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 1,189 records · Page 66Linked to original sources

PubMed2003

Role of healthcare workers in outbreaks of methicillin-resistant Staphylococcus aureus: a 10-year evaluation from a Dutch university hospital.

BACKGROUND AND OBJECTIVE: The benefit of screening healthcare workers (HCWs) at risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage and furloughing MRSA-positive HCWs to prevent spread to patients is controversial. We evaluated our MRSA program for HCWs between 1992 and 2002. SETTING: A university medical center in The Netherlands, where methicillin resistance has been kept below 0.5% of all nosocomial S. aureus infections using active surveillance cultures and isolation of colonized patients. DESIGN: HCWs caring for MRSA-positive patients or patients in foreign hospitals were screened for MRSA. MRSA-positive HCWs had additional cultures, temporary exclusion from patient-related work, assessment of risk factors for persisting carriage, decolonization therapy with mupirocin intranasally and chlorhexidine baths for skin and hair, and follow-up cultures. RESULTS: Fifty-nine HCWs were colonized with MRSA. Seven of 840 screened employees contracted MRSA in foreign hospitals; 36 acquired MRSA after contact with MRSA-positive patients despite isolation precautions (attack rate per outbreak varied from less than 1% to 15%). Our hospital experienced 17 MRSA outbreaks, including 13 episodes in which HCWs were involved. HCWs were index cases of at least 4 outbreaks. In 8 outbreaks, HCWs acquired MRSA after caring for MRSA-positive patients despite isolation precautions. CONCLUSION: Postexposure screening of HCWs allowed early detection of MRSA carriage and prevention of subsequent transmission to patients. Where the MRSA prevalence is higher, the role of HCWs may be greater. In such settings, an adapted version of our program could help prevent dissemination.

Adult↗

PubMed2004

Impact of surveillance for vancomycin-resistant enterococci on controlling a bloodstream outbreak among patients with hematologic malignancy.

OBJECTIVE: To determine the impact of stool surveillance cultures of critically ill patients on controlling vancomycin-resistant enterococci (VRE) outbreak bacteremia. DESIGN: Stool surveillance cultures were performed on patients who had hematologic malignancy or were critically ill at the time of hospital admission to identify those colonized with VRE. Hence, contact isolation was initiated. SETTING: A tertiary-care cancer center with a high prevalence of VRE. PARTICIPANTS: All patients with hematologic malignancy who were admitted to the hospital as well as all of those admitted to the intensive care unit were eligible. RESULTS: Active stool surveillance cultures performed between 1997 and 2001 decreased the incidence density of VRE bacteremias eightfold while vancomycin use remained constant. In fiscal year (FY) 1997 and FY 1998, there were five and three VRE outbreak bacteremias, respectively. The outbreak clones were responsible for infection in 69% of those patients with VRE bacteremia. However, the stool surveillance program resulted in the complete control of VRE bacteremia by FY 1999 until the end of the study. CONCLUSION: Despite the steady use of vancomycin, the active surveillance program among high-risk patients with hematologic malignancy and those who were critically ill resulted in the complete control of VRE outbreak bacteremia at our institution.

Bacteremia↗

PubMed2004

A protracted outbreak of Staphylococcus epidermidis infections among patients undergoing valve replacement.

OBJECTIVE: To investigate a Staphylococcus epidermidis outbreak among patients undergoing cardiac surgery. DESIGN: Retrospective cohort study. SETTING: A 260-bed community referral center. PATIENTS: Case-patients were patients with S. epidermidis mediastinitis, endocarditis, or both after valve implantation at Hospital de La Ribera from January to June 2002. The study population included patients undergoing valve surgery at Hospital de La Ribera from January 2000 to June 2002. RESULTS: From January to June 2002, 8 cases of mediastinitis, endocarditis, or both occurred among 53 patients undergoing cardiac surgery. In the same months of 2000, there had been no cases among 22 patients, and in 2001, only 1 case among 47 patients (P = .095 and P = .034, respectively). In 2002, there were 4 cases of mediastinitis and endocarditis, 3 cases of mediastinitis, and 1 case of endocarditis, all following aortic valve replacement. The epidemic curve suggested a protracted outbreak. Patients with chronic obstructive lung disease were six-fold more likely to be case-patients (95% confidence interval, 1.6-23.8). The mean duration of surgery tended to be longer in non-case-patients (161.4 +/- 57.9 minutes) than in case-patients (123.7 +/- 23.7 minutes) (P = .06). CONCLUSION: The cause of this protracted outbreak was likely multifactorial. Reemphasis of existing policies was associated with resolution of the outbreak.

