abuse and/or needle exposure. Incidence rates for HAV IgM+ test results were calculated for all reported outbreak counties and the 25 counties with the highest rates are shown in Figure 1.ConclusionsOccurrence of acute HAV infections among Veterans during October 2016 – June 2018 followed patterns reported by states with outbreaks during the same time frame, including high hospitalization rates. Risk factors of homelessness, substance abuse and/or needle exposures were noted in the Veteran population, similar to national HAV outbreak data. County-level clustering of cases in states with outbreaks was also observed among Veterans, with incidence rates of HAV IgM+ as high as 13 per 10,000 Veterans. Additional education of VA providers is needed regarding recognition of and appropriate testing for acute HAV infections. HAV IgM should not be ordered in asymptomatic patients with normal LFTs as the pretest probability of HAV infection is low, leading to false positives and confusion in interpreting test results. Improving Hepatitis A vaccination rates among Veterans is important, particularly among individuals who are at increased risk for infection or complications from HAV and in outbreak states to limit further spread of this outbreak.

Spatio-Temporal Analysis of Highly Pathogenic Avian Influenza outbreaks in Ghana.

ObjectiveThe purpose of the study was to characterize the spatial distribution and temporal patterns of laboratory confirmed H5N1 outbreaks from January 2007 to December 2017 in Ghana.IntroductionHighly pathogenic avian influenza (HPAI) subtype H5N1 virus causes a highly contagious disease in poultry with up to 100% mortality and occasionally causes sporadic human infection. The first outbreak of HPAI H5N1 in Africa was reported in Nigeria in 2006 and has since been reported in seven other African countries with confirmed human cases and outbreaks in poultry. Since the emergence of Highly Pathogenic Avian Influenza (HPAI), virus subtype H5N1 in Ghana in 2007, outbreaks in poultry have led to dire economic consequences for the poultry sector, resulting from mass destruction of affected flocks. An economy heavily dependent on agriculture, the persistence of outbreaks threaten the livelihood of farmers who depend on poultry production for survival.Despite significant efforts made in HPAI-H5N1 control and prevention in Ghana, outbreaks persist and continue to spread to new areas. It is uncertain to what extent different pathways contribute to the introduction and the dissemination of the virus in Ghana. There is a need to understand the complex nature of the interactions between local and migratory fowl, the risk of transmission due to human endeavor and trade mechanisms that increase the likelihood of HPAI-H5N1 outbreaks in Ghana.MethodsData for the study was sourced from national outbreak records at the Veterinary Services Directorate.The study analyzed outbreak data for the years 2007-2017. Data retrieved from outbreak reports included the date of onset of outbreak, location and geographic coordinates, type and number of poultry species affected, natural deaths of birds and type of farming system on outbreak farms. We calculated frequency distributions for the types of poultry species affected, the type of farming system and mortality rates on affected premises.We described the distribution of HPAI-H5N1 outbreaks using coordinate maps in ArcGIS and displayed relevant sites of waterfowl and wild bird habitation. To describe the temporal pattern of HPAI-H5N1 outbreaks in Ghana for the period, we created an epidemic curve by plotting the monthly number of outbreaks for the period January 2007 to December 2017 in Excel. We used space-time scan statistics to determine significant local clusters.ResultsA total of sixty-six (66) outbreaks of HPAI-H5N1 occurred in Ghana from January 2007 to December 2017. The outbreak sites were distributed in seven (7) out of ten (10) regions in Ghana. The affected regions are located in the southern and middle belt of Ghana. Most of the outbreaks (74.2%) occurred in densely populated areas of the Greater Accra region. Overall, layer flocks were mostly affected with 56% of affected premises constituting layer farms. Commercial farms and backyard farms made up the majority of affected farms (50% and 42.4%). Free ranging birds were the least affected farm type (7.6%). Two epidemic waves were identified for H5N1 in Ghana; the first wave with 6 outbreaks, lasted a period of four (4) months from April to July 2007, and the second with 60 outbreaks, spanned a period of 2 years from April 2015 to November 2016. Temporal distribution of the outbreaks showed that the outbreak peaked in May 2007 for the first wave and in July 2017 for the second wave with minor peaks observed in April and July 2016. The decrease in the number of the outbreaks after July in both waves is attributed to the onset of slaughter and trade restrictions for poultry in affected areas. Space-time scan statistics identified significant primary clusters of H5N1 outbreaks in the coastal belt of the Greater Accra region, characterized by major commercial activities and the presence of wetlands of relevance to wild birds and migratory waterfowl.ConclusionsTwo (2) major waves of H5N1 outbreaks occurred in Ghana between 2007 and 2017. The distribution of outbreaks and poultry species in both waves, show that the epidemiology of H5N1 virus in Ghana is changing. The findings highlight the importance of reviewing existing control and preventive measures as well as strengthening avian influenza surveillance in proposed high- risk areas.ReferencesForeign Animal Diseases. Revised 2008 Seventh Edition. Committee on foreign and emerging diseases of the United States Animal Health Association.Avian Influenza, OIE terrestrial manual 2015To K.K.W.et al. Avian influenza A H5N1 virus: a continuous threat to humans. Emerging Microbes Infections (2012) 1, e25.Watanabe Y. et al. The changing nature of avian influenza A virus (H5N1). Trends Microbiol. 2012 Jan; 20 (1):11-20. doi: 10.1016/j.tim.2011.10.003. Epub 2011 Dec 5

