SEARCH · PubMed Health

Results for “outbreak”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed1984

[Persistence of virus in swine stock and breeding farms following an outbreak of Aujeszky's disease].

On seven fattening farms and seven breeding farms, investigations were carried out to examine whether Aujeszky virus was capable of persisting in particular animal groups or units of the farm as a productive infection following a virologically verified outbreak. After an outbreak on fattening farms, virus persisted temporarily as newly arrived piglets became systematically infected. On the farms on which this could be accurately followed, virus persistence continued for at least 1 1/2 to 2 months. However, this cycle of infection was found to be interrupted on each farm within approximately three months after the outbreak, which resulted in a gradual return to a totally sensitive animal population, so that new outbreaks could occur. On the seven swine breeding farms, virus persistence in the farrowing house was examined by placing seronegative sentinel piglets with sows during the immediate post-partum period. Twelve sentinel piglets were placed in the various farrowing houses for a total period of sixty-seven weeks, during which time 172 sows farrowed. None of these piglets became seropositive during their stay on the breeding farms. The results of this study show that Aujeszky's disease virus did not persist on breeding farms and that the productive infection on fattening farms in only transient following an outbreak. Therefore, it is very likely that new outbreaks of the disease are due to reintroduction of Aujeszky's disease virus on the farm. Though the role of latent carrier animals cannot be totally disregarded, natural reactivation of latent virus is believed an exception rather than the general rule.

Animals↗

PubMed1994

The impact of college prematriculation immunization requirements on risk for measles outbreaks.

OBJECTIVE: To assess whether prematriculation immunization requirements (PIRs) affect the number of measles cases on college campuses. DESIGN: We surveyed a stratified random sample of 880 colleges and universities to determine their immunization policies and practices and occurrence of measles outbreaks from 1988 through 1991. We merged national measles surveillance data with survey data by county to determine the risk for measles introduction on college campuses. We used logistic regression methods to estimate the effect of PIRs and assess risk factors for college measles outbreaks. SETTING: A total of 3205 US colleges and universities listed in standard guides. RESULTS: Of selected schools, 91 (11%) of the 796 responding schools reported one or more measles cases occurring from 1988 through 1991. Schools with a state-mandated PIR were significantly less likely to report measles outbreaks of two or more cases than other institutions (adjusted relative risk [RR] = 0.30; 95% confidence interval [Cl], 0.11 to 0.84). None of the 14 schools that reported outbreaks of 10 or more cases was subject to state regulation or had a PIR specifying two doses of measles vaccine in place. Of schools with introduction of measles, residential colleges were more likely to report extensive spread of measles (five or more cases) than nonresidential colleges (RR = 35.8; 95% Cl, 2.08 to 617.0). Of public schools, 4-year programs had a higher risk of a large outbreak (five or more cases) than 2-year programs. CONCLUSIONS: These results strongly support current recommendations for requiring proof of vaccination of college students to decrease the risk for measles outbreaks on college campuses. State regulations mandating PIRs ensure the best protection against widespread measles transmission.

Adolescent↗

PubMedDate not supplied

A community-wide outbreak of cryptosporidiosis associated with swimming at a wave pool.

OBJECTIVE: To determine the cause of a community-wide outbreak of cryptosporidiosis. DESIGN: A matched case-control study. SETTING: General community of Lane County, Oregon. PATIENTS AND OTHER PARTICIPANTS: Persons with Cryptosporidium detected in their stool from June to October 1992 were identified by contacting laboratories serving the area. Exposures of the first 18 case patients identified were compared with those of 18 age- and neighborhood-matched controls selected from a reverse telephone directory. MAIN OUTCOME MEASURES: Reported exposures to risk factors for cryptosporidiosis and abatement of cryptosporidiosis outbreak. RESULTS: Fifty-five patients with cryptosporidiosis were detected, including 37 who were the first individuals ill in their households. The case-control study involving the first 18 case patients showed no association between illness and attendance at day care or drinking municipal water or drinking untreated surface waters (river or lake water) in the 2 weeks before onset of illness. However, nine of 18 case patients reported swimming at a local wave pool, compared with none of 18 controls. We ultimately identified 17 case patients who reported swimming at the same wave pool during their incubation periods, whose exposure dates spanned a 2-month period. Inspection of the pool's filtration system did not detect any abnormalities. The outbreak subsided after the pool water was drained and replaced. CONCLUSIONS: This prolonged outbreak of cryptosporidiosis was likely caused by exposure to fecally contaminated wave pool water. Since Cryptosporidium is highly chlorine resistant and inadequately removed by sand filters, such outbreaks may represent an unrecognized hazard of wave pools, where the likelihood of inadvertent water ingestion is high. Such outbreaks may go undetected in areas where cryptosporidiosis is not reportable or laboratory screening is infrequent.

