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K L MacDonald

Publications and source records attributed to K L MacDonald.

At least 55 records · Page 3Linked to original sources
PubMed1990

HIV-1 counseling and testing sites, Minnesota: analysis of trends in client characteristics.

We report here a summary of the data obtained from two HIV-1 antibody counseling and testing sites in Minneapolis-St. Paul for the first 48 months of operation (24,911 persons tested). The HIV-1 antibody seroprevalence rate for all persons tested was 5 percent. The highest seroprevalence rates were in male homosexual/bisexual intravenous drug users (23 percent) and homosexual/bisexual men (13 percent). There was a significant decrease in the HIV-1 antibody seroprevalence rate among clients during the 48-month period from 14 percent in the first six months to 3 percent in the last six months. This decrease coincided with an increase in the number of low-risk female clients and low-risk heterosexual male clients, and a decrease in the number of homosexual/bisexual males participating in the programs. These findings suggest the need for development and implementation of other strategies to identify and reach persons at highest risk for HIV-1 infection.

AIDS Serodiagnosis↗
PubMed1990

Drownings in Minnesota, 1980-85: a population-based study.

We conducted a population-based study of drownings in Minnesota from 1980 through 1985. Five hundred and forty-one drownings (2.1 per 100,000 person-years) were identified from death certificates and from incident reports filed with the Minnesota Department of Natural Resources. Most drownings (334, 62 percent) occurred during summer months (May-August) and involved boating (42 percent) and swimming (35 percent) events. However, 62 drownings (11 percent) occurred during winter months (December-February) and primarily involved snowmobiles and motor vehicles (71 percent) breaking through ice on lakes and waterways. The risk of drowning, estimated by the ratio of drownings to number of water-related activities, was highest during March and April, when the ice on lakes and waterway surfaces is melting, and during October and November, when lake and waterway surfaces are starting to freeze. Drowning rates were highest for males (3.7 per 100,000 person-years), persons 15 to 25 years of age (3.3 per 100,000 person-years), and children less than 5 years of age (2.5 per 100,000 person-years). These data can be used to target prevention strategies, particularly in northern climates.

Adolescent↗
PubMed1989

An outbreak of nitrogen dioxide-induced respiratory illness among ice hockey players.

During February 1987 an outbreak of nitrogen dioxide-induced respiratory illness occurred among players and spectators of two high school hockey games played at an indoor ice arena in Minnesota. The source of the nitrogen dioxide was the malfunctioning engine of the ice resurfacer. Case patients experienced acute onset of cough, hemoptysis, and/or dyspnea during, or within 48 hours of attending, a hockey game. One hundred sixteen cases were identified among hockey players, cheerleaders, and band members who attended the two games. Members of two hockey teams had spirometry performed at 10 days and 2 months after exposure; no significant compromise in lung function was documented. Nitrogen dioxide exposure in indoor ice arenas may be more common than currently is recognized; only three states require routine monitoring of air quality in ice arenas, and the respiratory symptoms caused by exposure to nitrogen dioxide are nonspecific and easily misdiagnosed.

Disease Outbreaks↗
PubMed1989

Performance characteristics of serologic tests for human immunodeficiency virus type 1 (HIV-1) antibody among Minnesota blood donors. Public health and clinical implications.

STUDY OBJECTIVE: To evaluate performance characteristics of sequential enzyme immunoassay (EIA) and Western blot human immunodeficiency virus type 1 (HIV-1) antibody testing in a low-risk population. DESIGN: Three-year prospective study of a selected sample from a community-based population. SETTING: Two blood collection facilities in Minnesota. POPULATION: Minnesota blood donors. RESULTS: During the study period, 630,190 units of blood (donations) from an estimated 290,110 Minnesota-resident donors were screened for HIV-1 antibody. Seventeen Minnesota-resident donors were identified as positive for HIV-1 antibody. Sixteen donors were available for follow-up HIV-1 culture: all were culture positive. The other donor, who was not available for follow-up culture, was likely infected with HIV-1 based on a history of high-risk behavior and positive serologic findings for hepatitis B surface antigen. Using 95% binomial confidence intervals, performance characteristics for sequential EIA and Western blot HIV-1 antibody serology were as follows: false-positive rate by number of donations, 0% to 0.0006%; specificity by number of donations, 99.9994% to 100%; predictive value of a positive test, 81% to 100%. CONCLUSIONS: In this low-risk population, the false-positive rate of serologic tests for HIV-1 antibody, using HIV-1 culture as the definitive standard for infection status, was extremely low and test specificity was extremely high.