Norovirus outbreaks on college and university campuses

Objective: To describe norovirus outbreaks at colleges and universities. Participants: None. Conducted September 2016 to March 2018. Methods: College and university norovirus outbreaks reported to the US National Outbreak Reporting System (NORS, 2009–2016) or published and indexed by EMBASE, PubMed, and Web of Science (1985–2017) were analyzed. Results: Seventy-seven norovirus outbreaks were reported to NORS and 23 were identified in the systematic literature review. Outbreaks occurred more frequently during the beginning of the school year (September–February). NORS outbreaks were more often spread by person-to-person transmission (61%) and, in published outbreaks, by food (57%). The reported exposures of published outbreaks were campus dining (n = 8) and ill food service workers (n = 7). Higher attack rates were associated with smaller on-campus population size, social networks or residences, and specific food exposures. Common control measures were communal area disinfection and health/hygiene education. Conclusions: Recommendations summarized to prevent and control norovirus outbreaks at colleges or universities.

Qatar experience on One Health approach for middle-east respiratory syndrome coronavirus, 2012–2017: A viewpoint

The emergence of the Middle East Respiratory Syndrome Corona Virus (MERS-CoV) in the Middle East in 2012 was associated with an overwhelming uncertainty about its epidemiological and clinical characteristics. Once dromedary camels (Camelus dromedarius) was found to be the natural reservoir of the virus, the public health systems across the Arabian Peninsula encountered an unprecedented pressure to control its transmission. This view point describes how the One Health approach was used in Qatar to manage the MERS-CoV outbreak during the period 2012–2017.One Health focuses on the association between the human, animals and environment sectors for total health and wellbeing of these three sectors. To manage the MERS outbreak in Qatar through a One Health approach, the Qatar National Outbreak Control Taskforce (OCT) was reactivated in November 2012. The animal health sector was invited to join the OCT. Later on, technical expertise was requested from the WHO, FAO, CDC, EMC, and PHE. Subsequently, a comprehensive One Health roadmap was delivered through leadership and coordination; surveillance and investigation; epidemiological studies and increase of local diagnostic capacity.The joint OCT, once trained had easy access to allocated resources and high risk areas to provide more evidence on the potential source of the virus and to investigate all reported cases within 24–48 h. Lack of sufficient technical guidance on veterinary surveillance and poor risk perception among the vulnerable population constituted major obstacles to maintain systematic One Health performance.

Molecular and genomic typing for tuberculosis surveillance: A survey study in 26 European countries.