Adolescent↗

PubMed1994

Piccadilly Circus legionnaires' disease outbreak.

BACKGROUND: An outbreak of legionnaires' disease occurred in central London in January and February 1989. An Infection Control Committee was established to investigate the outbreak and institute control measures. The objective of this paper is to describe the investigation and control of the outbreak. METHODS: An epidemiological survey and case-control study were carried out. The subjects were cases of community acquired pneumonia associated with central London with onset of illness in January and February 1989. RESULTS: Thirty-three confirmed cases, including five deaths, and ten suspected cases, including three deaths, were identified with dates of onset from 1 January to 11 February. A clustering of visits by cases to the vicinity of Piccadilly Circus was noted, and a case-control study demonstrated a strong association between illness and visits to this area in the two weeks before onset of symptoms. The causative organism, Legionella pneumophila serogroup 1, was isolated from six patients. Legionella pneumophila of the same serogroup was isolated from water samples from five wet cooling systems (cooling towers) in the area under investigation, but in only two systems was the organism indistinguishable by subtyping from the patients' strains. Many of the cooling towers examined were inadequately maintained, including one of the two above a building adjacent to Piccadilly Circus from which a strain indistinguishable from the outbreak strain was isolated. All cooling towers in the area were shut down until inspected, and only allowed to restart after appropriate maintenance had been instigated. CONCLUSIONS: This outbreak showed the continuing risk of legionnaires' disease posed by wet cooling systems, including cooling towers, and highlighted the need to assess this risk so that appropriate maintenance is carried out. Regulations have recently been introduced, under the Health and Safety at Work Act, requiring notification of all wet cooling systems to the local authority to facilitate the investigation of outbreaks of legionnaires' disease.

Adolescent↗

PubMed1995

An outbreak of encephalomyocarditis-virus infection in free-ranging African elephants in the Kruger National Park.

A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7,500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early in 1994 had lesions of cardiac failure suggestive of encephalomyocarditis (EMC)-virus infection, and the virus was isolated from the heart muscles of three fresh carcases. The results of tests for neutralizing antibody on 362 elephant sera collected for unrelated purposes from 1984 onwards and kept frozen, indicated that the virus had been present in the KNP since at least 1987. Antibody prevalences of 62 of 116 (53%) 18 of 139 (13%) and seven of 33 (21%) were found in elephants in three different regions of the KNP in 1993 and 1994. Studies had been conducted on myomorph rodents in the KNP for unrelated purposes since 1984, and trapping attempts were increased during the perceived outbreak of disease in elephants. There was a striking temporal correlation between the occurrence of a population explosion (as evidenced by markedly increased catch rates per trap-night) and a surge in prevalence of antibody to EM virus in rodents, and the occurrence of the outbreak of disease in elephants.

Animals↗

PubMed1988

Outbreak of staphylococcal scalded skin syndrome among neonates.

Over a period of 2 months, 12 babies born in the maternity unit at Guy's Hospital developed staphylococcal scalded skin syndrome in two distinct outbreaks. Staphylococci isolated from the babies, together with those from the mothers and attending medical staff were phage-typed. All isolates from the babies were of type 3A/3C. During the first outbreak only one carrier of the epidemic strain (a paediatrician) was found but a further 12 persons were identified as possible carriers during the second outbreak. In order to confirm the link between outbreaks, all phage group II isolates were subjected to reverse phage-typing, testing for metal-ion resistance, plasmid profiling and in-vivo testing for production of epidermolytic toxin. It was shown that the same epidemic strain of toxin-producing Staphylococcus aureus was responsible for both outbreaks. The affected neonates responded rapidly to a short course of intravenous flucloxacillin. The outbreak ceased after appropriate treatment of all carriers and the implementation of an extensive disinfection policy within the maternity unit.

Carrier State↗

PubMed1983

Use of electrophoresis of RNA from human rotavirus to establish the identity of strains involved in outbreaks in a tertiary care nursery.

