A national case-control study of risk factors for listeriosis in Australia.

Listeriosis is a foodborne disease associated with significant mortality. This study attempts to identify risk factors for sporadic listeriosis in Australia. Information on underlying illnesses was obtained from cases' treating doctors and other risk factors were elicited from the patient or a surrogate. We attempted to recruit two controls per case matched on age and primary underlying immune condition. Between November 2001 and December 2004 we recruited 136 cases and 97 controls. Of perinatal cases, living in a household where a language other than English was spoken was the main risk factor associated with listeriosis (OR 11·3, 95% CI 1·5-undefined). Of non-perinatal cases we identified the following risk factors for listeriosis: prior hospitalization (OR 4·3, 95% CI 1·0-18·3), use of gastric acid inhibitors (OR 9·4, 95% CI 2·4-37·4), and consumption of camembert (OR 4·7, 95% CI 1·1-20·6). Forty percent of cases with prior hospitalization were exposed to high-risk foods during hospitalization.

The cost of a food-borne outbreak of hepatitis A in Denver, Colo.

BACKGROUND: In 1992, a food-borne outbreak of hepatitis A associated with a catering facility in Denver, Colo, resulted in 43 secondary cases of hepatitis A and the potential exposure of approximately 5000 patrons. OBJECTIVES: To assess (1) disease control costs, including state and local health department personnel costs, provision and administration of immune globulin, and cost of extra hepatitis A serologic tests performed; (2) business losses; and (3) cost of the cases' illnesses. METHODS: Cost data were collected from hospitals, health maintenance organizations, health departments, laboratories, the caterer's insurance company, and the catering facility involved in the outbreak. RESULTS: The total costs assessed in the outbreak from a societal perspective were $809,706. Disease control costs were $689,314, which included $450,397 for 16,293 immune globulin injections and $105,699 for 2777 hours of health department personnel time. The cases' medical costs were $46,064, or 7% of the disease control costs. CONCLUSIONS: The cases' medical costs and productivity losses were only a minor component of the total cost of this outbreak. The high cost of food-borne outbreaks should be taken into account in economic analyses of the vaccination of food handlers with inactivated hepatitis A vaccine.

The prevalence of abnormal esophageal test results in patients with cardiovascular disease and unexplained chest pain.

The purpose of our study was to assess the prevalence of esophageal test abnormalities in patients with known cardiovascular disease and persistent chest pain. We performed a retrospective review of symptoms, manometry, and provocative test results performed on patients with undiagnosed chest pain. The 220 patients with angiographically determined cardiac disease and persistent chest pain were divided into three groups: coronary artery disease (125 patients), mitral valve prolapse (38 patients), and coronary bypass/angioplasty (57 patients). A comparison group consisted of 159 patients with noncardiac chest pain. All patients underwent esophageal manometry and placebo-controlled provocative testing (acid perfusion test and edrophonium chloride test). The prevalence of esophageal motility disorders in the noncardiac chest pain group (27%) was similar to that in the coronary artery disease (24%), mitral valve prolapse (37%), and coronary bypass/angioplasty (30%) groups. The frequency of nutcracker esophagus (11% to 16%) and diffuse esophageal spasm (2% to 7%) was remarkably constant. The prevalence of any positive provocative result in the noncardiac chest pain group (27%) was similar to that in the coronary artery disease (19%), mitral valve prolapse (32%), and coronary bypass/angioplasty (20%) groups. Furthermore, completely negative results of esophageal investigation occurred in 55%, 62%, 42%, and 59% of the respective patient groups.

Twenty-four-hour esophageal pH monitoring: the most useful test for evaluating noncardiac chest pain.