BackgroundMolecular typing and whole genome sequencing (WGS) information is used for (inter-) national outbreak investigations. To assist the implementation of these techniques for tuberculosis (TB) surveillance and outbreak investigations at European level there is a need for inter-country collaboration and standardization. This demands more information on molecular typing practices and capabilities of individual countries. We aimed to review the use of molecular/genomic typing for TB surveillance in European Union and European Economic Area countries in 2016; assess its public health value; and collect experiences on typing data use for cross-border cluster investigations.MethodA web-based questionnaire was provided to all TB National Focal Points. The questionnaire consisted of three parts: i) Use and integration of molecular and genomic typing data into TB surveillance; ii) Cross-border cluster investigation and international collaboration, and iii) Perception and evaluation of public health benefits of molecular and genomic typing for TB surveillance.ResultsOf 26 responding countries, 20 used molecular typing for TB surveillance, including nine applying WGS. The level of integration into the national surveillance was heterogeneous. Among six countries not using typing for TB surveillance, more than half planned its implementation soon. Overall, most countries perceived an added public health value of molecular typing for TB control. Concerning international cluster investigations, countries had little experience and did not have standard protocols to exchange typing data.ConclusionOur study shows a wide use of molecular and genomic typing data for TB surveillance in EU/EEA countries and reveals that transition to WGS-based typing is ongoing or is considered in most countries. However, our results also show a high heterogeneity in the use and integration of typing data for TB surveillance. Standardization of typing data use for TB surveillance is needed and formal procedures should be developed to facilitate international collaboration.

Analysis of the Cryptosporidium spp. and gp60 subtypes linked to human outbreaks of cryptosporidiosis in England and Wales, 2009 to 2017

BackgroundCryptosporidium spp. are important causes of gastroenteritis that can be transmitted from humans and animals. We elucidated the distribution of species and gp60 subtypes in human outbreaks classified by transmission vehicle.MethodsWe used a combined database of national outbreak surveillance and reference unit data to analyse outbreaks by setting, vehicle, season, and linkage with suspected sources.ResultsA total of 178 outbreaks involving 4031 laboratory confirmed cases were identified; 82 (46%) outbreaks involved recreational waters, 74 (42%) animal contact, 4 (2%) environmental contact, 4 (2%) person-to-person spread, 3 (2%) food, 2 (1%) drinking water supplies, and 9 (5%) were of unknown source. The infecting Cryptosporidium sp. was identified in 131 (74%) outbreaks; 69 were C. parvum, 60 C. hominis, and in two outbreaks cases were infected with either species. Animal contact, environmental contact, and food-borne outbreaks were exclusively C. parvum and were mainly in first half of the year. Recreational water outbreaks were predominantly C. hominis and were mainly in the second half of the year. Outbreaks attributed to person-to-person spread were exclusively C. hominis and all occurred in October. Both C. parvum and C. hominis caused drinking waterborne outbreaks. Gp60 subtypes were identified from patients in 48 C. parvum and 38 C. hominis outbreaks, revealing more subtypes among C. parvum (n = 14) than C. hominis (n = 7) outbreaks. Cryptosporidium hominis IbA10G2 predominated (30 outbreaks). Of C. parvum subtypes, IIaA15G2R1 predominated (17 outbreaks), followed by IIaA17G1R1 (12 outbreaks), IIaA19G1R1 (four outbreaks), and other subtypes caused three or fewer outbreaks each. Linkage between cases and suspected sources by gp60 subtype was established in nine animal contact, three swimming pool, and one drinking water outbreak.ConclusionsThe public health benefit of identifying infecting species and subtypes was twofold: (i) identifying and strengthening epidemiologic links between cases; and (ii) indicating possible exposures and sources to inform outbreak management. Gp60 subtype refined the epidemiological investigations, but a multilocus genotyping scheme would provide further benefit. Characterisation of Cryptosporidium spp. and subtypes needs to shift from predominantly supporting outbreak investigations to becoming nationally systematic.

Outbreaks of Salmonella enterica infections linked to animal contact: Demographic and outbreak characteristics and comparison to foodborne outbreaks-United States, 2009-2014.