Adult↗

PubMed2005

Impact of an outbreak of norovirus infection on hospital resources.

OBJECTIVE: To describe a nosocomial norovirus outbreak, its management, and its financial impact on hospital resources. DESIGN: A matched case-control study and microbiological investigation. METHODS: We compared 16 patients with norovirus infection with control-patients matched by age, gender, disease category, and length of stay. Bed occupancy-days during the peak incidence period of the outbreak were compared with the corresponding periods in 2001 and 2002. Expenses due to increased workload were calculated based on a measuring system that records time spent for nursing care per patient per day. RESULTS: The attack rates were 13.9% among patients and 29.5% among healthcare workers. The median number of occupied beds was significantly lower due to bed closure during the peak incidence in 2003 (29) compared with the median number of occupied beds in 2001 and 2002 combined (42.5). Based on this difference and a daily charge of 562.50 dollars per patient, we calculated a revenue loss of 37,968 dollars. Additional expenses totaled 10,300 dollars for increased nursing care. Extra costs for microbiological diagnosis totaled 2707 dollars. Lost productivity costs due to healthcare workers on sick leave totaled 12,807 dollars. The expenses for work by the infection control team totaled 1408 dollars. The financial impact of this outbreak on hospital resources comprising loss of revenue and extra costs for microbiological diagnosis but without lost productivity costs, increased nursing care, and expenses for the infection control team totaled 40,675 dollars. CONCLUSIONS: Nosocomial norovirus outbreaks result in significant loss of revenue and increased use of resources. Bed closures had a greater impact on hospital resources than increased need for nursing care

Caliciviridae Infections↗

PubMed2005

An outbreak of Pichia anomala fungemia in a Brazilian pediatric intensive care unit.

OBJECTIVE: To report an outbreak of Pichia anomala fungemia that occurred in a Brazilian pediatric intensive care unit (ICU) from October 2002 to January 2004. DESIGN: Unmatched case-control study. METHODS: We randomly selected four control-patients for each case-patient from a list of all patients admitted to the ICU for at least 48 hours during the outbreak. A second control group was composed of all consecutive patients with nosocomial candidemia in the ICU during the outbreak. An environmental study was performed, and genetic relatedness among the clinical isolates was characterized by randomly amplified polymorphic DNA assay. RESULTS: During the study period, 1,046 children were admitted to the pediatric ICU, 17 of whom developed P. anomala fungemia (attack rate, 1.6%). The median age was 1.1 years, and the main underlying conditions were congenital malformations (35.3%) and neoplastic diseases (11.8%). The overall mortality rate was 41.2%. Two patients received no antifungal treatment; all of the others were treated with amphotericin B. On multivariate analysis, only the presence of a central venous catheter was significantly associated with P. anomala fungemia. The yeast was not found on healthcare workers' hands or in the environment. Molecular studies showed that the outbreak was caused by a single strain. The distribution of risk factors was similar between patients with P. anomala fungemia and control-patients with candidemia. CONCLUSIONS: This study highlights the importance of P. anomala as an emerging nosocomial fungal pathogen. Patients with P. anomala fungemia seem to have risk factors in common with those who have candidemia.

Age Distribution↗

PubMed2006

Outbreak of infection with Acinetobacter strain RUH 1139 in an intensive care unit.

