Burkholderia cepacia lower respiratory tract infection associated with exposure to a respiratory therapist.

OBJECTIVE: To investigate and control a nosocomial outbreak of Burkholderia cepacia lower respiratory tract infection. DESIGN: Outbreak investigation and case-control study. SETTING: A 260-bed community hospital. PATIENTS: Participants were mechanically ventilated intensive care patients without cystic fibrosis. A case was defined as a hospitalized patient with a sputum culture positive for B. cepacia between January 1 and November 6, 1998. METHODS: Respiratory therapy infection control policies and practices were reviewed; laboratory and environmental studies and a retrospective case-control study were conducted. Case-patients were matched with control-patients on age, gender, diagnosis, and type of intensive care unit. RESULTS: Nine case-patients were identified; B. cepacia likely caused pneumonia in seven and colonization in two. Two respiratory therapy practices probably contributed to the transmission of B. cepacia: multidose albuterol vials were used among several patients, and nebulizer assemblies often were not dried between uses. B. cepacia was grown from cultures of three previously opened multidose vials; pulsed-field gel electrophoresis patterns of B. cepacia from seven case-patients and two multidose vials were indistinguishable. Case-patients had longer durations of heated humidified mechanical ventilation (mean, 9.8 days vs 4.4 days; P=.03) and were more likely to have exposure to one particular respiratory therapist than controls (odds ratio, undefined; 95% confidence interval, 4.7-infinity; P=.001). The association with the respiratory therapist, a temporary employee, persisted after controlling for duration of heated humidified ventilation. No new B. cepacia infections were identified after control measures were implemented. CONCLUSIONS: B. cepacia probably was transmitted among patients through use of extrinsically contaminated multidose albuterol vials. Respiratory therapy departments must pay close attention to infection control practices, particularly among new or temporary staff.

Multistate outbreak of Salmonella serovar Muenchen infections associated with alfalfa sprouts grown from seeds pretreated with calcium hypochlorite.

During September 1999, a multistate outbreak of Salmonella serovar Muenchen infection associated with eating raw alfalfa sprouts was identified in Wisconsin. Despite use of a calcium hypochlorite sanitizing procedure to pretreat seeds before sprouting, at least 157 outbreak-related illnesses were identified in seven states having sprouters who received alfalfa seed from a specific lot. The continued occurrence of sprout-related outbreaks despite presprouting disinfection supports the concern that no available treatment will eliminate pathogens from seeds before sprouting and reinforces the need for additional safeguards to protect the public. A lack of consumer knowledge regarding exposure to sprouts documented in this investigation suggests that more-targeted outreach to high-risk individuals may be needed to reduce their risk.

Escherichia coli O157:H7 infections in Wisconsin, 1992-1999.

Escherichia coli O157:H7 infection became a reportable condition in Wisconsin on April 1, 2000; previously cases were voluntarily reported by physicians and laboratories. During 1992 through 1999, 1333 cases of E. coli O157:H7 infection occurred in Wisconsin residents and were reported to the Wisconsin Division of Public Health. During this interval, the highest age-specific mean annual incidence, 13.2 cases per 100,000 population, occurred in persons 3 to 5 years old. Only 28% of patients with reported cases identified bloody diarrhea among their signs and symptoms. Of reported cases, 17% (231/1333) were involved in the eight outbreaks investigated during this interval. Among case patient identifiable risk exposures, farm related (13.4%), recreational water related (8.1%), and unpasteurized milk/dairy product (7.0%) exposures were the most frequently noted. Relatively few infections involved raw/undercooked ground beef consumption (5.8%). Recent use of pulsed-field gel electrophoresis has facilitated linkage of sporadically reported cases into recognized outbreaks. E. coli O157:H7 infections frequently occur in Wisconsin; acquisition of these infections in a wide variety of settings poses important challenges to their prevention and control.

An evaluation of the completeness of tuberculosis case reporting using hospital billing and laboratory data; Wisconsin, 1995.

