PubMed Health⌕ Search

Biomedical subjects

K L MacDonald

Publications and source records attributed to K L MacDonald.

69 records · Page 4Linked to original sources

An outbreak of a newly recognized chronic diarrhea syndrome associated with raw milk consumption.

A previously undescribed chronic diarrhea syndrome affected 122 residents of Brainerd, Minn, between December 1983 and July 1984. The illness lasted at least one year for 75% of case-patients and was characterized by acute onset, marked urgency, a lack of systemic symptoms, and a failure of response to antimicrobial agents. Clinical and laboratory data indicate that the diarrhea was caused by a secretory mechanism. Consumption of raw milk from a single dairy was associated with illness (odds ratio, 28.3; 95% confidence interval, 9.0 to 89.0). A median incubation period of 15 days was determined for seven case-patients. Possible secondary transmission was noted in one family. Extensive laboratory examination did not identify an etiologic agent. Outbreaks or sporadic cases of a similar illness have occurred in at least seven states; the outbreaks were less extensively investigated and findings were not published, but raw milk consumption was common in the affected persons. This illness appears to represent a previously unrecognized but important clinical entity and public health problem. The etiology and effective therapy for this illness must be determined by further studies of sporadic cases and outbreaks.

Aged↗

The changing epidemiology of adult botulism in the United States.

All forms of botulism are rare in the United States, and, as a result, descriptions of the pertinent epidemiologic features and clinical spectrum of illness are limited. This review describes the epidemiologic characteristics of the 355 cases of botulism in adults reported in the United States between 1976 and 1984, outlines current therapy, and emphasizes newly recognized features of the disease. Evaluation of recent data for botulism demonstrates several new associations and trends. These include the occurrence of large restaurant-associated outbreaks, several newly identified vehicles for foodborne botulism, wound botulism in parenteral drug abusers, and botulism from an unknown source in patients with underlying gastrointestinal disease. Recognition of these unusual features can lead to more effective preventive measures and to early diagnosis, which is essential for effective treatment.

Botulism↗

Type A botulism from sauteed onions. Clinical and epidemiologic observations.

Twenty-eight persons were hospitalized in Illinois with neurologic signs and symptoms compatible with botulism in October 1983. Twelve patients required ventilatory support, and 20 patients were treated with trivalent ABE antitoxin; one patient died while still in the hospital six months after onset of illness. Type A toxin and/or type A Clostridium botulinum were subsequently identified in specimens from 18 patients. Case-control studies implicated sauteed onions made from fresh raw onions and served on a patty-melt sandwich in a local restaurant as the vehicle of transmission. Although the original sauteed onions were not available for toxin testing, type A toxin was detected in washings from a wrapper in which a patty-melt sandwich was taken home by one of the ill persons. Also, type A C botulinum was cultured from five of 75 raw onions taken from the restaurant. This outbreak implicated an unusual vehicle for botulinal toxin that was initially not suspected and demonstrates the importance of considering all theoretically possible food items as potential vehicles for toxin until epidemiologic and laboratory data have been collected and analyzed.

Adult↗

Pasteurized milk as a vehicle of infection in an outbreak of listeriosis.

Between June 30th and August 30th, 1983, 49 patients in Massachusetts acquired listeriosis. Seven cases occurred in fetuses or infants and 42 in immunosuppressed adults; 14 patients (29 per cent) died. Of 40 Listeria monocytogenes isolates available for testing, 32 were serotype 4b. Two case-control studies, one matching for neighborhood of residence and the other for underlying disease, revealed that the illness was strongly associated with drinking a specific brand of pasteurized whole or 2 per cent milk (odds ratio = 9, P less than 0.01 for the neighborhood-matched study; odds ratio = 11.5, P less than 0.001 for the illness-matched study). The association with milk was further substantiated by four additional analyses that suggested the presence of a dose-response effect, demonstrated a protective effect of skim milk, associated cases with the same product in an independent study in another state, and linked a specific phage type with the disease associated with milk. The milk associated with disease came from a group of farms on which listeriosis in dairy cows was known to have occurred at the time of the outbreak. Multiple serotypes of L. monocytogenes were isolated from raw milk obtained from these farms after the outbreak. At the plant where the milk was processed, inspections revealed no evidence of improper pasteurization. These results support the hypothesis that human listeriosis can be a foodborne disease and raise questions about the ability of pasteurization to eradicate a large inoculum of L. monocytogenes from contaminated raw milk.

Adult↗

A multistate outbreak of gastrointestinal illness caused by enterotoxigenic Escherichia coli in imported semisoft cheese.

