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PubMed2003

Pasteurella multocida from outbreaks of avian cholera in wild and captive birds in Denmark.

An outbreak of avian cholera was observed among wild birds in a few localities in Denmark in 2001. The highest mortalities were among breeding eiders (Somateria mollissima) and gulls (Larus spp.). Pulsed-field gel electrophoresis (PFGE) was conducted using ApaI and SmaI as restriction enzymes and restriction enzyme analysis (REA) using HpaII. The Pasteurella multocida subsp. multocida strain isolated from birds in this outbreak was indistinguishable from a strain that caused outbreaks in 1996 and 2003. Most isolates from domestic poultry had other PFGE patterns but some were indistinguishable from the outbreak strain. Among 68 isolates from wild birds, only one PFGE and one REA pattern were demonstrated, whereas among 23 isolates from domestic poultry, 14 different SmaI, 12 different ApaI, and 10 different HpaII patterns were found. The results suggest that a P. multocida strain has survived during several years among wild birds in Denmark.

Animals↗

PubMed2006

Persistence of Pasteurella multocida in wetlands following avian cholera outbreaks.

Avian cholera, caused by Pasteurella multocida, affects waterbirds across North America and occurs worldwide among various avian species. Once an epizootic begins, contamination of the wetland environment likely facilitates the transmission of P. multocida to susceptible birds. To evaluate the ability of P. multocida serotype-1, the most common serotype associated with avian cholera in waterfowl in western and central North America, to persist in wetlands and to identify environmental factors associated with its persistence, we collected water and sediment samples from 23 wetlands during winters and springs of 1996-99. These samples were collected during avian cholera outbreaks and for up to 13 wk following initial sampling. We recovered P. multocida from six wetlands that were sampled following the initial outbreaks, but no P. multocida was isolated later than 7 wk after the initial outbreak sampling. We found no significant relationship between the probability of recovery of P. multocida during resampling and the abundance of the bacterium recovered during initial sampling, the substrate from which isolates were collected, isolate virulence, or water quality conditions previously suggested to be related to the abundance or survival of P. multocida. Our results indicate that wetlands are unlikely to serve as a long-term reservoir for P. multocida because the bacterium does not persist in wetlands for long time periods following avian cholera outbreaks.

Animals↗

PubMedDate not supplied

Japanese encephalitis surveillance in China (Province of Taiwan) during 1968-1971. I. Geographical and seasonal features of case outbreaks.

During 1968-1971 Japanese encephalitis (JE) surveillance was conducted with WHO-assisted programs in Taiwan area. Emphasis was placed on: (1) active case-finding by hospital visits; (2) blood collection from every patient at the suitable time; and (3) the enforcement of standard diagnostic criteria on the results of hemagglutination-inhibition tests. Each year, approximately 90% of reported patients were etiologically examined. JE virus etiology was established in 277 (1968), 279 (1969), 269 (1970) and 158 (1971) cases. Despite the apparent concentration of cases in several cities, practically all the cultivated plains and basins were established as potentially endemic for JE. JE outbreak is found to have been clearly associated with season, not only in subtropical but also in tropical Taiwan. Each year it occurred consistently in mid-July in the southernmost county, 2-3 weeks after the peak of rice transplantation and its duration was a few weeks. On the western side of the island, although less consistently, JE outbreak seems to occur one to three weeks later than in the south. Outbreak in eastern Taiwan was a mid-September phenomenon for 3 years. Observed seasonal lag, which was significant between two neighboring localities on same latitude, suggests that paddy water management is more directly related to date of outbreak than local climate. Seasonal characteristics further suggests that the area may be separated into eight ecologic subdivisions. JE-virus transmission to a man during April at temperatures below the average of 20 C was discussed.

Climate↗

PubMed1999

Tuberculosis outbreaks in prison housing units for HIV-infected inmates--California, 1995-1996.

During 1995-1996, staff from the California departments of corrections and health services and local health departments investigated two outbreaks of drug-susceptible tuberculosis (TB). The outbreaks occurred in two state correctional institutions with dedicated HIV housing units. In each outbreak, all cases were linked by IS6110-based DNA fingerprinting of Mycobacterium tuberculosis isolates. This report describes the investigations of both outbreaks; the findings indicated that M. tuberculosis can spread rapidly among HIV-infected inmates and be transmitted to their visitors and prison employees, with secondary spread to the community.