OBJECTIVE: To investigate a nosocomial outbreak of infection with Acinetobacter strain RUH 1139, in the unit of high neonatal risk at University Hospital of The Andes (Merida, Venezuela). METHODS: Twenty-eight Acinetobacter strains were detected by biochemical testing and further identified to the species level by examination of the gene encoding 16S ribosomal DNA, using restriction analysis and gene sequencing. The epidemiological relationship between the strains was established by means of repetitive extragenic palindromic polymerase chain reaction (REP-PCR) and pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibilities were determined by disk diffusion. RESULTS: The spread of an epidemic strain of Acinetobacter RUH 1139 among 16 patients over a period of 3 months was demonstrated using antimicrobial susceptibility testing, PFGE, and REP-PCR. The epidemic strain was also isolated in 2 of the sampled parenteral nutrition solutions. All the patients involved in the infection outbreak had received parenteral solution. Moreover, strains of Acinetobacter RUH 1139 with another PFGE pattern and of A. baumannii were sporadically isolated before and during the outbreak. CONCLUSION: This is the first description of an outbreak of infection with this genospecies of Acinetobacter in which parenteral nutrition solution was potentially the infection source.

Acinetobacter↗

PubMed2006

Measures to control an outbreak of pertussis in a neonatal intermediate care nursery after exposure to a healthcare worker.

BACKGROUND: Hospitalized premature infants are particularly vulnerable to morbidity and mortality from pertussis. Effective prevention and investigative and control measures are not well described. OBJECTIVE: To identify the source of nosocomial pertussis in a 2-month-old premature infant in a neonatal intermediate care nursery (ICN) and to critically review the investigation and outbreak control measures. SETTING: An ICN and a neonatal intensive care unit. METHODS: We queried healthcare workers (HCWs) and family members about cough illness and contacted potentially exposed patients to determine whether they had symptoms of pertussis. Culture and polymerase chain reaction (PCR) testing for Bordetella pertussis were performed by the hospital laboratory with specimens collected from symptomatic patients and HCWs. Levels of pertussis toxin immunoglobulin G antibodies were measured in HCWs with cough of at least 14 days' duration at a public health laboratory. Extensive control measures were instituted. RESULTS: Four ICN HCWs met the clinical case definition for presence of pertussis. Serologic test results were positive for 3 of the HCWs. The primary case patient was a 36-year-old HCW with a cough illness of 3-weeks' duration that was accompanied by paroxysms, whoop, posttussive emesis, and pneumothorax. Among the 4 affected HCWs, the duration of cough illness prior to identification of the infant index patient ranged from 11 to 25 days. Outbreak control measures included isolation of the infant case patient, furlough and treatment of symptomatic HCWs, administration of chemoprophylaxis to contacts, and surveillance for additional cases. Seventy-two infant patients and 72 HCWs were exposed and were given antibiotic prophylaxis. One additional case of pertussis, confirmed by PCR and culture, occurred in a resident physician who declined prophylaxis; she had cared for the index patient but had no contact with symptomatic HCWs. CONCLUSION: HCWs or patients may serve as the source of pertussis in nosocomial outbreaks, which can result in substantial morbidity and outlay of resources for control measures. Our review suggested that a diagnosis of pertussis should be an early consideration for HCWs with cough illness. Targeted pertussis immunization of HCWs, employee health policies that provide for testing and furlough of HCWs with prolonged cough, and monitoring of HCWs for compliance with infection control measures could reduce the morbidity and costs associated with pertussis outbreaks. These measures will require evaluation of their effectiveness.

Adult↗

PubMed2006

Outbreak of pertussis among healthcare workers in a hospital surgical unit.

BACKGROUND: In September 1999, a pertussis outbreak was detected among surgical staff of a 138-bed community hospital. Patients were exposed to Bordetella pertussis during the 3-month outbreak period. OBJECTIVE: To describe the outbreak among surgical staff, to evaluate implemented control measures, and to determine whether nosocomial transmission occurred. METHODS: Clinical pertussis was defined as acute cough illness with a duration of 14 days or more without another apparent cause; persons with positive culture, PCR, or serologic test results were defined as having laboratory-confirmed pertussis. Surgical healthcare workers (HCWs) were interviewed regarding pertussis symptoms, and specimens were obtained for laboratory analysis. Patients exposed to B. pertussis during an ill staff member's 3-week infectious period were interviewed by phone to determine the extent of nosocomial spread. PARTICIPANTS: A total of 53 HCWs assigned to the surgical unit and 146 exposed patients. HCWs with pertussis were defined as case subjects; HCWs without pertussis were defined as non-case subjects. RESULTS: Twelve (23%) of 53 HCWs had clinical pertussis; 6 cases were laboratory confirmed. The median cough duration in the 12 case subjects was 27 days (range, 20-120 days); 10 (83%) had paroxysms. Eleven (92%) of 12 case subjects and 28 (86%) of 41 non-case subjects received antibiotic treatment or prophylaxis. Seven case subjects (58%) reported they always wore a mask when near patients. Of 146 patients potentially exposed to pertussis from the 12 case subjects, 120 (82%) were interviewed; none reported a pertussis-like illness. CONCLUSIONS: Surgical staff transmitted B. pertussis among themselves; self-reported data suggests that these HCWs did not transmit B. pertussis to their patients, likely because of mask use, cough etiquette, and limited face-to-face contact. Control measures might have helped limit the outbreak once pertussis was recognized.

