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Biomedical subjects

J M Horan

Publications and source records attributed to J M Horan.

At least 19 recordsLinked to original sources
PubMed1999

Effect of the interval between pregnancies on perinatal outcomes.

BACKGROUND: A short interval between pregnancies has been associated with adverse perinatal outcomes. Whether that association is due to confounding by other risk factors, such as maternal age, socioeconomic status, and reproductive history, is unknown. METHODS: We evaluated the interpregnancy interval in relation to low birth weight, preterm birth, and small size for gestational age by analyzing data from the birth certificates of 173,205 singleton infants born alive to multiparous mothers in Utah from 1989 to 1996. RESULTS: Infants conceived 18 to 23 months after a previous live birth had the lowest risks of adverse perinatal outcomes; shorter and longer interpregnancy intervals were associated with higher risks. These associations persisted when the data were stratified according to and controlled for 16 biologic, sociodemographic, and behavioral risk factors. As compared with infants conceived 18 to 23 months after a live birth, infants conceived less than 6 months after a live birth had odds ratios of 1.4 (95 percent confidence interval, 1.3 to 1.6) for low birth weight, 1.4 (95 percent confidence interval, 1.3 to 1.5) for preterm birth, and 1.3 (95 percent confidence interval, 1.2 to 1.4) for small size for gestational age; infants conceived 120 months or more after a live birth had odds ratios of 2.0 (95 percent confidence interval, 1.7 to 2.4);1.5 (95 percent confidence interval, 1.3 to 1.7), and 1.8 (95 percent confidence interval, 1.6 to 2.0) for these three adverse outcomes, respectively, when we controlled for all 16 risk factors with logistic regression. CONCLUSIONS: The optimal interpregnancy interval for preventing adverse perinatal outcomes is 18 to 23 months.

Adolescent↗
PubMed1997

A large community outbreak of salmonellosis caused by intentional contamination of restaurant salad bars.

CONTEXT: This large outbreak of foodborne disease highlights the challenge of investigating outbreaks caused by intentional contamination and demonstrates the vulnerability of self-service foods to intentional contamination. OBJECTIVE: To investigate a large community outbreak of Salmonella Typhimurium infections. DESIGN: Epidemiologic investigation of patients with Salmonella gastroenteritis and possible exposures in The Dalles, Oregon. Cohort and case-control investigations were conducted among groups of restaurant patrons and employees to identify exposures associated with illness. SETTING: A community in Oregon. Outbreak period was September and October 1984. PATIENTS: A total of 751 persons with Salmonella gastroenteritis associated with eating or working at area restaurants. Most patients were identified through passive surveillance; active surveillance was conducted for selected groups. A case was defined either by clinical criteria or by a stool culture yielding S Typhimurium. RESULTS: The outbreak occurred in 2 waves, September 9 through 18 and September 19 through October 10. Most cases were associated with 10 restaurants, and epidemiologic studies of customers at 4 restaurants and of employees at all 10 restaurants implicated eating from salad bars as the major risk factor for infection. Eight (80%) of 10 affected restaurants compared with only 3 (11%) of the 28 other restaurants in The Dalles operated salad bars (relative risk, 7.5; 95% confidence interval, 2.4-22.7; P<.001). The implicated food items on the salad bars differed from one restaurant to another. The investigation did not identify any water supply, food item, supplier, or distributor common to all affected restaurants, nor were employees exposed to any single common source. In some instances, infected employees may have contributed to the spread of illness by inadvertently contaminating foods. However, no evidence was found linking ill employees to initiation of the outbreak. Errors in food rotation and inadequate refrigeration on ice-chilled salad bars may have facilitated growth of the S Typhimurium but could not have caused the outbreak. A subsequent criminal investigation revealed that members of a religious commune had deliberately contaminated the salad bars. An S Typhimurium strain found in a laboratory at the commune was indistinguishable from the outbreak strain. CONCLUSIONS: This outbreak of salmonellosis was caused by intentional contamination of restaurant salad bars by members of a religious commune.

Contact Tracing↗
PubMed1996

Management of an outbreak of tuberculosis in a small community.