California↗

PubMed1999

Outbreaks of gastrointestinal illness of unknown etiology associated with eating burritos--United States, October 1997-October 1998.

From October 1997 through October 1998, 16 outbreaks of gastrointestinal illness associated with eating burritos occurred in Florida, Georgia, Illinois, Indiana, Kansas, North Dakota, and Pennsylvania. All but one outbreak occurred in schools, and most of the approximately 1700 persons affected were children. This report summarizes investigations of two of these outbreaks and describes the collaborative efforts of CDC, the U.S. Department of Agriculture (USDA), and the Food and Drug Administration (FDA) to identify the etiologic agent(s); these outbreaks may have been caused by an undetected toxin or a new agent not previously associated with illness.

Child↗

PubMed1999

Economic analysis of an outbreak of avian influenza, 1997-1998.

OBJECTIVE: To determine economic losses associated with an outbreak of avian influenza in flocks in Pennsylvania during 1997 and 1998. SAMPLE POPULATION: 5 premises containing avian influenza-infected layer, pullet, and turkey flocks. PROCEDURE: Losses incurred before depopulation, those incurred at the time of depopulation, and those that were attributable to depopulation (unrealized loss of income) were evaluated. Results were extrapolated to provide values for all infected flocks. RESULTS: Extrapolating the costs determined on the basis of age and number of birds from the 5 sample flocks to all other flocks infected with nonpathogenic avian influenza H7N2 yielded an estimated total cost to the Pennsylvania poultry industry of $3.5 million. CLINICAL IMPLICATIONS: The H7N2 virus is not highly pathogenic. If the pathogenicity of the virus does not change, then the poultry industry and state and federal governments will not have severe economic losses for the 1997-1998 outbreak similar to those for the 1983-1984 avian influenza outbreak in Pennsylvania. To decrease the potential for financial losses that could result from future outbreaks of avian influenza, it is essential that the commercial industry and livebird market system be separated via increased use of biosecurity measures.

Animals↗

PubMed1999

[Investigation of foodborne outbreak due to Salmonella infantis using epidemiological and microbiological methods].

In foodborne outbreaks, direct microbiological diagnosis is often not possible due to lack of remaining food samples. Therefore, in this investigation of an outbreak of Salmonella infantis at a fair, we chose an epidemiological approach in addition to microbiological testing. In a case control study, fair participants with symptoms of acute gastroenteritis as well as participants showing no signs of disease were interviewed by telephone. Questions concerning what food had been eaten at the fair and the course of disease had priority. Data analysis showed a significantly elevated odds ratio of 144 (p < 0.00001) for the consumption of potato salad. Salmonella infantis was cultured in faeces of symptomatic individuals as well as from left-over potato salad in high concentration. In conclusion, our data show that the cause of a foodborne outbreak can be detected through the application of epidemiologic methods with a high degree of certainty. In order to eliminate memory bias, a structured interview should be carried out as soon as possible after the initial outbreak.

Antibodies, Bacterial↗

PubMed1999

Rubella outbreak, Fort Bragg, North Carolina, 1995: a clash of two preventive strategies.

An outbreak of rubella occurred among visiting German troops involved in a combined military exercise at Fort Bragg, North Carolina, in April 1995. Public health and military operational concerns centered on the significant contact the German soldiers had had with host battalion dependents and the impact of the outbreak on the exercise. Ten of the 120 German soldiers were found to be nonimmune; six of these soldiers developed clinical rubella. The four nonimmune soldiers who did not develop skin rashes had received serum immune globulin within 12 hours of identification of the index case. The impact of this outbreak on the Fort Bragg community and its military operations, and the methods used to control the outbreak and salvage the military mission, are described.

Disease Outbreaks↗

PubMed1999

Parainfluenza type 3 viral outbreak in a neonatal nursery.