In the United States, multistate Salmonella outbreaks are most commonly linked to a food source; however, contact with live animals can also result in outbreaks of human illness. To characterize Salmonella outbreaks linked to animal contact and examine differences compared to foodborne outbreaks, we analysed data reported to the Centers for Disease Control and Prevention through the National Outbreak Reporting System (NORS) from 2009 to 2014 with a primary mode of transmission listed as "animal contact" or "food." Four hundred and eighty-four outbreaks with animal contact or foodborne transmission were reported through NORS; of these outbreaks, 99 (20.5%) resulted from Salmonella transmission through animal contact and 385 (79.5%) resulted from foodborne transmission, which resulted in 3,604 (19.8%) and 13,568 (80.2%) illnesses, respectively. A higher proportion of illnesses among children aged <1year and children aged 1-4years were linked to animal contact outbreaks compared to foodborne outbreaks (15.2% vs. 1.4%, p<0.01 and 24.5% vs. 5.6%, p<0.01, respectively). Illnesses resulting in hospitalizations (OR: 1.81, 95% CI: 1.62, 2.02) were more likely to be associated with animal contact compared to food. Animal contact outbreaks reported to NORS were more likely to be multistate compared to foodborne outbreaks (OR: 5.43, 95% CI: 3.37, 8.76) and had a longer median duration (99.0days vs. 9.0days, p<0.01). Characterizing the differences between outbreaks of illness linked to animal contact and outbreaks linked to food provides useful information to investigators to improve public health response.

Foodborne Illness Outbreaks at Retail Establishments - National Environmental Assessment Reporting System, 16 State and Local Health Departments, 2014-2016.

Problem/ConditionState and local public health departments report hundreds of foodborne illness outbreaks each year to CDC and are primarily responsible for investigations of these outbreaks. Typically, investigations involve epidemiology, laboratory, and environmental health components. Health departments voluntarily report epidemiologic and laboratory data from their foodborne illness outbreak investigations to CDC through the Foodborne Disease Outbreak Surveillance System (FDOSS); however, minimal environmental health data from outbreak investigations are reported to FDOSS.Period Covered2014–2016.Description of SystemIn 2014, CDC launched the National Environmental Assessment Reporting System (NEARS) to complement FDOSS surveillance and to use these data to enhance prevention efforts. State and local health departments voluntarily report data from their foodborne illness outbreak investigations of retail food establishments. These data include characteristics of foodborne illness outbreaks (e.g., agent), characteristics of establishments with outbreaks (e.g., number of meals served daily), food safety policies and practices of these establishments (e.g., glove use policies), and characteristics of outbreak investigations (e.g., timeliness of investigation activities). NEARS is the only available data source that includes characteristics of retail establishments with foodborne illness outbreaks.ResultsDuring 2014–2016, a total of 16 state and local public health departments reported data to NEARS on 404 foodborne illness outbreaks at retail establishments. The majority of outbreaks with a suspected or confirmed agent were caused by norovirus (61.1%). The majority of outbreaks with identified contributing factors had at least one factor associated with food contamination by a worker who was ill or infectious (58.6%). Almost half (47.4%) of establishments with outbreaks had a written policy excluding ill workers from handling food or working. Approximately one third (27.7%) had a written disposable glove use policy. Paid sick leave was available for at least one worker in 38.3% of establishments. For most establishments with outbreaks (68.7%), environmental health investigators initiated their component of the investigation soon after learning about the outbreak (i.e., the same day) and completed their component in one or two visits to the establishment (75.0%). However, in certain instances, contacting the establishment and completing the environmental health component of the investigation occurred much later (>8 days).InterpretationMost outbreaks reported to NEARS were caused by norovirus, and contamination of food by workers who were ill or infectious contributed to more than half of outbreaks with contributing factors; these findings are consistent with findings from other national outbreak data sets and highlight the role of workers in foodborne illness outbreaks. The relative lack of written policies for ill workers and glove use and paid sick leave for workers in establishments with outbreaks indicates gaps in food safety practices that might have a role in outbreak prevention. The environmental health component of the investigation for most outbreaks was initiated quickly, yet the longer initiation timeframe for certain outbreaks suggests the need for improvement.Public Health ActionRetail establishments can reduce viral foodborne illness outbreaks by protecting food from contamination through proper hand hygiene and excluding workers who are ill or infectious from working. NEARS data can help prioritize training and interventions for state and local food safety programs and the retail food establishment industry by identifying gaps in food safety policies and practices and types of establishments vulnerable to outbreaks. Improvement of certain outbreak investigation practices (e.g., delayed initiation of environmental health investigations) can accelerate identification of the agent and implementation of interventions. Future analysis comparing establishments with and without outbreaks will contribute knowledge about how establishments’ characteristics and food safety policies and practices relate to foodborne illness outbreaks and provide information to develop effective prevention approaches.