During two nosocomial outbreaks in a tertiary care nursery, 22 of 102 infants had infections due to human rotavirus (HRV). The time sequence and proximity of the infected infants in the nursery rooms had suggested infant-to-infant spread of a single HRV strain in each outbreak. Polyacrylamide gel electrophoresis of virus permitted demonstration of four different HRV electropherotypes (strains) during the first outbreak period and seven during the second. One of the strains was detected during both outbreaks. All strains had fast-migrating RNA segments 10 and 11. Infant-to-infant spread of at least two different viruses apparently occurred in each outbreak period. Thus, electrophoretic analysis showed that infants in a tertiary care center can be infected with at least 10 different HRV strains within two months, that multiple HRV strains can spread independently and in parallel to different infants as part of a "single" outbreak, and that secondary spread of individual strains can be traced with considerable accuracy.

Cross Infection↗

PubMed1979

[Dimorphous Hansen's disease with outbreaks of Hansen reactions and visceral lesions].

The paper presents the case of a patient with borderline hanseniasis. After a long period of illness, he presented an outbreak with new lesions, that showed reactional tuberculoid aspects; he later presented lesions with clinical and histological aspects of Virchowian hanseniasis. This evolutional type is compatible with the pseudo-exacerbations outbreaks reported by Souza Lima. This patient also presented an Erythema Nodosum outbreak with cutaneous and visceral lesions, the latter occurring with great intensity in the liver parenchyma with clinical manifestations of icterus and hepatomegaly. The pathogenesis of the pseudo-exacerbations outbreaks is discussed, also the special situation of Borderline patients, subject to neurologic injuries during the pseudo-exacerbations outbreaks, and cutaneous, neurological and visceral lesions during the Erythema Nodosum Hansenicum outbreaks.

Erythema Nodosum↗

PubMed1993

[Clinical epidemiology of an outbreak of nosocomial infection caused by Staphylococcus aureus resistant to methicillin and aminoglycosides: efficacy of control measures. Comité de Control de Infecciones].

BACKGROUND: The appearance of outbreaks of nosocomial infections due to methicillin resistant Staphylococcus aureus (MRSA) is a current problem in Spain. The clinical and molecular epidemiology of these outbreaks as well as the efficacy of their control measures are a matter of controversy. METHODS: An outbreak of MRSA nosocomial infections in the Hospital Clínic i Provincial of Barcelona, a 953-bed University Hospital, with a total of 347 cases from September 1989 to October 1991 is described. The control measures used include prospective and continued surveillance of all MRSA isolations, identification of the reservoir, use of different types of isolation and control of nasal carriers among health care workers. The MRSA strains isolated were studied by standard microbiological procedures, phage-typing and extrachromosomal (plasmid) DNA analysis by means of restriction endonuclease analysis (REAP). RESULTS: From the Intensive Care Units, the outbreak extended to the medical and surgical wards. Seventy-one percent of the cases corresponded to infected patients and 29% to asymptomatic carrier patients. The MRSA strain responsible of the outbreak had a notable antibiotic multiple-resistance pattern. The studies performed showed that most of the strains belonged to phage group III and were lysed by phage 77. Plasmid DNA analysis showed that 95% of the strains isolated had a unique homogeneous profile. Despite the different control measures used, the MRSA infection has acquired a medium level endemic rate in the Hospital Clínic i Provincial. CONCLUSIONS: The introduction and spread of methicillin-resistant MRSA in a teaching hospital with more than 500-bed may be rapid and affecting large number of patients. Effective control measures carries multiple problems, which must be addressed with the collaboration of all hospital employees. The molecular typing techniques used (REAP) further identified that the outbreak is due to one single MRSA strain, with an epidemiologic behavior identical to the one showed by the epidemic strains previously described in the United Kingdom and Australia.

Aminoglycosides↗

PubMed1994

A sudden outbreak of illness suggestive of mass hysteria in schoolchildren.