PURPOSE: The study assesses the completeness of tuberculosis disease (TB) reporting in Wisconsin and evaluates the usefulness of laboratory and hospital discharge data as supplemental case ascertainment sources. METHODS: All 1995 hospital billing records with a discharge diagnosis code of TB (ICD-9 CM 010-018) were retrieved and matched to Wisconsin TB registry records. A hospital discharge summary was obtained for persons not in the registry to verify the TB diagnosis. A list of persons with specimens from which Mycobacterium tuberculosis was isolated in 1995 was requested from all Wisconsin and pertinent out-of-state laboratories and compared with the TB registry. RESULTS: Of the 88 TB cases identified from laboratory lists, one (1.1%) was unreported. Of the 51 TB cases identified from hospital discharge records, one (2.0%) was unreported. The positive predictive values of laboratory and hospital discharge data for a verified TB case were 98.9% and 38.3%, respectively. CONCLUSIONS: In Wisconsin during 1995, nearly all TB cases among hospitalized persons or persons from whom M. tuberculosis was isolated were reported. Most persons having a TB diagnosis code did not have TB.

An increase in sporadic and outbreak-associated Salmonella enteritidis infections in Wisconsin: the role of eggs.

In Wisconsin, reported Salmonella enterica serotype enteritidis (SE) infections during 1997 more than doubled compared with the previous 9 years. A case-control study was conducted to determine risk factors for sporadic infections, and results of outbreak investigations were reviewed. Eating raw eggs (matched odds ratio [MOR]=14.5; 95% confidence interval [CI], 1.7-591.6), eating raw or undercooked eggs (MOR=5.8; 95% CI, 1.3-28.0), eating any eggs (MOR=4.2; 95% CI, 1.2-16.2), and dining at a restaurant (MOR=4.7; 95% CI, 1.4-18.4) were associated with infection in the case-control study. For 3 of the 8 outbreaks, a probable source was identified, in each instance, foods containing eggs. Human infections decreased after eggs were diverted from implicated flocks. This epidemic demonstrates the continuing need for quality assurance on egg farms and enhanced education of consumers and commercial food preparers regarding safe handling of eggs.

Clinical features of infections due to Escherichia coli producing heat-stable toxin during an outbreak in Wisconsin: a rarely suspected cause of diarrhea in the United States.

In September 1994, a foodborne outbreak of enterotoxigenic Escherichia coli (ETEC) infection occurred in attendees of a banquet in Milwaukee. E. coli was isolated from stool specimens from 13 patients that were comprehensively tested; isolates from five patients were positive for E. coli producing heat-stable toxin, were biochemically identified and serotyped as E. coli O153:H45, and were all resistant to tetracycline, ampicillin, sulfisoxazole, and streptomycin. Diarrhea (100%) and abdominal cramps (83%) were the most prevalent symptoms in 205 cases; vomiting (13%) and fever (19%) were less common. The median duration of diarrhea and abdominal cramps was 6 days and 5 days, respectively. In the United States, health care providers rarely consider ETEC as a possible cause of diarrhea in their patients, and few laboratories offer testing to identify ETEC. Hence, outbreaks of ETEC infection may be underdiagnosed and underreported. As in this outbreak, the relatively high prevalence of diarrhea and cramps lasting > or = 4 days and the low prevalence of vomiting and fever can help distinguish ETEC infection from Norwalk-like virus infection and gastroenteritis due to other causes with incubation times of > or = 15 hours and can provide direction for confirmatory laboratory testing.

Surveillance data for waterborne illness detection: an assessment following a massive waterborne outbreak of Cryptosporidium infection.

Following the 1993 Milwaukee cryptosporidiosis outbreak, we examined data from eight sources available during the time of the outbreak. Although there was a remarkable temporal correspondence of surveillance peaks, the most timely data involved use of systems in which personnel with existing close ties to public health programmes perceived the importance of providing information despite workload constraints associated with an outbreak. During the investigation, surveillance systems which could be easily linked with laboratory data, were flexible in adding new variables, and which demonstrated low baseline variability were most useful. Geographically fixed nursing home residents served as an ideal population with nonconfounded exposures. Use of surrogate measurements of morbidity can trigger worthwhile public health responses in advance of laboratory-confirmed diagnosis and help reduce total morbidity associated with an outbreak. This report describes the relative strengths and weaknesses of these surveillance methods for community-wide waterborne illness detection and their application in outbreak decision making.