STUDY OBJECTIVE: To compare the diagnostic capabilities of traditional esophageal tests (manometry and provocative testing with acid and edrophonium) and 24-hour esophageal pH monitoring in identifying an esophageal cause of chest pain. DESIGN: A prospective study of 100 consecutive patients referred by cardiologists to the esophageal laboratory for evaluation of esophageal causes of chest pain. SETTING: Tertiary-referral university hospital. METHODS: Esophageal manometry performed with 10 wet swallows of water. Acid perfusion (0.1 N hydrochloric acid) and edrophonium (80 micrograms/kg intravenously) tests were placebo-controlled with a positive study defined as replication of typical chest pain. Esophageal pH monitoring identified (1) abnormal acid exposure times in the upright, supine, or combined position, and (2) correlation between symptoms and acid reflux, i.e., symptom index. The esophagus was identified as "probably" contributing to chest pain only if the acid or edrophonium test was positive or if there was a positive correlation between symptoms and acid reflux during pH monitoring. RESULTS: Esophageal manometry was abnormal in 32 patients (32%), but patients were asymptomatic during the study. The acid perfusion test was positive in 18 of 95 patients (19%), and the edrophonium test was positive in 15 of 78 patients (19%). Abnormal acid exposure times were found in 48 patients (48%). Of the 83 patients with spontaneous chest pain during 24-hour pH testing, 37 patients (46%) had abnormal reflux parameters and 50 patients (60%) had a positive symptom index (mean positive score 56%, range 6% to 100%). CONCLUSIONS: Acid reflux is a common and potentially treatable cause of noncardiac chest pain. Traditional esophageal tests usually miss this diagnosis. Twenty-four-hour esophageal pH monitoring with symptom correlation is the single best test for evaluating patients with noncardiac chest pain.

A cost-effectiveness analysis of directly observed therapy vs self-administered therapy for treatment of tuberculosis.

STUDY OBJECTIVES: To compare the costs and effectiveness of directly observed therapy (DOT) vs self-administered therapy (SAT) for the treatment of active tuberculosis. DESIGN: Decision analysis. SETTING: We used published rates for failure of therapy, relapse, and acquired multidrug resistance during the initial treatment of drug-susceptible tuberculosis cases using DOT or SAT. We estimated costs of tuberculosis treatment at an urban tuberculosis control program, a municipal hospital, and a hospital specializing in treating drug-resistant tuberculosis. OUTCOME MEASURES: The average cost per patient to cure drug-susceptible tuberculosis, including the cost of treating failures of initial treatment. RESULTS: The direct costs of initial therapy with DOT and SAT were similar ($1,206 vs $1,221 per patient, respectively), although DOT was more expensive when patient time costs were included. When the costs of relapse and failure were included in the model, DOT was less expensive than SAT, whether considering outpatient costs only ($1,405 vs $2,314 per patient treated), outpatient plus inpatient costs ($2,785 vs $10,529 per patient treated), or outpatient, inpatient, and patients' time costs ($3,999 vs $12,167 per patient treated). Threshold analysis demonstrated that DOT was less expensive than SAT through a wide range of cost estimates and clinical event rates. CONCLUSION: Despite its greater initial cost, DOT is a more cost-effective strategy than SAT because it achieves a higher cure rate after initial therapy, and thereby decreases treatment costs associated with failure of therapy and acquired drug resistance. This cost-effectiveness analysis supports the widespread implementation of DOT.

Effect of different coffees on esophageal acid contact time and symptoms in coffee-sensitive subjects.

The purpose of this study was to correlate the effects of different coffees on esophageal acid contact, heartburn, and regurgitation in patients with coffee-sensitivity. Twenty volunteers with coffee-sensitivity were studied in a double-blind, 3 period, crossover study examining the effect of three regular (caffeinated) coffees (a coffee from the USA--"A"; a "treated" coffee from Europe--"B"; and an "untreated" coffee from Europe--"C") before and after a high-fat test meal. The median acid contact times for coffees A, B, and C were 6.5%, 9%, and 10.5%, respectively (A vs. C, p = 0.005). Significantly fewer patients reported any symptoms with coffee A compared with coffee C (p < 0.05). Symptoms were usually more frequent and severe after the test meal. There was a trend toward fewer and less severe symptoms with the treated coffee (B) compared with its untreated counterpart (C). Our conclusions are as follows: (a) Different coffees induce variations in gastroesophageal reflux in coffee-sensitive individuals. (b) Coffee can be treated in a manner which decreases heartburn symptoms by 75% while decreasing acid contact by only 14%. (c) Gastroesophageal reflux and symptoms of coffee sensitivity increase with the concomitant ingestion of food. (d) Symptoms of dyspepsia appear to be influenced by variations in both the coffee itself and characteristics of susceptible individuals. (e) Although gastroesophageal reflux is important in the genesis of coffee-sensitivity, there must be other factors which act in concert with reflux to produce symptoms of coffee-sensitivity.

