Community outbreak of legionellosis and an environmental investigation into a community water system.

During two legionellosis outbreak investigations, one at a geriatric centre and the other in high-rise housing for seniors, it was observed that additional cases of legionellosis occurred in nearby smaller residential settings. This apparent geographical cluster of legionellosis occurred in the same general area of a community water storage tank. No potential airborne sources in or near the area could be identified, but a community water system storage tank that was centrally located among case residences spurred an investigation of water-quality factors in the identified investigation area. Conditions conducive for Legionella growth, particularly low chlorine residuals, were found. The rate of legionellosis among residents aged ⩾50 years in the investigation areas (61·0 and 64·1/100 000) was eight times higher than in the rest of the service area (9·0/100 000) and almost 20 times higher than the statewide annual average incidence rate (3·2/100 000). A water mains flushing programme in the area was launched by the water utility, and water samples taken before and during flushing found L. pneumophila.

Outbreak of Salmonella serotype Hartford infections associated with unpasteurized orange juice.

CONTEXT: Acidic foods such as orange juice have been thought to be unlikely vehicles of foodborne illness. OBJECTIVE: To investigate an outbreak of Salmonella enterica serotype Hartford (Salmonella Hartford) infections among persons visiting a theme park in Orlando, Fla, in 1995. DESIGN: Review of surveillance data, matched case-control study, laboratory investigation, and environmental studies. SETTING: General community. PARTICIPANTS: The surveillance case definition was Salmonella Hartford or Salmonella serogroup C1 infection in a resident of or a visitor to Orlando in May or June 1995. In the case-control study, case patients were limited to theme park hotel visitors and controls were matched to case patients by age group and hotel check-in date. MAIN OUTCOME MEASURES: Risk factors for infection and source of implicated food. RESULTS: Sixty-two case patients from 21 states were identified. Both Salmonella Hartford and Salmonella enterica serotype Gaminara (Salmonella Gaminara) were isolated from stool samples of 1 ill person. Thirty-two case patients and 83 controls were enrolled in the case-control study. Ninety-seven percent of case patients had drunk orange juice in the theme park vs 54% of controls (matched odds ratio, undefined; 95% confidence interval, 5.2 to undefined). The orange juice was unpasteurized and locally produced. Salmonella Gaminara was isolated from 10 of 12 containers of orange juice produced during May and July, indicating ongoing contamination of juice probably because of inadequately sanitized processing equipment. CONCLUSIONS: Unpasteurized orange juice caused an outbreak of salmonellosis in a large Florida theme park. All orange juice was recalled and the processing plant closed. Pasteurization or other equally effective risk-management strategies should be used in the production of all juices.

Emergence of Lyme disease in Hunterdon County, New Jersey, 1993: a case-control study of risk factors and evaluation of reporting patterns.

Reported cases of Lyme disease in Hunterdon County, New Jersey, increased almost 200% from 75 (67/100,000 population) in 1992 to 216 (193/100,000 population) in 1993. For evaluation of risk factors for Lyme disease and for determination of the cause of this increase, a case-control study was conducted, and the reporting practices of physicians' offices were evaluated. For cases reported in 1993, age and sex distribution, month of disease onset, and proportion of cases with erythema migrans rash were within expected limits. Analysis of age-matched case-control data showed that rural residence; clearing periresidential brush during spring and summer months; and the presence of rock walls, woods, deer, or a bird feeder on residential property were associated with incident Lyme disease. A review of physician reporting patterns suggested that the increase in reported cases in 1993 was due to improved reporting as well as to an increase in the numbers of patients diagnosed with Lyme disease. In addition, substantial underreporting of Lyme disease by physicians' offices was found.

Outbreak of Legionnaires' disease among cruise ship passengers exposed to a contaminated whirlpool spa.

BACKGROUND: Outbreaks of travel-related Legionnaires' disease present a public-health challenge since rapid, sensitive, and specific diagnostic tests are not widely used and because detection of clusters of disease among travellers is difficult. We report an outbreak of Legionnaires' disease among cruise ship passengers that occurred in April, 1994, but that went unrecognised until July, 1994. METHODS: After rapid diagnosis of Legionnaires' disease in three passengers by urine antigen testing, we searched for additional cases of either confirmed (laboratory evidence of infection) or probable Legionnaires' disease (pneumonia of undetermined cause). A case-control study was conducted to compare exposures and activities on the ship and in ports of call between each case-passenger and two or three matched control-passengers. Water samples from the ship, from sites on Bermuda, and from the ship's water source in New York City were cultured for legionellae and examined with PCR. FINDINGS: 50 passengers with Legionnaires' disease (16 confirmed, 34 probable) were identified from nine cruises embarking between April 30 and July 9, 1994. Exposure to whirlpool spas was strongly associated with disease (odds ratio 16.2, 95% Cl 2.8-351:7); risk of acquiring Legionnaires' disease increased by 64% (95% Cl 12-140) for every hour spent in the spa water. Passengers spending time around the whirlpool spas, but not in the water, were also significantly more likely to have acquired infection. Legionella pneumophila serogroup 1 was isolated only from the sand filter in the ship's whirlpool spa. This isolate matched a clinical isolate from the respiratory secretions of a case-passenger as judged by monoclonal antibody subtyping and by arbitrarily primed PCR. INTERPRETATION: This investigation shows the benefit of obtaining a recent travel history, the usefulness or urine antigen testing for rapid diagnosis of legionella infection, and the need for improved surveillance for travel-related Legionnaires' disease. New strategies for whirlpool spa maintenance and decontamination may help to minimise transmission of legionellae from these aerosol-producing devices.