An outbreak of parainfluenza virus type 3 infection that occurred in a special neonatal care unit is described. Birth weights of affected infants ranged from 1860 to 2080 g and gestational ages were between 28 and 32 weeks. Three infants presented with recurrent episodes of apnoea associated with oxygen desaturations on postnatal ages of 16 days, 26 days and 66 days respectively; upper respiratory tract infection symptoms such as coryza were absent in them. Two older infants who had oxygen dependent bronchopulmonary dysplasia presented with worsening of the respiratory status due to bronchiolitis at 5 and 6 months of age respectively. All infants required supplemental oxygen and assisted ventilatory support and there were no deaths. Parainfluenza virus type 3 was identified by direct antigen detection in 3 cases and was isolated in the other two. The outbreak was controlled by isolating the infected infants, use of gowns and strict hand washing. Nonporous surfaces contaminated with parainfluenza virus type 3 were cleansed with water and detergent. Viral respiratory infections should be considered in the differential diagnosis when growing premature infants present with recurrent apnoeic episodes and they may be severe enough to require assisted ventilatory support. The source of the outbreak was possibly a medical officer and a medical student who had an upper respiratory tract infection prior to the outbreak in the nursery. Medical and nursing staff with viral respiratory infections should avoid working in the nurseries until they are well.

Antigens, Viral↗

PubMed2000

Sequence analysis of measles virus hemagglutinin isolated in Argentina during the 1997-1998 outbreak.

Sequence analysis was performed on 50 measles viruses (MV) isolated in Argentina. Forty-six were obtained during the current outbreak (1997-1998), three from the previous outbreak (1991) and one sporadic case (1994). A 377-bp fragment of the hemagglutinin (H) gene was directly amplified by RT-PCR from nasopharyngeal secretions. Nucleotides 8152 to 8417 were sequenced and subjected to phylogenetic analysis. Multiple silent changes and point mutations were found in all MVs. In 1991, substitutions affected the third base in codons resulting in silent changes. In 1994 an A-->C substitution at position 8321 changed amino acids 351 (Leu-->Ile). In 1997-1998, an A-->G substitution at position 8339 changed amino acids 357 (Val-->Ile). In 3/46 viruses, guanine deletion at position 8205 changed the reading frame and insertion of an extra cytosine at nucleotide 8235 shifted it back to the original frame. Phylogenetic analysis revealed that viruses leading to the last two major outbreaks are clustered into two separate branches. MVs that prevailed until 1994 were related to genotype C1 and MVs of the current outbreak to D6. Random drift mutations rendered a 0.5 ratio of nonsilent over silent mutations in most of the MVs analyzed. However, in those showing a reading frame shift, the ratio was greater than 1, suggesting that it was driven by immune selection.

Amino Acid Sequence↗

PubMed1999

[Relatedness of Shigella sonnei isolates from six outbreaks in Tao-Yuan area, Taiwan].

Between November 1995 and January 1996, one larger-scale outbreak of Shigella sonnei infection occurred in the area of Tao-Yuan, Taiwan. Subsequently, five outbreaks of S. sonnei infection occurred in the same area during the period from October 1998 to February 1999. Fifty-five isolates obtained from these six outbreaks were differentiated by antimicrobial susceptibility testing, plasmid profile analysis (PPA) and pulsed-field gel electrophoresis (PFGE). They were classified into two and three types by antimicrobial susceptibility testing and PPA, respectively. However, only one pattern was observed by PFGE. The molecular epidemiology by PFGE in this study indicated that they were closely-related. These data suggest that the clinical isolates obtained during the period of January 1998 to January 1999 were probably derived from the outbreak strain of 1995.

Disease Outbreaks↗

PubMed1999

[An outbreak of Mycobacterium tuberculosis infection among young adults in close contact].

We experienced an outbreak of tuberculosis among young adults in close contact. The index case (case 1) was 22-year-old builder and was symptomatic for 9 months before diagnosis as pulmonary tuberculosis (PTB). His sputum smear was positive for tubercle bacilli. On immediate family contacts examination carried out at our hospital, his brother and sister (case 3, case 4) were detected as having PTB. His mother (case 5) and father (case 6) were later detected as having PTB by their symptomatic visits after some months, as tuberculin test as not done at first examination. Case 7 was 19-year-old-man, and was undiagnosed for 5 months. His sputum smear was positive. Immediately, contacts examination for case 7 as carried out at our hospital, and his colleague (case 8) was detected as having PTB. By interview with the case 7, it was found that the case 1 and the case 7 were close friends and spent long time together. Case 10 was 30-year-old builder, and he was accidentally referred to our hospital and was diagnosed as PTB. By the interview with the case 10, it was found that the case 1 and case 10 were members of builders group. This fact was informed to the F health center, and contacts examination for other members of the group were carried out by the F health center, and two young men were detected as having PTB. Analysis of restriction fragment length polymorphism (RFLP) showed that the case 1, the case 5, the case 7, and the case 10 were caused by the same strain of M. tuberculosis. Based on these findings, it is highly suspected that this outbreak was origined from the case 1, and 13 developed tuberculosis and 13 were primarily infected among contacts. The characteristics of this outbreak was that the family and contacts examination were enforced and most of the cases were detected at our hospital. If the outbreak of tuberculosis highly suspected, physicians should actively cooperate with health centers for contacts examination.