Blood lead levels in radiator repair workers in Colorado.

A laboratory-based blood lead surveillance system in Colorado identified radiator repair workers as having the highest blood lead levels of all worker groups reported. A survey of 42 radiator repair shops in ten locales throughout Colorado was undertaken to estimate the prevalence of workers with elevated blood lead levels > 25 micrograms/dL. The survey was designed to test the sensitivity of the surveillance system and to assess working conditions and practices in the radiator repair industry in Colorado. Of 63 workers, 39 (62%) had blood lead levels > 25 micrograms/dL. The sensitivity of the surveillance system for detecting radiator repair workers with elevated blood lead levels was estimated at 11%. None of the radiator repair shops had adequate local exhaust ventilation. Work practice and engineering modifications are needed to reduce lead exposure in this industry.

A retrospective search for lyssavirus in humans in the Northern Territory.

BACKGROUND: Following the 1996 discovery of a rabies-like lyssavirus in Australian flying foxes, it was unclear whether this was a new epizootic or an unrecognised, previously existing disease. OBJECTIVE: To review cases of unexplained encephalitis in the Northern Territory (NT) to test available clinical specimens for lyssavirus and survey the use of diagnostic tests by clinicians. METHODS: The NT hospital morbidity database was searched from January 1992 to September 1996 for all Royal Darwin Hospital (RDH) cases with an ICD-9 code encompassing encephalitis or viral meningitis. Final diagnoses were determined by hospital record review. For cases of unexplained encephalitis, we assessed the use of diagnostic tests and located clinical specimens for testing for lyssavirus-specific inclusion bodies via immunohistochemistry, immunofluorescence and reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS: Encephalitis occurred in 34/154 (22%) cases located by the search; 53% (18/34) of encephalitis cases were unexplained. Of these, 24% had no serology performed and 47% had no blood cultures taken. Four (22%) died and two had autopsies. These were the only two cases with clinical specimens available for testing. They were negative for lyssavirus. None of the 71 cases coded as viral meningitis had unexplained encephalitis. CONCLUSION: There was a considerable proportion of unexplained illness among NT cases of encephalitis. IMPLICATIONS: Clinicians should test for lyssavirus in patients with encephalitic symptoms and a postmortem should be sought where death is unexplained. Specimens should be stored to enable testing for emerging infectious diseases.

Timeliness of Salmonella notifications in South Australia.

OBJECTIVE: To evaluate the timeliness of Salmonella serotype and phage type notifications in South Australia. METHOD: We surveyed all notifications of Salmonella to the South Australian Department of Human Services between July 1995 and June 1996. We entered data onto an Epi Info 6.02 database and calculated the time interval between various stages of typing notification. RESULTS: The median time taken between collection of a faecal specimen and receipt of serotype notification was 10 days (range, 5-38), while phage type notification took a further seven days (range 0-40). The time interval between collection of a specimen and notification of a Salmonella final identity was 14 days (range 6-49). The internal mail system of the Department of Human Services delayed notification a median of two days. Environmental Health Officers supplied reports for 224 (58%) of 384 cases, 71% of which occurred before the final Salmonella isolate was known. CONCLUSIONS: We found that the internal departmental mail system delayed the notification of Salmonella. In South Australia, investigations should focus on clusters of cases of known Salmonella identity, rather than all notified cases. IMPLICATIONS: To improve communicable disease investigations, health agencies should evaluate the timeliness of surveillance systems and examine the feasibility of transferring laboratory data electronically.

Sesame seed products contaminated with Salmonella: three outbreaks associated with tahini.