Biliary complications in the treatment of unsubstantiated Lyme disease.

Treatment of unsubstantiated Lyme disease has led to serious complications in some cases. Two case-control studies, based on information in clinical records of patients discharged with a diagnosis of Lyme disease during 1990-1992, were conducted at a central New Jersey hospital. Twenty-five patients with biliary disease were identified, and 52 controls were selected from 1352 patients with suspected Lyme disease. Only 3% of 71 evaluatable subjects met the study criteria for disseminated Lyme disease. Patients with biliary disease were more likely than were antibiotic controls to have received ceftriaxone and more likely than ceftriaxone controls to have received a daily ceftriaxone dose > or = 40 mg/kg and to be < or = 18 years old. Fourteen of 25 biliary case-patients underwent cholecystectomy; all had histopathologic evidence of cholecystitis and 12 had gallstones. Thus, treatment of unsubstantiated diagnoses of Lyme disease is associated with biliary complications.

Hemolytic uremic syndrome in New Jersey.

In an 18-month study period, the authors identified 23 cases of hemolytic uremic syndrome (HUS) in New Jersey children. Increased identification and reporting of Escherichia coli O157:H7 are needed to prevent additional morbidity and mortality.

Boilerbaisse: an outbreak of methemoglobinemia in New Jersey in 1992.

BACKGROUND: On October 20, 1992, > 40 children from one elementary school visited the school nurse due to the acute onset of blue lips and hands, vomiting, and headache during and after the school lunch periods. Forty-nine children were seen by physicians that day and 14 were hospitalized. Laboratory analysis revealed methemoglobinemia in many of the children. All recovered in 36 hours. OBJECTIVE: A case-control study was supplemented by environmental and laboratory investigations to determine the outbreak source. METHODS: Cases were selected based on the laboratory diagnosis of methemoglobinemia (methemoglobin level > 2%). Children whose methemoglobin levels were missing or < 2% were excluded from analysis. Controls were obtained by selecting every third name from a school roster. The parents of 29 students who met the case definition and 52 controls were interviewed. RESULTS: All 29 cases and 33% (17/52) of the controls ate soup during the school lunch (odds ratio undefined, lower 95% confidence limit 16.1). Two pots of soup were prepared from ready-to-serve cans, which were diluted with water and enriched with a commercially prepared flavor enhancer. The school's boiler, dormant during the previous 5 months, was restarted on the morning of the outbreak. The boiler also served as a tankless hot water heater. Laboratory analysis of the soup identified abnormally high quantities of nitrite (459 ppm) and sodium metaborate, major components of the boiler water treatment solution. Undiluted soup from the same lot had 2.0 ppm nitrites; the flavor enhancer had 2.2 ppm nitrites. Nitrites were present in the hot potable water system (4 to 10 ppm) and absent in the cold potable water system. CONCLUSIONS: This outbreak of methemoglobinemia due to nitrite poisoning was traced to soup contaminated by nitrites in a boiler additive. Nitrites are ubiquitous and potentially hazardous inorganic ions. Extreme caution should be used when the possibility for toxic human exposure to nitrites exists.

Why bother the New Jersey State Department of Health?

The reporting of communicable diseases is a legal and professional responsibility. Individual case reports can be an important piece in a medical puzzle, allowing public health officials to describe new diseases and modes of transmission so preventive measures can be developed and implemented.

Postoperative group A beta-hemolytic Streptococcus outbreak with the pathogen traced to a member of a healthcare worker's household.

A cluster of four group A beta-hemolytic Streptococcus postoperative wound infections was investigated at a community hospital. The serotypes of the Streptococcus isolated from all four cases, an asymptomatic anesthesiologist and one of his household members were M nontypable T28. During the outbreak period, December 1988, the infection rate among the 40 patients of the anesthesiologist was 7.5%. Among other patients not having contact with this healthcare worker, it was 0.09% (p = .0002 Fisher's exact test). This is only the second reported Group A beta-hemolytic Streptococcus hospital outbreak in which the pathogen was traced to a member of a healthcare worker's household. Early outbreak detection and intervention limited the extent of the outbreak.