Adult↗

PubMed2006

An outbreak of poliomyelitis caused by type 1 vaccine-derived poliovirus in China.

BACKGROUND: In May-July 2004, type 1 vaccine-derived poliovirus (VDPV) was isolated from 2 case patients with polio and a contact of a third case patient in Guizhou Province. METHODS: We conducted a field investigation of the outbreak, characterized outbreak isolates, and retrospectively reviewed national polio surveillance data for other VDPVs. RESULTS: Case patients were unimmunized children, 0.9-3.2 years old, living in 2 villages 40 km apart. Immunization coverage in the affected villages was very low. Isolates differed from the Sabin 1 type by 9-11 VP1 nucleotides (1.0%-1.2%); which indicated, on the basis of known rates of mutation of Sabin strains, that they had been circulating for <1 year. A province-wide immunization response targeting all children <5 years old was initiated in August, and the strain has not been isolated since. During 1997-2004, 10 VDPV strains (5 of type 2, 3 of type 1, and 2 of type 3) were isolated from >50,000 children with acute flaccid paralysis and their contacts; 8 (80%) were found in southern provinces, and 9 (90%) spontaneously disappeared. CONCLUSION: This is the first polio outbreak in China in over a decade and the first due to VDPV. The short duration of circulation demonstrates the rapidity with which attenuated Sabin strains can revert to a wild phenotype. One to two VDPVs have been identified each year, primarily in densely populated subtropical regions of southern China. This outbreak highlights the need to consider risks of paralysis from vaccine-derived strains in development of national poliomyelitis immunization policy.

Child, Preschool↗

PubMed2006

Bacterial genetic determinants of non-O157 STEC outbreaks and hemolytic-uremic syndrome after infection.

Although O157:H7 Shiga toxin-producing Escherichia coli (STEC) are the predominant cause of hemolytic-uremic syndrome (HUS) in the world, non-O157:H7 serotypes are a medically important cause of HUS that are underdetected by current diagnostic approaches. Because Shiga toxin is necessary but not sufficient to cause HUS, identifying the virulence determinants that predict severe disease after non-O157 STEC infection is of paramount importance. Disease caused by O157:H7 STEC has been associated with a 26-gene pathogenicity island known as O island (OI) 122. To assess the public-health significance of this pathogenicity island, we examined the association between OI122 genes and outbreaks and HUS after non-O157 STEC infection. We found that a subset of OI122 genes is independently associated with outbreaks and HUS after infection with non-O157 STEC. The presence of multiple virulence genes in non-O157 serotypes strengthened this association, which suggests that the additive effects of a variable repertoire of virulence genes contribute to disease severity. In vivo, Citrobacter rodentium mutants lacking outbreak- and HUS-associated genes were deficient for virulence in mice; in particular, nleB mutant bacteria were unable to cause mortality in mice. The present study shows that virulence genes associated epidemiologically with outbreaks and HUS after non-O157 STEC infection are pivotal to the initiation, progression, and outcome of in vivo disease.

Animals↗

PubMed2006

Control of an outbreak of multidrug-resistant Acinetobacter baumannii-calcoaceticus colonization and infection in an intensive care unit (ICU) without closing the ICU or placing patients in isolation.