In November 2002, the first of three outbreaks of Salmonella Montevideo infection in Australia and New Zealand was identified in New South Wales, Australia. Affected persons were interviewed, and epidemiologically linked retail outlets inspected. Imported tahini was rapidly identified as the source of infection. The contaminated tahini was recalled and international alerts posted. A second outbreak was identified in Australia in June-July 2003 and another in New Zealand in August 2003. In a total of 68 S. Montevideo infections, 66 cases were contacted. Fifty-four (82%) reported consumption of sesame seed-based foods. Laboratory analyses demonstrated closely related PFGE patterns in the S. Montevideo isolates from human cases and sesame-based foods imported from two countries. On the basis of our investigations sesame-based products were sampled in other jurisdictions and three products in Canada and one in the United Kingdom were positive for Salmonella spp., demonstrating the value of international alerts when food products have a wide distribution and a long shelf life. A review of the controls for Salmonella spp. during the production of sesame-based products is recommended.

Diagnosis and treatment of irritable bowel syndrome.

Irritable bowel syndrome is a common disorder characterized by symptoms of abdominal pain with diarrhea and/or constipation. It is associated with significant disability and health care costs. A practical approach to diagnosis utilizes the symptom-based Rome criteria. Management of patients has been helped by recent findings relating to the pathophysiology of the disorder. Dysregulation of intestinal motor functions, sensory functions and central nervous system functions is currently believed to be the basis for irritable bowel symptoms. Symptoms are a result of both abnormal intestinal motility and enhanced visceral sensitivity. Psychosocial factors can affect the illness experience and the clinical outcome. An effective physician-patient relationship is required for a successful outcome. Individualized treatment involves an integrated pharmacologic and behavioral approach determined by the predominant symptom type, the severity of the symptoms and the degree of disability.

Diagnosis and treatment of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a common medical disorder characterized by symptoms of abdominal pain and bowel dysfunction. It is associated with significant disability and health care costs. A practical approach to diagnosis is the symptom-based Rome criteria. Management of patients has been helped by recent findings relating to the epidemiology, pathophysiology and psychosocial contributions of the disorder. Dysregulation of intestinal motor, sensory and central nervous system function is currently believed to be the basis for IBS symptoms. Symptoms are due to both abnormal intestinal motility and enhanced visceral sensitivity. Psychosocial factors are not a cause but can affect the illness experience and clinical outcome. Finally, treatment involves an effective physician-patient relationship and an integrated pharmacologic and behavioral approach that is determined by the needs of the patient, the type and severity of the symptoms and the degree of disability.

On-line computer analysis of human lower esophageal sphincter relaxation.

Lower esophageal sphincter (LES) relaxation is usually interpreted by a subjective, mostly qualitative analysis. We studied sphincter relaxation in humans using a computer program for on-line analysis that provides objective measures of gastric pressure, resting LES pressure, percent of relaxation, residual pressure during relaxation, duration of relaxation, and area of relaxation. The program was validated by comparing computer-analyzed values to mean values obtained from manual readings by five individuals. Excellent correlation was obtained for all standard parameters. The parameters of LES relaxation for both wet and dry swallows were similar using either a carefully placed single recording orifice or a Dent sleeve. The one exception was the duration of LES relaxation, which was significantly shorter with the sleeve. All relaxation parameters and peristaltic velocity were then studied in 10 volunteers during 5 dry and 5 wet swallows under base-line conditions and after both atropine (10 micrograms/kg iv) and bethanechol (40 micrograms/kg sc). These studies showed that LES relaxation is affected by type of swallow (dry vs. wet). Percent of relaxation may not be the best measure of relaxation because it is too dependent on resting pressure. Residual pressure is not dependent on base-line pressure and may better define relaxation. Duration of the relaxation is dependent on the velocity of the peristaltic wave.

The changing faces of the nutcracker esophagus.

