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PubMed1999

Outbreaks of Shigella sonnei infection associated with eating fresh parsley--United States and Canada, July-August 1998.

In August 1998, the Minnesota Department of Health reported to CDC two restaurant-associated outbreaks of Shigella sonnei infections. Isolates from both outbreaks had two closely related pulsed-field gel electrophoresis (PFGE) patterns that differed only by a single band. Epidemiologic investigations implicated chopped, uncooked, curly parsley as the common vehicle for these outbreaks. Through inquiries to health departments and public health laboratories, six similar outbreaks were identified during July-August (in California [two], Massachusetts, and Florida in the United States and in Ontario and Alberta in Canada). Isolates from five of these outbreaks had the same PFGE pattern identified in the two outbreaks in Minnesota. This report describes the epidemiologic, traceback, environmental, and laboratory investigations, which implicated parsley imported from a farm in Mexico as the source of these outbreaks.

Apiaceae↗

PubMed2000

A multi-state outbreak of tuberculosis among members of a highly mobile social network: implications for tuberculosis elimination.

SETTING: Baltimore, Maryland. OBJECTIVE: To describe a tuberculosis (TB) outbreak among a highly mobile population and the efforts required to control it. DESIGN: Epidemiologic outbreak investigation. RESULTS: Between June 1998 and January 2000, 20 TB outbreak cases were identified, of which 18 were culture-confirmed. Seventeen isolates of Mycobacterium tuberculosis had an identical 11-band DNA fingerprint; another isolate had one additional band and was considered a match. Two cases were diagnosed in New York City; another patient lived primarily in Atlanta, but was diagnosed in Baltimore. Persons in the outbreak were predominantly young (median age 24 years), black, male, infected with the human immunodeficiency virus (HIV), and gay, transvestite or transsexual. Activities common among many TB cases included attending two nightclubs, membership in one of three social 'Houses', attending balls or pageants in East Coast cities, marijuana use, and prostitution. Community outreach, extended contact tracing, DNA fingerprinting, directly-observed therapy, and expanded use of preventive therapy were utilized to assess and control the outbreak. During the outbreak period the Baltimore City TB rate declined by 10%. However, additional public health personnel were required to control the outbreak, resulting in a 17% increase in TB clinic staff. CONCLUSION: As TB rates decline, remaining cases are likely to occur in difficult-to-reach populations. Increased resources per case of TB treated will be required to eliminate TB.

AIDS-Related Opportunistic Infections↗

PubMed2001

Community surveys of self-reported diarrhoea can dramatically overestimate the size of outbreaks of waterborne cryptosporidiosis.

This paper describes a community-based study undertaken to assess the size of a waterborne outbreak of cryptosporidiosis in the North West region of England. The outbreak was linked to a single reservoir in the English Lake District and provided drinking water to over 1.2 million people. There were some 308 laboratory confirmed cases. We conducted a community-based survey for self-reported diarrhoea in four towns within the outbreak area and four control towns. The rate of self-reported diarrhoea was higher in the control towns than in the outbreak towns. It would appear that retrospective community-based studies of diarrhoeal disease are subject to recall bias that would overestimate the incidence of illness, especially following reporting in the media. In the light of our findings, we reviewed the study undertaken during the Milwaukee outbreak that produced the estimated size of 405,000 cases. It is suggested that the estimate of the size of the Milwaukee outbreak is severely flawed, and the actual size of this outbreak was between 1% and 10% of that claimed.

Bias↗

PubMed2001

General outbreaks of infectious intestinal disease linked with poultry, England and Wales, 1992-1999.

Between 1992 and 1999, 1426 foodborne general outbreaks of infectious intestinal disease (IID) were reported to the Public Health Laboratory Service Communicable Disease Surveillance Centre. A fifth were associated with the consumption of poultry. Chicken was implicated in almost three quarters of these outbreaks, turkey in over a fifth and duck in 2% of outbreaks. The organisms most frequently reported were Salmonella (30% of outbreaks), Clostridium perfringens (21%) and Campylobacter (6%). Over 7000 people were affected, with 258 hospital admissions and 17 deaths. During the summer, outbreaks were mainly of salmonellosis and attributed to the consumption of chicken. In December, C. perfringens and turkey were the organism and vehicle most often implicated. Most outbreaks occurred on commercial catering premises (56%) or in private houses (21%). The highlight of this surveillance period was the fall in outbreaks of salmonellosis linked with poultry products, probably due, at least in part, to the vaccination of poultry flocks.