OBJECTIVE: To investigate an outbreak of tuberculosis, determine the number of active cases and infections, and examine efforts to control the spread of disease. SETTING: A small town in Maine, in which no cases of tuberculosis had been reported in the previous 3 years. DESIGN: Epidemiologic investigation of an outbreak of tuberculosis infection and disease. MEASUREMENTS: A patient with an active case of tuberculosis was defined as a resident of the town or the surrounding area or an employee of the local shipyard who had a culture of sputum or tissue that was positive for Mycobacterium tuberculosis between June 1989 and May 1992. A case of tuberculous infection was defined as a positive tuberculin skin test result in a person with no previous positive test result. RESULTS: 21 active cases of tuberculosis occurred among shipyard workers and persons residing in the affected community between 1989 and 1992. One patient was the source of the outbreak; 8 months lapsed between the onset of this patient's illness and appropriate diagnosis and treatment. The M. tuberculosis strains isolated from this patient and from six other patients belonged to phage type I, auxiliary 14. All isolates were susceptible to drug treatment. Of 9898 persons who were tested, 697 (7%) were newly infected. Because isoniazid prophylaxis was not routinely offered to infected persons older than 35 years of age, only 341 (49%) infected persons completed isoniazid prophylaxis. CONCLUSIONS: Many secondary cases of tuberculosis occurred throughout this small Maine community because of delayed diagnosis and treatment of the source patient, delayed outbreak investigation, and failure to promote isoniazid prophylaxis to all persons infected during the outbreak. Aggressive efforts to identify persons with new infection are of limited value in controlling tuberculosis unless they are accompanied by an equally aggressive use of isoniazid prophylaxis.

Adult↗
PubMed1995

The reporting of communicable diseases: a controlled study of Neisseria meningitidis and Haemophilus influenzae infections.

Surveillance systems for communicable diseases in the United States are primarily passive. We compared the passive reporting system for invasive disease caused by Neisseria meningitidis and Haemophilus influenzae with a concurrent, active laboratory-based system in the four metropolitan counties of Tennessee. The passive reporting system identified approximately 50% of all cases that were identified by the active system and accurately reflected trends in disease occurrence during the study period. Of all reported cases, physicians contributed fewer than 4%. Nearly 40% of all hospitals in the study area did not participate in the passive system. This lack of participation resulted in disproportionately increased reporting of disease among blacks. Inconsistencies in case definition within the state also contributed substantially to underreporting and lack of demographic representativeness of reported cases. The median reporting interval (the time from the onset of disease to transmission of the case report to the Centers for Disease Control and Prevention) was 24 days (range, 5-157 days). Efforts to improve surveillance of those infections for which isolation of a pathogen is tantamount to a diagnosis should concentrate on laboratory-based reporting and the use of currently available computer telecommunication systems.

Centers for Disease Control and Prevention, U.S.↗
PubMed1994

Invasive group A streptococcus carriage in a child care centre after a fatal case.

After a fatal case of invasive group A streptococcal disease, serotype T-1, in a child care centre, group A streptococcal T-1 prevalence was measured and risk factors for carriage were determined. A total of 87% (224/258) had throat culture tests. Group A streptococcus was isolated from 57 (25%), and of the 50 isolates serotyped, 38 (76%) were T-1. Group A streptococcal T-1 prevalence was 18% (38/217) and six of nine rooms had children with group A streptococcal T-1 isolates. The risk of group A streptococcal T-1 carriage was increased for children who shared the index case's room (odds ratio (OR) = 2.7; 95% confidence interval (CI) = 0.8 to 9.4) and for each additional hour per week in child care (OR = 1.03; 95% CI = 1.001 to 1.061); and decreased in children taking antibiotics in the preceding four weeks (OR = 0.2; 95% CI = 0.1 to 0.9). Carriage of the invasive group A streptococcal strain could not be determined by identified risk factors alone.

Adult↗
PubMed1994

Injuries to international petroleum drilling workers, 1988 to 1990.