AIDS Serodiagnosis↗
PubMed1989

Risk factors for infant botulism in the United States.

To define risk factors for infant botulism, we performed a 2-year prospective case-control study of 68 laboratory-confirmed cases in infants living in the United States, outside of California. For each case patient, two control subjects were matched by date and hospital of birth or county birth records. By univariate analysis, breast-feeding (odds ratio = 2.9) and consumption of honey (odds ratio = 9.8) were associated with disease, but only 11 case patients (16%) had eaten honey. Decreased frequency of bowel movement (less than one per day for at least 2 months) was also associated with disease in infants 2 months of age and older (odds ratio = 5.2). Risk factors changed with the age of the patient at disease onset when analyzed by multivariate logistic regression methods. For infants less than 2 months old, living in a rural area or on a farm was the only significant risk factor (odds ratio = 6.4). For infants 2 months of age and older, breast-feeding (odds ratio = 3.8), less than one bowel movement per day for at least 2 months (odds ratio = 2.9), and ingestion of corn syrup (odds ratio = 5.2) were associated with disease. The severity of the disease was similar for breast- and bottle-fed infants. Clearly defined food exposures account for a minority of infant botulism cases. Preexisting host factors, such as intestinal flora and frequency of bowel movements, may be the most important risk factors for development of disease.

Botulism↗
PubMed1989

An outbreak of giardiasis in a nursing home with evidence for multiple modes of transmission.

During a 6-w period from 20 April through 7 June 1986, an outbreak of giardiasis occurred in residents and employees of a nursing home and children participating in day care at the nursing home. Eighty-eight cases of giardiasis (defined by presence of clinical symptoms or results of stool examination) were identified from groups associated with the nursing home including 35 in nursing home residents, 15 in children in day care, and 38 in employees (including kitchen staff and child care providers). Multiple modes of transmission of Giardia lamblia, including food-borne and person-to-person transmission, occurred for these groups. Evidence of transmission by food included a significant association between sandwich consumption and illness in nursing home staff (P = .04) and a significant lack of illness among nursing home residents who consumed only a pureed diet (P = .007), where all food items are cooked before serving. The primary case among the food handlers, whose illness began in mid-April, had an infected child in the day care center. Person-to-person transmission is supported by a significant association between illness and physical contact with children from the day care facility through an "adopted grandparent" program (P = .03). This is the first reported outbreak of giardiasis in a nursing home, and these findings have implications for disease control in other facilities that combine child day care and care of the elderly.

Aged↗
PubMed1989

An outbreak of psittacosis in Minnesota turkey industry workers: implications for modes of transmission and control.

From June through November 1986, an outbreak of psittacosis occurred in turkey industry workers in central Minnesota. A total of 186 suspect cases were identified, and 122 cases (66%) were serologically confirmed. Cases occurred in three turkey processing plants, two rendering plants, one farm, and one "further processing" plant (where meat is removed from previously eviscerated carcasses and consumer products, such as roasts, are made). As in previous outbreaks, workers exposed to the viscera of infected birds were at greatest risk of becoming infected. However, our data showed that 31 (25%) of the confirmed cases occurred in workers at the further processing plant who had contact only with previously eviscerated carcasses. Although the specific source of infection and the mode of transmission in these workers are unclear, the use of gloves and masks by all processing workers during an outbreak might help to limit exposure. Control measures, which focused on identifying and treating ill turkey flocks, were initiated in early September; however, cases continued to occur in turkey industry workers through November. One of the flocks suspected of causing illness appeared healthy and, therefore, was not treated. Chlamydia psittaci infection in this flock was confirmed by culture after the flock had been processed. A rapid test for diagnosing C. psittaci infection in turkey flocks at the time of processing might be useful in preventing exposure of large numbers of workers.