Animals↗

PubMed2001

General outbreaks of infectious intestinal disease linked with red meat, England and Wales, 1992-1999.

Between 1992 and 1999, 1,426 foodborne general outbreaks of infectious intestinal disease (IID) were reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC). Sixteen percent were linked with the consumption of red meat. Over 5,000 people were affected, with 186 hospital admissions and nine deaths. Beef (34%) and pig meat (32%) were the most frequently implicated meat types, with lamb implicated in 11% of outbreaks. The organisms most frequently reported were Clostridium perfringens (43.4%) and salmonellas (34.3%). During the summer, outbreaks were mainly of Salmonella spp. and attributed to the consumption of pig meat. In December, outbreaks of C. perfringens linked with beef predominated. Most outbreaks occurred as a result of food cooked on commercial catering premises (46%). The highlight of this surveillance period is a fall in the number of outbreaks linked with foods containing red meat. This corresponds with a steady decline in red meat consumption over the last two decades, as well as a transient though marked decline in the purchase and consumption of red meat in the UK during the BSE crisis in the early to mid 1990s. As cited in the Pennington Report, further reducing the morbidity and mortality from red meat outbreaks means targeting meat production at various points along the food chain from abattoir and butchering, to cooking and holding of cooked food, especially on commercial catering premises.

Bacterial Infections↗

PubMedDate not supplied

Outbreaks in drinking-water systems, 1991-1998.

During 1991-1998, 126 outbreaks, 429,021 cases of illness, 653 hospitalizations, and 58 deaths were reported in public and individual water systems in 41 states and three U.S. territories. A bacterial, viral, or protozoan etiology was identified in 41 percent of the outbreaks, and a chemical contaminant was identified in 18 percent. No etiological agent was determined in the remaining outbreaks. Important causes of outbreaks included contamination of untreated groundwater, inadequate disinfection of groundwater, and distribution system deficiencies, especially cross-connections and corrosive water. The responsible pathogen or chemical was identified in water samples collected during 31 percent of the reported outbreaks. Coliform bacteria were detected in water samples collected during the investigation of infectious-disease outbreaks in 83 percent of noncommunity and 46 percent of community water systems, but very few of these systems had exceeded the U.S. Environmental Protection Agency's maximum limit for total coliforms in the 12 months before the outbreak.

Animals↗

PubMed2003

Planning against biological terrorism: lessons from outbreak investigations.

We examined outbreak investigations conducted around the world from 1988 to 1999 by the Centers for Disease Control and Prevention's Epidemic Intelligence Service. In 44 (4.0%) of 1,099 investigations, identified causative agents had bioterrorism potential. In six investigations, intentional use of infectious agents was considered. Healthcare providers reported 270 (24.6%) outbreaks and infection control practitioners reported 129 (11.7%); together they reported 399 (36.3%) of the outbreaks. Health departments reported 335 (30.5%) outbreaks. For six outbreaks in which bioterrorism or intentional contamination was possible, reporting was delayed for up to 26 days. We confirmed that the most critical component for bioterrorism outbreak detection and reporting is the frontline healthcare profession and the local health departments. Bioterrorism preparedness should emphasize education and support of this frontline as well as methods to shorten the time between outbreak and reporting.

Bioterrorism↗

PubMed2003

Validation of guidelines for investigating foodborne disease outbreaks: the experience of the Lazio region, Italy.

Information about risk ratios, exposures, and vehicles for foodborne diseases tends to be more reliable when it is obtained from outbreak surveillance than when it is obtained from disease notifications. In 1997, guidelines for methods of investigating foodborne disease outbreaks (FBDOs) were implemented in the Lazio region. To evaluate the impact of these guidelines, we analyzed information about 410 FBDOs from 1996 to 2000. Under these guidelines, the delay in the reporting of outbreaks decreased from 10 to 2 days. An analysis of 82 large FBDOs (in which > 30 people were exposed) showed increases in the calculation of attack rates with a cohort approach (up to 83%), correctly drawn epidemic curves (up to 79%), and the calculation of food-specific relative risk (up to 60%). On the other hand, the level of the determination of etiology remained low: tests were performed on patients in 57% of the cases considered, resulting in an agent identification rate of 38%; for 22 outbreaks, tests were performed on food, resulting in three positive identifications. Analysis of the contamination route with the use of hazard analysis critical control point criteria a posteriori was carried out for 15 outbreaks, and nine of these analyses were successful. The implementation of the 1997 guidelines was successful with regard to epidemiological and statistical methods but did not improve etiological diagnosis for FBDOs. These guidelines improved surveillance for outbreaks in which > 30 people were exposed in well-defined exposure situations; however, the guidelines did not significantly improve epidemiological investigations of small household outbreaks.