Nonfatal work-related injury (NFI) rates are 49% higher among oil and gas field workers than among workers in all US industries combined, and these injuries are more severe (the rate of lost workdays in the oil and gas field services industry is 2.8 times that of all US industries combined). We analyzed the 1988 to 1990 incident reports submitted by drilling companies to the International Association of Drilling Contractors, an industry-wide international trade association representing 95% of the world's oil and gas drilling companies. We determined geographic and occupation-specific incidence rates by full-time equivalents, calculated per job category and year. Of the 5,251 reports, 5,218 (99.4%) were of NFI and 33 (0.6%) of fatal work-related injuries (FI). The overall NFI rate was 1.2/100 full-time equivalents and the overall FI rate was 7.5/100,000 full-time equivalents. Reported NFI in US territory was 4 times more common than in non-US territory. Reported FI in US and non-US waters were 4 and 5 times more common than on land, respectively. Three job categories--floormen, roustabouts, and derrickmen--accounted for 74% of the NFI and 64% of FI, with a rate ratio, compared with rates for all other occupations, of 10.5, 8.5, and 7.0 for NFI and 5.0, 9.4, and 4.0 for FI. Among all occupations, the body part most frequently injured was the upper extremity (1,631/5,218 [31%]). The four key NFI types and circumstances identified included the upper extremities "caught in" (857/5,218 [16%]),the back "strained" (592/5,218[11%]), the lower extremities "struck by" (538/5,218 [10%]), and the lower extremities injured while "slipping" (402/5,218 [8%]). Results of these analyses revealed several high-risk occupations in this industry and identified high-risk activities that can be targeted for further study.

Accidents, Occupational↗
PubMed1993

A large salmonellosis outbreak associated with a frequently penalized restaurant.

Between January and June 1990, Restaurant A in Greenville, South Carolina repeatedly failed local health department inspection and was repeatedly sanctioned. In September 1990, two persons, hospitalized with salmonellosis after attending a convention catered by Restaurant A, contacted the South Carolina Department of Health and Environmental Control. We inspected Restaurant A, interviewed food handlers, and surveyed by telephone persons from every sixth business attending the convention. Of 398 persons interviewed, 135 (34%) reported gastroenteritis. Nine had culture-confirmed salmonella infection. People who ate turkey were 4.6 times more likely to become ill than those who did not eat turkey (95% confidence interval 2.0, 10.6). We estimate that of 2430 attendees, 824 became ill. Sanitarians judged Restaurant A's kitchen too small to prepare over 500 meals safely. The cooked turkey was unrefrigerated for several hours, incompletely rewarmed, and rinsed with water to reduce its offensive odour prior to serving. Stronger sanctions may be needed against restaurants that repeatedly fail local health department inspection.

Animals↗
PubMed1993

Chronic obstructive pulmonary disease mortality. A role for altitude.

A map of US COPD mortality rates by state suggested that the relative hypoxia of increased altitude may be independently associated with COPD mortality. This was investigated using linear regression analysis of 1986 state-specific data on COPD mortality rates, history of cigarette consumption, and altitude. County seat altitudes and county populations were used to calculate the median altitude of state residents. We found independent significant associations between COPD and both smoking and altitude. State COPD mortality rose by 1/10(5) for every 5.4 increase in mean packs consumed per capita per year or for each 95-m increase in resident altitude. There was no association between altitude and smoking. If increased altitude does contribute to COPD mortality, persons with this disease may benefit from down-migration.

Altitude↗
PubMed1993

Gastroenteritis outbreak in a Maryland nursing home.

From December 25, 1990, to January 12, 1991, an outbreak of acute viral gastroenteritis occurred among 132 residents and 102 employees of a Maryland nursing home. Illness typically lasted 24 hours and was characterized by diarrhea, vomiting, and fever. The attack rate was 46.2% (61/132) for residents and 42.2% (43/102) for employees. No differences in attack rates were observed by station in the facility. The risk of having an early case (before the peak of the outbreak on January 2, 1991) was 3.5 times greater for employees with patient contact than for employees without patient contact. Analyses of temporal and geographic clustering of cases suggest that person-to-person transmission was an important transmission mode. Although an etiologic agent was not identified, the short duration of illness, high rates of vomiting and diarrhea, and high attack rate are consistent with Norwalk-like viral infection.

Adult↗
PubMed1992

An outbreak of hepatitis A associated with swimming in a public pool.

A multistate outbreak of hepatitis A was traced to a campground in Louisiana. Among 822 campers during one weekend, 20 developed hepatitis A. Case-patients ranged in age from 4 to 36 years; the highest attack rate (6.4%) was for children aged 5-9 years. A case-control study revealed that case-patients were more likely than controls to have swum in a public swimming pool on Saturday afternoon (19/19 vs. 26/38; odds ratio [OR], undefined; lower 95% confidence limit, 1.7). Case-patients were more likely than controls to have swum in the jacuzzi pool (16/19 vs. 10/26; OR, 8.0; 95% confidence interval, 1.5-47.1) or adult pool A (19/19 vs. 15/26; OR, undefined; lower 95% confidence limit, 2.6). Case-patients were also more likely to have swum for greater than 1 h and to have put their heads under the water. Because of the design of the filtering system of adult pool A, a cross-connection between a sewage line and the pool water intake line was possible. This outbreak may have been caused by transmission of hepatitis A through swimming; thus, swimming may serve as a mode of transmission of hepatitis A virus, especially among small children.