Animals↗
PubMed1988

Lack of efficacy of Haemophilus b polysaccharide vaccine in Minnesota.

We evaluated the efficacy of Haemophilus b polysaccharide vaccine in children in Minnesota using a case-control study. The vaccine became available in Minnesota in August 1985. During the subsequent 28 months, 88 cases of invasive H influenzae type b disease were identified in children 24 to 71 months of age, the group targeted for vaccination. Of the 88 cases, 36 (41%) occurred in vaccinated children. Fifty-eight (33%) of 176 controls were vaccinated during a similar period. The vaccine's protective efficacy for children with any history of vaccination was -58% (95% confidence interval = -204% to 18%). The vaccine's protective efficacy for children who were most likely to be protected by vaccination was -55% (95% confidence interval = -238% to 29%). Our results indicate that vaccination with Haemophilus b polysaccharide vaccine had no effect in preventing H influenzae type b disease in Minnesota children.

Bacterial Capsules↗
PubMed1988

Escherichia coli O157:H7, an emerging gastrointestinal pathogen. Results of a one-year, prospective, population-based study.

To examine the incidence of Escherichia coli O157:H7 enteric infections in the United States and to evaluate the vehicles of transmission for sporadic cases, we conducted a one-year, population-based study at a large health maintenance organization (HMO) in the Puget Sound area of Washington State. All stool specimens submitted for culture to the HMO laboratory were screened for E coli O157:H7; the organism was identified in 25 (0.4%) of 6485 stool specimens. All patients with E coli O157:H7 identified had diarrhea; 24 patients (96%) had bloody diarrhea. Exposure histories demonstrated that rare ground beef was consumed more often by patients (21%) than by age-matched control subjects (4%) in the week before onset of illness. Raw milk also was consumed by two patients but by none of the control subjects. Incidence rates for laboratory-confirmed enteric infections in the HMO population were as follows: Campylobacter, 50/100,000 person-years; Salmonella, 21/100,000 person-years; E coli O157:H7, 8/100,000 person-years; and Shigella, 7/100,000 person-years. The organism is a more common pathogen in the United States than is generally recognized, and the diagnosis should be considered for patients with suspected enteric infection.

Adolescent↗
PubMed1987

Changes in antimicrobial resistance of Salmonella isolated from humans in the United States.

Changes were examined that occurred in the antimicrobial susceptibility between 1979-1980 and 1984-1985 of Salmonella organisms isolated from humans who resided in a random sample of counties in the United States. Resistance to one or more antimicrobials rose significantly from 16% (82 of 511 isolates) in 1979-1980 to 24% (117 of 485 isolates) in 1984-1985. In addition, statistically significant increases occurred in the proportion of organisms resistant to only one antimicrobial (from 4% to 9%), the rate of resistance of Salmonella typhimurium (from 14% to 26%), and the rate of resistance to tetracycline. For one commonly occurring serotype, Salmonella heidelberg, the proportion of resistant strains fell significantly from 67% in 1979-1980 to 35% in 1984-1985. When epidemiologic characteristics of patients were examined, previous use of antimicrobials for treatment of other illnesses was a significant risk factor for acquiring clinically important infections with antimicrobial-resistant Salmonella. Changes detected in the antimicrobial resistance of Salmonella during this time will ultimately affect the efficacy of antimicrobial therapy in treating human disease.

Drug Resistance, Microbial↗
PubMed1987

An outbreak of thyrotoxicosis caused by the consumption of bovine thyroid gland in ground beef.