Cohort Studies↗

PubMed2004

Using pulsed-field gel electrophoresis in the molecular investigation of an outbreak of Serratia marcescens infection in an intensive care unit.

INTRODUCTION: Serratia marcescens is a well-known cause of nosocomial infections and outbreaks, particularly in immunocompromised patients with severe underlying disease. An outbreak due to S. marcescens infection was detected from 13 to 22 February 2001 at the intensive care unit (ICU) of our institution. We used pulsed-field gel electrophoresis (PFGE) typing to analyse the outbreak strains involved. METHODS: A total of 25 isolates were included in this study: 12 isolates from infected patients, nine isolates from insulin solution, one isolate from sedative solution (midazolam and morphine infusion) and one isolate from frusemide solution. Two isolates from other wards which were epidemiologically-unrelated were also included. RESULTS: The S. marcescens from patients, insulin solution and sedative solution showed an identical PFGE fingerprint pattern. The isolate from the frusemide solution had a closely-related PFGE pattern to the outbreak strain with one band difference. Attempts were made in the present study to identify the environmental reservoir of S. marcescens during the outbreak. We found that the insulin and sedative solutions used by the patients were contaminated with S. marcescens which was proven to be the source of the outbreak. CONCLUSION: Using PFGE, we showed that the outbreak in the ICU of our hospital was due to the clonal spread of a single strain of S. marcescens.

Bacterial Typing Techniques↗

PubMed2004

[Outbreaks of acute schistosomiasis in Anhui province in 2003].

OBJECTIVE: To analyze the outbreak patterns of acute schistosomiasis in Anhui province in 2003. METHODS: The criteria of emergency event for schistosomiasis issued by the Ministry of Health were applled in this study. Epidemiological data of acute schistosomiasis outbreak in Anhui province in 2003 were collected, checked and analyzed. RESULTS: In 2003, there were 6 episodes of acute schistosomiasis outbreaks in Anhui which had met the criteria of being emergency events, issued by the Ministry of Health. The preplanning was initiated in 5 outbreaks to respond to the outbreaks of acute schistosomiasis. All of the acute schistosomiasis cases received timing treatment, except those misdiagnosed cases coming from the non-endemic areas. There were no deaths or follow-up cases during the outbreaks. Health education, preventive treatment for people living in high risk villages were conducted in order to timely control the epidemics of schistosomiasis. CONCLUSION: The implementation of preplanning has played an important role in early cases-finding, timing report and response to the outbreaks of acute schistosomiasis.

Adolescent↗

PubMed2005

[Serological antibodies comparison of a hepatitis E outbreak].

OBJECTIVE: To compare the serological characters of an outbreak of hepatitis E and evaluate sensitivity and specificity of anti-HEV E2-IgM. METHODS: The sera collected from the employees of an outbreak unit were detected for anti-HEV E2-IgM and IgG, and the serum samples from a neighboring department were used as control. The results detected with anti-HEV E2-IgM, IgG and Genelab anti-HEV IgM, IgG in some samples were compared. RESULTS: The positive rate of anti-HEV E2-IgM in the control group was 0.11%. The results between the positive and the negative samples can be distinguished easily. The specificity of anti-HEV E2-IgM is about 99.89%. The positive rate of anti-HEV E2-IgM in outbreak stricken population was 8.66%, significantly higher than that in the control group (P < 0.001). The results from HEV patients' serial samples in the outbreak unit showed that the anti-HEV E2-IgM titer was high 30-60 days after the infected and then declined clearly. The positivity seemed unrelated to neither sex nor age. Among the 115 positive to anti-HEV E2-IgM, 27 were negative to Genelab anti-HEV IgG, the fact indicated a rather high risk of misdiagnosis of about 23.48%. In the 179 randomized samples of the control group, the positive rate of Genelabs anti-HEV IgG was about 11.17%. In 110 samples for the positive anti-HEV E2-IgM, the positive ratio of Genelabs anti-HEV IgG was about 76.36%, and that of Genelabs anti-HEV IgM only 69.09%. There were 16 samples negative for both Genelabs anti-HEV IgG and IgM. The ratio of the difference between the Genelabs anti-HEV IgG and IgM was about 25.45%. CONCLUSION: The specificity of anti-HEV E2-IgM was about 99%, and false positive rate was low. The sensitivity of anti-HEV E2-IgM in acute hepatitis E infection was 25%-30% higher than that of Genelabs anti-HEV IgM,IgG. The infected persons in the outbreak unit can be preferably distinguished from the non-infected persons by anti-HEV E2-IgM. Anti-HEV E2-IgM can image the characters of the outbreak of HEV and played a great role in the control of outbreak and in the early diagnosis for hepatitis E.

