Updated guidelines for evaluating public health surveillance systems: recommendations from the Guidelines Working Group.

The purpose of evaluating public health surveillance systems is to ensure that problems of public health importance are being monitored efficiently and effectively. CDC's Guidelines for Evaluating Surveillance Systems are being updated to address the need for a) the integration of surveillance and health information systems, b) the establishment of data standards, c) the electronic exchange of health data, and d) changes in the objectives of public health surveillance to facilitate the response of public health to emerging health threats (e.g., new diseases). This report provides updated guidelines for evaluating surveillance systems based on CDC's Framework for Program Evaluation in Public Health, research and discussion of concerns related to public health surveillance systems, and comments received from the public health community. The guidelines in this report describe many tasks and related activities that can be applied to public health surveillance systems.

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.

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.

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.

Correlates of gun-carrying among adolescents in south Louisiana.

In the majority of episodes of fatal interpersonal violence, the weapon used is a firearm. Amid frequent reports of youths carrying weapons, including firearms, we conducted a case-control study to identify risk factors for being charged with gun-carrying and gun-carrying, per se, among adolescents in Jefferson Parish, Louisiana. Cases were defined as incidents of gun-carrying among adolescents < 19 years of age, legally charged in the Jefferson Parish, Louisiana, juvenile court from January 1, 1992, through April 15, 1993. For each case, we randomly drew three age-, gender-, and school-matched control subjects from the enrollment rosters of the Jefferson Parish public schools and administered a questionnaire. The data set comprised 38 case subjects and 103 matched control subjects. Thirty (29%) control subjects reported gun-carrying. Both case subjects and gun-carrying control subjects reported self-defense (40%) as the main reason for gun-carrying. Most case subjects (25 [66%]) were African Americans, but only 8 (27%) gun-carrying and 27 (37%) non-gun-carrying control subjects were African Americans. Case subjects were significantly more likely than gun-carrying control subjects to report being African American (odds ratio [OR] = 5.3, 95% confidence intervals [CI] = 1.6, 17.5). In crude analyses, case subjects were more likely than non-gun-carrying control subjects to report adult-male unemployment among households with adult men, to foresee a likelihood to be shot in school, to have seen a shooting, to use marijuana, to watch television > 6 hours per day, and to be African American. After the effect estimates were adjusted in conditional logistic regression modeling, case subjects were more likely than non-gun-carrying control subjects to report adult-male unemployment among households with adult men, using marijuana, and watching television > 6 hours per day (OR = 8.6, 95% CI = 1.2, 61,2; OR = 11.7, 95% CI = 2, 70.2; and OR = 6.5, 95% CI = 0.8, 51.9, respectively). Gun-carrying control subjects were significantly more likely than non-gun-carrying control subjects to report their school not safe, having seen a shooting, using marijuana, and having fired a gun (OR = 9, 95% CI = 1, 82.1; OR = 7, 95% CI = 1.3, 38.2; OR = 6.8, 95% CI = 1.8, 25.5; and OR = 17, 95% CI = 1.8, 156.6, respectively). We found that gun-carrying was very common, and that adolescent youths who carry guns were more likely to have familiarity with guns and experience with or perception of an unsafe environment. Together, these lead to the conclusion that gun-carrying is a common response of youths who live in a risky environment, who do not have the social support to learn how to deal effectively with that risk, and who have access to guns, which they think may provide them with some protection.

Female employee participation in a worksite mammography screening program.

We conducted a survey of 1,184 women 35 years of age or older who were employees of a company in Los Angeles County, California, to determine why some women participated in a worksite mammography screening program whereas others did not. Of the 111 who accepted a mammogram, 90 responded to the survey; of the 1,073 who declined mammography, 620 responded. The women were predominantly white, were well educated, and had health insurance. Of the 111 women who received mammograms, one was diagnosed with carcinoma. Seventy-three percent of the respondents to the survey 40 years of age or older who declined mammograms had already fulfilled American Cancer Society (ACS) guidelines for mammography screening at the time of the program. Women who accepted a mammogram were more likely to have had at least one previous mammogram than were women who had not met ACS guidelines yet who declined screening. We conclude that many female employees who are white, are well educated, and have health insurance may not participate in a worksite mammography screening program because they have been screened elsewhere. Companies providing worksite mammography screening should target education to women who have not met ACS guidelines, especially those who have never had a mammogram.