We report an outbreak of thyrotoxicosis without true hyperthyroidism that occurred between April 1984 and August 1985 among residents of southwestern Minnesota and adjacent areas of South Dakota and Iowa. One hundred twenty-one cases were identified through surveillance of medical clinics, laboratories, hospitals, and physicians' offices. Investigation of the outbreak demonstrated an association between the occurrence of thyrotoxicosis and the consumption of ground beef prepared from neck trimmings processed by a single slaughtering plant (odds ratio, 19.0; P = 0.0001). The cause was confirmed by the findings of bovine thyroid tissue in samples of these trimmings and high concentrations of thyroid hormone in implicated samples of ground beef and the demonstration of prompt increases in serum thyroid hormone concentrations in volunteers who ate the implicated ground beef. Bovine thyroid tissue had been introduced into the neck trimmings inadvertently during the process of "gullet trimming," a procedure that harvests muscles from the bovine larynx. The outbreak resolved after this procedure was discontinued at the plant. The clinical features of the illness suggested the diagnosis of silent thyroiditis, and it is possible that sporadic cases--or even outbreaks--of thyrotoxicosis factitia caused by this mechanism may have occurred in the past but were not recognized.

Adolescent↗
PubMed1987

Toxic shock syndrome. A newly recognized complication of influenza and influenzalike illness.

Nine cases of severe hypotension or death compatible with toxic shock syndrome (TSS) as a complication of influenza and influenzalike illness were identified in Minnesota with onsets between Jan 2, 1986, and Feb 23, 1986, in which five of the patients died. During this time, an influenza outbreak was occurring in the state. Cultures of respiratory secretions were performed in eight patients; Staphylococcus aureus was isolated from all of them. Seven S aureus isolates were available for determination of exotoxin production; five isolates produced toxic shock syndrome toxin-1, one produced enterotoxin B, and one produced both. Acute influenza B infection was confirmed in three of four patients for whom throat cultures or acute and convalescent serum samples were available. Two patients fulfilled the Centers for Disease Control-confirmed case definition for TSS. Four additional patients fulfilled the CDC criteria for a probable case of TSS, and TSS was a likely diagnosis in the remaining three patients. The initial presentation was suggestive of nonsuppurative tracheitis or viral pneumonia in eight patients. In the remaining patient, the initial clinical presentation was compatible with staphylococcal pneumonia. This report demonstrates that TSS can occur as a complication of influenza and influenzalike illness.

Adolescent↗
PubMed1987

Aeromonas veronii, a new ornithine decarboxylase-positive species that may cause diarrhea.

In 1983, the vernacular name Enteric Group 77 was coined for a group of strains that had been referred to our laboratory as "possible Vibrio cholerae except for gas production." By DNA-DNA hybridization (hydroxyapatite, 32P), 8 of 10 strains of Enteric Group 77 were very highly related to the labeled strain 1169-83 (74 to 100% at 60 degrees C and 75 to 100% at 75 degrees C; percent divergence, 0.0 to 2.5). Type strains of six other Aeromonas species were 45 to 66% related (60 degrees C) to strain 1169-83, but type strains of 27 Vibrio species were only 2 to 6% related. The name Aeromonas veronii is proposed for the highly related group of nine strains formerly known as Enteric Group 77. The type strain is designated as ATCC 35604 (CDC 1169-83). Strains of A. veronii grew well at 36 degrees C and had positive reactions at this temperature for indole, methyl red, Voges-Proskauer, citrate, lysine and ornithine decarboxylases, DNase, lipase, and motility; the strains had negative reactions for arginine decarboxylase, H2S, urea, and malonate. The following sugars were fermented: D-glucose (acid and gas), cellobiose (seven of nine strains), D-galactose, maltose, D-mannitol, D-mannose, alpha-methyl-D-glucoside (eight of nine strains), salicin, sucrose, and trehalose. The following sugars were not fermented: adonitol, L-arabinose, D-arabitol, dulcitol, erythritol, myo-inositol, lactose, raffinose, L-rhamnose, D-sorbitol, and D-xylose. The positive ornithine decarboxylase reaction differentiates A. veronii from other Aeromonas species. The antibiogram of A. veronii is typical of other Aeromonas strains (resistance to ampicillin and carbenicillin and susceptibility to most other agents). A. veronii strains were isolated from three clinical sources: respiratory secretions of four victims of drowning or near drowning in fresh water (probably not clinically significant); infected wounds of two patients previously exposed to fresh water (unknown clinical significance); and stools from three patients with diarrhea (probably clinically significant).

Adult↗