Antibodies, Viral↗

PubMed2006

Multiple outbreaks of gastrointestinal illness among school children associated with consumption of flour tortillas--Massachusetts, 2003-2004.

Ten outbreaks of gastrointestinal illness among school children at nine different schools were reported during February 2003-May 2004 to the Massachusetts Department of Public Health (MDPH). These outbreaks occurred among children who ate lunch provided by the schools and were characterized by short incubation periods and short durations of illness. The clinical and epidemiologic characteristics of the outbreaks were similar to those of previously reported outbreaks of vomiting associated with burritos served at multiple schools in the United States in 1997-1998. Epidemiologic investigation of the 1997-1998 outbreaks implicated burritos made with flour tortillas as the suspect vehicle; no etiologic agent was identified, but symptoms suggested either a biotoxin or chemical agent. This report describes epidemiologic and laboratory findings from three of the 10 outbreaks in Massachusetts. Consumption of flour tortillas from a single manufacturer was significantly associated with illness. Preliminary results indicated elevated levels, relative to common industry practices, of potassium bromate and calcium propionate in the implicated tortillas. School officials should be aware of the need for rapid action during outbreaks with short incubation periods and short durations and should notify local and state health officials immediately to ensure rapid response and collection of epidemiologic information, clinical specimens, and food samples.

Bread↗

PubMed1990

[The main characteristics of outbreaks of hospital infections in the USSR in 1986-1988].

The analysis of 69 outbreaks of hospital infections in different regions of the USSR in 1986-1989 (the number of patients affected by these infections was 1,517) showed that most of these outbreaks (41) occurred at hospital wards for newborn infants. Acute enteric infections prevailed in the total structure of the outbreaks (73.7%). Purulent septic infections among newborns constituted a quarter of all outbreaks. Opportunistic microbes, and mainly Klebsiella, were the dominating element in the etiology of outbreaks in hospital wards for newborn infants. In pediatric wards in among adult hospital patients the etiology of outbreaks was completely, or almost completely, determined by pathogenic microorganisms, mainly salmonellae and shigellae. Outbreaks among hospital patients of three above-mentioned groups were characterized by differences in sources, routes and factors of the transmission of infection.

Adult↗

PubMed1988

Three outbreaks of yersinia pseudotuberculosis infection.

Three outbreaks of Yersinia pseudotuberculosis infection during 1982 to 1984 in Okayama Prefecture, Japan are described. In outbreak A, Yersinia pseudotuberculosis a causal organism was detected in 16 patients (serotype 5A). The latent period of the infection was 2 to 20 days estimating, from time of ingesting food suspected of being contaminated and onset of the illness. Outbreak B and C occurred in remote mountain areas. In outbreak B, Yersinia pseudotuberculosis bacilli were detected in the feces of 35 out of 276 people (serotype 4B in 34 stools, 2C and 4B in one stool). In outbreak C, 12 children became sick; one of the 4 patients whose stools were examined, showed an organism belonging to serotype 4B. The inhabitants in the area of outbreak B and C took unchlorinated mountain stream and well water for drinking. After the outbreak B and C, we examined water and wild animals fecea in these areas for the bacilli. As a result, they were detected in 3 out of 51 water samples (serotype 4A in one, 6 in 2 samples) and 2 out of 57 wild animal fecal samples (serotype 2C in 2 samples) in B area, and 4 out of 33 water samples (serotype 4A in 2, 4B in 2 samples) in C area.

Adolescent↗

PubMed1988

An outbreak of typhoid fever due to contamination of the municipal water supply in northern Israel.