Genomic comparisons and Shiga toxin production among Escherichia coli O157:H7 isolates from a day care center outbreak and sporadic cases in southeastern Wisconsin.

Contour-clamped homogeneous electric field pulsed-field gel electrophoresis (CHEF-PFGE) was used to compare Wisconsin isolates of Escherichia coli O157:H7, including 39 isolates from a 1994 day care center outbreak, 28 isolates from 18 individuals from the surrounding geographic area with sporadic cases occurring during the 3 months before the outbreak, and 3 isolates, collected in 1995, from patients with hemolytic-uremic syndrome (HUS) who were from eastern Wisconsin counties other than those inhabited by the day care center and sporadic-case individuals. The technique of CHEF-PFGE using XbaI identified seven highly related restriction endonuclease digestion profiles (REDPs) (93 to 98% similarity) among the 39 day care center isolates and nine XbaI REDPs (63 to 93% similarity) among the 28 isolates from sporadic-case individuals, including REDP 33, which was exhibited by both day care and sporadic-case isolates. PFGE analyses of sequential E. coli O157:H7 isolates from symptomatic day care center attendees revealed that the REDPs of 25 isolates from eight patients were indistinguishable whereas the REDPs of 2 of 6 isolates from two patients differed slightly (93 to 95% similarity). The REDPs of the three isolates from 1995 HUS patients were 78 to 83% similar, with REDP 26 being exhibited by one HUS-associated isolate and an isolate from one day care attendee who did not develop HUS. The genes for both Shiga toxins I and II (stx1 and stx2, respectively) were detected in all but one isolate (sporadic case), and Shiga toxin production by the day care center isolates was not significantly different from that of the other isolates, including the three HUS-associated isolates. Analyses of E. coli O157:H7 isolates from both the day care center outbreak and sporadic cases by CHEF-PFGE permitted us to define the REDP variability of an outbreak and geographic region and demonstrated that the day care center outbreak and a HUS case in 1995 were caused by E. coli O157:H7 strains endemic to eastern Wisconsin.

Incomplete sanitation of a meat grinder and ingestion of raw ground beef: contributing factors to a large outbreak of Salmonella typhimurium infection.

Consumers in the United States continue to eat raw or undercooked foods of animal origin despite public health warnings following several well-publicized outbreaks. We investigated an outbreak of Salmonella serotype Typhimurium infection in 158 patients in Wisconsin during the 1994 Christmas holiday period. To determine the vehicle and source of the outbreak, we conducted cohort and case-control studies, and environmental investigations in butcher shop A. Eating raw ground beef purchased from butcher shop A was the only item significantly associated with illness [cohort study: relative risk = 5.8, 95% confidence interval (CI) = 1.5-21.8; case control study: odds ratio = 46.2, 95% CI = 3.8-2751]. Inadequate cleaning and sanitization of the meat grinder in butcher shop A likely resulted in sustained contamination of ground beef during an 8-day interval. Consumer education, coupled with hazard reduction efforts at multiple stages in the food processing chain, will continue to play an important role in the control of foodborne illness.

An outbreak of gastroenteritis and fever due to Listeria monocytogenes in milk.