Adolescent↗

PubMed2000

Illness outbreak associated with Escherichia coli O157:H7 in Genoa salami. E. coli O157:H7 Working Group.

BACKGROUND: An outbreak of Escherichia coli O157:H7 infection was identified in the spring of 1998, with a 7-fold increase in the number of laboratory-confirmed E. coli O157:H7 cases in southern Ontario. This prompted an intensive investigation by local, provincial and federal public health officials. METHODS: Case interviews of 25 people from southern Ontario were conducted using a broad food history and environmental exposure survey. Laboratory investigations involved both case and food sampling. Specimens of foods sold locally and reportedly consumed by those affected were tested. Common suppliers of suspected foods were identified by cross-referencing suppliers' lists with stores frequented by those who fell ill. A case-control study involving 25 cases and 49 age-matched controls was conducted. This was followed by a comprehensive environmental investigation of the meat processing plant identified as the source of the E. coli. RESULTS: Thirty-nine outbreak-related cases occurred between April 3 and June 2, 1998. Of the 36 case specimens tested all were positive for E. coli O157:H7. The case-control study identified Genoa salami as the most probable (odds ratio 8 [confidence interval 2-35]) source of the outbreak. Samples of Genoa salami produced by the most commonly identified supplier later tested positive for E. coli O157:H7, and the pathogen matched the same pulsed-field gel electrophoresis pattern and phage type of the case specimens. INTERPRETATION: Our investigation, which led to a national recall of the brand of dry fermented Genoa salami identified as the source of the outbreak, supports an adherence to stringent manufacturing requirements for fermented meat products. A review of the Canadian standards for fermented meat processing and the effectiveness of their implementation is warranted.

Adolescent↗

PubMed1975

Recent outbreaks of lymphocytic choriomeningitis in the United States of America.

Lymphocytic choriomeningitis (LCM) has been rarely reported in the American literature since 1960. It is interesting that each of the 3 epidemics reported since then has been associated with exposure to hamsters. In 1973, 48 cases of LCM spanning the years 1971-1973 occurred at the University of Rochester Medical School associated with hamsters implanted with tumour tissues. These tissues were found to be LCM-positive, as in an earlier outbreak in 1965 at the National Institutes of Health. A nationwide outbreak of LCM occurred in late 1973 and early 1974 totalling at least 181 cases in 12 states; all were associated with pet hamsters from a single breeder in Birmingham, Alabama. He was an employee of a biological products firm whose tumour tissues were found positive for LCM and were also incriminated in the 1973 Rochester outbreak. The last outbreak occurred in a graduate school laboratory in New York State involving 7 individuals working with hamster tumours from the same Birmingham biological firm. The nationwide epidemic ended in middle April 1974 following removal of incriminated hamsters from pet shops throughout the country and voluntary cessation of distribution of hamsters from the incriminated breeder. The biological firm notified all laboratories of the possible contamination of tumours and has voluntarily stopped distribution of known positive tumours.

Adolescent↗

PubMed2000

[An outbreak of pulmonary tuberculosis in the dormitory of construction labors suspected to have been due to exogenous reinfection].