OBJECTIVE: To describe the control of multidrug-resistant Acinetobacter baumannii-calcoaceticus (MDRABC) colonization and infection in an intensive care unit (ICU). SETTING: An 18-bed ICU in a large tertiary care teaching hospital in London. INTERVENTIONS: After recognition of the outbreak, a range of infection control measures were introduced over several months that were primarily aimed at reducing environmental contamination with the outbreak strain. Strategies included use of a closed tracheal suction system for all patients receiving mechanical ventilation, use of nebulized colistin for patients with evidence of mild to moderate ventilator-associated pneumonia, improved availability of alcohol for hand decontamination, and clearer designation of responsibilities and strategies for cleaning equipment and the environment in the proximity of patients colonized or infected with MDRABC. RESULTS: The outbreak lasted from June 2001 through November 2002 and involved 136 new cases of MDRABC infection or colonization. The number of newly diagnosed cases per month reached a maximum of 15 in February 2002, and the number of new cases slowly decreased over the next 9 months. CONCLUSION: This outbreak was controlled by emphasizing the control of environmental reservoirs and did not require recourse to ward closure or placement of affected patients in isolation.

Acinetobacter Infections↗

PubMed1997

Report on an outbreak of postinjection abscesses due to Mycobacterium abscessus, including management with surgery and clarithromycin therapy and comparison of strains by random amplified polymorphic DNA polymerase chain reaction.

An outbreak of postinjection abscesses occurred in Barranquilla, Colombia, and was associated with local injections of lidocaine given in a single physician's office. Over a 5-month period, 350 (18%) of approximately 2,000 injected patients developed localized cutaneous abscesses or cellulitis; of 210 abscess specimens that were cultured, 205 were positive for rapidly growing mycobacteria, subsequently identified as Mycobacterium abscessus. The source of the outbreak was not identified. M. abscessus could not be characterized by pulsed-field gel electrophoresis, but all isolates were identical in terms of drug and heavy metal resistance patterns and random amplified polymorphic DNA PCR profiles. We believe this is the first report of the use of this latter technique for investigation of an outbreak due to M. abscessus. Therapy with a combination of surgical excision and 3-6 months' administration of clarithromycin was successful for 95% of 148 patients treated in this manner; in contrast, therapy was successful for less than one-third of patients treated with surgery alone or clarithromycin alone. This is the largest of the nine known outbreaks of postinjection abscesses that have occurred due to rapidly growing mycobacteria and is the first in which an effective method of therapy was demonstrated.

Abscess↗

PubMed1998

Enhanced control of an outbreak of Mycoplasma pneumoniae pneumonia with azithromycin prophylaxis.

There are currently no recommended epidemic-control measures for Mycoplasma pneumoniae pneumonia outbreaks in closed communities. Previous studies have suggested the usefulness of chemoprophylaxis administered to close contacts of case-patients. To evaluate the effectiveness of various epidemic-control measures during an institutional outbreak, an observational study was undertaken during a very large outbreak of M. pneumoniae pneumonia at a facility for developmentally disabled residents (n = 142 cases). Control measures evaluated included no control, standard epidemic-control measures, and targeted azithromycin prophylaxis (500 mg on day 1, 250 mg/day on days 2-5) plus standard epidemic-control measures. The combined use of azithromycin prophylaxis and standard epidemic-control measures was associated with a significant reduction in the secondary attack rate. This study suggests that the addition of antibiotic prophylaxis to standard epidemic-control measures can be useful during institutional outbreaks of M. pneumoniae pneumonia.

Adolescent↗

PubMed1998

Outbreak of paralytic poliomyelitis in Albania, 1996: high attack rate among adults and apparent interruption of transmission following nationwide mass vaccination.

After >10 years without detection of any cases of wild virus-associated poliomyelitis, a large outbreak of poliomyelitis occurred in Albania in 1996. A total of 138 paralytic cases occurred, of which 16 (12%) were fatal. The outbreak was due to wild poliovirus type 1, isolated from 69 cases. An attack rate of 10 per 100,000 population was observed among adults aged 19-25 years who were born during a time of declining wild poliovirus circulation and had been vaccinated with two doses of monovalent oral poliovirus vaccines (OPVs) that may have been exposed to ambient temperatures for prolonged periods. Control of the epidemic was achieved by two rounds of mass vaccination with trivalent oral poliovirus vaccine targeted to persons aged 0-50 years. This outbreak underscores the ongoing threat of importation of wild poliovirus into European countries, the importance of delivering potent vaccine through an adequate cold chain, and the effectiveness of national OPV mass vaccination campaigns for outbreak control.