In September 1983, three clusters of gastrointestinal illness with similar symptoms affected 45 persons in Washington, D.C., after office parties. The illness lasted a mean of 4.4 days and was characterized by watery diarrhea (91%), abdominal cramps (80%), headache (38%), nausea (38%), and subjective fever (20%). Illness was strongly associated with having eaten imported French Brie cheese one to six days before onset of illness (P less than .0001 by Fisher's two-tailed exact test). After publicity about these outbreaks, additional cheese-associated cases were identified over an eight-week period in Illinois, Wisconsin, Georgia, and Colorado. Stool specimens from ill persons in four states yielded Escherichia coli serotype O27:H20. These organisms produced heat-stable enterotoxin and had similar plasmid profiles. When commercially distributed foods are contaminated, enterotoxigenic E. coli can cause widespread disease even in a developed country, and the disease can easily escape correct diagnosis.

Adolescent↗

Botulism and botulism-like illness in chronic drug abusers.

From 1982 to 1983 we received reports of a neurologic illness characterized by a symmetric descending paralysis in six drug abusers from widely separated geographic areas. Botulism was confirmed in two patients; type B botulinal toxin was found and Clostridium botulinum was isolated from a small abscess in one, and type A botulinal toxin was found in the serum of the other. The clinical illness in the remaining four patients, although not laboratory confirmed, was also compatible with botulism. None of the patients had histories suggestive of foodborne botulism, and wound botulism was suspected as the cause of illness. There are several reports of tetanus associated with parenteral drug abuse; wound botulism is another toxin-mediated clostridial infection that may occur as a complication of chronic drug abuse.

Abscess↗

Sporadic cases of hemorrhagic colitis associated with Escherichia coli O157:H7.

After two outbreaks of hemorrhagic colitis associated with a previously unrecognized pathogen, Escherichia coli O157:H7, a surveillance system was established to identify and study sporadic cases of this distinct clinical illness in the United States. Between August 1982 and April 1984, we identified 28 persons from 11 states who met our case definition and whose stool specimens yielded E. coli O157:H7. Patients ranged in age from 1 to 80 years. Seventeen patients required hospitalization. All patients recovered, although one developed hemolytic-uremic syndrome 7 days after the onset of bloody diarrhea. Detection of E. coli O157:H7 in stools from persons with hemorrhagic colitis was highly associated with collection of stool specimens within the first 6 days after onset of illness. All E. coli O157:H7 isolates produced a Vero cytotoxin. Hemorrhagic colitis caused by E. coli O157:H7 is widely distributed in the United States as a sporadic illness; clinicians should be aware of its distinctive clinical presentation, and should collect specimens promptly when the diagnosis is suspected.

Adolescent↗

Infection with human T-lymphotropic virus type III/lymphadenopathy-associated virus: considerations for transmission in the child day care setting.

Many public health and social issues relate to infection with the human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV)-the virus that causes the acquired immunodeficiency syndrome. One such issue is the care and education of infected children, both in schools and in day care facilities. To date, transmission of HTLV-III/LAV in either the school or the day care setting has not been documented. However, because the virus has been isolated from a variety of body fluids, contact with such fluids from an infected child poses at least a theoretical risk of transmission. Past experience with transmission of hepatitis B virus provides a possible model to aid in understanding the epidemiology of HTLV-III/LAV infection. The risk of transmission of HTLV-III/LAV in day care settings is not known, and infection with this virus carries serious public health and clinical implications.

Acquired Immunodeficiency Syndrome↗

Epidemiology of travelers' diarrhea: current perspectives.

Identification of the characteristics that make certain travelers more likely to develop diarrhea, the most common illness affecting international travelers, can lead to prevention of the illness and to improved understanding of endemic diarrheal disease in developing countries. Travelers' diarrhea, a syndrome with a spectrum of clinical symptoms, is most frequently characterized by watery diarrhea, cramps, and nausea. The highest attack rates have been reported in travelers from the United States or northern Europe to less-developed, particularly tropical, countries. Among travelers from less-developed countries, diarrhea has been correlated with higher socioeconomic status. The findings that country of origin and socioeconomic status may affect the frequency of previous exposures to enteric pathogens suggest that persons with prolonged exposure acquire immunity and are at lower risk of developing travelers' diarrhea. Although few studies have shown a clear correlation between the eating of specific foods and the development of travelers' diarrhea, the syndrome has been associated with eating in public places.

Diarrhea↗

Factors associated with the geographic variation of reported Chlamydia infection in Minnesota.