OBJECTIVE: To clarify factors contributing to mass illness of sudden onset by studying an outbreak that was apparently triggered by a gaseous odor and that involved a rapid, extensive response by school and fire officials. SETTING: Urban elementary school. MAIN OUTCOME MEASURE: A standardized student questionnaire was designed to identify potential illness predictors. DESIGN: Four weeks following the outbreak, public health officials distributed the questionnaire to all students in regular classes in grades 3 through 6 (N = 319), representing 46% of the estimated 680 students present the day of the outbreak. RESULTS: Seventy-seven percent of the students who completed the questionnaire reported that they experienced physical symptoms during the epidemic. A stepwise regression analysis demonstrated several independent variables that predicted the severity of illness, including the intensity of the odor smelled during the outbreak (P < .0001), becoming sick after the fire trucks arrived (P < .0001), and believing in an environmental cause for the illness (P < .002). CONCLUSIONS: These results indicate that both psychological and environmental factors, real or perceived, may contribute to sudden-onset epidemics of hysteria. Moreover, the response intervention of officials may influence the extent of such outbreaks. Early recognition of psychological causes and dispersion of groups at risk could reduce morbidity and associated health care costs.

Child↗

PubMed1990

Nosocomial outbreak of neonatal gastroenteritis caused by a new serotype 4, subtype 4B human rotavirus.

A nosocomial outbreak of rotavirus gastroenteritis involving 52 newborns occurred between June and September 1988 at the University Children's Hospital of Freiburg, Federal Republic of Germany. Stools from 27 representative patients were examined for rotavirus serotypes, using a monoclonal antibody-based enzyme-linked immunosorbent assay. The electropherotype was also examined by polyacrylamide gel electrophoresis of genomic RNA. As many as 18 patients were found to be infected by serotype 4, subtype 4B strain, and in all of them the same electropherotype was detected. Although rotavirus from the remaining nine patients could not be typed, the electropherotype in four was identical to that of the serotype 4, subtype 4B strain. Thus, most of the patients in the outbreak were infected by the same rotavirus strain. Retrospective epidemiological studies showed that the 4B strain began to circulate at the hospital in January 1988, whereas only rotavirus serotypes 1, 3, and 4A were detected in 1985-1987. The primary case of the outbreak was presumably a newborn with acute gastroenteritis, admitted to the hospital from a small maternity unit in the same urban area. During the outbreak, 12 of 44 healthy newborns in the nurseries of the Children's Hospital and other maternity hospitals were found to be asymptomatic rotavirus carriers, and in three of the newborns the same 4B strain was detected. This is the first reported outbreak caused by a serotype 4, subtype 4B strain.

Cross Infection↗

PubMed1994

Analysis of nosocomial outbreaks with multiply and methicillin-resistant Staphylococcus aureus (MRSA) in Germany: implications for hospital hygiene.

Two outbreaks of nosocomial infections with MRSA, one in a urological unit in connection with transurethral prostatectomy and the other in an orthopaedic clinic with infections after implantation of prosthetic hips, have been analyzed on the basis of typing MRSA by phage-patterns, plasmid profiles and genomic DNA fragment patterns. Main reasons for these outbreaks were obviously mistakes in hospital hygiene and an inappropriate antibiotic prophylaxis (in the first outbreak a quinolone over about 7 days, in the second a third generation cephalosporin). Both outbreaks could be stopped by measures of hospital hygiene including isolated or cohort nursing of affected patients, and change in antibiotic prophylaxis. Intensive care units (ICUs) are more often affected by MRSA than other clinical settings. As described by the example of an outbreak with MRSA in a municipal hospital, ICUs can play a special role in intrahospital spread of MRSA. The recently observed inter-regional clonal interhospital dissemination of MRSA in Germany is mainly due to a transfer of patients between hospitals; prewarning of the hospital of destination and a number of hygiene measures can prevent further spread.

Anti-Bacterial Agents↗

PubMedDate not supplied

A second community outbreak of waterborne giardiasis in Canada and serological investigation of patients.

A waterborne outbreak of giardiasis which occurred 5 years after another in the same town in Canada was investigated. Sera from residents defined as cases or non-cases were tested by enzyme-linked immunosorbent assay (ELISA) and compared with sera from symptomatic and asymptomatic control groups. The outbreak-associated Giardia isolate was retrieved from contaminated drinking water and antigen from this strain was used in the serological investigation. Up to 84% of cases were identified by ELISA. More cases were identified by elevated immunoglobulin (Ig) G than by either elevated anti-Giardia IgA or IgM levels. Residents of the community infected during the first outbreak were significantly less likely to have been reinfected during the second outbreak. This is the first report of a second waterborne outbreak occurring in a community and results of the investigations are consistent with an acquired, protective immunity lasting at least 5 years.