Although the nutcracker esophagus, characterized by high amplitude peristaltic contractions with mean distal amplitude greater than 180 mm Hg, is the most common esophageal motility disorder associated with noncardiac chest pain, little is known about its natural history. Therefore, we reviewed the manometric tracings of 23 patients with the nutcracker esophagus who had an average of 4.6 studies during a mean period of 32 months. Ten age-matched volunteers with normal baseline manometry who had undergone multiple studies (mean 5.8) over a mean time span of 32 months served as controls. In the 17 nutcracker patients with three or more motility studies, the variability of mean distal amplitudes between studies was 41.9% +/- 4.1 (+/- SE) compared to 27.0% +/- 3.3 for the control subjects (p less than 0.01). Highest distal pressures were noted during the first study in 11 of 17 patients (65%) compared to two of 10 controls (20%). The consistency of the diagnosis of nutcracker esophagus varied considerably: four patients always had high amplitude pressures, three patients only had the nutcracker diagnosis on the initial study, and 10 patients intermittently had pressures in the nutcracker range. Overall, these 17 patients had the diagnosis of the nutcracker esophagus confirmed on only 54% of subsequent studies. Changes in motility patterns were intermittently seen in six of 23 patients: one diffuse spasm and five nonspecific motility disorders. None of the control subjects developed high amplitude contractions or changed their motility pattern on serial testing. The possible pathophysiological implications of the changing faces of the nutcracker esophagus are discussed.

Musculoskeletal chest wall syndromes in patients with noncardiac chest pain: a study of 100 patients.

One hundred patients with chest pain and negative coronary arteriography were evaluated for musculoskeletal chest wall findings. Sixty-nine patients had chest wall tenderness. Typical chest pain was evoked by palpation in 16 patients. Tender areas were not found in a control group of patients without chest pain. A diagnosis of fibrositis could be made in five patients, including two in whom chest palpation reproduced typical chest pain. The sternal and xiphoid area, left costosternal junctions, and left anterior chest wall were the areas where tenderness was most common, but no significant differences were found comparing locations of tenderness in those with reproduction of typical pain. There was no significant difference in location, exacerbating factors, or other musculoskeletal symptoms among different groups of patients. Thus, most patients with noncardiac chest pain have chest wall tenderness that is not found in a control group without chest pain. However, reproduction of pain by palpation, a more specific diagnostic finding, is found in a minority of these patients.

Comparison of esophageal manometry, provocative testing, and ambulatory monitoring in patients with unexplained chest pain.

Prolonged ambulatory esophageal pH and pressure monitors are being developed to evaluate noncardiac chest pain. This new technology needs comparison with conventional esophageal tests before determining which studies are most useful in diagnosing and treating esophageal chest pain. Therefore, we studied 45 patients with esophageal manometry, acid perfusion and edrophonium tests, and 24 hr pH and pressure monitoring. Manometry was abnormal in 20 patients (44%) with nutcracker esophagus, the most common motility disorder. Fifteen (33%) had positive acid perfusion test and 24 (55%) positive edrophonium test. During ambulatory monitoring, all patients experienced chest pain with a total of 202 individual events: 32 events (15%) secondary to acid reflux, 15 (7%) secondary to motility abnormalities, 7 (3%) to both pH and pressure changes, and 149 events (74%) occurred in the absence of any abnormal pH or motility changes. Patients with normal manometry were significantly (P less than 0.01) more likely to have acid reflux chest pain events than did nutcracker patients, who had an equal frequency of pH and motility events. A positive acid perfusion test was significantly associated with abnormal pressure events (P = 0.02; odds ratio 5.95), while a positive edrophonium test more likely predicted acid reflux chest pain during 24-hr monitoring (P = 0.007; odds ratio 7.25). Therefore, abnormal manometry and positive provocative tests point to the esophagus as the likely source of chest pain. However, ambulatory pH and pressure monitoring are required to accurately define the relationship between chest pain and acid reflux or motility disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharyngeal and upper esophageal sphincter manometry in humans.

Manometric studies of pharyngeal-upper esophageal sphincter (UES) coordination during swallowing have proven difficult. Asymmetry of the UES makes pressure measurements with a single, unoriented transducer suspect. Perfused systems lack the necessary response rate for measuring peak pharyngeal contraction pressures. Precise quantification of the coordination of pharyngeal contractions and UES relaxations during swallowing is difficult because of rapid pressure changes. We tested a modified solid-state transducer that measures pressures over 360 degrees. This transducer was placed in the proximal UES with a second, single transducer 5 cm proximal. Data were collected and analyzed with an Apple IIe microcomputer. A computer program was developed to measure nine timing sequences, UES resting pressure, nadir of UES relaxation, and pharyngeal contraction pressures. We studied 21 volunteers with six swallows each for dry, 5, 10, and 20 ml of water. Dry swallows differed significantly (P less than 0.05) from wet (5 ml). All timing sequences became progressively longer with increasing bolus size. Residual pressures were unchanged. Timing sequences were also measured for wet (5 ml) and dry swallows in seven volunteers using a Dent sleeve and single perfused orifice in the UES; no differences were seen.