BACKGROUND AND OBJECTIVES: In Minnesota, physicians have been required to report cases of Chlamydia trachomatis infection since 1985. The distribution of reported cases suggests that there is substantial geographic variation in the rate of chlamydia infection. GOAL OF THIS STUDY: We conducted chlamydia screening at selected sites and a survey of primary care physicians in counties with high and low rates of reported chlamydia infection. We hypothesized that chlamydia infections are uniformly distributed in nonmetropolitan areas, and the geographic differences in reported cases can be attributed to variable testing and reporting practices by physicians. STUDY DESIGN: The number of reported female chlamydia cases per 1,000 women was calculated for each rural Minnesota county in 1990. Fourteen counties with high and low rates of reporting were selected for further investigation. From September to December 1991, universal chlamydia screening was carried out at 11 clinics serving patients in these counties. A questionnaire was mailed to all primary care physicians in these counties. RESULTS: In 1990, the rate of reported chlamydia cases was 4.7/100,000 and 0.1/100,000 for women living in the high-reporting and low-reporting counties, respectively. Chlamydia infection was present in 5.5% and 9.7% of women screened at selected clinics in high- and low-reporting counties, respectively. Physicians in high- and low-reporting counties did not differ significantly in terms of age, gender, number of pelvic exams, or frequency of chlamydia testing. However, physicians in high-reporting counties were significantly more likely to test for chlamydia when evaluating mucopurulent cervicitis or salpingitis, and they were more likely to test a woman whose sex partner had urethritis. Physicians in high-reporting counties were also more likely to have reported a case of chlamydia.

Adolescent↗

Risk factors for lack of detectable antibody following hepatitis B vaccination of Minnesota health care workers.

OBJECTIVE: To assess the presence of antibody to hepatitis B surface antigen (anti-HBs) at postvaccination testing in Minnesota health care workers receiving recombinant hepatitis B vaccines, and to identify risk factors for lacking anti-HBs following hepatitis B vaccination. DESIGN: Retrospective cohort study. SETTING: Ten acute care hospitals in Minnesota. PARTICIPANTS: A total of 595 health care workers who had received hepatitis B vaccine (Recombivax HB or Engerix-B) between June 1987 and December 1991 and who underwent postvaccination testing for anti-HBs within 6 months after receiving the third dose of vaccine. MAIN OUTCOME MEASURE: Presence or absence of anti-HBs following hepatitis B vaccination. RESULTS: Five variables were independently associated with lacking anti-HBs by multivariate analysis: vaccine brand, smoking status, gender, age, and body mass index. Stratifying by vaccine brand demonstrated that age (P = .01), body mass index (P < .01), and smoking status (P < .01) were associated with lacking anti-HBs only for Recombivax HB recipients; and gender (P = .03) was associated with lacking anti-HBs only for Engerix-B recipients. After controlling for smoking status, age, gender, and body mass index, recipients of Recombivax HB were more likely to lack anti-HBs than recipients of Engerix-B (relative risk, 2.3; 95% confidence interval, 1.1 to 4.7; P = .02). CONCLUSIONS: Results indicate that certain populations of health care workers are at increased risk of not responding to hepatitis B vaccination. Further studies evaluating immunogenicity of currently available recombinant hepatitis B vaccines in persons at high risk for primary vaccine failure are needed.

Adult↗

Statewide survey of laboratories performing Mycobacterium tuberculosis testing in Minnesota.

Rapid and accurate laboratory detection and identification of Mycobacterium tuberculosis, particularly multidrug-resistant strains, is critical to both public health control measures and patient management. The authors surveyed microbiology laboratories to evaluate whether their methods met national guidelines. As needed, laboratories received individualized recommendations for improvement. The laboratories were resurveyed a year later to assess changes in methods. Current guidelines recommend fluorochrome acid-fast smears, broth cultures, identification by nucleic acid probe or BACTEC-NAP, and BACTEC primary susceptibility panels, which should include pyrazinamide. Of 27 laboratories performing acid-fast smears, 15 used fluorochrome methods. Six of 16 laboratories performing mycobacterial cultures used broth media. Of six laboratories performing species identification, five used nucleic acid probes or BACTEC-NAP. Of five laboratories evaluating drug sensitivity, two used BACTEC and two included pyrazinamide in their protocols. Overall, 24 (89%) laboratories needed improvements; a year later, 16 (67%) of those had altered their methods or made definite plans to do so. Survey results suggest that health departments can facilitate improvements in laboratory testing for pathogens of public health importance.

Data Collection↗