Adolescent↗

PubMed1988

An outbreak of Salmonella gastroenteritis in an urban jail.

An outbreak of gastroenteritis in New York City's largest jail involved 145 cases over a two-month period. The outbreak was unusual in that two Salmonella strains (serogroups B and D) were involved. Management of the outbreak involved screening kitchen workers by culture of stool samples, and education regarding personal hygiene. Obstacles to investigation and management of the outbreak arose out of the special nature of the jail environment; these included jurisdictional problems and high turnover of the inmate population.

Disease Outbreaks↗

PubMed1989

The importance of nosocomial transmission of measles in the propagation of a community outbreak.

In late January 1985, a measles outbreak occurred at a community hospital in Columbia county, Florida. The outbreak spread throughout the county and to two neighboring counties (Alachua and Marion), resulting in 79 cases with a 29% hospitalization rate. Hospitals represented the site with the highest frequency of transmission. At the Alachua county hospitals, where strict respiratory isolation measures were taken, no secondary cases occurred among hospitalized patients. Two independent risk factors existed for hospitalization: measles exposure in a hospital setting (P less than 0.05) and nonvaccination (P less than 0.001). Of the total measles cases, 24% were under the age of 16 months and 47% of those aged 16 months or older had a history of appropriate vaccination. Columbia county, which experienced 86% of the cases, had a 5% frequency of unvaccinated students compared to 0.6% frequency at Alachua (P less than 0.001) where only 10% of the cases occurred. This outbreak demonstrates the role of uncontrolled nosocomial transmission of measles in the propagation of a community outbreak.

Cross Infection↗

PubMed1990

Postoperative group A beta-hemolytic Streptococcus outbreak with the pathogen traced to a member of a healthcare worker's household.

A cluster of four group A beta-hemolytic Streptococcus postoperative wound infections was investigated at a community hospital. The serotypes of the Streptococcus isolated from all four cases, an asymptomatic anesthesiologist and one of his household members were M nontypable T28. During the outbreak period, December 1988, the infection rate among the 40 patients of the anesthesiologist was 7.5%. Among other patients not having contact with this healthcare worker, it was 0.09% (p = .0002 Fisher's exact test). This is only the second reported Group A beta-hemolytic Streptococcus hospital outbreak in which the pathogen was traced to a member of a healthcare worker's household. Early outbreak detection and intervention limited the extent of the outbreak.

Adult↗

PubMed1990

Influenza outbreaks in nursing homes: how effective is influenza vaccine in the institutionalized elderly?

During the 1984-1985 influenza season, outbreaks of influenza A (H3N2) occurred in three Connecticut nursing homes. Influenza vaccination rates were 67% (96 out of 144), 35% (30 out of 85) and 69% (332 out of 483), respectively. The relative risk of illness for vaccinated compared to unvaccinated residents was 1.8 (95% confidence interval, 0.6, 5.9), 1.6 (95% confidence interval, 0.8, 3.0) and 1.1 (95% confidence interval, 0.8, 1.7) for each of the three nursing homes, respectively. In the third outbreak, 22 vaccinated residents without clinical illness had a geometric mean titer of hemagglutination-inhibition (HI) antibody of 20. Although low, this titer was significantly higher than that of nine unvaccinated residents without clinical illness (12, p less than .05); only three (14%) vaccinated residents had HI titers of greater than or equal to 40. These results suggest that levels of HI antibody in vaccinated residents were not protective at the time of the third outbreak, four to five months after vaccination. In general, the study of vaccine effectiveness in nursing homes is limited by sample size and statistical power. Despite these limits, the retrospective investigation of influenza outbreaks in nursing homes is often the only practical way to evaluate influenza vaccine effectiveness in the elderly on a yearly basis.

Adult↗