Listeriosis in Australia - January to July 2018

A national outbreak of listeriosis is linked to the consumption of rockmelon (cantaloupe) originating from New South Wales and has affected other states of Australia, including Victoria, Queensland and Tasmania.The outbreak began after 10 elderly people were diagnosed with Listeriosis after consuming cantaloupe and became ill between 17 January and 9 February, 2018 .

Measuring timeliness detection of outbreak of food and water borne diseases in Albania, 2005-2016

Purpose: This study aimed to evaluate timeliness and data quality of national outbreak of food and water borne diseases reporting in Albania during 2005-2016. Methods & Materials: The study used aggregated data at national level from public health surveillance reports. Data on disease outbreaks of food and water borne diseases occurring from 2005 to 2016 were obtained from the national disease surveillance database and outbreak investigation reports. The dataset consisted of basic epidemiological information, regarding time, place, and total cases of each outbreak occurrence. Time variables included date of symptom onset in the index case, date when the outbreak start, outbreak detection date, date of laboratory confirmation, date of public health response and date of report to Ministry of Health and WHO and date of first public communication. The total number of outbreaks of food and water borne diseases reported during 2005 to 2016 were described. The number of confirmed cases and suspected cases reported for each disease outbreak were also summarized by year, using median and interquartile range. Results: Almost all date data in outbreak reports in Albania were complete but missing data were found only in the date of laboratory confirmation, date of disease treatment, date of patient hospitalization and date of disease end. During 2005-2016, 43 outbreaks were reported to Institute of Public Health, Albania. 36 (83.7%) outbreaks were confirmed by region and by pathogen. Food and water borne outbreaks are more common during the summer months and too often, outbreaks of food and water borne diseases go unrecognized or unreported or are not investigated. Salmonela is most common cause of food borne illness and most persistent. Conclusion: Confirmation of food and waterborne outbreak is low and timeliness data related to it are often missing. There is a need to have a joint platform for surveillance data, outbreak reporting and response and communication activities to measure timeliness but also the effectiveness of the response and communication activities especially related to IHR implementation.

Impact of whole genome sequencing on the investigation of food-borne outbreaks of Shiga toxin-producing Escherichia coli serogroup O157:H7, England, 2013 to 2017.

We aim to provide insight and guidance on the utility of whole genome sequencing (WGS) data for investigating food-borne outbreaks of Shiga toxin-producing Escherichia coli (STEC) O157:H7 in England between 2013 and 2017. Analysis of WGS data delivered an unprecedented level of strain discrimination when compared with multilocus variable number tandem repeat analysis. The robustness of the WGS method ensured confidence in the microbiological identification of linked cases, even when epidemiological links were obscured. There was evidence that phylogeny derived from WGS data can be used to trace the geographical origin of an isolate. Further analysis of the phylogenetic data provided insight on the evolutionary context of emerging pathogenic strains. Publically available WGS data linked to the clinical, epidemiological and environmental context of the sequenced strain has improved trace back investigations during outbreaks. Expanding the use of WGS-based typing analysis globally will ensure the rapid implementation of interventions to protect public health, inform risk assessment and facilitate the management of national and international food-borne outbreaks of STEC O157:H7.

Understanding ASF dynamic in South Africa: from spatio-temporal analysis at national level to fine special network analysis.