We report an outbreak of pulmonary tuberculosis (TB) in a dormitory of construction labors, and this outbreak is suspected to have been caused by exogenous reinfection, based on the restriction fragment length polymorphism (RFLP) analysis and other findings. After a patient entered our hospital with active TB, 12 new other patients were discovered by contacts examination. These patients lived together in the same dormitory. They were all male and single, and were aged from 43 to 63 years old. Except one patient (No. 3) previously treated for TB for three months about 2 years ago and was suspected to be the index case of this outbreak, 12 other patients did not have a medical history of TB. The bacilli cultured from 11 patients (No. 1-11) were tested by RFLP analysis, three patterns were identified, and the fingerprints from 9 patients (No. 1-9) were identical, and the patterns of incomplete resistance of some antituberculous drugs were quite similar between No. 1-9 and No. 12 and between No. 10 and No. 13, respectively. The locations of the main lesions of TB on chest X-ray pictures were the apico-posterior segments of bilateral upper lobes. No signs suspected to indicate primary tuberculosis were detected. Considering the rate of tuberculous infection in Japan among the middle age and above as well as the identical RFLP results, most of patients in this outbreak except the index case No. 3 were suspected to have TB due to the exogenous reinfection.

Adult↗

PubMed2000

Outbreak of tuberculosis associated with a church.

Investigation of an outbreak of tuberculosis (TB) in a West Midlands health district in 1999 revealed spread in an extended family network and to church contacts. Within the family four cases of smear positive TB, four cases of smear negative infection, and 14 cases requiring chemoprophylaxis were identified. One of the infectious cases visited a local church on two occasions, which resulted in a further 16 cases of infection including one case of tuberculous meningitis. DNA fingerprinting of isolates from five culture positive cases indicated that the same strain of Mycobacterium tuberculosis was responsible. This outbreak is a reminder that while outbreaks of TB usually arise within households or family networks, where close contact over extended periods provides more opportunity for exposure, community outbreaks of TB can occur after only causal contact.

Adult↗

PubMed2000

Foodborne botulism outbreaks following consumption of home-canned bamboo shoots in Northern Thailand.

We report epidemiological investigations of 2 outbreaks of foodborne botulism following consumption of home-canned bamboo shoots in northern Thailand. The first outbreak affecting 4 female and 2 male cases occurred in Mae Sot District, Tak Province, in December 1997. All 6 cases were hospitalized, 4 of whom required mechanical ventilation. All cases experienced neurological features and 4 had gastrointestinal symptoms. One case died, giving a case-fatality rate of 16.7 per cent. A case-control study revealed a significant association (p < 0.01) between the disease and consumption of home-canned bamboo shoots purchased from the same foodshop in the village. The second outbreak of a similar clinical syndrome occurred in Thawangpha District, Nan Province, in April 1998. A total of 13 cases were identified, 9 (69.2%) of whom were female. Nine cases (69.2%) were hospitalized, 4 (30.8%) of whom required mechanical ventilation. Two early hospitalized cases died due to ventilatory failure, giving a case-fatality rate of 15.4 per cent. A case-control study indicated that home-canned bamboo shoots prepared by a local foodshop served as the vehicle for the disease transmission. One bamboo shoot specimen from one affected house was positive for botulinum toxin type A by enzyme-linked immunosorbent assay and mouse antitoxin bioassay. Improper home-canning procedures for bamboo shoot preservation were similarly detected in both outbreaks although performed by different merchants. Prompt recognition and treatment of the disease are essential in reducing the fatality rate. Safe home-canning procedures should be widely distributed and instructed to persons who perform bamboo shoot preservation for sale.

Adolescent↗

PubMed2000

[Vancomycin-resistant Enterococcus faecium outbreak in a nephrology ward].

In April 2000, an outbreak of vancomycin-resistant Enterococcus faecium (VRE) was discovered in an internal medicine/nephrology and dialysis ward of the Eemland Hospital, Amersfoort, the Netherlands. Although enterococci are considered relatively non-virulent, VRE are resistant to almost all commercially available antibiotics. Surveillance cultures were obtained from all patients at the ward, all patients visiting the dialysis ward and the environment of patients. VRE were determined and clustering of strains was analysed using molecular genotyping. In all, 12 patients were colonized with the outbreak strain. Transmission of VRE usually occurs via the hands of health care workers. The ward was closed for new admissions, patients were divided in cohorts of colonized and non-colonized patients, and rooms were disinfected after patient discharge. Infection control measures (such as handwashing and use of gloves and gowns) were enforced and prescriptions of vancomycin and cephalosporins were reduced. With these measures the outbreak could be controlled. Epidemiological analysis demonstrated that earlier admission and previous use of ciprofloxacin, amoxicillin and amoxicillin-clavulanic acid were risk factors for colonization. A nearby hospital was a possible source of this outbreak.

Aged↗