Patient-care directives and infection control: the potential conflict of interest during epidemics in long-term care facilities.

Patient-care directives in long-term care facilities ensure that the aggressiveness of diagnostic and therapeutic interventions accurately reflects the desires of the patient. The results of our investigation of two outbreaks of fatal respiratory illness in long-term care facilities illustrate how patient-care directives may have delayed response to the outbreaks. Despite a cluster of deaths in each facility, staff delayed collection of laboratory specimens until patients with no directives restricting the medical workup became ill. Directives focus on the needs of the individual patient and family, but when an outbreak occurs, they may conflict with community needs. The challenge for the infection control practitioner is to recognize when community needs outweigh individual desires so that appropriate laboratory investigations can identify the cause of the illness.

Evaluation of a two-dose measles, mumps, and rubella vaccination schedule in a cohort of college athletes.

Despite high vaccination levels, measles outbreaks continue to occur among vaccinated adults. In response, new guidelines call for two doses of measles vaccine. To determine seroprevalence and response to vaccination in seronegative persons, we tested serums from 256 college athletes at a Maryland State college by enzyme-linked immunosorbent assay, vaccinated seronegatives, then re-tested vaccinees. High school records were obtained for persons seronegative to measles. Of 256 students, 53 (21 percent) were seronegative to measles alone, 13 (5 percent) were seronegative to rubella alone, and 5 (2 percent) were seronegative to both. Among those seronegative to measles, 86 percent had previously received a dose of measles vaccine. After vaccination, 37 persons initially seronegative to measles and 9 seronegative to rubella were 97 percent and 100 percent seropositive, respectively. The high measles seroconversion rate suggests that the two-dose vaccine schedule should effectively control campus measles outbreaks and, if given as measles-mumps-rubella vaccine, will also improve immunity to rubella and mumps.

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.

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.

Non-01 Vibrio cholerae gastroenteritis in New Hampshire: a case report.

Non-01 Vibrio cholerae gastroenteritis has been reported in the literature in association with foreign travel, or seafood ingestion, particularly raw shellfish harvested from warm-water climates. Non-01 V. cholerae gastroenteritis has not been reported before from New England. The case presented describes a previously healthy female who developed non-01 V. cholerae gastroenteritis approximately 26 hours after ingestion of raw cherrystone clams.

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.

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.

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.

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.

Neurologic dysfunction from exposure to 2-t-butylazo-2-hydroxy-5-methylhexane (BHMH): a new occupational neuropathy.

Seven cases of subacute central and peripheral neurologic dysfunction developed in 18 workers employed in the manufacture of reinforced plastic bathtubs. Cases were characterized by weight loss, dizziness, paresthesias, muscle weakness, incontinence, memory loss, and loss of peripheral, color, and night vision. Neuropathies began distally, involved both sensory and motor function, and were associated with prolonged sensory latency, muscle fibrillation, and reduced numbers of functioning motor units. One patient developed posterior lenticular cataracts. Slow improvement occurred on removal from exposure, but residual neuropathies persisted for as long as two years. Epidemiologic investigation disclosed that the first case developed approximately two weeks after introduction of a new plastic foaming agent, 2-t-butylazo-2-hydroxy-5-methylhexane (BHMH). All cases occurred in workers exposed directly to BHMH. No new cases developed after use of BHMH was discontinued. A survey of the firm which produced BHMH and of 68 user firms found two additional clusters of mild neuropathy which may have been caused by BHMH. BHMH was withdrawn from distribution following discovery of these cases. Subsequently, BHMH has been shown in rats to be a potent neurotoxin. Adequate premarket testing could have averted this outbreak.

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.

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.

KIE: The authors attempted to notify and to offer HIV antibody testing to all patients who had been operated on by a Tennessee surgeon with AIDS during the seven years prior to his diagnosis. They found no evidence of HIV transmission to patients from the surgeon. Six hundred and sixteen former patients were screened for HIV; only one, an intravenous drug user, tested positive for HIV antibody. None of 2,160 former patients appeared on the Tennessee AIDS registry. None of 264 deceased patients were reported to have died of AIDS or of AIDS-related diseases. Mishu, et al. argue that their findings support the conclusion that risks to patients operated on by HIV-positive surgeons are probably quite low, and that each instance of a HIV-infected health worker should be assessed individually.

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.