BACKGROUND: After an outbreak of gastroenteritis and fever among persons who attended a picnic in Illinois, chocolate milk served at the picnic was found to be contaminated with Listeria monocytogenes. METHODS: In investigating this outbreak, we interviewed the people who attended the picnic about what they ate and their symptoms. Surveillance for invasive listeriosis was initiated in the states that receive milk from the implicated dairy. Stool and milk samples were cultured for L. monocytogenes. Serum samples were tested for IgG antibody to listeriolysin O. RESULTS: Forty-five persons had symptoms that met the case definition for illness due to L. monocytogenes, and cultures of stool from 11 persons yielded the organism. Illness in the week after the picnic was associated with the consumption of chocolate milk. The most common symptoms were diarrhea (present in 79 percent of the cases) and fever (72 percent). Four persons were hospitalized. The median incubation period for infection was 20 hours (range, 9 to 32), and persons who became ill had elevated levels of antibody to listeriolysin O. Isolates from stool specimens from patients who became ill after the picnic, from sterile sites in three additional patients identified by surveillance, from the implicated chocolate milk, and from a tank drain at the dairy were all serotype 1/2b and were indistinguishable on multilocus enzyme electrophoresis, ribotyping, and DNA macrorestriction analysis. CONCLUSIONS: L. monocytogenes is a cause of gastroenteritis with fever, and sporadic cases of invasive listeriosis may be due to unrecognized outbreaks caused by contaminated food.

Hospitals' responses to universal infant hepatitis B vaccination recommendations.

OBJECTIVE: To assess the extent to which hospitals in a midwestern state with low acute hepatitis B virus (HBV) morbidity offered hepatitis B (Hep B) vaccine to all infants, whether offering infants Hep B vaccine was associated with hospital geographic location or size, as measured by the number of births, and how hospital staff resolved key programmatic issues. METHODS: The managers of hospital newborn nurseries (N = 110) were surveyed by mail. The written response rate was 72%; all of the nonresponders were interviewed by telephone. The outcome measured was the number of hospitals offering Hep B vaccine to all infants by geographic region and hospital size. RESULTS: Sixty-five percent of the hospitals routinely offered Hep B vaccine to all infants; these hospitals accounted for 80% of reported Wisconsin births. In univariate analysis, the decision to offer infants Hep B vaccine was associated with both hospital size and hospital location. After controlling for size, hospitals in the northeastern region were eight times more likely (relative risk, 8.21; 95% confidence interval, 1.30, 51.79) to offer infants Hep B vaccine than hospitals in the southeastern (referent) region. Regional differences in reported rates of acute HBV infection do not explain this finding, because morbidity in the northeastern region (1 per 100,000) is among the lowest in Wisconsin. Although more than 80% of hospitals with Hep B vaccination programs required written informed consent for vaccination, had standing orders for administering Hep B vaccine to infants whose mothers' hepatitis B surface antigen (HBsAg) test results were known, and had mechanisms to notify the infants' physicians that the infants had been vaccinated, only 38% had standing orders for testing mothers whose HBsAg test results were unknown.

Use of pulsed-field gel electrophoresis to link sporadic cases of invasive listeriosis with recalled chocolate milk.

Pulsed-field gel electrophoresis established the linkage between recalled chocolate milk and a multistate invasive listeriosis outbreak during a four-product recall period. Listeria monocytogenes isolates from four hospitalized patients and an environmental dairy sample displayed AscI restriction endonuclease digestion profiles identical to that of the chocolate milk isolate.

Utility of anti-WI-1 serological testing in the diagnosis of blastomycosis in Wisconsin residents.

WI-1, a 120-kD protein found in the outer cell wall of Blastomyces dermatitidis, has been purified, labeled with 125I, and used as a target in a radioimmunoassay (RIA). In an assessment of the usefulness of anti-WI-1 serology in the diagnosis of blastomycosis, the RIA was used to test four panels of sera from residents of Wisconsin, a state in which blastomycosis is endemic. Twenty-four (75%) of 32 patients whose blastomycosis had been reported to the Wisconsin Division of Health had at least one serum sample positive for antibody to WI-1; 25 (93%) of 27 serum samples obtained from these patients within 60 days of diagnosis were positive. In an effort to simulate clinical practice, 132 serum samples were assayed from another 107 patients in whom blastomycosis was being considered as a cause of illness. The result was positive for at least one sample from 83% of the 23 patients with confirmed blastomycosis and from 5% of the 84 patients from whom the fungus was not documented. Serum samples from another five patients with blastomycosis identified during investigation of a 1990 outbreak in Oconto Falls, Wisconsin, also gave a positive result, whereas none of the serum specimens from 57 healthy family members or neighbors did so. Only three (0.56%) of 535 serum samples from random blood donors residing in two counties with a high annual incidence of blastomycosis were positive for antibody to WI-1. Modification of the RIA so that IgM rather than IgG antibody was detected did not enhance diagnostic sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

A massive outbreak in Milwaukee of cryptosporidium infection transmitted through the public water supply.