An outbreak of typhoid fever followed a large outbreak of dysentery in northern Israel. Both outbreaks resulted from contamination of a drilled well that supplied water to the municipal water system. The well was contaminated with sewage from a broken main-pipe coming from Shefaram (an Arab town). The outbreak of typhoid involved 77 persons, of whom 75 were hospitalized. In 67, phage-type C1 (the phage type dominant in Shefaram since the 1950s) was isolated. The incubation period was relatively long, between 12 and 40 days (median 22) following exposure. Over 50% of the cases were children aged 0 to 14, and only two patients were older than 35 years; the sex ratio among the patients was 1:1. The incidence rate in Shefaram was 2.3 times higher than in the Krayot (outlying suburbs of Haifa). This difference was due mainly to the high incidence in young females in Shefaram. The opposite was observed during the outbreak of dysentery, when the attack rates of the disease were higher in the Krayot. Relapses occurred in 12% (9 cases). This outbreak demonstrates the potential that still exists for serious outbreaks due to contamination of the municipal water supply.

Adolescent↗

PubMed1995

[Outbreak of serogroup C meningococcal disease among teenagers in Randers--preventive measures and examination of the meningococcal carrier conditions].

An outbreak involving 20 cases of serogroup C meningococcal disease, predominantly among teenagers, occurred over a seven-month period in the Randers area of Denmark. The cases were caused by a serogroup C:2a:P1.2 sulphonamide-resistant strain. The available evidence was against the transmission being related to particular schools. The outbreak was experienced as three clusters. At two schools involved in the first and the third cluster of the outbreak, 351 students were examined regarding pharyngeal carriage of meningococci, 282 of whom were tested again 17 weeks later; 308 students attending two similar schools in a nearby area were examined once. The majority of strains isolated from group C carriers in the high-risk area were serologically indistinguishable from the outbreak strain (13/14 = 95%), but less often sulphonamide-resistant (5/13 = 38%). In both areas, the overall carrier rate (30%), the overall group C rate (3%) and, the carrier rate for the outbreak strain (1%) were the same. The attack rate for the outbreak strain differed significantly: 1/40 in the high-risk area versus 1/2.500 in the normal risk area. No conditions that might explain this difference were revealed. Immediately after recognition of the first and the third cluster, 780 and 13,300 students, respectively, were vaccinated with meningococcal polysaccharide vaccine A+C. It was concluded that the definition of target groups for vaccination should be liberal, because the "at risk" population may be difficult to recognize at the onset of an outbreak.

Adolescent↗

PubMedDate not supplied

Complicated infectious coryza outbreaks in Argentina.

Seventeen complicated outbreaks of infectious coryza in layer, broiler-breeder, and broiler flocks were studied. In the layer flock outbreaks, drops in egg production of up to 35% were seen. In the broiler flocks and several of the layer flocks, losses due to persistent mortality and/or culling varied between 2 and 5%. Signs of infectious coryza in both layers and broiler-breeders were typical; in broilers, however, swollen head-like syndrome was seen. Except in one flock, no viral diseases were clinically or serologically detected. Excluding broiler-breeders, birds from most other flocks were serologically positive for Mycoplasma gallisepticum, and some were also positive for M. synoviae. Haemophilus paragallinarum was isolated from all of the outbreaks, but only as a pure culture in three outbreaks. Isolation of H. paragallinarum from sites such as liver, kidney, and particularly tarsal arthritis and ocular globes appears to be reported for the first time. Serovar A was isolated in eight outbreaks, serovar B in six, serovar C in one, and untypable serovars in two. The severity of these infectious coryza outbreaks may have been increased by concurrent salmonellosis, pasteurellosis, and mycoplasmosis, although under certain conditions H. paragallinarum is able to cause septicemia. Ten of the outbreaks occurred in birds vaccinated against infectious coryza; this may be due to the use of vaccines that do not provide protection against the types of H. paragallinarum that affect poultry in the region.

Animals↗

PubMed1996

Outbreaks of infectious intestinal disease in schools and nurseries in England and Wales 1992 to 1994.

We present data on outbreaks of infectious intestinal disease in schools and nurseries obtained from the surveillance scheme of all general outbreaks of infectious intestinal disease in England and Wales reported to the PHLS Communicable Disease Surveillance Centre between 1992 and 1994. A minimum set of data was received for 1280 outbreaks, 95 of which (7%) arose in schools and nurseries. The commonest pathogens were salmonellas, Shigella sonnei, and small round structured viruses. The mode of transmission was described as mainly from person to person in 55 outbreaks and mainly foodborne in 30. The mean attack rate was 30% and median duration was 10 days. The attack rate and duration varied with the pathogen involved. Forty-five of the 3118 people reported to have been ill were admitted to hospital. Outbreaks in schools and nurseries are common. Attack rates are high and such outbreaks are often prolonged. Effective infection control policies and appropriate training of staff are needed. Good local systems for surveillance can help identify outbreaks quickly and allow control measures to be applied early.

Adolescent↗