Adolescent↗
PubMed1990

A surgeon with AIDS. Lack of evidence of transmission to patients.

In January 1989 [corrected], the media reported the identity of a surgeon who was recently diagnosed with the acquired immunodeficiency syndrome (AIDS). Concern about surgeon-to-patient transmission of human immunodeficiency virus (HIV) persisted despite reassurances from health authorities. Therefore, HIV antibody testing was offered to the surgeon's patients. We identified 2160 patients operated on since 1982; none had been reported to Tennessee's AIDS registry. A total of 264 had already died; none were reported to have died of AIDS or other HIV-related diseases. Of the 1896 patients remaining, we contacted 1652; 616 (37%) were tested. Only one (an intravenous drug user) was HIV antibody positive, and his medical history suggested that he may already have had AIDS at the time of his surgery. These results support the concept that the risks to patients operated on by HIV-infected surgeons are most likely quite low and support recommendations for the individualized assessment of HIV-infected health care workers.

AIDS Serodiagnosis↗
PubMed1990

Partner notification: can it control epidemic syphilis?

STUDY OBJECTIVE: During 1987, the rate of syphilis among heterosexual adults in Oregon increased 159%, yet the number of cases of gonorrhea remained stable. Our study was done to evaluate why the same control measures contained gonorrhea but not syphilis in this population. DESIGN: Exploratory case-control study. SETTING: Public health clinics in Portland, and Salem, Oregon. PATIENTS: All 146 heterosexual adults with early syphilis and all 164 heterosexual adults with acute gonorrhea reported to the public health clinics during April to July 1988. INTERVENTION: A questionnaire was administered to all syphilis case-patients and control patients (those with gonorrhea) at the beginning of the routine, sexually transmitted disease (STD), investigative interview. MEASUREMENTS AND MAIN RESULTS: Syphilis case-patients had contact with an average of 5.0 sex partners for whom they could not supply locating information sufficient to initiate partner notification. In contrast, patients with gonorrhea had contact with an average of 0.4 sex partners for whom they could not supply locating information (P less than 0.005). The 28% (41 of 146) of syphilis case-patients who reported having exchanged sex for drugs or money accounted for 72% (527 of 729) of the unlocatable partners exposed to syphilis. In contrast, the 17% (28 of 164) of patients with gonorrhea who reported having exchanged sex for drugs or money accounted for 36% (25 of 69) of the unlocatable partners exposed to gonorrhea. CONCLUSIONS: Because patients infected with syphilis have relatively large numbers of anonymous sexual encounters, prevention strategies that supplement partner notification are urgently needed to control the syphilis epidemic among adults.

Adolescent↗
PubMed1990

Foodborne hepatitis A: evidence that microwaving reduces risk?

During July 1988, 68 persons in Chattanooga, Tennessee, developed serologically confirmed hepatitis A. Between 15 June and 3 July, 93% of case-patients ate at a specific restaurant compared with only 3% of the local community. An intravenous drug user who worked as a cook was identified as the source. A case-control study was done to identify the vehicle of transmission. Case-patients were more likely than controls to have eaten hamburger buns and pickles, the only foods routinely handled after cooking. Of the restaurant patrons included in the study, 12 microwaved their food before consumption; none developed clinical illness despite eating large amounts of food handled after cooking. Sandwiches that were not microwaved were significantly associated with illness (odds ratio = 9.6; P less than .02). This epidemiologic evidence suggests that microwaves inactivate hepatitis A virus in food.

Adolescent↗
PubMed1990

A large outbreak of antibiotic-resistant shigellosis at a mass gathering.

In July 1987, a large outbreak of shigellosis occurred among attendees at a mass gathering in a national forest, the annual Rainbow Family Gathering. Sanitation in the campsite was poor, allowing widespread transmission of disease, probably by food, water, and person-to-person spread. The attack rate may have been greater than 50% among the estimated 12,700 attendees. The outbreak was caused by Shigella sonnei, resistant to ampicillin, tetracycline, and trimethoprim-sulfamethoxazole; the organism was of colicin type 9 and contained a 90-kilobase plasmid not found in non-outbreak-related strains. The dispersal of the group resulted in nationwide dissemination of the organism, and outbreaks in three states were linked to transmission from attendees at the Gathering. This outbreak demonstrates the potential for rapid dissemination of disease in such a setting and the necessity for careful planning of mass gatherings.