Adolescent↗

PubMed1984

Silver staining of DNA restriction fragments for the rapid identification of adenovirus isolates: application during nosocomial outbreaks.

The ultrasensitive photochemical silver stain for nucleic acids, described by Beidler et al. (1982), has been applied to the detection of adenovirus restriction fragments as a relatively rapid technique for the identification of virus isolates. In this study, restriction enzyme cleavage analysis was used to characterize adenovirus isolates from what appeared to be two nosocomial outbreaks. The first outbreak was thus shown to include two clusters of patients, and involved two serotypes Ad7c and Ad40. The second outbreak was unrelated and involved Ad35. Although restriction analysis does not replace serum neutralization as a routine method for typing adenoviruses, it is a much more rapid means of discriminating between different patient isolates, providing a current rather than retrospective analysis of a nosocomial outbreak. During the first outbreak, restriction analysis identified two distinct adenovirus serotypes from one patient--Ad7c from a nasopharyngeal aspirate and Ad41 from a stool specimen. Restriction analysis is also valuable for the sub-typing of virus isolates. In this study, the Ad40 and Ad41 isolates were shown to be variants of the respective prototype strains.

Adenoviridae Infections↗

PubMed1987

A hospital outbreak caused by a chlorhexidine and antibiotic-resistant Proteus mirabilis.

An outbreak of urinary-tract infection involving a strain of Proteus mirabilis resistant to gentamicin and several other antibiotics affected 90 patients in Southampton between July 1980 and May 1985. The outbreak strain was also resistant to chlorhexidine and this, in combination with the antibiogram and Dienes' test, permitted differentiation from other P. mirabilis strains. The outbreak had features in common with other Enterobacteriaceae outbreaks, although certain aspects of the population involved have made it particularly difficult to control. The outbreak commenced shortly after the introduction of a catheter care policy which involved the use of chlorhexidine, and although the majority of the cases were colonized before this policy was enforced, chlorhexidine had been used extensively for other procedures within the district. Preliminary evidence suggests that there is no genetic linkage between the chlorhexidine and multiple antibiotic resistance.

Age Factors↗

PubMed1989

Outbreaks of astrovirus type 1 and rotavirus gastroenteritis in a geriatric in-patient population.

Two outbreaks of viral gastroenteritis occurred in seven psychogeriatric wards of a 469-bed psychiatric hospital. The outbreaks occurred over an eight-week period; the first affected 30 people and rotavirus was detected in 12 of 14 persons from whom faecal specimens were available. The second affected 32 people (15 of whom were affected in the previous outbreak) and astrovirus was detected in 5 of the 24 people from whom specimens were available. Specific IgM to astrovirus was demonstrated in 3 patients. The rotavirus outbreak was characterised by a longer duration of illness (mean 4 days), and more severe symptoms; two elderly female patients had severe symptoms over a 14-15 day period but recovered. In the astrovirus outbreak the duration of illness was shorter and symptoms were milder although the attack rate was higher than that observed for rotavirus.

Adult↗

PubMed1992

Costs of an outbreak of wound infections in an orthopaedic ward.

An outbreak of serious wound infections occurring in an orthopaedic ward is reported. The outbreak involved 10 patients, all of whom had undergone clean, orthopaedic operative procedures. The outbreak was eventually terminated by discarding five damaged and contaminated mattresses. The costs incurred during this outbreak were calculated using a retrospective comparative study. The infected patients had an average increased hospital stay of 17 days and average increased costs of 2220 pounds. The outbreak demonstrated the high costs of hospital-acquired infection and the need for further investment in infection control programmes.

Beds↗

PubMed1994

An outbreak of group C streptococcal infection in a maternity unit.

An outbreak of Group C streptococcal infection (Streptococcus equisimilis serotype T204) occurred in a Maternity Unit in Durham over a 2-week period. The outbreak strain possessed an M-protein antigen identical to that found in a previously reported Maternity Unit outbreak. Seven patients in total were affected, and in two patients infected perineal wounds took several weeks to heal. The source of the outbreak appeared to be a patient who developed a perineal wound infection and who subsequently returned to the ward for reassessment. Environmental contamination is likely to have been the reservoir of infection for the subsequent patients. The outbreak was controlled by applying strict infection control procedures and establishing a high standard of routine cleaning.

Cross Infection↗