BACKGROUND: Early in the spring of 1993 there was a widespread outbreak of acute watery diarrhea among the residents of Milwaukee. METHODS: We investigated the two Milwaukee water-treatment plants, gathered data from clinical laboratories on the results of tests for enteric pathogens, and examined ice made during the time of the outbreak for cryptosporidium oocysts. We surveyed residents with confirmed cryptosporidium infection and a sample of those with acute watery diarrhea consistent with cryptosporidium infection. To estimate the magnitude of the outbreak, we also conducted a survey using randomly selected telephone numbers in Milwaukee and four surrounding counties. RESULTS: There were marked increases in the turbidity of treated water at the city's southern water-treatment plant from March 23 until April 9, when the plant was shut down. Cryptosporidium oocysts were identified in water from ice made in southern Milwaukee during these weeks. The rates of isolation of other enteric pathogens remained stable, but there was more than a 100-fold increase in the rate of isolation of cryptosporidium. The median duration of illness was 9 days (range, 1 to 55). The median maximal number of stools per day was 12 (range, 1 to 90). Among 285 people surveyed who had laboratory-confirmed cryptosporidiosis, the clinical manifestations included watery diarrhea (in 93 percent), abdominal cramps (in 84 percent), fever (in 57 percent), and vomiting (in 48 percent). We estimate that 403,000 people had watery diarrhea attributable to this outbreak. CONCLUSIONS: This massive outbreak of watery diarrhea was caused by cryptosporidium oocysts that passed through the filtration system of one of the city's water-treatment plants. Water-quality standards and the testing of patients for cryptosporidium were not adequate to detect this outbreak.

Household-acquisition of measles and illness severity in an urban community in the United States.

Studies from developing countries suggest that persons with household-acquired (HA) measles are at greater risk of severe illness than persons with community-acquired (CA) infection. Reported measles cases occurring among Milwaukee residents from May 1989 to June 1990 were used to assess whether household-acquisition was a risk factor for severe measles in the United States. A case was classified as HA if onset of rash occurred 7-18 days after onset of rash in another case in the same household. Hospitalization rates were similar for 128 patients with HA measles (27%) and for 1004 patients with CA measles (26%). Multiple logistic regression was used to evaluate the association between hospitalization and household-acquisition after controlling for socioeconomic status, measles vaccination history, age, race, and date of onset of rash. Patients with HA measles were no more likely to be hospitalized than patients with CA measles (odds ratio 0.9, 95% confidence interval 0.6, 1.5). HA measles cases were not more severe than CA measles cases during this urban outbreak in the United States.

Determination and relationship of C-reactive protein in human dental pulps and in serum.

C-reactive protein (CRP), an acute phase protein synthesized by the liver, increases in serum as much as 3000 times above its normal level in response to acute inflammation. The purpose of this study was to determine whether CRP levels in dental pulps could be correlated with the histological disease status of the pulp and with systemic blood levels of CRP. Inflamed and necrotic pulps were extirpated during routine endodontic therapy. Normal pulps were removed from extracted, intact third molars. One half of each pulp specimen was placed in formalin for histological study; the other half was frozen for immunological study. A serum sample was obtained from each patient at the end of the dental visit. CRP levels were determined by the enzyme-linked immunosorbent assay. Pulps were categorized histologically as normal, inflamed, inflamed/necrotic, or necrotic. The correlation between CRP levels of pulp and serum was not significant. CRP levels of normal pulps differed significantly only from inflamed pulps (p less than 0.05, Dunnett). This increase in CRP appears to be a local phenomenon resulting from the interaction of CRP with various inflammatory mediators in the pulp.