Age Factors↗
PubMed1990

Patterns of transmission of epidemic hysteria in a school.

An outbreak of epidemic hysteria, in which 210 students at a North Carolina elementary school became ill and 102 were evaluated in hospital emergency departments, is described in terms of an outbreak of infectious disease. The outbreak began when a radiator boiler was fired for the first time in the 1985-1986 school year. The most common symptoms were headache, light-headedness, abdominal pain, and nausea; anxiety was later proposed to be the agent of illness. The outbreak appeared to have propagated by friend-to-friend transmission of anxiety within social (grade, race, and sex) cohorts, and by other audiovisual cues in the absence of person-to-person contact. An environmental survey found no plausible toxic or infectious cause of the outbreak. Separation of vectors and susceptible hosts preceded recovery from the outbreak, and reassurance and discussion of the findings of the investigating team with students, teachers, and parents may have prevented the recurrence of symptoms by alleviating anxiety.

Adolescent↗
PubMed1990

Nonosmotic stimuli alter osmoregulation in patients with spinal cord injury.

Studies on two quadriplegic patients who developed severe hyponatremia during episodes of acute respiratory distress were performed to determine whether differences in osmoregulation of vasopressin release could be identified in these patients compared to other quadriplegic subjects previously studied in a similar manner. Both patients were clinically stable and normonatremic, with no signs or symptoms of respiratory distress, when the studies were performed. However, both exhibited evidence of hemodynamic instability in the sitting posture. Linear regression analysis of the plasma vasopressin/plasma osmolality (Pavp:Posm) relationship during infusions of 0.85 M sodium chloride showed no significant differences in either the slope (sensitivity) or abscissal intercept (osmotic threshold) of this relationship compared to that of other quadriplegic subjects when the patients were supine. In contrast, when the patients were studied in the sitting posture there was a marked shift in the relationship of Pavp:Posm indicative of increased sensitivity and reduced osmotic threshold for vasopressin release. The slopes of the Pavp:Posm relationships were 0.249 and 0.178 for the two patients, respectively, compared to 0.092 +/- 0.03 ( +/- SD) for previously studied quadriplegic subjects. Oral water-loading studies performed on one patient revealed marked impairment of urine-diluting ability and free water clearance in the sitting posture compared with observations in similar studies performed when the patient was supine. Impairment of renal water excretion could not be attributed to an effect of vasopressin, which was reduced to unquantifiable levels by water loading. These studies have shown that hemodynamic stress related to autonomic dysfunction in quadriplegic patients may result in marked alteration of osmoregulation of vasopressin release in more severely affected individuals. Such altered osmoregulation, which may also be associated with vasopressin-independent impairment of renal water excretion in the sitting posture, may be a predisposing factor in the development of hyponatremia, especially in the presence of other potent nonosmotic stimuli.

Aged↗
PubMed1990

An outbreak of hepatitis B associated with jet injections in a weight reduction clinic.

From January 1984 through November 1985, 31 clinical cases of hepatitis B occurred among attendees of a weight reduction clinic (clinic 1). Before the onset of illness, each case-patient had received a series of injections of human chorionic gonadotropin administered by jet injectors at clinic 1. Clinical history, risk factor assessment, serologic evaluation, and review of clinic injection records were obtained on 287 (84%) of 341 persons who had attended clinic 1 in the first 6 months of 1985. Of this cohort, 21% (60/287) had evidence of acute infection with hepatitis B virus (either documented clinical cases or antibody to hepatitis B core antigen, IgM positive). Of persons who had been given human chorionic gonadotropin at the clinic during the period studied, 24% (57/239) of those receiving human chorionic gonadotropin only by jet injector experienced acute hepatitis B virus infection. None of the 22 persons who had received injections only by syringe experienced hepatitis B virus infection. Stopping the use of the jet injectors on July 2, 1985, at clinic 1, was associated with the termination of this outbreak. This investigation demonstrated that jet injectors can become contaminated with hepatitis B virus and then may be vehicles for its transmission.

Adult↗