Effects of body position and bolus consistency on the manometric parameters and coordination of the upper esophageal sphincter and pharynx.

The development of a solid-state intraluminal sphincter transducer has alleviated many of the problems associated with manometric studies of the upper esophageal sphincter (UES) and pharynx (P). We used this technology to study the effect of position (upright vs. supine) on resting UES pressures and the pressure dynamics of the UES/P complex during both wet and dry swallows in 11 normal volunteers and the effects of foods of different consistencies on the UES/P swallow dynamics in 10 normal volunteers. The UES/P coordination parameters were defined as the 15 time intervals that can be measured between any 2 of 6 pertinent points: the beginning, peak, and end of the pharyngeal contraction and the beginning, nadir, and end of the UES relaxation. Data from both the circumferential transducer used to measure sphincter pressures and a standard microtransducer used to measure pharyngeal pressures were collected on-line by an Apple IIe microcomputer and analyzed by programs written in our laboratory. Significant changes in swallow coordination were measured between upright and supine swallows of the same bolus size, between wet and dry swallows in the same position, and among foods of varying consistencies. Resting UES pressure was unchanged by position and pharyngeal contraction pressure was unchanged by bolus size or consistency.

Oral pirenzepine does not affect esophageal pressures in man.

Pirenzepine has been proposed to selectively inhibit gastric acid production. In contrast to classical anticholinergics, pirenzepine does not appear to produce systemic side effects or to strongly inhibit contractions in gastrointestinal tract smooth muscle. This study compares the effects of two doses of pirenzepine (25 and 50 mg per os) with a standard anticholinergic, propantheline, 30 mg per os, and with placebo on esophageal contraction pressures in 12 healthy volunteers in a random double-blind study sequence. No significant change in lower esophageal sphincter pressure (LESP) or in peristaltic pressures occurred with placebo or pirenzepine 25 or 50 mg. However, propantheline produced marked reduction in peristaltic contraction pressures and increased velocity (4 of 12 subjects had complete loss of peristalsis). LESP decrease was almost significant. Seven of 12 subjects experienced dry mouth after propantheline, but none after either dose of pirenzepine or placebo. This study indicates that, as opposed to a classical anticholinergic, pirenzepine does not adversely affect esophageal contraction pressures nor does it have anticholinergic side effects with the oral doses studied.

Oral nifedipine in the treatment of noncardiac chest pain in patients with the nutcracker esophagus.

Placebo-controlled trials are not available to assess the efficacy of smooth muscle relaxants in the treatment of painful esophageal motility disorders. Therefore, we compared the effects of oral nifedipine (10-30 mg t.i.d.) and placebo in 20 patients (mean age 50 yr) with chronic noncardiac chest pain and the nutcracker esophagus in a 14-week double-blind crossover study. Compared to placebo, nifedipine significantly decreased distal esophageal contraction amplitude (mean +/- SEM, 198 +/- 11 mmHg to 123 +/- 9 mmHg; p less than 0.005), as well as duration and lower esophageal sphincter pressure. Nifedipine, however, was no better than placebo in the relief of daily chest pain frequency, severity, or index (frequency X severity) as assessed by patient diaries. Despite these disappointing results, long-term follow-up (mean, 16.6 mo) suggests these patients do improve. Mean daily chest pain index significantly (p less than 0.005) decreased from 10.3 +/- 2.0 at the beginning of the study to 3.2 +/- 0.8 at follow-up. Prescription drug use and physician visits for chest pain also significantly decreased. Distal esophageal contraction pressures significantly fell during the long-term follow-up but there was poor correlation with chest pain improvement. This study suggests that identification of the esophagus as the cause of chest pain coupled with supportive intervention may be more effective than drug therapy in improving these patients' chest pain.