Since the first probable ASF outbreak occurred in the Koedoesrand Ward in 1926, South Africa has experienced many other outbreaks that can be divided temporally into 2 time periods; the period before the development of the OIE disease database and the period after. More than 143 outbreaks of swine fever were reported during the first period but not all were clearly defined as classical swine fever (CSF) or ASF. Since the development of the OIE disease database (1993), 72 outbreaks directly involving 2968 cases mainly in smallholder pig farms were reported. Outbreaks occurred mainly in Northern provinces part of the control zone defined in 1935. Since 2012, outbreaks tended to be more likely to occur in the free zone. In order to better understand the context in which African Swine Fever (ASF) outbreaks occurred in South Africa we described temporal, spatial distribution of reported ASF outbreaks in South Africa and examined spatio-temporal structure of ASF outbreak clusters in South Africa. Multi-Distance Spatial Cluster Analysis was used to assess the spatial clustering using ArcGIS 10.6, spatiotemporal clusters analyses were carried out using the R package splancs and scanning was utilised to identify spatiotemporal clusters of the disease using SaTScan. A specific focus was the particular zone of Northern Kwa-Zulu Natal (NKZN) bordering Mozambique and Eswatini (formerly Swaziland) defined by the zoning policy as a control zone. A spatialized social network analysis was used in order to assess the relevance of this zoning as no ASF outbreak was ever reported. Pig movement patterns were analysed using Social Network analysis (SNA) in R software. This network was georeferenced and a map of pig movements was produced. In the second phase farms, origins and destinations were grouped by villages and the villages represented the nodes of the network while directed arcs referred again to pig movement. Sociograms or link graphs were drawn using the igraph package in R. At national level ASF outbreaks exhibit statistically significant clustering while the interaction between time and space have shown qualitatively a negative space-time interaction that was significant at month scale (p=0.003) but not significant at year scale (p= 0.577). Different spatial and temporal clusters (2 up to 5 clusters) associated to high-rate ASF outbreaks were detected, always including municipalities located in both control and free zones (p<0.001). Thus, surveillance strategies should be applied not only to the control zone but rather in all areas identified as high risk areas. Our study provided evidence of an extensive pig network connecting all villages in the rural control area in NKZN. The SNA revealed that pigs are not only bought and sold within these closely linked villages but stock is brought from as far as 500km within South Africa and from Mozambique where ASF is endemic and regularly reported. In terms of sale, pig transactions occurred beyond the ASF control zone without any official permits. Despite the absence or very low prevalence of the diseases, proximity with endemic countries in addition to lack of such records of pig movements place the zone at an increased risk of introduction and spread of ASF and therefore confirmed the relevance of the current zoning policy. Understanding the social networks that drive observed movements enable the state veterinarian to implement effective interventions in case of an outbreak or for prevention sensitisation. Such sensitisation in addition to a real enforcement of the law (pigs kept in pens, animals and animal movements records) would allow countries such as South Africa to protect their investments by practicing disease control and surveillance i.e. their zoning policy. In addition, further studies should be implemented in order to evaluate the presence of ASF sylvatic cycle in transboundary protected areas, in order to finalize the assessment of the status of this zoning policy.

Improving emergency preparedness and response in the Asia-Pacific

### Summary box The severe acute respiratory syndrome (SARS) outbreak in 2002/2003,1 which affected 37 countries and resulted in nearly 800 deaths,2 prompted a critical re-think of the global health...

Perspectives on Acute Hepatitis A Control in Korea.

Until 1995, the incidence of symptomatic acute hepatitis A was minimal and there were no cases of national outbreak in Korea. However, there was a nationwide outbreak of hepatitis A that peaked in 2009. In 2019, a total of 10,083 cases of acute hepatitis A were reported for seven months of the year according to the Korea Center for Disease Control and Prevention. This may be attributed to the proportion of susceptible subjects in the Korean population, as about 10 years have passed since herd immunity was induced by the epidemic occurring during the late 2000s. Recent studies have shown that the rate of seropositivity for anti-hepatitis A virus antibodies (anti-HAV) is the lowest in adults in their 20s and has not changed much over the past 10 years, and seropositivity of anti-HAV in adults in their 30s has continued to decline from 69.6% in 2005 to 32.4% in 2014. Most young adults who have not yet experienced hepatitis A and are not vaccinated are vulnerable to hepatitis A infection. This year's epidemic of hepatitis A is a predictable outcome for vulnerable populations. Therefore, effective acute hepatitis A control and prevention strategies are needed, particularly for those in their 20s and 30s.